High Blood Pressure

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.

 

How Much Omega-3s Are Best For Blood Pressure?

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What Does This Study Mean For You?

Author: Dr. Stephen Chaney

high blood pressureI am continuing my series on recent omega-3 breakthroughs. Today I am going to cover a recent systematic review and meta-analysis (X Zhang et al, Journal of the American Heart Association, 11: e025071, 2022) that analyzed 71 double blind, placebo-controlled clinical studies with 4,973 subjects to determine the optimal dose of omega-3s needed to lower blood pressure.

But first, I will cover why this study is so important.

High blood pressure is called a “silent killer”. For most of us our blood pressure creeps up year after year, decade after decade. Factors like inactivity, obesity, smoking, poor diet, and excess alcohol consumption speed the increase.

Unfortunately, the symptoms of high blood pressure – things like headaches, anxiety, fatigue, and blurred vision – are easy to ignore or confuse with other health problems. And if these symptoms are ignored long enough, the result can be sudden death due to a stroke or heart attack.

Alternately, the consequence could be things like congestive heart failure, kidney failure, vision loss, and memory loss that change your quality of life forever. And once the genie is out of the bottle, it can never be put back again. The damage is permanent.

Omega-3s are often recommended for keeping blood pressure in the normal range. In fact, in 2019 the FDA approved a qualified health claim stating, “Consuming eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 fatty acids in food or dietary supplements may reduce the risk of hypertension (high blood pressure) and coronary heart disease.”

But the amount of omega-3s needed to reduce the risk of high blood pressure is uncertain. Previous studies have come up with conflicting results. That is the question the study I will discuss today was designed to answer.

How Was This Study Done?

Clinical StudyThe investigators included 71 studies published between 1987 and 2020 with a total of 4,793 subjects ranging in age from 22 to 86 years in their systematic review and meta-analysis. The studies were all randomized, placebo-controlled trials looking at the effectiveness of omega-3 intake (primarily in the form of food or supplements containing both EPA and DHA) at lowering blood pressure. The placebo used in these studies was olive oil or other vegetable oils.

The studies included in this meta-analysis:

  • Included omega-3 intake from both diet (mackerel, salmon, trout, or tuna) and supplements (fish oil, algal oil, or purified omega-3 ethyl esters).
  • Were conducted in populations from Europe, North America, Australia and other Pacific islands, and Asia.
  • Included subjects with normal blood pressure as well as those with high blood pressure.
  • Ranged in length from 5 to 52 weeks (the average was 10 weeks).
  • Included approximately equal numbers of men and women.

The meta-analysis excluded studies that:

  • Lacked a placebo.
  • Lasted less than 4 weeks.
  • Included blood pressure medications.
  • Included individuals with preexisting cardiovascular events.

The data from these trials was analyzed by a statistical method called a 1-stage cubic spline regression model. This is a recently developed statistical method which the investigators stated was superior to the statistical methods used in previous studies because it reduces the likelihood the results are influenced by investigator bias.

How Much Omega-3s Are Best For Blood Pressure?

Fish Oil and Blood PressureWhen the investigators combined the data from all 71 studies:

  • The maximum reduction in both systolic and diastolic blood pressure was observed between 2g/d and 3 g/d.
  • The dose response was non-linear. Doses above 3 g/d offered no additional benefit.

When the investigators looked at subgroups within the studies:

  • Reduction in blood pressure was seen in both subjects with normal blood pressure and those with high blood pressure.
    • However, reduction in blood pressure and the dose response were different in the two groups.
      • In subjects with normal blood pressure the dose response was non-linear with the optimum reduction between 2 and 3 g/d.
      • In subjects with high blood pressure the reduction in blood pressure was greater and the dose response was linear. The authors recommended a dose ≤ 3 g/d EPA + DHA for people with high blood pressure.
  • Subjects with hyperlipidemia had a greater reduction in blood pressure than subjects with normal lipid levels, and the dose-response was linear.
  • Subjects over the age of 45 had a greater reduction in blood pressure than subjects under the age of 45, and the dose response was linear.
  • There were no significant differences between:
    • Diet versus supplementation.
    • Type of omega-3 supplement (natural fish oil versus purified ethyl ester).
    • Sex.

The authors concluded, “This dose-response meta-analysis demonstrates that the optimal combined intake of omega-3 fatty acids for blood pressure lowering is likely between 2 g/d and 3 g/d. Doses of omega-3 fatty acid intake above the recommended 3 g/d may be associated with additional benefits in lowering blood pressure among groups at high risk of cardiovascular disease.”

I should probably explain the reasoning behind this conclusion.

  • 79% of the studies included in this meta-analysis were performed with subjects who had normal blood pressure. This group had a non-linear reduction in blood pressure with an optimal reduction between 2 and 3 g/d EPA + DHA.
    • Because of its size this group exerted a major influence on the results, which explains why the average results for the entire group showed a non-linear reduction in blood pressure with an optimal reduction between 2 and 3 g/d EPA + DHA.
    • Subjects with normal blood pressure and normal lipid levels are at low risk of cardiovascular disease. The high-risk groups (high blood pressure, high cholesterol and/or triglyceride levels, and over 45) all had a linear dose response suggesting that doses above 3 g/d EPA + DHA may be optimal.

The authors also said, “We found associations [between omega-3 intake and blood pressure] among both hypertensive (high blood pressure) and nonhypertensive (normal blood pressure) groups, suggesting that omega-3 fatty acids could be beneficial for controlling blood pressure even before the onset of hypertension.

This means that the intake of omega3 fatty acids could have implications on a person’s future risk of stroke, ischemic heart disease, and all-cause mortality.”

In other words, they are saying their data suggests that EPA + DHA intakes in the 2-3 g/d range may prevent high blood pressure and the effects it can have on our health.

What Does This Study Mean For You?

Question MarkThe authors of this study claim their data support a dose of 2-3 mg/d of EPA + DHA to prevent a future increase in blood pressure and all its associated health consequences. They also say that an EPA+ DHA dose ≥ 3g/d may be optimal for people who already have high blood pressure and/or other risk factors for heart disease.

I am not an expert on statistics, so I cannot evaluate the author’s claim that their statistical method was superior to the methods used in earlier studies that gave conflicting results.

However, their results are consistent with recommendations of several major health and government agencies.

  • For example, the European Food Safety Authority has said, “An intake of EPA and DHA of ~3 g/d is required to bring out the claimed hypotensive (blood pressure lowering) effect”.
  • The FDA has approved qualified health claims stating that consuming EPA and DHA in foods or dietary supplements may reduce the risk of hypertension (high blood pressure) and coronary heart disease but did not recommend a dose to achieve these results.
  • The American Heart Association has recommended ~ 1 g/d of EPA + DHA for patients with documented coronary heart disease and 2–4 g/day of EPA + DHA to lower triglycerides.
  • And the American Heart Association features this article on their website with the headline, “Consuming about 3 grams of omega-3 fatty acids a day may lower blood pressure.”

When we contrast that with the fact that the average American gets less than 100 mg/d of EPA + DHA from their diet it is obvious that many Americans would likely benefit from increasing the amount of EPA and DHA in their diet.

The Rest Of The Story

ProfessorThere are four additional points I would like to make:

  • In trying to explain the differences between dose response in high and low risk subjects, the authors said, “There could be mechanistic differences in bioavailability and efficacy of omega-3 fatty acid intake in these populations.”

