stroke

The Good News About Omega-3s And Stroke

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How Do Omega-3s Affect The Two Types Of Stroke?

Author: Dr. Stephen Chaney 

strokeI am continuing my series on recent omega-3 breakthroughs. Last week I reviewed a study showing that the omega-3s EPA and DHA lowered blood pressure. Since high blood pressure is a major contributing factor to stroke risk, it only makes sense that EPA and DHA would also decrease the risk of strokes.

In last week’s article I mentioned that high blood pressure is called a silent killer. That is because the symptoms of high blood pressure are easy to ignore and often confused with other illnesses.

For many people the first indication they have a problem is when they have a stroke, which either kills them or forever impacts their quality of life. Let me share some statistics with you.

  • Every 40 seconds someone in the United States has a stroke. One in four adults over the age of 25 will have a stroke in their lifetime.
  • Every 4 minutes someone in the United States dies from a stroke. For many of them sudden death is the first indication they had a health problem.
  • The overall incidence of strokes has increased 60% in the last 20 years with most of that increase (65%) coming from younger adults (ages 20 to 45)
  • The cost of treatment, rehabilitation, and lost wages from stroke was $891 billion in 2020 and is projected to increase to $2.3 trillion in 2050.

Any way you look at it, the personal and financial costs of strokes are immense.

How Do Omega-3s Affect The Two Types Of Stroke?

There are two major kinds of stroke – ischemic stroke, which is caused by a thrombus (blood clot) in the carotid arteries leading to the brain, and hemorrhagic stroke, which is caused by bleeding from small blood vessels in the brain. Ischemic stroke accounts for around 85% of all strokes.

Ischemic strokes are caused by atherosclerosis, the buildup of fatty plaques in the walls of the carotid arteries, followed by the formation of a blood clot which lodges in the narrowed arteries. As you might expect, the prevention and treatment of ischemic strokes are similar to the prevention and treatment of heart attacks.

EPA and DHA have been shown to:

  • Reduce inflammation, which is associated with increased risk of heart disease and stroke.
  • Reduce blood pressure. High blood pressure damages the endothelial lining of blood vessels, which can lead to either build up of atherosclerotic plaque or rupturing of the blood vessels.
  • Reduce platelet aggregation and blood viscosity, which reduces the potential for inappropriate blood clots forming in the carotid arteries.

[When you cut yourself, you want a blood clot to form to stop the bleeding. That is an example of appropriate blood clot formation. However, when a blood clot forms within your arteries, it can prevent blood from reaching surrounding tissues. This is an example of inappropriate blood clot formation.]

  • Reduce the risk of atherosclerotic plaques rupturing. Rupturing of atherosclerotic plaques triggers blood clot formation, so this also decreases the risk of inappropriate blood clots forming in the carotid arteries.

Based on the known effects of EPA and DHA, it is not surprising that they would decrease the risk of ischemic strokes. But what about hemorrhagic strokes? Here the answer is not as clear cut.

  • In a previous clinical study 4 gm/day of purified EPA without DHA was associated with a slightly increased risk of bleeding events but did not increase the risk of hemorrhagic stroke.
  • High doses of pharmaceutical grade EPA have also been associated with a slightly increased risk of atrial fibrillation (Afib). In contrast, previous studies have shown that higher dietary intake of EPA + DHA are associated with a lower risk of Afib.

At present, we don’t know whether the increased risk of bleeding events and Afib are only seen at very high doses of omega-3s or are due to the use of pharmaceutical grade EPA without DHA and any of the other naturally occurring omega-3s.

However, this uncertainty has led some experts to warn that omega-3s may be a two-edge sword. They might increase the risk of hemorrhagic stroke while decreasing the risk of ischemic stroke. This uncertainty was part of the rationale for the study (JH O’Keefe et al, Stroke, 55: 50-58, 2024) I am describing today.

How Was This Study Done?

clinical studyThis study was a meta-analysis of 29 clinical studies looking at the effect of omega-3 fatty acids on the risk of both ischemic and hemorrhagic stroke. These studies were performed in 15 countries from around the world and included a total of 183,291 participants.

One major drawback of many meta-analyses is that each study in the meta-analysis is independently designed. Sometimes the studies are so different that it is difficult to fit them together in a coherent pattern.

A major strength of this meta-analysis is that all the studies were conducted within the “Fatty Acid and Outcome Research Consortium” which specifies a general protocol for the design of each study within that consortium.

For example, estimates of dietary omega-3 intake can be inaccurate and the uptake and utilization of both dietary and supplemental omega-3s vary from person to person. Because of that the Fatty Acid and Outcomes Research Consortium guideline specifies that studies rely on biomarkers of omega-3 levels in the body rather than the amount of omega-3s consumed.

The most frequently used biomarker was the percentage of omega-3s incorporated into the fatty portion of red blood cell membranes. Some studies used other biomarkers, such as the percentage of omega-3s incorporated into the fatty portion of plasma phospholipids or cholesterol-containing phospholipid particles (LDL and HDL for example).

In each case, the percentage of omega-3s is used to calculate something called an “Omega-3 Index”. Previous studies have shown that an Omega-3 Index of 4% or less correlates with a high risk of heart disease, and an Omega-3 Index of 8% or more correlates with a low risk of heart disease. In essence, this study correlated Omega-3 Index with the risk of stroke.

The Fatty Acids and Outcomes Research Consortium harmonized the studies included in this meta-analysis in several other ways, but the use of Omega-3 Index rather than omega-3 consumption was the most important.

Other key characteristics of the studies included in this meta-anaysis were:

  • The average age of participants was 65 years.
  • 82% of the participants were white and 53% were women.
  • The average length of follow-up was 14 years (range = 5-30 years).
  • 10,561 participants (5.8%) suffered a stroke during follow-up (78% ischemic, 11% hemorrhagic, and 11% unspecified).

The Good News About Omega-3s and Stroke 

good newsThe participants in these studies were divided into quintiles based on their Omega-3 Index. When those in the highest quintile (≥ 8%) were compared with those in the lowest quintile (≤ 4%):

  • Risk was reduced by 17% for total stroke and 18% for ischemic stroke. There was no effect on hemorrhagic stroke.

When the effect of individual components of the Omega-3 Index were analyzed:

  • For EPA + DHA risk was reduced by 17% for total stroke and 18% for ischemic stroke. There was no effect on hemorrhagic stroke.
  • For EPA risk was reduced by 17% for total stroke and 18% for ischemic stroke. There was no effect on hemorrhagic stroke. (You are probably starting to detect a pattern).
  • For DHA the results were only slightly different. Risk reduction was 12% for total stroke and 16% for ischemic stroke. There was no effect on hemorrhagic stroke.
  • For DPA, a minor component of the Omega-3 Index, there was no significant effect on total, ischemic, or hemorrhagic stroke.
  • There was a linear dose-response for the effect of EPA, DHA, and the two combined on the reduction in risk for both total and ischemic stroke.

When they looked at subgroups within the analysis, the results were the same for:

  • Age (<65 compared to >65).
  • Gender.
  • Studies that lasted less than 10 years and studies that lasted more than 10 years.
  • The presence of preexisting Afib.
  • The presence of preexisting cardiovascular disease.

The authors concluded, “In summary, this harmonized and pooled analysis of prospective studies showed that long-chain omega-3 levels were inversely associated with risk of total and ischemic stroke but were unrelated to risk of hemorrhagic stroke. Thus, higher dietary intake of DHA and EPA would be expected to lower risk of stroke.”

What Does This Study Mean For You?

Key Takeaways From This Study: The most important takeaway from this study is that reasonable amounts of EPA and DHA from either diet or supplementation are unlikely to increase your risk of hemorrhagic stroke (I will define reasonable below).

That is important to know because this and several other studies show that EPA and DHA decrease the risk of ischemic stroke, which accounts for around 85% of total strokes. This study shows you can reduce your risk of ischemic stroke without fearing that you will increase your risk of hemorrhagic stroke.

This study also reaffirms the importance of relying on Omega-3 Index rather than the dosage of omega-3s in a supplementation. Previous studies have shown there is significant individual variability in the uptake and utilization of dietary omega-3s.

Finally, this study shows you don’t need huge amounts of EPA and DHA to significantly decrease your risk of stroke and cardiovascular disease in general. An Omega-3 Index of ≥ 8% is sufficient to accomplish both.

How Much Omega-3s Do You Need? The authors of this manuscript are experts on the Omega-3 Index, and they estimated that:

  • To raise your Omega-3 Index from 5.4% (the median Omega-3 Index in these studies) to 8% would require about 1,000 mg/d of EPA + DHA.
  • To raise your Omega-3 Index from 3.5% (the lowest Omega-3 Index quintile in these studies) to 8% would require about 1,600 mg/d of EPA + DHA.

These intakes are well within the American Heart Association recommendations for reducing the risk of stroke and cardiovascular disease and are easily achievable from diet and supplementation.

But these estimates are based on averages, and, as I noted above, none of us are average. We differ in our ability to absorb and utilize omega-3s. So, I recommend relying on your Omega-3 Index rather than a dose of omega-3s that’s right for the average person but may not be right for you.

My recommendation would be to start with an Omega-3 test. If you are below 8%, start with the dosage of EPA + DHA the authors of today’s study recommended. Then retest in 6 months and adjust your dose based on the results of that test.

Question MarkHow Much Is Too Much? As I mentioned above, the dose response was linear for Omega-3 Index versus reduction in risk of total and ischemic strokes. So, the question becomes whether you might wish to increase your Omega-3 Index above 8% to achieve an even better reduction in stroke risk.

That is a very personal decision that only you can make but let me share some facts to help you make that decision.

  • As I mentioned above, a previous clinical trial showed an increased risk of bleeding events and Afib at a dosage of 4 gm/day of pure EPA. We don’t know whether that was because of the dose or the use of a formulation that contained only EPA without DHA and other naturally occurring long-chain omega-3s.
  • In that study the increase in bleeding events and Afib was observed in <5% of participants, which suggests that those side effects may be limited to certain high-risk individuals.
    • In this context, high risk might include individuals with preexisting Afib, individuals with a tendency towards excess bleeding, and patients on blood thinning medications.
    • However, only your physician knows all your risk factors. If you have health issues or are on medications, it is always a good idea to check with your physician before changing your omega-3 intake. And if you are considering high-dose omega-3 supplementation or exceeding an 8% Omega-3 Index, I strongly recommend that you consult with your physician first.

The Bottom Line

A recent study looked at the effect of omega-3 levels in red blood cells and other tissues (something called Omega-3 Index) on the risk of various types of stroke.

When individuals with an Omega-3 Index ≥ 8% were compared with those with an Omega-3 Index of ≤ 4%:

  • Risk was reduced by 17% for total stroke and 18% for ischemic stroke (stroke caused by blood clots in the carotid arteries). There was no effect on hemorrhagic stroke (stroke caused by bleeding from small blood vessels in the brain).

The authors concluded, “In summary, this harmonized and pooled analysis of prospective studies showed that long-chain omega-3 levels were inversely associated with risk of total and ischemic stroke but were unrelated to risk of hemorrhagic stroke. Thus, higher dietary intake of DHA and EPA would be expected to lower risk of stroke.”

This study represents an important breakthrough. There is good evidence that increased EPA + DHA from food and/or supplements reduces the risk of ischemic stroke. But some experts have cautioned it might also increase the risk of hemorrhagic stroke. This study puts that fear to rest.

For more details about the study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance 

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

 

Which Diets Are Heart Healthy?

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Which Diet Is Best For You?

Author: Dr. Stephen Chaney 

strong heartThe top 3 claims the advocates of every popular diet make are:

  • It will help you lose weight.
  • It reduces your risk of diabetes.
  • It reduces your risk of heart disease.

The truth is any restrictive diet helps you lose weight. And when you lose weight, you improve blood sugar control. Which, of course, reduces your risk of developing diabetes.