In last week’s “Health Tips From the Professor” article I reviewed a study that measured individual differences in the utilization of EPA and DHA and concluded that a blood measurement called Omega-3 Index was a more reliable indicator of health outcomes than the dose of omega-3s consumed.

For that reason, I recommend personalizing your dose of EPA + DHA to reach an Omega-3 Index of 8%, which appears to be optimal for heart health and provides significant blood pressure reduction. This is an iterative process which will require frequent measurement of your omega-3 index and adjustment of EPA + DHA dose until you find the level of EPA + DHA supplementation you need to achieve an Omega-3 Index of 8%.

  • This study and similar studies measure the health benefits of the long chain omega-3 fatty acids EPA and DHA. Short chain omega-3s from nuts, seeds, and plant oils are healthy, but their conversion to EPA and DHA is very inefficient.
  • Both the FDA and American Heart Association recommend that doses of EPA + DHA above 3 g/d should be taken under a physician’s supervision because high doses can cause bleeding problems.

This is another reason for basing your intake of EPA + DHA on Omega-3 Index rather than on the dose recommended by a clinical study. Based on dozens of clinical studies, an Omega-3 Index of 8% appears to be safe unless you have a bleeding disorder or are on a blood-thinning medication (see below).

  • If you are on a medication to thin your blood, you should consult with your physician before increasing or decreasing your omega-3 intake because changes in dietary omega-3s can affect the optimal dose of medication they prescribe.

The Bottom Line 

A recent study looked at the dose of EPA + DHA needed to lower blood pressure.

  • The study concluded that a dose of 2-3 mg/d of EPA + DHA was optimal for preventing a future increase in blood pressure and all its associated health consequences.
  • It also concluded that an EPA+ DHA dose ≥ 3g/d was optimal for lowering blood pressure in people who already have high blood pressure and/or other risk factors for heart disease.
  • Based on previous studies, I recommend optimizing your omega-3 index rather than relying on a dose of EPA + DHA that may not be right for you.

For more details about this study and what it means to 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.

Can Healthy Eating Help You Lose Weight?

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Who Benefits Most From A Healthy Diet?

Author: Dr. Stephen Chaney 

fad dietsFad diets abound. High protein, low carb, low fat, vegan, keto, paleo – the list is endless. They all claim to be backed by scientific studies showing that you lose weight, lower your cholesterol and triglycerides, lower your blood pressure, and smooth out your blood sugar swings.

They all claim to be the best. But any reasonable person knows they can’t all be the best. Someone must be lying.

My take on this is that fad diet proponents are relying on “smoke and mirrors” to make their diet look like the best. I have written about this before, but here is a brief synopsis:

  • They compare their diet with the typical American diet.
    • Anything looks good compared to the typical American diet.
    • Instead, they should be comparing their diet with other weight loss diets. That is the only way we can learn which diet is best.
  • They are all restrictive diets.
    • Any restrictive diet will cause you to eat fewer calories and to lose weight.
    • As little as 5% weight loss results in lower cholesterol & triglycerides, lower blood pressure, and better control of blood sugar levels.

Simply put, any restrictive diet will give you short-term weight loss and improvement in blood parameters linked to heart disease, stroke, and diabetes. But are these diets healthy long term? For some of them, the answer is a clear no. Others are unlikely to be healthy but have not been studied long term. So, we don’t know whether they are healthy or not.

What if you started from the opposite perspective? Instead of asking, “Is a diet that helps you lose weight healthy long term?”, what if you asked, “Can healthy eating help you lose weight?” The study (S Schutte et al, American Journal of Clinical Nutrition, 115: 1-18, 2022) I will review this week asked that question.

More importantly, it was an excellent study. It compared a healthy diet to an unhealthy diet with exactly the same degree of caloric restriction. And it compared both diets to the habitual diet of people in that area. This study was performed in the Netherlands, so both weight loss diets were compared to the habitual Dutch diet.

How Was The Study Done?

clinical studyThis was a randomized controlled trial, the gold standard of clinical studies. The investigators recruited 100 healthy, abdominally obese men and women aged 40-70. At the time of entry into the study none of the participants:

  • Had diabetes.
  • Smoked
  • Had a diagnosed medical condition.
  • Were on a medication that interfered with blood sugar control.
  • Were on a vegetarian diet.

The participants were randomly assigned to:

  • A high-nutrient quality diet that restricted calories by 25%.
  • A low-nutrient-quality diet that restricted calories by 25%.
  • Continue with their habitual diet.

The study lasted 12 weeks. The participants met with a dietitian on a weekly basis. The dietitian gave them the foods for the next week and monitored their adherence to their assigned diet. They were advised not to change their exercise regimen during the study.

At the beginning and end of the study the participants were weighed, and cholesterol, triglycerides, and blood pressure were measured.

Can Healthy Eating Help You Lose Weight?

Vegetarian DietTo put this study into context, these were not healthy and unhealthy diets in the traditional sense.

  • Both were whole food diets.
  • Both included fruits, vegetables, low-fat dairy, and lean meats.
  • Both restricted calories by 25%.

The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other simple sugars than the “low-nutrient-quality” diet.

At the end of 12 weeks:

  • Participants lost significant weight on both calorie-restricted diets compared to the group that continued to eat their habitual diet.
    • That is not surprising. Any diet that successfully restricts calories will result in weight loss.
  • Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).
  • Participants on the high-nutrient quality diet lost 50% more inches in waist circumference than participants on the low-nutrient-quality diet (1.8 inches compared to 1.2 inches).
    • This is a direct measure of abdominal obesity.

When the investigators measured blood pressure, fasting total cholesterol levels, and triglyceride levels:Heart Healthy Diet

  • These cardiovascular risk factors were significantly improved on both diets.
    • Again, this would be expected. Any diet that causes weight loss results in an improvement in these parameters.
  • The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
  • The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”

In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, healthy eating helped them lose weight and improved their health.

Who Benefits Most From A Healthy Diet?

None of the participants in this study had been diagnosed with diabetes when the study began. However, all of them were middle-aged, overweight, and had abdominal obesity. That means many of them likely had some degree of insulin resistance.

Because of some complex metabolic studies that I did not describe, the investigators suspected that insulin resistance might influence the relative effectiveness of the two energy-restricted diets.

To test this hypothesis, they used an assay called HOMA-IR (homeostatic model assessment of insulin resistance). Simply put, this assay measures how much insulin is required to keep your blood sugar under control.

They used a HOMA-IR score of 2.5 to categorize insulin resistance among the participants.

  • Participants with a HOMA-IR score >2.5 were categorized as insulin-resistant. This was 55% of the participants.
  • Participants with a HOMA-IR score ≤2.5 were categorized as insulin-sensitive. This was 45% of the participants.

When they used this method to categorize participants they found:

  • Insulin-resistant individual lost about the same amount of weight on both diets.
  • Insulin-sensitive individuals lost 66% more weight on the high-nutrient-quality diet than the low-nutrient-quality diet (21.6 pounds compared to 13.0 pounds).

The investigators concluded, “Overweight, insulin-sensitive subjects may benefit more from a high- than a low-nutrient-quality energy-restricted diet with respect to weight loss…”

What Does This Study Mean For You?

Questioning WomanSimply put this study confirms that:

  • Caloric restriction leads to weight loss, and…
  • Weight loss leads to improvement in cardiovascular risk factors like total cholesterol, triglycerides, and blood pressure.
    • This is not new.
    • This is true for any diet that results in caloric restriction.

This study breaks new ground in that a high-nutrient quality diet results in significantly better:

  • Weight loss and…
  • Reduction in cardiovascular risk factors…

…than a low-nutrient quality diet. As I said above, the distinction between a “high-nutrient-quality” diet and a “low-nutrient-quality” diet may not be what you might have expected.

  • Both diets were whole food diets. Neither diet allowed sodas, sweets, and highly processed foods.
  • Both included fruits, vegetables, grains, and lean meats.
  • Both reduced caloric intake by 25%.
    • If you want to get the most out of your weight loss diet, this is a good place to start.

In this study the investigators designed their “high-nutrient-quality” diet so that it contained:

  • More plant protein in the form of soy protein.
    • In this study they did not reduce the amount of animal protein in the “high-nutrient-quality” diet. They simply added soy protein foods to the diet. I would recommend substituting soy protein for some of the animal protein in the diet.
  • More fiber.
    • The additional fiber came from substituting whole grain breads and brown rice for refined grain breads and white rice, adding soy protein foods, and adding an additional serving of fruit.
  • More healthy fats (monounsaturated and omega-3 fats).
    • The additional omega-3s came from adding a fish oil capsule providing 700mg of EPA and DHA.
  • Less simple sugars. While this study focused on fructose, their high-nutrient-quality diet was lower in all simple sugars.

ProfessorAll these changes make great sense if you are trying to lose weight. I would distill them into these 7 recommendations.

  • Follow a whole food diet. Avoid sodas, sweets, and highly processed foods.
  • Include all 5 food groups in your weight loss diet. Fruits, vegetables, whole grains, dairy, and lean proteins all play an important role in your long-term health.
  • Eat a primarily plant-based diet. My recommendation is to substitute plant proteins for at least half of your high-fat animal proteins. And this study reminds us that soy protein foods are a convenient and effective way to achieve this goal.
  • Eat a diet high in natural fibers. Including fruits, vegetables, whole grains, beans, nuts, seeds, and soy foods in your diet is the best way to achieve this goal.
  • Substitute healthy fats (monounsaturated and omega-3 fats) for unhealthy fats (saturated and trans fats) in your diet. And this study reminds us that it is hard to get enough omega-3s in your diet without an omega-3 supplement.
  • Reduce the amount of added sugar, especially fructose, from your diet. That is best achieved by eliminating sodas, sweets, and highly processed foods from the diet. I should add that fructose in fruits and some healthy foods is not a problem. For more information on that topic, I refer you to a previous “Health Tips” article .
  • Finally, I would like to remind you of the obvious. No diet, no matter how healthy, will help you lose weight unless you cut back on calories. Fad diets achieve that by restricting the foods you can eat. In the case of a healthy diet, the best way to do it is to cut back on portion sizes and choose foods with low caloric density.

I should touch briefly on the third major conclusion of this study, namely that the “high-nutrient quality diet” was not more effective than the “low-nutrient-quality” diet for people who were insulin resistant. In one sense, this was not news. Previous studies have suggested that insulin-resistant individuals have more difficulty losing weight. That’s the bad news.

However, there was a silver lining to this finding as well:

  • Only around half of the overweight, abdominally obese adults in this study were highly insulin resistant.
    • That means there is a ~50% chance that you will lose more weight on a healthy diet.
  • Because both diets restricted calories by 25%, insulin-resistant individuals lost weight on both diets.
    • That means you can lose weight on any diet that successfully reduces your caloric intake. That’s the good news.
    • However, my recommendation would still be to choose a high-nutrient quality diet that is designed to reduce caloric intake, because that diet is more likely to be healthy long term.

The Bottom Line 

A recent study asked, “Can healthy eating help you lose weight?” This study was a randomized controlled study, the gold standard of clinical studies. The participants were randomly assigned to:

  • A high-nutrient quality diet that restricted calories by 25%.
  • A low-nutrient-quality diet that restricted calories by 25%.
  • Continue with their habitual diet.

These were not healthy and unhealthy diets in the traditional sense.

  • Both were whole food diets.
  • Both included fruits, vegetables, low-fat dairy, and lean meats.
  • Both restricted calories by 25%.

The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other simple sugars than the “low-nutrient-quality” diet.

At the end of 12 weeks:

  • Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).

When the investigators measured cardiovascular risk factors at the end of 12 weeks:

  • The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
  • The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”

In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, healthy eating helped them lose weight and improved their health.

For more details on this study, what this study means for you, and my 7 recommendations for a healthy weight loss diet, 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 Low Carb Diets?

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Why Is The Cochrane Collaboration The Gold Standard?

Author: Dr. Stephen Chaney 

low carb dietAtkins, South Beach, Whole30, Low Carb, high Fat, Low Carb Paleo, and Keto. Low carb diets come in many forms. But they have these general characteristics:

  • They restrict carbohydrate intake to <40% of calories.
  • They restrict grains, cereals, legumes, and other carbohydrate foods such as dairy, fruits, and some vegetables.
  • They replace these foods with foods higher in fat and protein such as meats, eggs, cheese, butter, cream, and oils.
  • When recommended for weight loss, they generally restrict calories.

What about the science? Dr. Strangelove and his friends tell you that low carb diets are better for weight loss, blood sugar control, and are more heart healthy than other diets. But these claims are controversial.

Why is that? I have discussed this in previous issues of “Health Tips From The Professor”. Here is the short version.

  • Most studies on the benefits of low carb diets compare them with the typical American diet.
    • The typical American diet is high in fat, sugar and refined flour, and highly processed foods. Anything is better than the typical American diet.
  • Most low carb diets are whole food diets.
    • Any time you replace sodas and highly processed foods with whole foods you will lose weight and improve your health.
  • Most low carb diets are highly structured. There are rules for which foods to avoid, which foods to eat, and often additional rules to follow.
    • Any highly structured diet causes you to focus on what you eat. When you do that, you lose weight. When you lose weight, your health parameters improve.
    • As I have noted before, short term weight loss and improvement in health parameters are virtually identical for the very low carb keto diet and the very low-fat vegan diet.

With all this uncertainty you are probably wondering, “What is the truth about low carb diets?”

A recent study by the Cochrane Collaboration (CE Naude et al, Cochrane Database of Systematic Reviews, 28 January 2022) was designed to answer this question.

The Cochrane Collaboration is considered the gold standard of evidence-based medicine. To help you understand why this is, I will repeat a summary of how the Cochrane Collaboration approaches clinical studies that I shared two weeks ago.

Why Is The Cochrane Collaboration The Gold Standard?

ghost bustersWho you gonna call? It’s not Ghostbusters. It’s not Dr. Strangelove’s health blog. It’s a group called the Cochrane Collaboration.

The Cochrane Collaboration consists of 30,000 volunteer scientific experts from across the globe whose sole mission is to analyze the scientific literature and publish reviews of health claims so that health professionals, patients, and policy makers can make evidence-based choices about health interventions.

In one sense, Cochrane reviews are what is called a “meta-analysis”, in which data from numerous studies are grouped together so that a statistically significant conclusion can be reached. However, Cochrane Collaboration reviews differ from most meta-analyses found in the scientific literature in a very significant way.

Many published meta-analyses simply report “statistically significant” conclusions. However, statistics can be misleading. As Mark Twain said: “There are lies. There are damn lies. And then there are statistics”.