But what about heart disease? Which diets are heart healthy? When it comes to heart disease the claims of diet advocates are often misleading. That’s because the studies these advocates use to support their claims are often poor quality studies. Many of these studies:

  • Look at markers of heart disease risk rather than heart disease outcomes. Markers like LDL cholesterol, triglycerides, c-reactive protein, etc. are only able to predict possible heart disease outcomes. To really know which diets are heart healthy you have to measure actual heart disease outcomes such as heart attacks, stroke, and cardiovascular deaths.
  • Are too short to provide meaningful results. Many of these studies last only a few weeks. You need much longer to measure heart disease outcomes.
  • Are too small to provide statistically significant results. You need thousands of subjects to be sure the results you are seeing are statistically significant.
  • Have not been confirmed by other studies. The Dr. Strangeloves of the world like to “cherry pick” the studies that support the effectiveness of their favorite diet. Objective scientists know that any individual study can be wrong. So, they look for consensus conclusions from multiple studies.

A recent study (G Karam et al, British Medical Journal, 380: e072003, 2023) avoided all those pitfalls. The investigators conducted a meta-analysis of 40 high-quality clinical studies with 35,548 participants to answer the question, “Which diets are heart healthy?”

How Was The Study Done?

Clinical StudyThe authors started by searching all major databases of clinical studies for studies published on the effect of diets on heart disease outcomes through September 2021.

They then performed a meta-analysis of the data from all studies that:

  • Compared the effect of a particular diet to minimal dietary intervention (defined as not receiving any advice or receiving dietary information such as brochures or brief advice from their clinician with little or no follow-up).
  • Looked at heart disease outcomes such as all cause mortality, cardiovascular mortality, non-fatal heart attacks, stroke, and others.
  • Lasted for at least 9 months (average duration = 3 years).
  • Were high-quality studies.

Using these criteria:

  • They identified 40 studies with 35,548 participants for inclusion in their meta-analysis.
    • From those 40 studies, they identified 7 diet types that met their inclusion criteria (low fat (18 studies), Mediterranean (12 studies), very low fat (6 studies), modified fat (substituting healthy fats for unhealthy fats rather than decreasing fats, 4 studies), combined low fat and low sodium (3 studies), Ornish (3 studies), Pritikin (1 study).

One weakness of meta-analyses is that the design of the studies included in the meta-analysis is often different. Sometimes they don’t fit together well. So, while the individual studies are high-quality, a combination of all the studies can lead to a conclusion that is low quality or moderate quality.

Finally, the data were corrected for confounding factors such as obesity, exercise, smoking, and medication use.

Which Diets Are Heart Healthy?

Now that you understand the study design, we are ready to answer the question, “Which diets are heart healthy?” Here is what this study found:

Compared to minimal intervention,

  • The Mediterranean diet decreased all cause mortality by 28%, cardiovascular mortality by 45%, stroke by 35%, and non-fatal heart attacks by 52%.
  • Low fat diets decreased all cause mortality by 16% and non-fatal heart attacks by 23%. The effect of low fat diets on cardiovascular mortality and stroke was not statistically significant in this meta-analysis.
    • For both the Mediterranean and low fat diets, the heart health benefits were significantly better for patients who were at high risk of heart disease upon entry into the study.
    • The evidence supporting the heart health benefits for both diets was considered moderate quality evidence for this meta-analysis. [Remember that the quality of any conclusion in a meta-analysis is based on both the quality of evidence of the individual studies plus how well the studies fit together in the meta-analysis.]
  • While the percentage of risk reduction appears to be different for the Mediterranean and low fat diets, the effect of the two diets on heart health was not considered significantly different in this study.
  • The other 5 diets provided little, or no benefit, compared to the minimal intervention control based on low to moderate quality evidence.

The authors concluded, “This network meta-analysis found that Mediterranean and low fat dietary programs probably reduce the risk of mortality and non-fatal myocardial infarction [heart attacks] in people at increased cardiovascular risk. Mediterranean dietary programs are also likely to reduce the risk of stroke. Generally, other dietary programs were not superior to minimal intervention.”

Which Diet Is Best For You?

confusionThe fact that this study found both the Mediterranean diet and low fat diets to be heart healthy is not surprising. Numerous individual studies have found these diets to be heart healthy. So, it is not surprising when the individual studies were combined in a meta-analysis, the meta-analysis also concluded they were heart healthy. However, there are two important points I would like to make.

  • The diets used in these studies were designed by trained dietitians. That means the low fat studies did not use Big Food, Inc’s version of the low fat diet in which fatty foods are replaced with highly processed foods. In these studies, fatty foods were most likely replaced with whole or minimally processed foods from all 5 food groups.
  • The Mediterranean diet is probably the most studied of current popular diets. From these studies we know the Mediterranean diet improves brain health, gut health, and reduces cancer risk.

As for the other 5 diets (very low fat, modified fat, low fat and low sodium, Ornish, and Pritikin), I would say the jury is out. There is some evidence that these diets may be heart healthy. But very few of these studies were good enough to be included in this meta-analysis. Clearly, more high-quality studies are needed.

Finally, you might be wondering why other popular diets such as paleo, low carb, and very low carb (Atkins, keto, and others) were left out of this analysis. All I can say is that it wasn’t by design.

The authors did not select the 7 diets described in this study and then search for studies testing their effectiveness. They searched for all studies describing the effect of diets on heart health. Once they identified 40 high-quality studies, they grouped the diets into 7 diet categories.

I can only conclude there were no high-quality studies of paleo, low carb, or very low carb diets that met the criteria for inclusion in this meta-analysis. The criteria were:

  • The effect of diet on heart health must be compared to a control group that received no or minimal dietary advice.
  • The study must measure heart disease outcomes such as all cause mortality, cardiovascular mortality, non-fatal heart attacks, and stroke.
  • The study must last at least 9 months.
  • The study must be high-quality.

Until these kinds of studies are done, we have no idea whether these diets are heart healthy or not.

So, what’s the takeaway for you? Which diet is best for you? Both low fat diets and the Mediterranean diet are heart healthy provided the low fat diet consists of primarily whole or minimally processed foods. Which of these two diets is best for you depends on your food preferences.

The Bottom Line 

Many of you may have been warned by your doctor that your heart health is not what it should be. Others may be concerned because you have a family history of heart disease. You want to know which diets are heart healthy.

Fortunately, a recent study answered that question. The authors performed a meta-analysis of 40 high-quality studies that compared the effect of various diets with the effect of minimal dietary intervention (doctors’ advice or diet brochure) on heart disease outcomes.

From this study they concluded that both low fat diets and the Mediterranean diet probably reduce mortality and the risk of non-fatal heart attacks, and that the Mediterranean diet likely reduces stroke risk.

Other diets studied had no significant effect on heart health in this study. That does not necessarily mean they are ineffective. But it does mean that more high-quality studies are needed before we can evaluate their effect on heart health.

So, what’s the bottom line for you? Both low fat diets and the Mediterranean diet are heart healthy provided the low fat diet consists of primarily whole or minimally processed foods Which of these two diets is best for you depends on your food preferences.

For more information on this study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Is Whole Fat Dairy Healthy?

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Is It Dairy Or Diet?

Author: Dr. Stephen Chaney 

CheesesFor years we have been told to select low fat dairy foods. But recent headlines claim, “That’s nonsense. Whole fat dairy foods are healthy.” Are those headlines true?

In previous issues of “Health Tips From the Professor” I have kept you abreast of recent studies suggesting that whole fat dairy foods may not be as bad for us as we thought. I also cautioned you that the headlines may not have accurately represented the studies they described.

Headlines have to be simple. But truth is often more nuanced. If we believed the current headlines, we might be asking ourselves questions like, “Should we ditch the current health guidelines recommending low-fat dairy foods? Are foods like ice cream, sour cream, and cheddar cheese actually be good for us?

To answer these questions, I will look at the study (A Mente et al, European Heart Journal, 44, 2560-2579, 2023) behind the current headlines and put the study into perspective.

Spoiler alert: If I could summarize the study findings in two sentences, they would be, “Whole fat dairy can be part of a healthy diet. But can it be part of an unhealthy diet?”

Stay tuned. I will discuss the science behind that statement below.

How Was This Study Done?

clinical studyThis study started with data collected from the Prospective Urban Rural Epidemiology (PURE) study. The PURE study is an ongoing study correlating diet, lifestyle, and environmental effects on health outcomes. It has enrolled 166,762 individuals, age 35-70, from 21 low-, middle-, and high-income countries on 5 continents.

Habitual food intake was determined using country-specific food frequency questionnaires at the time participants joined the study. Participants (166,762) from the PURE study who had complete dietary information were included in this study and were followed for an average of 9.3 years.

Based on preliminary analysis of data from the PURE study, the authors developed their version of a healthy diet, which they call the PURE diet. Like most other healthy diets, the PURE diet emphasizes fruits, vegetables, legumes, nuts, and fish. However:

  • Based on studies suggesting that whole fat dairy foods can be part of a healthy diet, the PURE diet includes whole fat dairy foods.

This is different from most other healthy diet recommendations.

They went on to develop what they referred to as the PURE healthy diet score by:

  • Determining the median intake for each of the 6 food groups included in their PURE diet (fruits, vegetables, legumes, nuts, fish, and whole fat dairy).
  • Assigning each participant in the study a score of 0 or 1 depending on whether their intake for that food group was below or above the median intake.
  • Adding up the points. Since 6 food groups were included in the PURE diet, this means that each participant in the study was assigned a PURE diet score ranging from 0-6.

Once they had developed a PURE diet score, they expanded their data by including five additional large independent studies that included people from 70 countries. The combined data from all six studies amounted to 245,597 people from 80 countries. Of the people included in the data analysis:

  • 21% came from high income countries.
  • 60% came from middle income countries.
  • 19% came from low-income countries.

This is very similar to the global population distribution. This is a strength of this study because it allowed them to ask whether the PURE diet score worked as well in low-income countries as in high-income countries.

Finally, they correlated the PURE diet score with outcomes like all-cause mortality, heart attack, and stroke.

Is Whole Fat Dairy Healthy?

QuestionsThe authors of this study divided the participants of all 6 studies into quintiles based on their PURE diet score and compared those in the highest quintile (PURE score of ≥ 5) with those in the lowest quintile (PURE score of ≤ 1).

The people in the highest quintile were eating on average 5 servings/day of fruits and vegetables, 0.5 servings/day of legumes, 1.2 servings/day of nuts, 0.3 servings/day of fish, 2 servings/day of dairy (of which 1.4 servings/day was whole fat dairy), 0.5 servings/day of unprocessed red meat, and 0.3 servings/day of poultry.

 

The people in the lowest quintile ate significantly less fruits, vegetables, nuts, fish, and dairy; and slightly less legumes, unprocessed red meat, and poultry than those in the highest quintile.

However, they consumed significantly more refined wheat foods and white rice. This study did not track consumption of highly processed foods, but the high consumption of white flour leads me to suspect they ate a lot more highly processed food.

With that in mind, when the authors compared people with the highest PURE diet scores to those with the lowest PURE diet scores:

  • All-cause mortality was reduced by 30%.
  • Cardiovascular disease was reduced by 18%.
  • Heart attacks were reduced by 14%.
  • Strokes were reduced by 19%.
  • The PURE healthy eating score was slightly better at predicting health outcomes than the Mediterranean, DASH, and HEI (Healthy Eating Index) scores. But the differences were small. So, I still recommend choosing the healthy diet that best fits your preferred foods and your lifestyle.
  • The PURE healthy eating score was significantly better at predicting health outcomes than the Planetary diet score. I will discuss the nutritional inadequacy of “sustainable diets” like the Planetary diet in next week’s “Health Tips From the Professor” article.

Because of the size and design of this study, they were able to make three interesting observations.

  1. The PURE, Mediterranean, DASH, and HEI diet scores were predictive of health outcomes in every country across the globe. You no longer have to wonder if what works in the United States will work in low-income countries and in countries with very different food preferences. Previous studies have not been able to make that claim.

2) You don’t have to be perfect.

    • A 20% increase (one quintile) in PURE score was associated with a 6% lower risk of major cardiovascular events and an 8% lower risk of mortality. In other words, even small improvements in your diet may improve your health outcomes.
    • The health benefits of the PURE diet started to plateau at a score of 3 (with 6 being the highest score). The authors concluded that most of the health benefits were associated with a modestly higher consumption of healthy foods compared to little or no consumption of healthy foods.