The Cochrane Collaboration also reports statistically significant conclusions from their meta-analyses. However, they carefully consider the quality of each individual study in their analysis. They look at possible sources of bias. They look at the design and size of the studies. Finally, they ask whether the conclusions are consistent from one study to the next. They clearly define the quality of evidence that backs up each of their conclusions as follows:

  • High-quality evidence. Further research is unlikely to change their conclusion. This is generally reserved for conclusions backed by multiple high-quality studies that have all come to the same conclusion. These are the recommendations that are most often adopted into medical practice.
  • Moderate-quality evidence. This conclusion is very likely to be true, but further research could have an impact on it.
  • Low-quality evidence. Further research is needed and could alter the conclusion. They are not judging whether the conclusion is true or false. They are simply saying more research is needed to reach a definite conclusion.

This is why their reviews are considered the gold standard of evidence-based medicine. If you are of a certain age, you may remember that TV commercial “When EF Hutton talks, people listen.” It is the same with the Cochrane Collaboration. When they talk, health professionals listen.

How Was The Study Done?

Clinical StudyThe authors of this Cochrane Collaboration Report included 61 published clinical trials that randomized participants into two groups.

  • The first group was put on a low carbohydrate diet (carbohydrates = <40% of calories).
  • The second group was put on a “normal carbohydrate” diet (carbohydrates = 45-65% of calories, as recommended by the USDA and most health authorities).
    • The normal carbohydrate diet was matched with the low carbohydrate diet in terms of caloric restriction.
    • Both diets were designed by dietitians and were generally whole food diets.

The participants in these studies:

  • Were middle-aged.
  • Were overweight or obese.
  • Did not have diagnosed heart disease or cancer.
  • May have diagnosed type-2 diabetes. Some studies selected participants that had diagnosed type 2 diabetes. Other studies excluded those patients.

The studies were of 3 types:

  • Short-term: Participants in these studies followed their assigned diets for 3 to <12 months.
  • Long-term: Participants in these studies followed their assigned diets for >12 to 24 months.
  • Short-term with maintenance: Participants in these studies followed their assigned diets for 3 months followed by a 9-month maintenance phase.

What Is The Truth About Low Carb Diets?

The TruthAll the studies included in the Cochrane Collaboration’s meta-analysis randomly assigned overweight participants to a low carbohydrate diet (carbohydrates = <40% of calories) or to a “normal carbohydrate” diet (carbohydrates = 45-65% of calories) with the same degree of caloric restriction.

If low carb diets have any benefit in terms of weight loss, improving blood sugar control, or reducing heart disease risk, these are the kind of studies that are required to validate that claim.

This is what the Cochrane Collaboration’s meta-analysis showed.

When they analyzed studies done with overweight participants without type 2 diabetes:

  • Weight loss was not significantly different between low carb and normal carb diets in short-term studies (3 to <12 months), long-term studies (>12 to 24 months), and short-term studies followed by a 9-month maintenance period.
  • There was also no significant difference in the effect of low carb and normal carb diets on the reduction in diastolic blood pressure and LDL cholesterol.

Since diabetics have trouble controlling blood sugar, you might expect that type 2 diabetics would respond better to low carb diets. However, when they analyzed studies done with overweight participants who had type 2 diabetes:

  • Weight loss was also not significantly different on low carb and normal carb diets.
  • There was no significant difference in the effect of low carb and normal carb diets on the reduction in diastolic blood pressure, LDL cholesterol, and hemoglobin A1c, a measure of blood sugar control.

Of course, the reason Cochrane Collaboration analyses are so valuable is they also analyze the strength of the studies that were included in their analysis.

You may remember in my article two weeks ago, I reported on the Cochrane Collaboration’s report supporting the claim that omega-3 supplementation reduces pre-term births. In that report they said that the studies included in their analysis were high quality. Therefore, they said their report was definitive and no more studies were needed.

This analysis was different. The authors of this Cochrane Collaboration report said that the published studies on this topic were of moderate quality. This means their conclusion is very likely to be true, but further research could have an impact on it.

What Does This Study Mean For You?

confusionIf you are a bit confused by the preceding section, I understand. That was a lot of information to take in. Let me give you the Cliff Notes version.

In short, this Cochrane Collaboration Report concluded:

  • Low carb diets (<40% of calories from carbohydrates) are no better than diets with normal carbohydrate content (45-65% of calories from carbohydrates) with respect to weight loss, reduction in heart disease risk factors, and blood sugar control. Dr. Strangelove has been misleading you again.
  • This finding is equally true for people with and without type 2 diabetes. This calls into question the claim that people with type 2 diabetes will do better on a low carb diet.
  • The published studies on this topic were of moderate quality. This means their conclusion is very likely to be true, but further research could have an impact on it.

If you are thinking this study can’t be true because low carb diets work for you, that is because you are comparing low carb diets to your customary diet, probably the typical American diet.

  • Remember that any whole food diet that eliminates sodas and processed foods and restricts the foods you eat will cause you to lose weight. Whole food keto and vegan diets work equally well short-term compared to the typical American diet.
  • And any diet that allows you to lose weight improves heart health parameters and blood sugar control.

If you are thinking about the blogs, books, and videos you have seen extolling the virtues of low carb diets, remember that the Dr. Strangeloves of the world only select studies comparing low carb diets to the typical American diet to support their claims.

  • The studies included in this Cochrane Collaboration report randomly assigned participants to the low carb and normal carb diets and followed them for 3 to 24 months.
    • Both diets were whole food diets designed by dietitians.
    • Both diets reduced caloric intake to the same extent.

What about the claims that low carb diets are better for your long-term health? There are very few studies on that topic. Here are two:

  • At the 6.4-year mark a recent study reported that the group with the lowest carbohydrate intake had an increased risk of premature death – 32% for overall mortality, 50% for cardiovascular mortality, 51% for cerebrovascular mortality, and 36% for cancer mortality. I will analyze this study in a future issue of “Health Tips From The Professor”.
  • At the 20-year mark a series of studies reported that:
    • Women consuming a meat-based low carb diet for 20 years gained just as much weight and had just as high risk of heart disease and diabetes as women consuming a high carbohydrate, low fat diet.
    • However, women consuming a plant-based low carb diet for 20 years gained less weight and had reduced risk of developing heart disease and diabetes as women consuming a high carbohydrate, low fat diet.

My recommendation is to avoid low-carb diets. They have no short-term benefits when compared to a healthy diet that does not eliminate food groups. And they may be bad for you in the long run. Your best bet is a whole food diet that includes all food groups but eliminates sodas, sweets, and processed foods.

However, if you are committed to a low carb diet, my recommendation is to choose the low-carb version of the Mediterranean diet. It is likely to be healthy long term.

The Bottom Line 

The Cochrane Collaboration, the gold standard of evidence-based medicine, recently issued a report that evaluated the claims made for low carb diets.

All the studies analyzed in the Cochrane Collaboration’s report randomly assigned overweight participants to a low carbohydrate diet (carbohydrates = <40% of calories) or to a “normal carbohydrate” diet (carbohydrates = 45-65% of calories) with the same degree of caloric restriction.

If low carb diets have any benefit in terms of weight loss, improving blood sugar control, or reducing heart disease risk, these are the kind of studies that are required to validate that claim.

The Cochrane Collaboration Report concluded:

  • Low carb diets (<40% of calories from carbohydrates) are no better than diets with normal carbohydrate content (45-65% of calories from carbohydrates) with respect to weight loss, reduction in heart disease risk factors, and blood sugar control.
  • This is equally true for people with and without type 2 diabetes.
  • The published studies on this topic were of moderate quality. This means their conclusion is very likely to be true, but further research could have an impact on it.

My recommendation is to avoid low carb diets. They have no short-term benefits when compared to a healthy diet that does not eliminate food groups. And they may be bad for you in the long run. Your best bet is a whole food diet that includes all food groups but eliminates sodas, sweets, and processed foods.