Simply put, that means the health benefits gained by going from a moderately healthy diet to a very healthy diet are not as great as the health benefits gained by going from a poor diet to a moderately healthy diet.

[Note: There are still improvements in health outcomes when you go from a moderately healthy diet to a very healthy diet.  My recommendation: “You don’t need to achieve perfection, but you shouldn’t accept mediocrity”.]

3) The PURE diet score was more predictive of health outcomes in some countries than in others.

    • The PURE diet score was more predictive of health outcomes in low-income countries. The authors felt that was because low-income countries started with average PURE scores of 2.1, whereas higher-income countries started with average PURE scores of 3.5.

The authors felt this was another example getting more “bang for the buck” by going from a poor diet to a moderately healthy diet than from a moderately healthy diet to a very healthy diet. (Remember, the health benefits associated with improving PURE diet scores start to plateau at a PURE score of 3.

    • The difference in benefits for low-income countries compared to high-income countries was observed for the Mediterranean, DASH, and HEI diet scores. So, it is probably safe to say for any healthy diet you don’t need to be perfect. You just need to be better.

The authors concluded, “A diet composed of higher amounts of fruit, vegetables, nuts, legumes, fish, and whole fat dairy is associated with a lower risk of cardiovascular disease and mortality in all world regions, especially in countries with lower income where consumption of these foods is low.”

Is It Dairy Or Diet?

CheesesThe headlines are telling us that recommendations to choose low-fat dairy products are out of date. They say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. Let me provide perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context. What do I mean by that? Let’s dig a little deeper into this study.

  • Let’s start with a description of the PURE diet. It is a diet that emphasizes fruits, vegetables, legumes, nuts, and fish. In other words, it is a primarily plant-based diet.
  • Although the authors keep referring to the diet as one that includes whole fat dairy. It would be more accurate to say that it includes dairy, which was 30% low-fat and 70% whole fat.
  • The authors said that removal of any one food group from this combination reduced the predictive power of the PURE diet. In other words, the beneficial effect of 70% whole fat dairy is best seen in the context of a primarily plant-based diet.
  • The PURE diet was most effective at predicting health outcomes in low-income countries where a significant percent of the population consumes a primarily plant-based diet because meats are expensive.

So, a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

To answer that question let’s compare the potential effects of whole fat dairy on a primarily plant-based diet compared to the typical American or European diet.

  • Milk and other dairy foods are excellent sources of calcium, vitamin B12, and iodine and good sources of protein, vitamin D, choline, zinc, and selenium – nutrients that are often low or missing in plant-based diet. And this is true whether the dairy foods are low-fat or whole fat.
  • Primarily plant-based diets tend to be low in saturated fat, so the potential negative effects of adding a small amount of saturated fat to the diet may be outweighed by the beneficial effects of the nutrients dairy foods provide.

On the other hand,

  • The typical American or European diet provides plenty of protein and vitamin B12 and significantly more choline, vitamin D, iodine, and zinc than a plant-based diet. The added nutrients from adding dairy foods to this kind of diet is still beneficial, but the benefits are not as great as adding dairy foods to a primarily plant-based diet.
  • If you read the American Heart Association statement on saturated fats, it does not say that any amount of saturated fat is bad for you. In fact, small amounts of saturated fats play some beneficial roles in our bodies. The American Heart Association says, “Eating too much saturated fat can raise the level of LDL cholesterol in your blood…[which] increases your risk of heart disease and stroke.”
  • Here is where the problem lies. The typical American or European diet already contains too much saturated fat. Whole fat dairy just adds to that excess.

So, the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

The Bottom Line 

Once again, the headlines are telling us that recommendations to choose low-fat dairy products are out of date. The articles say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. In this post I looked at the study behind the most recent headlines and provided perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context.

When you consider diet context a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

When you consider that question the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

For more information on this study, and the science behind my summary of the study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Are All Carbs Bad?

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Are Low Carb Enthusiasts Right About The Dangers Of Carbohydrates?

Author: Dr. Stephen Chaney 

Low carb enthusiasts have been on the warpath against carbohydrates for years.

Almost everyone agrees that sugar-sweetened sodas and highly processed, refined foods with added sugar are bad for us. But low carb enthusiasts claim that we should also avoid fruits, grains, and starchy vegetables. Have they gone too far?

Several recent studies suggest they have. For example, both association studies and randomized controlled studies suggest that total carbohydrate intake is neither harmful nor beneficial for heart health.

In addition, recent studies suggest that free sugar intake is associated with both elevated triglyceride levels and an increase in heart disease risk.

But those studies have mostly looked at free sugar intake from sugar-sweetened sodas. The authors of this study (RK Kelley et al, BMC Medicine, 21:34, 2023) decided to look more carefully at the effect of all free sugars and other types of carbohydrates on triglyceride levels and heart disease risk.

How Was This Study Done?

clinical studyThe 110,497 people chosen for this study were a subgroup of participants in the UK Biobank Study, a large, long-term study looking at the contributions of genetic predisposition and environmental exposure (including diet) to the development of disease in England, Scotland, and Wales.

The participants in this study were aged between 37 and 73 (average age = 56) on enrollment and were followed for an average of 9.4 years. None of them had a history of heart disease or diabetes or were taking diabetic medications at the time of enrollment.

During the 9.4-year follow-up, five 24-hour dietary recalls were performed, so that usual dietary intake could be measured rather than dietary intake at a single time point. The people in this study participated in an average of 2.9 diet surveys, and none of them had less than two diet surveys.

The averaged data from the dietary recalls were analyzed for the amount and kinds of carbohydrate in the diet. With respect to the types of carbohydrate, the following definitions would be useful.

  • The term free sugars includes all monosaccharides and disaccharides added to foods by the manufacturer, cook, or consumer, plus sugars naturally present in honey, syrups, and unsweetened fruit juices.
  • The term non-free sugars includes all sugars not in the free sugar category, mostly sugars naturally occurring in fruits, vegetables, and dairy products.
  • The term refined grains includes white bread, white pasta, white rice, most crackers and cereals, pizza, and grain dishes with added fat.
  • The term whole grains includes wholegrain bread, wholegrain pasta, brown rice, bran cereal, wholegrain cereals, oat cereal, and muesli.

Finally, the study looked at the association of total carbohydrate and each class of carbohydrate defined above with all heart disease, heart attacks, stroke, and triglyceride levels.

Are All Carbs Bad?

Question MarkThe study looked at total carbohydrate intake, free sugar intake, and fiber intake. In each case, the study divided the participants into quartiles and compared those in the highest quartile with those in the lowest quartile.

Using this criterion:

  • Total carbohydrate intake was not associated with any cardiovascular outcome measured (total heart disease risk, heart attack risk, and stroke risk).
  • Free sugar intake was positively associated with all cardiovascular outcomes measured. Each 5% increase in caloric intake from free sugars was associated with a:
    • 7% increase in total heart disease risk.
    • 6% increase in heart attack risk.
    • 10% increase in stroke risk.
    • 3% increase in triglyceride levels.
  • Fiber intake was inversely associated with total heart disease risk. Specifically, each 5 gram/day increase in fiber was associated with a:
    • 4% decrease in total heart disease risk.

The investigators also looked at the effect of replacing less healthy carbohydrates with healthier carbohydrates. They found that:

  • Replacing 5% of caloric intake from refined grains with whole grains reduced both total heart disease risk and stroke risk by 6%.
  • Replacing 5% of caloric intake from free sugars (mostly sugar-sweetened beverages, fruit juices, and processed foods with added sugar) with non-free sugars (mostly fruits, vegetables, and dairy products) reduced total heart disease risk by 5% and stroke risk by 9%.

Are Low Carb Enthusiasts Right About The Dangers Of Carbohydrates?

With these data in mind let’s look at the claims of the low-carb enthusiasts.

Claim #1: Carbohydrates raise triglyceride levels. This study shows:

  • This claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake (fruits, vegetables, and whole grains. This study did not measure intake of beans, nuts, and seeds, but they would likely be in the same category).
  • However, this claim is true with respect to foods high in free sugars (sugar-sweetened beverages, fruit juices, and processed foods with added sugar).

Claim #2: Carbohydrates increase heart disease risk. This study shows:

  • That claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake.
  • However, this claim is true with respect to foods high in free sugars.

Claim #3: Carbohydrates cause weight gain [Note: Low carb enthusiasts usually word it differently. Their claim is that eliminating carbohydrates will help you lose weight. But that claim doesn’t make sense unless you believed eating carbohydrates caused you to gain weight.] This study shows:

  • This claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake.
  • Once again, this claim is true with respect to foods high in free sugars.

The data with high fiber carbohydrates was particularly interesting. When the authors compared the group with the highest fiber intake to the group with the lowest fiber intake, the high-fiber group:

  • Consumed 33% more calories per day.
  • But had lower BMI and waste circumference (measures of obesity) than the low-carbohydrate group.

This suggests that you don’t need to starve yourself to lose weight. You just need to eat healthier foods.

And, in case you were wondering, the high fiber group ate:

  • 5 more servings of fruits and vegetables and…
  • 2 more servings of whole grain foods than the low fiber group.

This is consistent with several previous studies showing that diets containing a lot of fruits, vegetables, and whole grains are associated with a healthier weight.

The authors concluded, “Higher free sugar intake was associated with higher cardiovascular disease incidence and higher triglyceride concentrations…Higher fiber intake and replacement of refined grain starch and free sugars with wholegrain starch and non-free sugars, respectively, may be protective for incident heart disease.”

In short, with respect to heart disease, the type, not the amount of dietary carbohydrate is the important risk factor.

What Does This Mean For You?

Questioning WomanForget the low carb “mumbo jumbo”.

  • Carbohydrates aren’t the problem. The wrong kind of carbohydrates are the problem. Fruit juice, sugar-sweetened sodas, and processed foods with added sugar:
    • Increase triglyceride levels.
    • Are associated with weight gain.
    • Increase the risk for heart disease.
  • In other words, they are the villains. They are responsible for the bad effects that low carb enthusiasts ascribe to all carbohydrates.
  • Don’t fear whole fruits, vegetables, dairy, and whole grain foods. They are the good guys.
    • They have minimal effect on triglyceride levels.
    • They are associated with healthier weight.
    • They are associated with a lower risk of heart disease and diabetes.

So, the bottom line for you is simple. Not all carbs are created equal.

  • Your mother was right. Eat your fruits, vegetables, and whole grains.
  • Avoid fruit juice, sodas and other sugar-sweetened beverages, and processed foods with added sugar. [Note: Artificially sweetened beverages are no better than sugar-sweetened beverages, but that’s another story for another day.]

And, if you were wondering why low carb diets appear to work for weight loss, it’s because any restrictive diet works short term. As I have noted previously, keto and vegan diets work equally well for short-term weight loss.

The Bottom Line 

Low carb enthusiasts have been telling us for years to avoid all carbohydrates (including fruits, starchy vegetables, and whole grains) because carbohydrates:

  • Increase triglyceride levels.
  • Cause weight gain.
  • Increase our risk for heart disease.

A recent study has shown that these claims are only true for some carbohydrates, namely fruit juices, sodas and other sugar-sweetened beverages, and processed foods with added sugar.

Whole fruits, vegetables, and whole grain foods have the opposite effect. They:

  • Have a minimal effect on triglyceride levels.
  • Are associated with a healthier weight.
  • Are associated with a lower risk of heart disease and diabetes.

So, forget the low carb “mumbo jumbo” and be sure to eat your fruits, vegetables, and whole grains.

For more information on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Is Erythritol Bad For Your Heart?

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Who Should Be Concerned About Erythritol Intake?

Author: Dr. Stephen Chaney 

Everyone is searching for the perfect sweetener. And if you were in the marketing department of Big Food Inc, the perfect sweetener would be defined as:

  • Natural, meaning that it is found in fruits, vegetables, or other plant foods.
  • Low in calories. Of course, a perfect sweetener would have zero calories because it is not metabolized in our bodies.
  • Low glycemic, meaning that it would have a minimal effect on blood sugar levels. Once again, a perfect sweetener would have zero effect on blood sugar levels.
  • Safe, meaning that it has no adverse effects on our health.