However, if you are committed to a low carb diet, my recommendation is to choose the low carb version of the Mediterranean diet. It is likely to be healthy long term.

For more details on 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.

Eating Of The Green

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Why Is Eating Green Good For Your Heart? 

Author: Dr. Stephen Chaney

You may be one of the millions of Americans who celebrated St. Patrick’s Day a couple of weeks ago. If so, you may have sung the famous Irish folk song “The Wearing of the Green”. If you are Irish, that song has special meaning for you. However, when I hear that song, I think of “Eating of the Green.”

And when I think of eating green, I don’t mean that everything we eat should be green. I am thinking of whole fruits and vegetables in a variety of colors. We have known for years that fruits and vegetables are good for our health. Consumption of fruits and vegetables is associated a lower risk of high blood pressure, heart disease, cancer, inflammatory diseases, and much more.

For today’s health tip, I am going to focus on heart health and an unexpected explanation for how fruits and vegetables reduce our risk of heart disease.

Why Is Eating Green Good For Your Heart?

health benefits of beetroot juiceWe have assumed that whole fruits and vegetables lower our risk of heart disease because they are low in saturated fats and provide heart-healthy nutrients, phytonutrients, and fiber. All of that is true. But could there be more?

Recent research has suggested that the nitrates found naturally in fruits and vegetables may also play a role in protecting our hearts. Here is what recent research shows:

  • The nitrates from fruits and vegetables are converted to nitrite by bacteria in our mouth and intestines.
    • Fruits and vegetables account for 80% of the nitrate in our diet. The rest comes from a variety of sources including the nitrate added as a preservative to processed meats.
    • Although all fruits and vegetables contain nitrates, the best sources are green leafy vegetables and beetroot. [Beet greens are delicious and also a good source of nitrate, but beetroot is the part of the beet we usually consume.]
  • Nitrite is absorbed from our intestine and converted to nitric oxide by a variety of enzymes in our tissues.
  • Both reactions require antioxidants like vitamin C, which are also found in fruits and vegetables.

Nitric oxide has several heart healthy benefits. For example:

  • It helps reduce inflammation in the lining of blood vessels. Inflammation stimulates atherosclerosis, blood clot formation, and is associated with an increased risk of heart disease.
  • It relaxes the smooth muscle cells that surround our blood vessels. This makes the blood vessels more flexible and helps reduce blood pressure.
  • It prevents smooth muscle cells from proliferating, which prevents them from invading and constricting our arteries. This, in turn, has the potential to reduce the risk of atherosclerosis.
  • It prevents platelet aggregation. This, in turn, has the potential to reduce the risk of heart attack and stroke due to blood clots that block the flow of blood to our heart or brain.

It is well established that nitrates from fruits and vegetables reduce blood pressure. More importantly, they can help slow the gradual increase in blood pressure as we age.

However, few studies have asked whether this reduction in blood pressure translates into improved cardiovascular outcomes. This study (CP Bondonno et al, European Journal of Epidemiology, 36: 813-825, 2021) was designed to answer that question.

How Was This Study Done?

Clinical StudyThis study made use of data from the Danish Diet, Cancer, and Health Program. That program enrolled 53,150 participants from Copenhagen and Aarhus between 1993 and 1997 and followed them for an average of 21 years. None of the participants had a diagnosis of cancer or heart disease at the beginning of the study.

Other characteristics of the participants at the time they were enrolled in the study were:

  • 46% male
  • Average age = 56
  • BMI = 26 (>20% overweight)
  • Average systolic blood pressure = 140 mg Hg
  • Average diastolic blood pressure = 84 mg Hg

At the beginning of the study, participants filled out a 192-item food frequency questionnaire that assessed their average intake of various food and beverage items over the previous 12 months. The vegetable nitrate content of their diets was analyzed using a comprehensive database of the nitrate content of 178 vegetables. For those vegetables not consumed raw, the nitrate content was reduced by 50% to account for the nitrate loss during cooking.

Blood pressure was measured at the beginning of the study. Data on the incidence (first diagnosis) of heart disease during the study was obtained from the Danish National Patient Registry. Data were collected on diagnosis of the following heart health parameters:

  • Cardiovascular disease (all diseases of the circulatory system).
  • Ischemic heart disease (lack of sufficient blood flow to the heart). The symptoms of ischemic heart disease range from angina to myocardial infarction (heart attack).
  • Ischemic stroke (lack of sufficient blood flow to the brain).
  • Hemorrhagic stroke (bleeding in brain).
  • Heart failure.
  • Peripheral artery disease (lack of sufficient blood flow to the extremities).

Is Nitrate From Vegetables Good For Your Heart?

strong heartIntake of nitrate from vegetables ranged from 18 mg/day (<1/3 serving of nitrate-rich vegetables per day) to 168 mg (almost 3 servings of nitrate-rich vegetables per day). The participants were grouped into quintiles based on their vegetable nitrate intake. When the group with the highest vegetable nitrate intake was compared to the group with the lowest vegetable nitrate intake:

  • Systolic blood pressure was reduced by 2.58 mg Hg.
  • Diastolic blood pressure was reduced by 1.38 mg Hg.
  • Risk of cardiovascular disease was reduced by 14%.
  • Risk of ischemic heart disease (angina and heart attack) was reduced by 13%.
  • Risk of ischemic stroke (stroke caused by lack of blood flow to the brain) was reduced by 14%.
  • Risk of heart failure was reduced by 17%.
  • Risk of peripheral artery disease was reduced by 31%.
  • Risk of hemorrhagic stroke (bleeding in the brain) was not significantly reduced.

Two other observations were of interest:

  • Blood pressure and risk of peripheral artery disease decreased with increasing vegetable nitrate intake in a relatively linear fashion. However, the other parameters of heart disease plateaued at a modest intake of vegetable nitrate intake (around one cup of nitrate-rich vegetables per day). This suggests that as little as one serving of nitrate-rich vegetables a day is enough to provide some heart health benefits.
  • Only about 21.9% of the improvement in heart health could be explained by the decrease in blood pressure. This is not surprising when you consider the other beneficial effects of nitric oxide described above.

The authors concluded, “Consumption of at least ~60 mg/day of vegetable nitrate (~ one serving of green leafy vegetables or beets) may mitigate risk of cardiovascular disease.”

Are Nitrates Good For You Or Bad For You?

questionsYou are probably thinking, “Wait a minute. I thought nitrates and nitrites were supposed to be bad for me. Which is it? Are nitrates good for me or bad for me?”

It turns out that nitrates and nitrites are kind of like Dr. Jekyll and Mr. Hyde. They can be either good or bad. It depends on the food they are in and your overall diet.

Remember the beginning of this article when I said that the conversion of nitrates to nitric oxide depended on the presence of antioxidants? Vegetables are great sources of antioxidants. So, when we get our nitrate from vegetables, most of it is converted to nitric oxide. And, as I discussed above, nitric oxide is good for us.

However, when nitrates and nitrites are added to processed meats as a preservative, the story is much different. Processed meats have zero antioxidants. And the protein in the meats is broken down to amino acids in our intestine. The amino acids combine with nitrate to form nitrosamines, which are cancer-causing chemicals. Nitrosamines are bad for us.

Of course, we don’t eat individual foods by themselves. We eat them in the context of a meal. If you eat small amounts of nitrate-preserved processed meats in the context of a meal with antioxidant-rich fruits and vegetables, some of the nitrate will be converted to nitric oxide rather than nitrosamines. The processed meat won’t be as bad for you.