Sugar alcohols appear to meet all these criteria, so they have become the sweetener of choice for lots of highly processed foods. This is especially true for the sugar alcohol, erythritol, since it is currently the least expensive of the sugar alcohols.

So, a recent study (M Witowski et al, Nature Medicine, 2023) suggesting that erythritol might increase the risk of heart disease was quite surprising.

This is the first study to suggest a link between erythritol and heart disease, and it was a flawed study (I will discuss the flaws below).

Reputable scientists don’t put much credence in a weak first study like this one. We generally consider the conclusions of a first study like this one to be an unproven hypothesis at this point.

But we are cautious. There will be many follow-up, better designed studies, to test this hypothesis. Once these studies have been published, the scientific community will look at all the evidence and either issue a warning or conclude that there is no reason for concern.

But that doesn’t stop the Dr. Strangeloves of the world from warning you of the “dangers” of erythritol and telling you to avoid it at all costs.

For that reason, I felt it was appropriate to address this issue. I will:

  • Describe the study and its flaws.
  • Put the study into the broader perspective of what we know about sweeteners.
  • Identify the two population groups who should be most concerned about erythritol.

How Was The Study Done And What Did It Show?

This study can be divided into three parts.

heart disease#1: An Association Between Erythritol Blood Levels And Heart Disease.

There were three separate experiments included in this section of the study. In each experiment patients were recruited after visiting cardiac clinics for diagnostic procedures. The average age of these patients was 67 and 45% of them already had experienced a non-fatal heart attack prior to the study. In other words, these were all older patients with pre-existing heart disease who were at high risk of heart attack or stroke in the near future.

The first study was a metabolomic study. In simple terms this means that high-tech equipment and computing were used to measure hundreds of metabolites in the blood of the patients and, in this case, correlate each of them with the occurrence of heart attacks and strokes over the next three years.

  • This study identified 16 sugar alcohols and related metabolites in the blood of these patients that were associated with an increased risk of heart attack and stroke. (I will discuss the significance of this observation in more detail later.)

Because erythritol was among the top 6 compounds in terms of association with increased heart attack and stroke risk, and erythritol is the most commonly used sugar alcohol in processed foods, the next two studies focused on the association between blood levels of erythritol and heart attack/stroke risk. Their results were predictable.

  • High blood levels of erythritol were associated with an increased risk of heart attack and stroke over the next three years.

Flaws In This Portion Of The Study:thumbs down symbol

  • As the authors of the study pointed out, these studies were done with older patients with pre-existing heart disease who were at high risk of heart attack or stroke. They acknowledged that it is not known whether these associations exist with younger, healthier patients.
  • As the authors also pointed out, these are associations. They do not prove cause and effect. In particular, the studies did not measure the diet, exercise habits, and other lifestyle factors of these patients that may have contributed to their increased risk of heart attack and stroke.
  • When you look closely at the data, it is clear that the association is only seen at the highest blood levels of erythritol. Specifically, the blood levels of erythritol in these patients were divided into quartiles. The risk of heart attack and stroke in the first three quartiles (low to moderate blood levels of erythritol) were identical to the control. However, the fourth quartile (highest blood levels of erythritol) was associated with a dramatically increased risk of heart attack and stroke. That raises three important questions:
    • “How much erythritol were patients in the fourth quartile consuming?”
      • The authors did not look at dietary intake of erythritol but did note a previous study estimated that Americans consume up to 30 grams of erythritol a day.
    • 30 grams of erythritol a day is a huge amount of erythritol. Where does that erythritol come from?
      • Much of it comes from erythritol-containing highly processed foods like zero calorie sugar substitutes (either erythritol alone or erythritol mixed with artificial sweeteners to improve the taste); reduced- and low calorie carbonated and non-carbonated beverages; hard candy and cough drops, cookies, cakes, pastries, and bars; puddings and pie fillings; soft candies; syrups and toppings; ready to eat cereals; fruit novelty snacks; and frozen desserts.
      • But it is also found in foods you might not suspect, such as plant-based “milk” substitutes; chocolate and flavored milks; barbecue and tomato sauce, fruit-based smoothies, the syrup used in canned fruits, yoghurt; low calorie salad dressings; and salty snacks.
      • In other words, the only way anyone can consume 30 grams of erythritol in a day is to consume large quantities of erythritol-containing highly processed foods (I will discuss the significance of this observation later).
    • “What else was different about patients in the fourth quartile?”
      • When you look carefully at the data, the patients in the fourth quartile were significantly older, with a higher incidence of diabetes, pre-existing coronary artery disease, previous non-fatal heart attacks, congestive heart failure, and greater triglycerides – all of which significantly increase their risk of heart attack and stroke.

#2: Mechanistic Studies:

Next the authors did in vitro and animal studies looking at the effect of high levels of erythritol on blood clotting.

  • These studies showed that high levels of erythritol promoted blood clotting both in vitro and in mice. The authors concluded that these studies provided a plausible mechanism for a link between high erythritol blood levels and increased risk of heart attack and stroke.

Flaws In This Portion Of The Study:thumbs down symbol

  • Other critics have pointed out that the assays used were not accurate models of blood clotting in humans. This particular critique is beyond my expertise, so I won’t comment further. However:
    • As someone who was involved in cancer drug development for over 30 years, I know that in vitro and animal models are poor indicators of how things work in humans.
    • And as a biochemist, I have two concerns:
      • The authors provided no mechanistic rationale for why erythritol would enhance blood clotting.
      • The authors made no effort to show that the effect of erythritol was unique. Would high levels of other sugar alcohols or other naturally occurring sugars have the same effect on blood clotting in their assays? We don’t know.

#3: Blood Levels Of Erythritol After Oral Intake.

Finally, the authors gave subjects 30 grams of erythritol and measured blood levels over the next several days.

  • This experiment showed that very high blood levels of erythritol were attained and maintained for at least two days before gradually decreasing to baseline. The authors concluded this experiment showed that it was feasible to attain and maintain high blood levels of erythritol for several days following a single ingestion of 30 grams of erythritol.

Flaws In This Portion Of The Study:thumbs down symbol

  • I have already pointed out that 30 grams per day is a huge amount of erythritol. However, erythritol in the diet will come from a variety of foods, some of which will contain components (fiber etc.) that slow the absorption of erythritol.
  • In contrast, the subjects in this experiment were given 300 ml of liquid containing 30 grams of erythritol and told to drink it in two minutes!
  • In other words, these subjects were consuming 30 grams of erythritol in 2 minutes rather than 24 hours, and they were consuming it in the most easily absorbable form. For a study like this, that makes the effective dose orders of magnitude greater than the amount of erythritol that anyone consumes from their diet over a 24-hour period. The study design was completely unrealistic.

Is Erythritol Bad For Your Heart?

Question MarkAs described above, this is the first study to suggest an association between erythritol and heart disease, and it was a highly flawed study.

It is also important to know that erythritol is not an artificial sweetener. It is found naturally in foods like grapes, peaches, pears, watermelons, and mushrooms. It is also found in some fermented foods like cheese, soy sauce, beer, sake, and wine.

It is also a byproduct of normal human metabolism, so we always have some of it circulating in our bloodstream. Our body knows how to handle low to moderate intakes of erythritol.

However, to help you really understand what this study means, I need to put it into the context of other studies. I will do this in story form (You will find more details about these studies in my book “Slaying The Food Myths”).

First, let’s look at highly processed food consumption:

  • Multiple recent studies have shown that high consumption of highly processed food is associated with increased risk of obesity, diabetes, heart disease, and premature death. We don’t know what it is about highly processed food consumption that is responsible for the increased risk, but it is unlikely to be just one thing.
  • As I pointed out above, the only way to achieve the high blood levels of erythritol associated with increased heart disease risk is to consume large quantities of erythritol-containing highly processed foods.

Next, let’s follow the history of sweeteners in highly processed foods.

  • When I was a young man, sucrose (table sugar) was added to most highly processed foods. Sucrose is foundsugar cubes naturally in many fruits and vegetables. Small to moderate intake of sucrose in unprocessed and minimally processed foods posed no problem. However, large intakes of sugar in highly processed foods were found to increase the risk of obesity, diabetes, heart disease, and premature death.
  • At that point, sucrose became a “sugar villain”, and Big Food, Inc substituted fructose and high fructose corn syrup (a mixture of fructose and glucose) for sugar in their highly processed foods. As with sucrose, fructose is found naturally in many foods, and small to moderate intakes of fructose and high fructose corn syrup posed no health risks. However, large intakes of fructose and high fructose corn syrup in highly processed foods were found to increase the risk of obesity, diabetes, heart disease, and premature death.
  • Fructose and high fructose corn syrup then became the sugar villains. And because high fructose corn syrup is chemically and biologically indistinguishable from natural sugars like honey, date sugar, coconut sugar, it is likely that high intakes of these sugars in highly processed foods would cause the same problem.
  • So Big Food, Inc started relying on artificial sweeteners in their highly processed foods. But guess what? Artificial SweetenersRecent studies have suggested that artificial sweeteners in highly processed foods are associated with obesity, diabetes, and heart disease.
  • That has caused Big Food, Inc to rely more on sugar alcohols in their highly processed foods, particularly erythritol because it is the least expensive of the sugar alcohols. Now the current study comes along and suggests that high intake of erythritol in highly processed foods may increase the risk of heart disease.
  • If this hypothesis is confirmed by better designed studies, it is not clear what Big Food, Inc will do next. The metabolomic study described above showed that high blood levels of several other sugar alcohols are associated with an increased risk of heart disease.

Hopefully, you are starting to see a pattern here. It’s time to ask the question, “Is it the sweetener, or is it the food?”

Clearly, it doesn’t matter what sweetener we are talking about. Large intake of any natural sweetener in the context of a diet rich in highly processed foods appears to have an adverse effect on our health. And we don’t know whether these adverse health effects are caused by the sweetener or some other component of the highly processed foods.

If you want to improve your health, the best solution is to decrease your intake of highly processed foods. That will automatically reduce your intake of sweeteners and other unhealthy components of highly processed foods and increase your intake of healthy components from the whole foods you will be eating instead.

Who Should Be Concerned About Erythritol Intake?

The authors of this study identified two groups who should be most concerned about erythritol consumption – diabetics and adherents of the keto diet.

  • Diabetics are at high risk because they are told to consume non-caloric sweeteners instead of sugars, and they are not told to avoid highly processed foods. Consequently, they consume much higher amounts of non-caloric sweeteners than the average American.
  • I must admit that I didn’t foresee keto adherents as a high-risk group. However, it appears that keto enthusiasts love their sweets as much as the rest of us, and the sweetener of choice for keto-friendly sweets is erythritol. The authors said that a single serving of keto ice cream contains 30 grams of erythritol. I can hardly imagine how much erythritol they must be getting in their diet.

And, once again, the best advice for both groups is to simply decrease the amount of highly processed food in their diet.

The Bottom Line 

Erythritol is not an artificial sweetener. It is found naturally in foods like grapes, peaches, pears, watermelons, and mushrooms. It is also found in some fermented foods like cheese, soy sauce, beer, sake, and wine.

It is also a byproduct of normal human metabolism, so we always have some of it circulating in our bloodstream. Our body knows how to handle erythritol.

That is why it was a surprise when a recent study claimed that high intake of erythritol is associated with an increased risk of heart attack and stroke. The Dr. Strangeloves of the world are already starting to tell you that erythritol is deadly and you should avoid it at all costs. But reputable scientists are saying, “Not so fast”.

This is the first study to suggest an association between erythritol and heart disease, and it was a highly flawed study.

In fact, the study showed that low to moderate intakes of erythritol had no effect on heart disease risk. It was only the highest intake of erythritol that was associated with increased risk of heart disease. And given the distribution of erythritol in the American diet, the only way someone could take in that much erythritol is to consume large amounts of erythritol-sweetened highly processed foods.

A brief review of the literature on sweeteners reveals that this is a common pattern for every natural sweetener tested. Low to moderate intake of these sweeteners has no adverse health effects. However, high intake of every sweetener tested in the context of a highly processed food diet is associated with an increased risk of obesity, diabetes, heart disease, and premature death.

That raises the question, “Is it the sweetener, or is it the food?”

Clearly, it doesn’t matter what sweetener we are talking about. Large intake of any natural sweetener in the context of a diet rich in highly processed foods is likely to have an adverse effect on our health. And we don’t know whether these adverse health effects are caused by the sweetener or some other component of a highly processed food diet.

If you want to improve your health, the best solution is to decrease your intake of highly processed foods. That will automatically reduce your intake of sweeteners and other unhealthy components of highly processed foods and increase your intake of healthy components from the whole foods you will be eating instead.

For more details on the study and information about which foods are likely to contain erythritol and the population groups who should be most concerned about erythritol consumption, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease

Does Red Meat Cause Frailty In Older Women?

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Which Proteins Are Best?

Author: Dr. Stephen Chaney

Fatty SteakThe ads from the meat lobby say, “Red meat does a body good”. Are the ads true?

If we consider the health consequences of regularly eating red meat, the answer appears to be a clear, “No”. Multiple studies have shown a link between red meat consumption and:

  • Coronary heart disease.
  • Stroke
  • Type 2 diabetes.
  • Colon cancer, prostate cancer, and breast cancer.

And, if we consider the environmental consequences of red meat production, the answer also appears to be, “No”. I have discussed this in a recent issue of “Health Tips From the Professor”.

But what about muscle mass and strength? Red meat is a rich source of protein, and we associate meat consumption with an increase in muscle mass. Surely, red meat consumption must help us build muscle mass and strength when we are young and preserve muscle mass and strength as we age.

This is why the recent headlines claiming that red meat consumption increases the risk of frailty in older women were so confusing. I, like you, found those headlines to be counterintuitive. So, I have investigated the study (EA Struijk et al, Journal of Cachexia, Sarcopenia and Muscle, 13: 210-219, 2022) behind the headlines. Here is what I found.

How Was The Study Done?

Clinical StudyThis study utilized data acquired from the Nurses’ Health Study (NHS). The NHS began in 1976 with 121,700 female nurses aged 30 to 55. This study followed 85,871 nurses in the NHS once they reached age 60 for an average of 14 years.

Dietary intake was assessed using a food frequency questionnaire that was administered to all participants in the study every four years between 1980 and 2010. The long-term intake of red meat and other protein sources was based on a cumulative average of all available diet questionnaires for each participant.

The participants also filled out a Medical Outcomes Short Report every four years between 1992 and 2014. Data from this survey was used to calculate something called the FRAIL scale, which includes the following frailty criteria:

  • Fatigue
  • Low muscle strength.
  • Reduced aerobic capacity.
  • Having ≥5 of the following chronic diseases:
    • Cancer
    • High blood pressure
    • Type 2 diabetes
    • Angina
    • Myocardial infarction (heart attack)
    • Congestive heart failure
    • Asthma
    • COPD (chronic obstructive pulmonary disease)
    • Arthritis
    • Parkinson’s disease
    • Kidney disease
    • Depression
  • Greater than ≥5% weight loss in two consecutive assessments.

Frailty was defined as having met 3 or more criteria in the FRAIL scale. The study looked at the effect of habitual consumption of red meat or other protein sources on the development of frailty during the 14-year follow-up period.

Does Red Meat Cause Frailty In Older Women?

The investigators separated the participants into 5 quintiles based on total red meat consumption, unprocessed red meat construction, or processed red meat consumption. The range of intakes was as follows.

Total red meat: 0.4 servings per day to 1.8 servings per day.

Unprocessed red meat: 0.3 servings per day to 1.3 servings per day.

Processed red meat: 0.04 servings per day to 0.6 servings per day.

Clearly none of the women in this study were consuming either vegan or keto diets. As might be expected from a cross-section of the American public, there was a fairly narrow range of daily meat consumption.

Here are the results of the study:

  • Each serving per day of total red meat increased frailty by 13%.
  • Each serving per day of unprocessed red meat increased frailty by 8%.
  • Each serving per day of processed red meat increased frailty by 26%.
  • When each component of the frailty index was examined individually, all of them were positively associated with red meat consumption except for weight loss.

This was perhaps the most unexpected finding of the study. Not only did red meat consumption increased the risk of chronic diseases in these women, which would be expected from many previous studies. But red meat consumption also made these women more tired, weaker, and shorter of breath.

The authors concluded, “Habitual consumption of any type of red meat was associated with a higher risk of frailty.”

Which Proteins Are Best?

Red Meat Vs White MeatThe investigators then asked if replacing one serving/day of red meat with other protein sources was associated with a significantly lower risk of frailty. Here is what they found:

  • Replacing one serving per day of unprocessed red meat with a serving of:
    • Fish reduced frailty risk by 22%.
    • Nuts reduced frailty risk by 14%.
  • Replacing one serving per day of processed red meat with a serving of:
    • Fish reduced frailty risk by 33%
    • Nuts reduced frailty risk by 26%
    • Low-fat dairy reduced frailty risk by 16%
    • Legumes reduced frailty risk by 13%.

The authors concluded, “Replacing red meat with another source of protein including fish, nuts, legumes, and low-fat dairy may be encouraged to reduce the risk of developing frailty syndrome. These findings are in line with dietary guidelines promoting diets that emphasize plant-based sources of protein.” [I would note that fish and low-fat dairy are hardly plant-based protein sources.]

What Does This Study Mean For You?

Questioning WomanI am not yet ready to jump on the “eating red meat causes frailty” bandwagon. This is a very large, well-designed study, but it is a single study. It needs to be replicated by future studies.

And, as a biochemist, I am skeptical about any study that does not offer a clear metabolic rationale for the results. As I said earlier, increased protein intake is usually associated with an increase in muscle mass when we are young and a preservation of muscle mass as we age. There is no obvious metabolic explanation for why an increase in red meat consumption in older women would cause a decrease in muscle mass and other symptoms of frailty.

On the other hand, there are plenty of well documented reasons for decreasing red meat intake. Consumption of red meat is bad for our health and bad for the health of the planet as I have discussed in an earlier issue of “Health Tips From the Professor”. And substituting other protein sources, especially plant proteins, is better for our health and the health of our planet.

Finally, we also need to consider the possibility that this study is correct and that future studies will confirm these findings. Stranger things have happened.

As we age, we begin to lose muscle mass, a process called sarcopenia. Increased protein intake and resistance exercise can help slow this process. While I am not ready to say that red meat causes decreased muscle mass, I do think this study should make us think about which protein sources we use to prevent sarcopenia. At the very least we should not use age-related muscle loss as an excuse to increase our red meat intake. That might just be counterproductive.

The Bottom Line

A recent study looked at the effect of red meat consumption on frailty in older women. It came to the unexpected conclusion that:

  • Each serving per day of total red meat increased frailty by 13%.
  • Each serving per day of unprocessed red meat increased frailty by 8%.
  • Each serving per day of processed red meat increased frailty by 26%.
  • The increase in frailty could be reduced by replacing one serving/day of red meat with a serving of fish, nuts, low-fat dairy, or legumes.

I am not yet ready to jump on the “eating red meat causes frailty” bandwagon. This is a very large, well-designed study, but it is a single study. It needs to be replicated by future studies. And, as a biochemist, I am skeptical about any study that does not offer a clear metabolic rationale for the results.

On the other hand, there are plenty of well documented reasons for decreasing red meat intake. Consumption of red meat is bad for our health and for the health of the planet.

Finally, we also need to consider the possibility that this study is correct and that future studies will confirm these findings. Stranger things have happened.

As we age, we begin to lose muscle mass, a process called sarcopenia. Increased protein intake and resistance exercise can help slow this process. This study should make us think about which protein sources we use to prevent sarcopenia. At the very least we should not use age-related muscle loss as an excuse to increase our red meat intake. That might just be counterproductive.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

The Omega-3 Pendulum

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Who Benefits Most From Omega-3s? 

Author: Dr. Stephen Chaney

Pendulum
Pendulum

If you were around in the 60’s, you might remember the song “England Swings Like a Pendulum Do”. It was a cute song, but it had nothing to do with pendulums. This week I am talking about something that really does resemble a pendulum – the question of whether omega-3s reduce heart disease risk.

There is perhaps nothing more confusing to the average person than the “truth” about omega-3s and heart disease risk. The headlines and expert opinion on the topic swing wildly between “omega-3s reduce heart disease risk” to “omega-3s have no effect on heart disease risk” and back again. To me these swings resemble the swings of a pendulum – hence the title of this article.

Part of the reason for the wild swings is that journalists and most “experts” tend to rely on the latest study and ignore previous studies. Another contributing factor is that most journalists and experts read only the main conclusions in the article abstract. They don’t read and analyze the whole study.

So, in today’s “Health Tips From the Professor” I plan to:

  • Analyze 3 major studies that have influenced our understanding of the relationship between omega-3 intake and heart disease risk. I will tell you what the experts missed about these studies and why they missed it.
  • Summarize what you should know about omega-3 intake and your risk of heart disease.

Why Is The Role Of Omega-3s In Preventing Heart Disease So Confusing?

SecretsIn answering that question, let me start with what I call “Secrets Only Scientists Know”.

#1: Each study is designed to disprove previous studies. That is a strength of the scientific method. But it guarantees there will be studies on both sides of every issue.

Responsible scientists look at all high-quality studies and base their opinions on the weight of evidence. Journalists and less-responsible “experts” tend to “cherry pick” the studies that match their opinions.

#2: Every study has its flaws. Even high-quality studies have unintended flaws. And I have some expertise in identifying unintended flaws.

I published over 100 papers that went through the peer review process. And I was involved in the peer review of manuscripts submitted by other scientists. In the discussion below I will use my experience in reviewing scientific studies to identify unintended flaws in 3 major studies on omega-3s and heart disease risk.

Next, let me share the questions I ask when reviewing studies on omega-3s and heart disease. I am just sharing the questions here. Later I will share examples of how these questions allowed me to identify unintended flaws in the studies I review below.

#1: How did they define heart disease? The headlines you read usually refer to the effect of omega-3s on “heart disease”. However, heart disease is a generic term. In layman’s terms, it encompasses angina, heart attacks, stroke due to blood clots, stroke due brain bleeds, congestive heart failure, impaired circulation, and much more.

Omega-3s have vastly different effects on different forms of heart disease, so it is important to know which form(s) of heart disease the study examined. And if the study included all forms of heart disease, it is important to know whether they also looked at the forms of heart disease where omega-3s have been shown to have the largest impact.

#2: What was the risk level of the patients in the study? If the patients in the study are at imminent risk of a heart attack or major cardiovascular event, it is much easier to show an effect than if they are at low risk.

For example, it is easy to show that statins reduce the risk of a second heart attack in someone who has just suffered a heart attack. These are high-risk patients. However, if you look at patients with high cholesterol but no other risk factors for heart disease, it is almost impossible to show a benefit of statins. These are low-risk patients.

If it is difficult to show that statins benefit low-risk patients, why should we expect to be able to show that omega-3s benefit low-risk patients?

[Note: I am not saying that statins do not benefit low-risk patients. I am just saying it is very difficult to prove they do in clinical studies.]

#3: How much omega-3s are the patients getting in their diet? The public reads the headlines. When the headlines say that omega-3s are good for their hearts, they tend to take omega-3 supplements. When the headlines say omega-3s are worthless, they cut back on omega-3 supplements. So, there is also a pendulum effect for omega-3 intake.

Omega-3s are fats. So, omega-3s accumulate in our cell membranes. The technical term for the amount of omega-3s in our cellular membranes is something called “Omega-3 Index”. Previous studies have shown that:

    • An omega-3 index of 4% or less is associated with high risk of heart disease, and…
    • An omega-3 index of 8% or more is associated with a low risk of heart disease.

When the omega-3 index approaches 8%, adding more omega-3 is unlikely to provide much additional benefit. Yet many studies either don’t measure or ignore the omega-3 index of patients they are enrolling in the study.