Eating Of The Green

spinachYour mother was right. You should eat your fruits and vegetables!

  • The USDA recommends at least 3 servings of vegetables and 2 servings of fruit a day.
  • Based on this study, at least one of those servings should be nitrate-rich vegetables like green leafy vegetables and beets.
  • If you don’t like any of those, radishes, turnips, watercress, Bok choy, Chinese cabbage, kohlrabi, chicory leaf, onion, and fresh garlic are also excellent sources of nitrate.
  • The good news is that you may not need to eat green leafy vegetables and beets with every meal. If this study is correct, one serving per day may have heart health benefits. That means you can enjoy a wide variety of fresh fruits and vegetables as you try to meet the USDA recommendations.

Finally, if you don’t like any of those foods, you may be asking, “Can’t I just take a nitrate supplement?”

  • For blood pressure, there are dozens of clinical trials, and the answer seems to be yes – especially when the nitrate comes from vegetable sources and the supplement also contains an antioxidant like vitamin C.
  • For heart health benefits, the answer is likely to be yes, but clinical trials to confirm that would take decades. Double blind, placebo-controlled trials of that duration are not feasible, so we will never know for sure.
  • Moreover, you would not be getting all the other health benefits of a diet full of fresh fruits and vegetables. Supplementation has its benefits, but it is not meant to replace a healthy diet.

The Bottom Line

We have known for years that fruits and vegetables are good for our hearts. We have assumed that was because whole fruits and vegetables are low in saturated fats and provide heart-healthy nutrients, phytonutrients, and fiber. But could there be more?

It is well established that nitrates from fruits and vegetables reduce blood pressure. More importantly, they can help slow the gradual increase in blood pressure as we age.

However, few studies have asked whether this reduction in blood pressure translates into improved cardiovascular outcomes. A recent study was designed to answer that question.

When the study compared people with the highest vegetable nitrate intake to people with the lowest vegetable nitrate intake:

  • Blood pressure was significantly reduced.
  • The risk of cardiovascular disease was reduced by 14%.
  • Risk of ischemic heart disease (angina and heart attack) was reduced by 13%.
  • Risk of ischemic stroke (stroke caused by lack of blood flow to the brain) was reduced by 14%.
  • Risk of heart failure was reduced by 17%.
  • Risk of peripheral artery disease was reduced by 31%.
  • Blood pressure and risk of peripheral artery disease decreased with increasing vegetable nitrate intake in a relatively linear fashion.
  • However, the other parameters of heart disease plateaued at a modest intake of vegetable nitrate intake (around one cup of nitrate-rich vegetables per day). This suggests that as little as one serving of nitrate-rich vegetables a day is enough to provide some heart health benefits.

The authors concluded, “Consumption of at least ~60 mg/day of vegetable nitrate (~ one serving of green leafy vegetables or beets) may mitigate risk of cardiovascular disease.”

Of course, you may have heard that nitrates and nitrites are bad for you. I discuss that in the article above.

For more details about 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.

Does Olive Oil Help You Live Longer?

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Which Fat Is Healthiest?

Author: Dr. Stephen Chaney

If you believe the headlines, olive oil is a superfood. It is often described as the star of the Mediterranean diet. It is referred to as the healthiest of dietary fats. Is this true, or is it hype?

Olive oil’s resume is impressive:

  • It is rich in monounsaturated fatty acids, which…
    • Are less susceptible to oxidation than polyunsaturated oils.
    • Make our arteries more flexible, which lowers blood pressure.
    • Lower LDL-cholesterol levels, which reduces the risk of heart disease.
  • Extra-virgin olive oil contains phytonutrients and tocopherols (various forms of vitamin E), which…
    • Have anti-inflammatory properties.
    • Improve insulin sensitivity and blood sugar control.
  • Olive oil consumption is also associated with healthier gut bacteria, but it is not clear whether this is due to olive oil or to the fact that a Mediterranean diet is also richer in fresh fruits, vegetables, and whole grains.

Several recent studies have shown that olive oil consumption is associated with a lower risk of heart disease. However, these studies were conducted in Mediterranean countries where the average intake of olive oil (3 tablespoons/day) is much greater than in the United States (0.3 tablespoons/day).

The current study (M Guasch-Ferré et al, Journal of the American College of Cardiology, 79: 101-112, 2022) was designed to test whether:

  • The amount of olive oil Americans consume decreases the risk of heart disease.
  • Whether olive oil consumption had benefits beyond a reduction in heart disease risk.

How Was This Study Done? 

Clinical StudyThis study combined data from 60,582 women enrolled in the Nurses’ Health Study and 31,801 men enrolled in the Health Professionals Follow-Up Study). The participants:

  • Were free of heart disease and diabetes at the start of the study.
  • Were 56 at the start of the study with an average BMI of 25.6 (Individuals with BMIs in the 25-30 range are considered overweight, so they were at the lowest end of the overweight range).

The Nurses’ Health Study and Health Professional Follow-Up Study are both association studies, meaning they looked at the association between olive oil consumption and health outcomes. They cannot directly prove cause and effect. However, they are very strong association studies because:

  • Every 2 years, participants filled out a questionnaire that updated information on their body weight, smoking status, physical activity, medications, multivitamin use, and physician-diagnosed diseases.
  • Every 4 years, participants filled out a comprehensive food frequency questionnaire.
  • In other words, this study did not just rely on the participant’s lifestyle, dietary intake, and health at the beginning of the study, as so many association studies do. It tracked how each of these variables changed over time.

The participants were followed for an average of 28 years and their average olive oil intake over those 28 years was correlated with all-cause mortality and mortality due to specific diseases.

  • Deaths were identified from state vital statistics, the National Death index, reports by next of kin, or reports by postal authorities.
  • Causes of death were determined by physician review of medical records, medical reports, autopsy reports, or death certificates.

Does Olive Oil Help You Live Longer?

During the 28 years of this study:

  • Olive oil consumption in the United States increased from an average of ~1/3 teaspoon/day to ~1/3 tablespoon/day.
  • Margarine consumption decreased from 12 g/day to ~4 g/day.
  • The consumption of all other fats and oils remained about the same.

As I mentioned above, olive oil consumption was averaged over the life of the study for each individual. When the investigators compared people consuming the highest amount of olive oil (>0.5 tablespoon/day) with people consuming the least olive oil (0 to 1 teaspoon/day):

  • Mortality from all causes was decreased by 35% for the group consuming the most olive oil.

However, the group consuming the most olive oil also was more physically active, had a healthier diet, and consumed more fruits and vegetables than the group who consumed the least olive oil.

  • After correcting for all those factors, mortality from all causes was decreased by 19% for the group consuming the most olive oil.

The authors concluded, “We found that greater consumption of olive oil was associated with lower risk of total…mortality… Our results support current dietary recommendations to increase the intake of olive oil…to improve overall health and longevity.” (I will fill in the blanks in this statement once I have covered other aspects of this study)

The authors also said, “Of note, our study showed that benefits of olive oil can be observed even when consumed in lower amounts than in Mediterranean countries.”

Are There Other Benefits From Olive Oil Consumption?

Mediterranean dietThe study didn’t stop there. The investigators also looked at the effect of olive oil consumption on the major killer diseases in the United States and other developed countries. When they compared the effect of olive oil consumption on cause-specific mortality, they found that the group who consumed the most olive oil reduced their risk of dying from:

  • Cardiovascular disease by 19%.
  • Cancer by 17%
  • Respiratory disease by 18%.
  • Neurodegenerative disease (cognitive decline and Alzheimer’s disease) by 29%.
    • The reduction in neurodegenerative disease was much greater for women (34% decrease) than for men (19% decrease).