#4: How many and what drugs were the patients taking? Many heart disease patients are taking drugs that lower blood pressure, lower triglycerides, reduce inflammation, and reduce the risk of blood clot formation. These drugs do the same things that omega-3s do. This decreases the likelihood that you can see any benefit from increasing omega-3s intake.

The Omega-3 Pendulum

With all this in mind let’s examine three major double-blind, placebo-controlled studies that looked at the effect of omega-3s on heart disease risk and came to different conclusions. Here is a summary of the studies.

GISSI Study ASCEND Study VITAL Study
11,000 participants 15,480 participants 25,871 participants
Followed for 3.5 years Followed for 7.4 years Followed for 5.3 years
Europe USA USA
Published in 1999 Published in 2018 Published in 2019
Dose = 1 gm/day Dose = 1 gm/day Dose = 1 gm/day
20% ↓ in heart disease deaths No effect on fatal or non-fatal heart attack or stroke Significant ↓ in some forms of heart disease
45% ↓ in fatal heart attack or stroke – as effective as statins Significant ↓ in heart disease risk for some patients

heart attacksAt first glance the study designs look similar, so why did these studies give such different results. This is where the unintended flaws come into play. Let’s look at each study in more detail.

The GISSI Study:

  • The patients enrolled in this study all had suffered a heart attack in the previous 3 months. They were at very high risk of suffering a second heart attack within the next couple of years.
  • Omega-3 intake was not measured in this study. But it was uncommon for Europeans to supplement with omega-3s in the 90’s. And European studies on omega-3 intake during that period generally found that omega-3 intake was low.
  • Patients enrolled in this study were generally taking only 2 heart disease drugs, a beta-blocker and a blood pressure drug.

The ASCEND Study:

  • The patients enrolled in this study had diabetes without any evidence of heart disease. Only 17% of the flawspatients enrolled in the study were at high risk of heart disease. 83% were at low risk. Remember, it is difficult to show a benefit of any intervention in low-risk patients.
  • The average omega-3 index of patients enrolled in this study was 7.1%. That means omega-3 levels were near optimal at the beginning of the study. Adding additional omega-3s was unlikely to show much benefit.
  • Most of the patients in this study were on 3-5 heart drugs and 1-2 diabetes drugs which duplicated the effects of omega-3s.

That means this study was asking a very different question. It was asking whether omega-3s provided any additional benefit for patients who were already taking multiple drugs that duplicated the effects of omega-3s.

However, you would have never known that from the headlines. The headlines simply said this study showed omega-3s were ineffective at preventing heart disease.

Simply put, this study was doomed to fail. However, despite its many flaws the authors reported that omega-3s did reduce one form of heart disease, namely vascular deaths (primarily due to heart attack and stroke). Somehow this observation never made it into the headlines.

The VITAL Study:

  • This study enrolled a cross-section of the American population aged 55 or older (average age = 67). As you might suspect for a cross-section of the American population, most of the participants in this study were at low risk for heart disease. This limited the ability of the study to show a benefit of omega-3 supplementation in the whole population.

However, there were subsets of the group who were at high risk of heart disease (more about that below).

  • This study excluded omega-3 supplement users The average omega-3 index of patients enrolled in this study was 2.7% at the beginning of the study and increased substantially during the study. This enhanced the ability of the study to show a benefit of omega-3 supplementation.
  • Participants in this study were only using statins and blood pressure medications. People using more medications were excluded from the study. This also enhanced the ability of the study to show a benefit of omega-3 supplementation.

The authors reported that “Supplementation with omega-3 fatty acids did not result in a lower incidence of major cardiovascular events…” This is what lazy journalists and many experts reported about the study.

good newsHowever, the authors designed the study so they could also:

  • Look at the effect of omega-3s on heart disease risk in high-risk groups. They found that major cardiovascular events were reduced by:
    • 26% in African Americans.
    • 26% in patients with diabetes.
    • 17% in patients with a family history of heart disease.
    • 19% in patients with two or more risk factors of heart disease.
  • Look at the effect of omega-3s on heart disease risk in people with low omega-3 intake. They found that omega-3 supplementation reduced major cardiovascular events by:
    • 19% in patients with low fish intake.
  • Look at the effect of omega-3s on the risk of different forms of heart disease. They found that omega-3 supplementation reduced:
    • Heart attacks by 28% in the general population and by 70% for African Americans.
    • Deaths from heart attacks by 50%.
    • Deaths from coronary heart disease (primarily heart attacks and ischemic strokes (strokes caused by blood clots)) by 24%.

In summary, if you take every study at face value it seems like the pendulum is constantly swinging from “omega-3s reduce heart disease risk” to “omega-3s are worthless” and back again. There appears to be no explanation for the difference in results from one study to the next.

However, if you remember that even good studies have unintended flaws and ask the four questions I proposed Question Markabove, it all makes sense.

  • How is heart disease defined? Studies looking at heart attack and/or ischemic stroke are much more likely to show a benefit of omega-3s than studies that include all forms of heart disease.
  • Are the patients at low-risk or high-risk for heart disease? Studies in high-risk populations are much more likely to show a benefit than studies in low-risk populations.
  • What is the omega-3 intake of participants in the study? Studies in populations with low omega-3 intake are more likely to show a benefit of omega-3 supplementation than studies in populations with high omega-3 intake.
  • How many heart drugs are the patients taking? Studies in people taking no more than one or two heart drugs are more likely to show a benefit of omega-3 supplementation than studies in people taking 3-5 heart drugs.

When you view omega-3 clinical studies through the lens of these 4 questions, the noise disappears. It is easy to see why these studies came to different conclusions.

Who Benefits Most From Omega-3s?

omega 3s and heart diseaseThe answers to this question are clear:

  • People at high risk of heart disease are most likely to benefit from omega-3 supplementation.
  • People with low omega-3 intake are most likely to benefit from omega-3 supplementation.
  • Omega-3 supplementation appears to have the biggest effect on heart attack and ischemic stroke (stroke due to blood clots). Its effect on other forms of heart disease is less clear.
  • Omega-3 supplementation appears to be most effective at preventing heart disease if you are taking no more than 1 or 2 heart drugs. It may provide little additional benefit if you are taking multiple heart drugs. However, you might want to have a conversation with your doctor about whether omega-3 supplementation might allow you to reduce or eliminate some of those drugs.

What about the general population? Is omega-3 supplementation useful for patients who are at low to moderate risk of heart disease?

  • If we compare omega-3 studies with statin studies, the answer would be yes. Remember that statins cannot be shown to reduce heart attacks in low-risk populations. However, because they are clearly effective in high-risk patients, the medical community assumes they should be beneficial in low-risk populations. The same argument could be made for omega-3s.
  • We also need to recognize that our ability to recognize those who are at high risk of heart disease is imperfect. For too many Americans, the first indication that they have heart disease is sudden death!

When I was still teaching, I invited a cardiologist to speak to my class of first year medical students. He told the students, only partly in jest, that he felt statins were so beneficial they “should be added to the drinking water”.

I feel the same way about omega-3s:

  • Most Americans do not get enough omega-3s in our diet.
  • Our omega-3 index is usually much closer to 4% (high risk of heart disease) than 8% (low risk of heart disease).
  • Many of us may not realize that we are at high risk of heart disease until it is too late.
  • And omega-3s have other health benefits.

For all these reasons, omega-3 supplementation only makes sense.

The Bottom Line

There is perhaps nothing more confusing to the average person than the “truth” about omega-3s and heart disease risk. The headlines and expert opinion on the topic swing wildly between “omega-3s reduce heart disease risk” to “omega-3s have no effect on heart disease risk” and back again. To me these swings resemble the swings of a pendulum – hence the title of this article.

If you take every study at face value, there appears to be no explanation for the difference in results from one study to the next. However, if you recognize that even good studies have unintended flaws and ask four simple questions to expose these flaws, it all makes sense.

For the four questions you should ask when reviewing any omega-3 study and my recommendations for who benefits the most from omega-3 supplementation, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

A Diet To Die For

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Which Diet Is Best? 

Author: Dr. Stephen Chaney

Heart AttackMany clinical studies focus on the benefits or risks associated with individual components of our diet. For example, we have been told:

  • Saturated and trans fats are bad for us and monounsaturated and omega-3 fats are good for us.
  • Sugar and refined carbohydrates are bad for us, but complex carbohydrates are good for us.

However, we don’t eat saturated fats or sugars in isolation. They are part of a diet with many other foods. Do other foods in our diet affect the risks we associate with saturated fat or sugar? We don’t know.

Simply put, we don’t eat foods, we eat diets. We don’t eat saturated fats, we eat diets. It would be more helpful for the average person if research focused on which diets are good and bad for us instead of which foods are good and bad for us.

One recent study (JM Shikany et al, Journal of the American Heart Association, 10:e019158, 2021) did just that. It evaluated the effect of 6 different dietary patterns on the risk of sudden cardiac death (dropping dead from a stroke or heart attack).

  • It turns out that one of the diets significantly increases your risk of sudden cardiac death. I call that one, “A diet to die for”.
  • Another diet significantly decreases your risk of sudden cardiac death. I call that one, “A diet to live for”.
  • The other diets had no significant effect on the risk of sudden cardiac death.

You are probably wondering, “What were the diets?”; “Which diet is best?”; and “Which diet is worst?” I cover that below, but first we should look at how the study was designed.

How Was The Study Designed?

Clinical StudyThe study involved 21,069 participants in the REGARDS (Reasons for Geographical and Racial Differences in Stroke) clinical trial who were followed for an average of 10 years. This clinical trial enrolled:

  • 30% of its participants from what is called the “the stroke belt” (North Carolina, South Carolina, Georgia, Tennessee, Alabama, Mississippi, Arkansas, and Louisiana).
  • 20% of its participants from what is called “the stroke buckle” (the coastal plain of North Carolina, South Carolina, and Georgia).
  • 50% of its participants from elsewhere in the continental United States.

At the beginning of the study, participants were given a medical exam and filled out an extensive questionnaire on diet.

Based on the diet analysis, the participants were ranked for adherence to six dietary patterns.

#1: The Convenience Pattern. This dietary pattern relied heavily on pre-packaged or restaurant meals, pasta dishes, pizza, Mexican food, and Chinese food.

#2: The Plant-Based Pattern. This dietary pattern relied heavily on vegetables, fruits, fruit juice, cereal, beans, fish, poultry, and yogurt.

#3: The Sweets Pattern. This dietary pattern relied heavily on added sugars, desserts, chocolate, candy, and sweetened breakfast foods.

#4: The Southern Pattern. This dietary pattern relied heavily on added fats, fried food, eggs and egg dishes, organ meats, processed meats, and sugar-sweetened beverages.

#5: The Alcohol and Salad Pattern. This dietary pattern relied heavily on beer, wine, liquor, green leafy vegetables, tomatoes, and salad dressing.

#6: The Mediterranean Pattern. Adherence to the Mediterranean dietary pattern was based on the well-established Mediterranean Diet Score.

  • Points are added for beneficial foods (vegetables, fruits, legumes, whole grain cereals, nuts, and fish).
  • Points are subtracted for detrimental foods (meat and dairy).
  • Points are added for a high ratio of monounsaturated fats to saturated fats (think diets rich in olive oil).
  • One point is added for moderate alcohol consumption, Zero or excess alcohol consumption is assigned 0 points.

The study looked at the correlation of these dietary patterns with the incidence of sudden cardiac death during the 10-year study.

A Diet To Die For

deadThe results were striking.

  • The Southern Diet increased the 10-year risk of sudden cardiac death 2.2-fold. Basically, it doubled the risk.
    • In people with no previous history of heart disease at the beginning of the 10-year study, the Southern Diet increased the risk of sudden cardiac death by 2.3-fold.
    • In people with a previous history of heart disease at the beginning of the 10-year study, the Southern Diet increased the risk of sudden cardiac death by 2-fold.
  • The Mediterranean Diet decreased the 10-year risk of sudden cardiac death 41%.
    • In people with no previous history of heart disease at the beginning of the 10-year study, the Mediterranean Diet decreased the risk of sudden cardiac death by 51%. Basically, it cut the risk in half.
    • In people with a previous history of heart disease at the beginning of the 10-year study, the Mediterranean Diet decreased the risk of sudden cardiac death by 23%, but that decrease was not statistically significant.
  • None of the other diets had a significant effect on the 10-year risk of sudden cardiac death.

In the words of the authors, “We identified a trend towards an inverse association of the Mediterranean diet score and a positive association of adherence to the Southern dietary pattern with risk of sudden cardiac death.” [That is a fancy way of saying the Mediterranean diet decreased the risk of sudden cardiac death, and the Southern dietary pattern increased the risk of sudden cardiac death.]

Which Diet Is Best?

AwardThe Mediterranean Diet Is Best: In this analysis of the effects of 6 different dietary patterns on the risk of sudden cardiac death, it is obvious that the Mediterranean diet is best. It cut the risk of sudden cardiac death in half.

This should come as no surprise:

  • I have reported on a previous study showing that the Mediterranean diet decreases the risk of heart disease by 47%.
  • In the Woman’s Health Study the Mediterranean diet decreased the risk of sudden cardiac death by 36%.
  • In the Nurses’ Health Study there was an inverse association between the Mediterranean Diet Score and sudden cardiac death.

The Southern Dietary Pattern Was Worst. It doubled the risk of sudden cardiac death. As someone who grew up in the South, this comes as no surprise to me. Let me count the ways:

  • It starts with a breakfast of fried eggs, grits with “red-eye gravy” (a mixture of ham drippings and coffee), ham or sausage, and biscuits made with lots of lard and sugar.
  • When I was growing up, a snack might be an RC cola and moon pies (look that one up).
  • Dinner might be fried chicken and hushpuppies or fried fish and hushpuppies.
  • Instead of picnics we have pig pickins (which is pretty much what it sounds like).
  • And we boil our vegetables with fatback (pig fat) and sugar.

I could go on, but you get the picture. Don’t get me wrong, I have fond memories of the foods I ate while growing up in the South. I just don’t eat them much anymore.

Why Didn’t The Plant-Based Dietary Pattern Score Better? One of the surprises from this study was that the Plant-Based Dietary Pattern didn’t score better. After all, numerous studies have shown that mostly plant-based diets reduce the risk of heart disease. Why did it strike out in this study?Vegan Foods

My feeling is that the study did not adequately describe a true Plant-Based Dietary Pattern. As I described above, participants following the Plant-Based Dietary Pattern were identified as having above average consumption of vegetables, fruits, fruit juice, cereal, beans, fish, poultry, and yogurt compared to others in this study. I have two concerns with this classification.

  • As described, this is a semi-vegetarian diet, while the best results for reducing heart disease risk are seen with strict vegetarian and lacto-ovo-vegetarian diets.
  • However, my biggest concern is that we don’t know what other foods they were consuming. Were they also consuming convenience foods? Were they consuming sweets? We don’t know.

That is very different from the two dietary patterns that stood out in this study.

  • 50% of the participants in this study came the Southeastern region of the United States. So, when the study identified participants as following a Southern Dietary Pattern based on a few southern foods, it is likely that those participants ate many other southern foods as well.

If 50% of the participants in the study had come from the Loma Linda area of California where vegetarianism is much more common, the study might have done a better job of identifying participants consuming a plant-based diet.

  • While participants consuming the Mediterranean diet were more scattered geographically, the Mediterranean Diet Score used to identify people consuming a Mediterranean diet is much more detailed and has been validated in numerous previous studies.

In short, the Southern and Mediterranean Dietary Patterns may have stood out in this study because they provided a more precise distinction between those consuming a Southern or Mediterranean diet and those following other dietary patterns. If the Plant-Based Dietary Pattern had been more precisely described, it might have shown a statistically significant benefit as well.

The Bottom Line

Many clinical studies focus on the benefits or risks associated with individual components of our diet.

However, we don’t eat foods, we eat diets. It would be more helpful for the average person if research focused on which diets are good and bad for us instead of which foods are good and bad for us.

One recent study did just that. It evaluated the effect of 6 different dietary patterns on the risk of sudden cardiac death (dropping dead from a stroke or heart attack).

  • It turns out that the Southern diet doubles your risk of sudden cardiac death. I call that one, “A diet to die for”.
  • In contrast, the Mediterranean diet cuts your risk of sudden cardiac death in half. I call that one, “A diet to live for”.
  • The other diets had no significant effect on the risk of sudden cardiac death.

For more details on the study, why the Southern diet is so bad for us, and why the Mediterranean diet is so good for us, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

What Is The Truth About Eating Eggs And Heart Disease?

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Have The Dangers Of Eggs Been “Eggagerated”?

egg confusionIt’s no wonder you are confused about whether or not eggs are good for you. The advice you have been given about eggs over the years has been constantly changing.

Eggs are an affordable source of high-quality protein, iron, unsaturated fats, phospholipids like lecithin and choline, and carotenoids. That almost qualifies them as a health food. However, they are also a major source of cholesterol in the American diet. Back when we thought of dietary cholesterol was bad for us, that made eggs the enemy.

Then we discovered that dietary cholesterol has relatively little effect on blood cholesterol levels. It was obesity plus saturated fat and sugar in our diet that raised blood cholesterol levels and increased our risk of heart disease.

Then several studies reported that eggs did not increase our risk of heart disease. A study out of China even found that eggs decreased the risk of heart attack and hemorrhagic stroke. Suddenly, eggs became our best friend.

That only lasted a few years until a study from the United States reported that eggs increased your risk of heart disease, and a study from Europe reported that eggs increased your risk of hemorrhagic stroke. Eggfusion (egg confusion) reigned.

Most of these studies were large studies. They followed their participants for 5-10 years. Why were their results so confusing? A careful analysis of the studies shows that most of them suffered from three major weaknesses.

  • They only measured egg consumption at the beginning of the study. This fails to account for the fact that egg consumption has waxed and waned over the years as eggs have gone from enemy to friend and back to enemy.
  • They did not assess how the overall diet influences the effect of egg consumption on heart disease. If we believe the previous studies, eggs lower the risk of heart disease and hemorrhagic stroke in China and increase the risk of both in the United States and Europe. This suggests that overall diet is important, but this hypothesis has not been tested.
  • They also did not address the question of whether eggs, because of their cholesterol, might have a more adverse effect on heart disease in individuals who already have high blood cholesterol and have difficulty controlling their cholesterol levels.

That is why the study (JP Drouin-Chartier et al, British Medical Journal, 368:m513, 2020) I am reporting on today is so important. It is a huge study, much larger than any previous study on the topic. Plus, it was designed in such a way that it had none of the weaknesses of previous studies.

How Was The Study Done?

Clinical StudyThis study started by combining the data from three major clinical trials:

  • The first Nurse’s Health Study, which ran from 1980 to 2012,
  • The second Nurse’s Health Study, which ran from 1991-2013, and
  • The Health Professional’s Follow-Up Study, which ran from 1986-2012.

These studies combined enrolled 173,563 women and 42,055 men and followed them for an average of 32 years. All the participants were free of heart disease, type 2 diabetes, and cancer at the time they were enrolled. The design of these studies was extraordinary.

  • A detailed food frequency questionnaire was administered every 2-4 years. This allowed the investigators to calculate cumulative averages of all dietary variables, including egg intake. This assured that the effects of egg consumption and diet represented the participant’s diet over the 32-year duration of the study.
  • Participants also filled out questionnaires that captured information on disease diagnosis, disease risk factors, medicines taken, weight, and lifestyle characteristics every 2 years with follow-up rates >90%. This allowed the investigators to measure the onset of disease and medicine use for each participant during the study. More importantly, 32 years is long enough to measure the onset of diseases like heart disease, diabetes, and cancer – diseases that require decades to develop.
  • The endpoint of the study was “incident heart disease”, which the investigators defined as non-fatal heart attack, death from heart disease, and fatal and non-fatal stroke. During this study, 14,806 participants developed incident heart disease. This was a large enough number for a detailed statistical analysis of the data.
  • For example, statistical analysis showed that the participants with the highest egg intake also were more likely to be obese and more likely to consume red meat, bacon and other processed meats, refined grains, French fries, and sugar-sweetened beverages. These are what we refer to as “confounding variables” because they also increase the risk of heart disease and are likely to confound (confuse) the analysis. Therefore, the investigators statistically corrected the data on egg consumption for these confounding variables. Many previous studies did not have the data or statistical power to correct their egg consumption data for these confounding variables.

In short, this study was much larger, ran far longer, and was better designed that any of the previous studies on egg consumption and heart disease risk. However, the authors did not stop there. They also performed a meta-analysis of 28 previous studies with a total of 1,720,108 participants and 139,195 cardiovascular disease events.

The only weakness in this study is that only 2% of the participants ate more than one egg per day. Consequently, it cannot address the health consequences of eating more than one egg per day on a regular basis.

Before sharing the results of this study with you, I need to provide some background about how our bodies regulate blood cholesterol levels. So, let’s move on to my favorite topic, “Biochemistry 101”.

Biochemistry 101: Cholesterol Metabolism

ProfessorMost people think of cholesterol only as a bad thing – something that can kill us. Nothing could be further from the truth. In fact, cholesterol is essential for life.

  • Our body makes vitamin D and coenzyme Q10 from cholesterol.
  • Our body makes steroid hormones such as cortisol, estrogen, and testosterone from cholesterol.
  • Cholesterol is a vital component of the myelin sheath that coats our nerve cells.
  • And that is just the beginning.

Because cholesterol is essential, our body makes its own cholesterol and has an elegant control system that keeps our blood cholesterol levels right where they should be.

  • When we get lots of cholesterol from our diet, our body makes less and excretes any excess.
  • When we get little cholesterol from our diet, our body makes more and excretes less.

Unfortunately, many Americans muck up this elegant control system. There are several factors that can throw our body’s ability to regulate blood cholesterol levels out of whack, leading to elevated blood cholesterol levels and increased risk of heart disease. For example:

  • Obesity
  • Type 2 diabetes
  • Diets high in saturated fats
  • Diets high in sugar and refined carbohydrates
  • Genetics

And it’s not just elevated cholesterol that is the problem. These same factors are associated with inflammation, which also increases the risk of heart disease.

Of course, we can’t do anything about our genetics, but the other factors are under our control. Let’s keep that in mind as we look at the results of this study.

What Is The Truth About Eating Eggs And Heart Disease?

the truth signWhen the investigators looked at their combined data from the Nurse’s Health Studies and the Health Professional’s Study:

  • There was no difference in heart disease outcomes for participants consuming an average of one egg/day and participants consuming less than one egg/month.
  • When the investigators examined heart attack and stroke separately, there was no difference in either outcome for participants consuming an average of one egg/day and participants consuming less than one egg/month.
  • As mentioned above the participants who consumed the most eggs weighed more; were less physically active; were more likely to be current smokers; and were more likely to consume red meat, processed meats, refined grains, potatoes (think French fries and potato chips), full fat milk, and sugar-sweetened beverages.
    • Without correcting for these factors eating one egg/day resulted in a 10% increase in heart disease risk.
    • After correcting for these factors, eating one egg/day resulted in a 7% decrease in heart disease risk.
    • In both cases the differences were statistically non-significant. However, they were in line with the previous studies mentioned above.

When they looked at the data generated by their meta-analysis of 28 studies:

  • There was no association between heart disease risk and egg consumption.
    • In Asian countries where the diet was primarily unrefined, plant-based foods, egg consumption decreased heart disease risk.
    • In people with type 2 diabetes, egg consumption increased heart disease risk.

The authors concluded “…moderate egg consumption (up to one egg/day) is not associated with cardiovascular disease risk overall, and is associated with potentially lower cardiovascular disease risk in Asian populations.”

The authors also noted that their data did not allow them to evaluate the effect of consuming more than one egg/day.

Have The Dangers Of Eggs Been “Eggagerated”?

are eggs good for youThis study clears up a lot of confusion about egg consumption and heart disease risk. The problem is that the scientific and medical communities have been looking for a “one size fits all” recommendation about egg consumption. This study shows us that the reality is much more complicated. Let me describe my interpretation of the data.

I think the results of this and previous studies are best described by the phrase, “Eggs are a healthy part of a healthy diet”. Here is what I mean by that.