With this information I can fill in one of the blanks in the author’s conclusions: “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality… Our results support current dietary recommendations to increase the intake of olive oil…to improve overall health and longevity.”

Which Fats Are Healthiest?

Good Fat vs Bad FatThe sample size was large enough and the dietary information complete enough for the investigators to also estimate the effect of substituting olive oil for other dietary fats and oils.

They found that every ¾ tablespoon of olive oil substituted for an equivalent amount of:

  • Margarine decreased total mortality by 13%.
  • Butter decreased total mortality by 14%.
  • Mayonnaise deceased total mortality by 19%
  • Dairy fat decreased total mortality by 13%.
    • The same beneficial effects of substituting olive oil for other fats were seen for cause-specific mortality (cardiovascular disease, cancer, respiratory disease, and neurodegenerative disease).
    • There was a linear dose-response. This means that substituting twice as much olive oil for other dietary fats doubled the beneficial effects on total and cause-specific mortality.
  • However, substituting olive oil for polyunsaturated vegetable oils had no effect on total and cause-specific mortality.

Now I can fill in the remaining blanks in the author’s conclusion: “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality. Replacing other types of fat, such as margarine, butter, mayonnaise, and dairy fat, with olive oil was also associated with a lower risk of mortality. Our results support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils in place of other fats to improve overall health and longevity.”

What Does This Study Mean For Us?

ConfusionAs I said above, this is an association study, and association studies do not prove cause and effect. However:

1) This is a very strong association study because:

    • It is a very large study (92,383 participants).
    • It followed the participants over a long time (28 years).
    • It utilized a very precise dietary analysis.
    • Most importantly, it tracked the participant’s lifestyle, dietary intake, and health at regular intervals throughout the study. Most association studies only measure these variables at the beginning of the study. They have no idea how they change over time.

2) This study is consistent with several previous studies showing that olive oil consumption decreases the risk of dying from heart disease.

3) This study draws on its large population size and precise dietary analysis to strengthen and extend the previous studies. For example:

    • The study showed that increased olive oil consumption also reduced total mortality and mortality due to cancer, respiratory disease, and neurodegenerative disease.
    • The study measured the effect of substituting olive oil for other common dietary fats.
    • The study showed that increased olive oil consumption in the context of the American diet was beneficial.

I should point out that the headlines you have seen about this study may be misleading.

  • While the headlines may have depicted olive oil as a superfood, this study did not find evidence that olive oil was more beneficial than other unsaturated vegetable oils. Again, this is consistent with many previous studies showing that substituting vegetable oils for other dietary fats reduces the risk of multiple diseases.
  • The headlines focused on the benefits of increasing olive oil consumption. However, they neglected the data showing that increasing olive oil (and other vegetable oils) was even more beneficial (35% reduction in total mortality) in the context of a healthy diet – one with increased intake of fruits, vegetables, whole grains, nuts, legumes, and long-chain omega-3s and decreased intake of red & processed meats, sodium, and trans fats.

So, my recommendation is to follow a whole food, primarily plant-based diet and substitute extra-virgin olive oil and cold pressed vegetable oils for some of the animal fats in your diet.

Some vegan enthusiasts recommend a very low-fat whole food plant-based diet. They point to studies showing that such diets can actually reverse atherosclerosis. However:

  • Those studies are very small.
  • The overall diet used in those studies is a very healthy plant-based diet.
  • The studies did not include a control group following the same diet with olive oil or other vegetable oils added to it, so there is no comparison of a healthy vegan diet with and without vegetable oils.

If you have read my book, “Slaying the Food Myths”, you know that my recommendations encompass a variety of whole food, primarily plant-based diets ranging all the way from very-low fat vegan diets to Mediterranean and DASH diets. Choose the one that best fits your food preferences and the one you will be most able to stick with long term. You will be healthier, and you may live longer.

The Bottom Line

A recent study looked at the effect of olive oil consumption on the risk dying from all causes and from heart disease, cancer, respiratory disease, and neurodegenerative diseases. When the study compared people consuming the highest amount of olive oil (>0.5 tablespoon/day) with people consuming the least olive oil (0 to 1 teaspoon/day):

  • Mortality from all causes was decreased by 19% for the group consuming the most olive oil.

They also found that the group who consumed the most olive oil reduced their risk of dying from:

  • Cardiovascular disease by 19%.
  • Cancer by 17%
  • Respiratory disease by 18%.
  • Neurodegenerative disease (cognitive decline and Alzheimer’s disease) by 29%.

They also found that every ¾ tablespoon of olive oil substituted for an equivalent amount of:

  • Margarine decreased total mortality by 13%.
  • Butter decreased total mortality by 14%.
  • Mayonnaise deceased total mortality by 19%
  • Dairy fat decreased total mortality by 13%.
  • However, substituting olive oil for polyunsaturated vegetable oils had no effect on total and cause-specific mortality.

The authors concluded, “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality. Replacing other types of fat, such as margarine, butter, mayonnaise, and dairy fat, with olive oil was also associated with a lower risk of mortality. Our results support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils in place of other fats to improve overall health and longevity.”

For more details and a summary of what this study 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.

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.

 

Omega-3 Benefits: Lower High Blood Pressure

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What Does the FDA Say About Omega-3 Benefit Claims?

Author: Dr. Stephen Chaney

 

 

Among omega-3 benefits is lower high blood pressure.  That claim can be made according to the FDA. 

lower high blood pressureHeart Disease is still the number 1 cause of death in this country. And, while deaths from heart disease have been declining in recent years, deaths due to high blood pressure have been increasing.  That is concerning because:

High blood pressure is a killer! It can kill you by causing heart attacks, strokes, congestive heart failure, kidney failure and much more.

High blood pressure is a serial killer. It doesn’t just kill a few people. It kills lots of people. The American Heart Association estimates that high blood pressure directly or indirectly caused 410,000 deaths in 2014. That is almost 1 person every second and represents a 41% increase from 2000. It’s because high blood pressure is not a rare disease.

  • 32% of Americans have high blood pressure, also called hypertension, (defined as a systolic blood pressure of 140 mm Hg or more or a diastolic blood pressure of 90 mm Hg or more).
  • Another 33% of Americans have prehypertension (systolic blood pressure of 120-139 mm Hg or diastolic blood pressure of 80-89 mm Hg).

That’s over 65% of Americans with abnormal blood pressure!

High blood pressure is a silent killer. That’s because it is a very insidious disease that sneaks up on you when you least expect it. Systolic blood pressure increases 0.6 mm Hg/year for most adults over 50. By age 75 or above 76-80% of American adults will have high blood pressure.  Even worse, many people with high blood pressure have no symptoms, so they don’t even know that their blood pressure is elevated. For them the first symptom of high blood pressure is often sudden death.

Blood pressure medications can harm your quality of life. Blood pressure medications save lives. However, like most drugs, blood pressure medications have a plethora of side effects – including weakness, dizziness, fainting, shortness of breath, chest pain, nausea, diarrhea or constipation, heartburn, depression, heart palpitations, and even memory loss. The many side effects associated with blood pressure medications lead to poor compliance, which is probably why only 46% of patients with high blood pressure are adequately controlled.