  • If you are consuming a primarily plant-based diet, your body is fully able to regulate your blood cholesterol levels. Then, you can reap the full benefits of the egg, namely the protein, iron, unsaturated fats, lecithin, choline, and carotenoids it provides. Under these conditions, eating up to one egg/day reduces your risk of heart disease.
  • If you are consuming a diet that contains primarily chicken or fish and unprocessed plant foods, egg consumption is neutral. It neither increases nor decreases your risk of heart disease.
  • If you are consuming a diet that contains sugar-sweetened beverages, red and processed meats, high fat dairy products, refined grains, and junk foods (ie, the typical American diet), your body is no longer able to regulate blood cholesterol levels well. Now the cholesterol content of eggs becomes an issue and consuming one egg/day slightly increases your risk of heart disease.
  • If you are overweight and have developed type 2 diabetes, your body has become insulin resistant. This also interferes with your body’s ability to regulate blood cholesterol levels. In this situation, consuming one egg/day also increases your risk of heart disease.

The caveat is, of course, that these conclusions are based averages, and none of us are average.

The Bottom Line

You are probably aware that the effect of egg consumption on heart disease risk is controversial. Some studies report that egg consumption has no effect on heart disease risk. Other studies report egg consumption decreases heart disease risk. Still other studies report that egg consumption increases heart disease risk. No wonder you are confused.

A recent study has cleared up much of the confusion. This was not just another study. This study was much larger, ran far longer, and was better designed that any of the previous studies.

If you look at this and previous studies, it becomes clear that the effect of egg consumption on heart disease risk is strongly influenced by your overall diet and lifestyle.

  • If you are consuming a primarily plant-based diet, your body is fully able to regulate your blood cholesterol levels. Then, you can reap the full benefits of the egg, namely the protein, iron, unsaturated fats, lecithin, choline, and carotenoids it provides. Under these conditions, eating up to one egg/day reduces your risk of heart disease.
  • If you are consuming a diet that contains primarily chicken or fish and unprocessed plant foods, egg consumption is neutral. It neither increases nor decreases your risk of heart disease.
  • If you are consuming a diet that contains sugar-sweetened beverages, red and processed meats, high fat dairy products, refined grains, and junk foods (ie, the typical American diet), your body is no longer able to regulate blood cholesterol levels well. Now the cholesterol content of eggs becomes an issue and consuming one egg/day slightly increases your risk of heart disease.
  • If you are overweight and have developed type 2 diabetes, your body has become insulin resistant. This also interferes with your body’s ability to regulate blood cholesterol levels. In this situation, consuming one egg/day also increases your risk of heart disease.

In short, eggs are a healthy part of a healthy diet.

For more details, read the article above. You may also want to read the section “Biochemistry 101: Cholesterol Metabolism” to gain a better understanding of the mechanism behind these statements.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease

Which Foods Affect Stroke Risk?

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Why Is Diet And Stroke Risk So Confusing?

strokeOne day we are told vegetarian diets reduce our stroke risk. The next day we are told they increase stroke risk. It’s the same with red meat, dairy, and eggs. We keep getting mixed messages. It’s enough to make your head spin. Why is diet and stroke risk so confusing?

Part of the problem is that there are two distinct types of stroke. The technical names for them are ischemic stroke and hemorrhagic stroke.

An ischemic stroke occurs when an artery in the brain becomes blocked, shutting off blood flow and damaging part of the brain. This is usually caused by the gradual buildup of fatty deposits and cholesterol plaques in the arteries. When a blood clot forms and lodges in one of the narrowed arteries leading to the brain, an ischemic stroke occurs.

  • Ischemic strokes account for 87% of all strokes.
  • Ischemic strokes are associated with obesity, elevated cholesterol, diabetes, high blood pressure, and smoking.

A hemorrhagic stroke occurs when a weakened blood vessel bursts and bleeds into the surrounding region of the brain. Because our brains are surrounded by a protective skull, that blood has nowhere to go. Pressure from the buildup of blood damages brain cells in the vicinity of the bleed.

  • Hemorrhagic strokes account for only for only 15% of strokes but are responsible for 40% of stroke deaths.
  • The most common cause of a hemorrhagic stroke is the localized enlargement of a blood vessel due to chronic high blood pressure. This weakens the wall of the blood vessel, making it prone to rupturing.

Part of the confusion about diet and stroke risk is because many earlier studies did not distinguish between the two types of stroke.

  • If the studies just measured the incidence of stroke, the data were dominated by ischemic strokes (87% of strokes are ischemic).
  • However, if the studies focused on stroke deaths, hemorrhagic stroke made a larger contribution to the data set (40% of stroke deaths are hemorrhagic).

Fortunately, recent studies have started to focus on the effect of diet on ischemic and hemorrhagic strokes separately. However, many of those studies have been too small to accurately assess the effects of diet on hemorrhagic stroke.

The latest study (TYN Tong et al, European Heart Journal, ehaa007, published February 24, 2020) is one of the largest studies to look at the effect of diet on both kinds of stroke. It has enough patients in the hemorrhagic group to get an accurate estimate of the effect of diet on hemorrhagic stroke.

How Was The Study Done?

Clinical StudyThis study analyzed data on diet and stroke from 418,329 participants in the EPIC (European Prospective Investigation into Cancer and Nutrition). Although the study has cancer in the title, it actually investigated the effect of nutrition on multiple diseases (Presumably, the study title was chosen because EPIC is a more appealing acronym than EPID (European Prospective Investigation into Diseases and Nutrition)).

The participants were recruited from 9 European countries (Denmark, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the UK). The average age of participants was 50, and they were followed for an average of 12.7 years.

At the beginning of the study participants completed country-specific dietary and lifestyle questionnaires.

The dietary assessment was a food frequency questionnaire that asked participants about their dietary intake for the year prior to enrollment in the study. The food frequency data were used to estimate daily intake of red meat, processed meat, poultry, fish, dairy products, eggs, grains, fruits, vegetables, legumes, nuts, seeds, and dietary fiber (It measured total fiber and fiber from grains, fruits and vegetables individually).

The outcome measured was the incidence of ischemic and hemorrhagic strokes during the 12.7-year follow-up.

Which Foods Affect Stroke Risk?

Heart Healthy DietFor ischemic stroke:

  • Each 200 gram/day increase in consumption of fruits and vegetables decreased ischemic stroke risk by 13% (200 grams roughly corresponds to one large apple or one large orange without the skin).
  • Each 10 gram/day increase in consumption of fiber decreased ischemic stroke risk by 23%. Most of this decreased stroke risk was due to fiber from whole grains, fruits, and vegetables.
    • Each 4 gram/day increase in fiber from whole grains decreased ischemic stroke risk by 10%.
    • Each 4 gram/day increase in fiber from fruits and vegetables decreased ischemic stroke risk by 12%.
  • Dairy foods decreased ischemic stroke risk with the following breakdown:
    • Each cup of milk decreased ischemic stroke risk by 5%.
    • Each half cup of yogurt decreased ischemic stroke risk by 9%.
    • Each ounce of cheese decreased ischemic stroke risk by 12%.
  • Each 50 grams/day (2 ounces) of red meat increased ischemic stroke risk by 14%.
    • However, red meat was only half as likely to increase risk of ischemic stroke when the diet was also rich in fruits, vegetables, whole grains, and legumes.

For hemorrhagic stroke:

  • Each 20 gram/day increase in consumption of eggs increased hemorrhagic stroke risk by 25% (20 grams roughly corresponds to about 1/2 of a small egg or 1/3 of a jumbo egg).
  • This study did not measure the effect of salt intake on hemorrhagic stroke risk.

No other foods measured in this study had a significant effect on hemorrhagic stroke risk.

high blood pressureHowever, hemorrhagic stroke is highly associated with high blood pressure. When we look at the influence of foods on high blood pressure, here are the Harvard School of Medicine recommendations for keeping blood pressure low:

  • Eat more fish, nuts and beans in place of high-fat meats.
  • Choose fruits and vegetables instead of sugary, salty snacks and desserts.
  • Select whole grains rather than refined grains.Eat fruit instead of drinking fruit juice.
  • Use unsaturated fats like olive, canola, soybean, peanut, corn or safflower oils instead of butter, coconut oil, or palm-kernel oil.
  • Use herbs, spices, vinegar, and other low-sodium flavorings instead of salt; Choose low-sodium foods whenever possible.

Why Is Diet And Stroke Risk So Confusing?

egg confusionAs I mentioned at the start of this article, part of the reason that the headlines about diet and stroke risk are so confusing is:

  • Many studies did not distinguish between the two types of stroke.
  • Other studies were too small to reliably estimate the effect of food on hemorrhagic stroke risk.

However, there are still some unexplained inconsistencies among recently published studies. It is these inconsistencies I would like to address. For example:

1) In a recent issue of Health Tips From the Professor I reported on a major study (500,000 people followed for 8.9 years) in China. That study came to the opposite conclusion about eggs and risk of hemorrhagic than the EPIC study I discussed above. It found:

  • People consuming one egg per day had a 26% decrease in hemorrhagic stroke risk and a 28% decrease in hemorrhagic stroke deaths compared to people who never or rarely consumed eggs.

In other words, the two studies came to opposite conclusions. In the China study eggs decreased risk of hemorrhagic stroke. In the European study (EPIC) eggs increased risk of hemorrhagic stroke. The reason for this discrepancy is not clear, but one can speculate it might be explained by differences in the underlying diets of the two countries:

  • In China the diet is primarily plant-based. The addition of an egg/day may provide needed protein, fat, and cholesterol (Some cholesterol is essential. We just overdo it in this country).
  • In Europe the diet is already high in protein, saturated fat, and cholesterol. Getting more of them from eggs may not be such a good thing.

In short, if your diet is primarily plant-based, the addition of an egg/day may be a good thing. However, if your diet is already high in meat, saturated fat, and cholesterol, the addition of an egg/day may not be a good thing.

Vegan Foods2) In another recent issue of Health Tips From the Professor I reported on the EPIC-Oxford study that claimed vegetarians had 20% increased risk of hemorrhagic stroke compared to meat eaters.

Interestingly, the EPIC-Oxford study represented a very small portion (~10%) of the overall EPIC study and differed from the rest of the EPIC study in two important ways.

  • It looked at the effect of diets rather than foods on stroke risk.
  • Oxford was the only one of the 22 research centers involved in the EPIC study to invite people following a vegetarian diet to enroll in the study, so it had a much higher proportion of vegetarians than other centers that participated in the study.

The current study did not find any evidence that fruits, vegetables, nuts, seeds, beans, or whole grains influenced the risk of hemorrhagic stroke. In other words, in this much larger data set there was no evidence that the foods associated with a vegetarian diet increased hemorrhagic stroke risk.

However, most of the participants in larger EPIC study were also eating meats. They were not following a pure vegetarian diet.

As I said previously, “If the data on hemorrhagic stroke risk in the EPIC-Oxford study are true, it suggests it may not be a good idea to completely eliminate meat from our diet. However, you don’t need to add much meat to a vegetarian diet. The fish eaters in this study were consuming 1.4 ounces of fish per day. That was enough to eliminate the increased risk of hemorrhagic stroke.”

What Does This Mean For You?

Questioning WomanFor ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

  • Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)
  • Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.
  • These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

  • If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.
  • If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.
  • A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.
  • The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

In terms of an overall take-home lesson on diet and stroke risk, my advice is: “A primarily plant-based diet is a good idea, but you don’t need to become a vegan purist. Nor do you want to follow fad diets that eliminate whole food groups. We have 5 food groups for a reason. Eliminating any of them may not be a good idea.”

The Bottom Line

A recent study examined the effect of various foods on the risk of the two major forms of stroke.

For ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

  • Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)
  • Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.
  • These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

  • If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.
  • If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.
  • A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.
  • The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

In terms of an overall take-home lesson on diet and stroke risk, my advice is: “A primarily plant-based diet is a good idea, but you don’t need to become a vegan purist. Nor do you want to follow fad diets that eliminate whole food groups. We have 5 food groups for a reason. Eliminating any of them may not be a good idea.”

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

Health Tips From The Professor