You do have natural options. By now you are probably wondering whether there are natural approaches for controlling your blood pressure that are both effective and lack side effects. The answer is a resounding YES! I’ll outline a holistic natural approach for keeping your blood pressure under control in a minute but let me start with the FDAs recent approval of what they call “qualified claims” that omega-3s lower blood pressure.

 

What Does the FDA Say About Omega-3 Benefits?

omega-3 benefitsIn my book “Slaying The Supplement Myths” I talk about the “dark side” of the supplement industry. There are far too many companies who try to dupe the public by making outrageous and unsubstantiated claims about their products.

Only the FDA stands between us and those unscrupulous companies, and they take their role very seriously. That is why it is big news whenever the FDA allows companies to make health claims about their products.

Even then, the FDA is very cautious. They allow what they call “qualified” health claims. Basically, that means they are saying there is enough evidence that the health claim is probably true, but not enough evidence to say it is proven.

Of course, if you understand the scientific method, you realize there will always be some studies on both sides of every issue. That is why the only health claims the FDA allows are qualified health claims.

With that background in mind, let’s look at the qualified health claims the FDA allows for omega-3 benefits.

  • Since 2004 the FDA has allowed the qualified claim “Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.”
  • A few weeks ago, they added five qualified health claims about omega-3s and blood pressure. The 5 claims are very similar, so I will only list two below for the sake of brevity.
  • “Consuming EPA and DHA combined may reduce blood pressure and reduce the risk of hypertension, a risk factor for CHD (coronary heart disease).”
  • Consuming EPA and DHA combined may reduce the risk of CHD (coronary heart disease) by lowering blood pressure.
  • Of course, they add the usual wording about the evidence being inconsistent and inconclusive.

 

Omega-3 Benefits?

measure omega-3 benefits levelWe’ve known for some time that omega-3 fatty acids help lower blood pressure, but two recent studies were instrumental in convincing the FDA to allow these qualified health claims. These studies have highlighted just how strong the effect of omega-3s on lowering blood pressure is.

The first study was a meta-analysis of 70 randomized, placebo-controlled clinical trials of long chain omega-3 (EPA + DHA) supplementation and blood pressure (Miller et al, American Journal of Hypertension, 27: 885-896, 2014 ).

This study showed:

  • In the group with normal blood pressure at the beginning of the study EPA + DHA supplementation decreased systolic blood pressure by 1.25 mm Hg.
  • Given that systolic blood pressure rises an average of 0.6 mm Hg/year in adults over 50, the authors estimated that omega-3 supplementation alone would delay the onset of age-related high blood pressure by 2 years.
  • In the group with elevated blood pressure not taking medication at the beginning of the study, EPA + DHA supplementation decreased systolic blood pressure by an impressive 4.51 mm Hg and diastolic blood pressure by 3.05 mm Hg.
  • The authors noted that this decrease in systolic blood pressure could “prevent an individual from requiring medication [with all its side effects] to control their hypertension” or decrease the amount of medication required.

However, the doses of omega-3s used in these studies ranged from 1 to over 4 grams/day (mean dose = 3.8 grams/day). That sparked a second study (Minihane et al, Journal of Nutrition, 146: 516-523, 2016) to see whether lower levels of omega-3s might be equally effective. This study was an 8-week double-blind, placebo-controlled study comparing the effects of 0.7 or 1.8 grams of EPA + DHA per day (versus an 8:2 ratio of palm and soybean oil as a placebo) on blood pressure.

This study showed:

  • In the group with normal blood pressure at the beginning of the study, EPA + DHA supplementation caused no significant decrease in blood pressure. This could be due to the smaller number of subjects or the lower doses of EPA + DHA used in this study.
  • In the group with elevated blood pressure not taking medication at the beginning of the study, EPA + DHA supplementation decreased systolic blood pressure by 5 mm Hg and, the effect was essentially identical at 0.7 grams/day and 1.8 grams/day.
  • The authors concluded “Our data suggest that increased EPA + DHA intakes of only 0.7 grams/day may be an effective strategy for blood pressure control.”

 

A Holistic Approach to Lower High Blood Pressure

holistic approach to lower high blood pressureThe FDA’s allowed claims about omega-3s are good news indeed, but that’s not the only natural approach that lowers blood pressure. You have lots of other arrows in your quiver. For example:

  • The DASH diet (A diet that has lots of fresh fruits and vegetables; includes whole grains, low fat dairy, poultry, fish, beans, nuts and oils; and is low in sugar and red meats) reduces systolic blood pressure by 5-6 mm Hg. [Low fat, low carb and Mediterranean diets also lower blood pressure, but not by as much as the DASH diet].
  • Reducing sodium by about 1,150 mg/day reduces systolic blood pressure by 3-4 mm Hg.
  • Reducing excess weight by 5% reduces systolic blood pressure by 3 points.
  • Doing at least 40 minutes of aerobic exercise 3-4 times/week reduces systolic blood pressure by 2-5 mm Hg.
  • Nitrates, whether derived from fresh fruits and vegetables or from supplements probably also reduce blood pressure, but we don’t yet know by how much.

If you’ve been keeping track, you’ve probably figured out that a holistic lifestyle that included at least 0.7 grams/day of long chain omega-3s (EPA + DHA) plus the other omega-3 benefits in the list above could reduce your systolic blood pressure by a whopping 18-22 mm Hg.  What

That’s significant because, the CDC estimates that reducing high systolic blood pressure by only 12-13 mm Hg could reduce your risk of:

  • Stroke by 37%.
  • Coronary heart disease by 21%.
  • Death from cardiovascular disease by 25%.
  • Death from all causes by 13%.

 

A Word of Caution

While holistic approaches have the potential to keep your blood pressure under control without the side effects of medications, it is important not to blindly rely on holistic approaches alone. There are also genetic and environmental risk factors involved in determining blood pressure. You could be doing everything right and still have high blood pressure. Plus, you need to remember that high blood pressure is a silent killer that often doesn’t have any detectable symptoms prior to that first heart attack or stroke.

My recommendations are:

  • Monitor your blood pressure on a regular basis.
  • If your blood pressure starts to become elevated, consult with your doctor about starting with natural approaches to bring your blood pressure back under control. Doctors are fully aware of the side effects of blood pressure medications, and most doctors are happy to encourage you to try natural approaches first.
  • Continue to monitor blood pressure as directed by your doctor. If natural approaches are insufficient to bring your blood pressure under control, they will prescribe the lowest dose of blood pressure medication possible to get your blood pressure where it needs to be.
  • Don’t stop making holistic lifestyle choices to reduce blood pressure just because you are on medication. The more you do to keep your blood pressure under control with a healthy diet and lifestyle, the less medication your doctor will need to use (That means fewer side effects).

 

The Bottom Line

Heart Disease is still the number 1 cause of death in this country. And, while deaths from heart disease have been declining in recent years, deaths due to high blood pressure have been increasing. That is why anything we can do lower blood pressure naturally is important. What does the FDA say about omega-3s and blood pressure?

  • Since 2004 the FDA has allowed the qualified claim “Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.”
  • A few weeks ago, they added qualified health claims about omega-3s and blood pressure. For example, they now allow the following claims.
  • “Consuming EPA and DHA combined may reduce blood pressure and reduce the risk of hypertension, a risk factor for CHD (coronary heart disease).”
  • Consuming EPA and DHA combined may reduce the risk of CHD (coronary heart disease) by lowering blood pressure.

For more information on the studies that convinced the FDA to allow claims about omega-3s and blood pressure and for a discussion of holistic natural approaches for lowering blood pressure, 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