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The Good News About Omega-3s And Stroke

April 9, 2024 by Dr. Steve Chaney

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

Author: Dr. Stephen Chaney

I 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?

This 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

The 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.

How 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).

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.

Are Calcium Supplements Heart Healthy?

February 6, 2024 by Dr. Steve Chaney

Should You Follow Your Doctor’s Advice About Calcium Supplementation?

Author: Dr. Stephen Chaney

Are calcium supplements good for your heart or bad for your heart? If you don’t know the answer to that question, don’t feel badly. You have every right to be confused. Some studies say that calcium supplements increase heart disease risk while others say they decrease heart disease risk. The headlines have veered between “killer calcium” and “beneficial calcium”.

The trend appears to be moving in a positive direction. In recent years most of the studies have suggested that calcium supplements either decrease heart disease risk or have no effect on heart disease risk.

However, the medical profession has been slow to take note of this trend. Most medical societies and health professionals have focused on earlier studies and are still recommending that their patients get calcium from food rather than from supplements. I will talk more about that recommendation below.

With this context in mind, this week I will review and discuss the results from the latest study (MG Sim et al, Heart, Lung and Circulation, 32: 1230-1239, 2023) on the effect of calcium supplementation on heart disease risk.

How Was This Study Done?

The authors of this study performed a meta-analysis of 12 double-blinded randomized clinical trials with 87,899 participants comparing the effect of a calcium supplement versus a placebo on heart disease outcomes (heart attack, stroke, heart failure, cardiovascular mortality, and all-cause mortality).

The studies included in this analysis:

Used calcium doses from 500 mg/day to 2,000 mg/day.

Used supplements with calcium coming from a variety of sources (calcium carbonate, calcium citrate, calcium gluconolactate, and tricalcium phosphate).

Ranged from 18 months to almost 12 years in length.

Were performed with population groups from a wide range of countries (United States, England, France, Australia, New Zealand, European Union, Denmark, and Thailand).

Included calcium supplements with and without vitamin D.

Were primarily (86% of participants) conducted with post-menopausal women. One small study (0.3% of participants) was conducted with non-osteoporotic men. The rest were conducted with mixed populations (men and women) diagnosed with colorectal adenoma.

Are Calcium Supplements Heart Healthy?

This is the largest meta-analysis performed to date of double-blind, placebo-controlled randomized clinical trials on the effect of calcium supplementation versus a placebo on heart disease outcomes. This study found no effect of calcium supplementation on:

Heart attack.
Stroke
Heart failure.
Cardiovascular mortality.
All-cause mortality.

This study also evaluated potential confounding variables and found no effect of calcium supplementation on heart disease risk for:

Calcium supplements with and without vitamin D.

Dosage of calcium in the supplements (The dosage ranged from 500 mg/day to 2,000 mg/day).

Females (I suspect the number of males in this study was too small to come to a statistically significant conclusion).

Duration of calcium supplementation ≤ 5 years (The shortest duration of calcium supplementation in these studies was 18 months).

Different geographical regions.

However, this meta-analysis reported considerable variation between studies included in the analysis. Simply put,

Some studies showed an increase in heart disease risk.
Some studies showed a decrease in heart disease risk.
Some studies showed no effect on heart disease risk.

What this analysis showed was that when you combine all the studies, the aggregated data is consistent with calcium supplementation having no effect on heart disease risk.

The authors concluded, “Calcium supplementation was not associated with myocardial infraction [heart attack], stroke, heart failure, and cardiovascular/all-cause mortality. Further studies are required to examine and understand these associations.

Should You Follow Your Doctor’s Advice About Calcium Supplementation?

As I said above, most medical societies and health professionals have focused on earlier studies and are still recommending that their patients get calcium from food rather than from supplements. That may be the advice you are getting from your doctor.

Before you assume your doctor isn’t keeping up with the latest science and ignore his or her advice, we should ask why they are giving that advice. The top three reasons most medical societies give for recommending dietary sources of calcium are:

1) Some studies do show an increased risk of heart disease associated with calcium supplementation. The prime directive for health professionals is to do no harm. Yes, the average of all studies shows no effect of calcium supplementation on heart disease risk. But what if the studies showing increased risk are true for some of their patients? Those patients could be harmed.

Are you someone who might be at increased risk for heart disease if you take calcium supplements. The short answer is we don’t know because previous studies have not asked the right questions.

In my opinion, it is time to pause additional studies and meta-analyses on calcium supplementation and heart health until we have gone over existing studies with a fine-tooth comb to figure out why the results differ so wildly. For example, we need to ask whether the effect of calcium supplements on heart disease risk is influenced by things like:

- Age or ethnicity of participants.

- Other preexisting health conditions.

- Other lifestyle factors (exercise is probably the most important, but others may be involved as well).

- Diet context. For example, we already know that the effect of eggs and dairy on heart health is influenced by diet context. [I have covered this for eggs in a previous issue of “Health Tips From the Professor”.]

- Other unanticipated variables.

Only when we have identified variables that might influence the effect of calcium supplements on heart disease risk, will the scientific community be able to design studies to identify the population groups who might be adversely affected by calcium supplementation.

This would allow health professionals to make informed decisions about which of their patients should avoid calcium supplementation and which of their patients would benefit from calcium supplementation.

2) We really don’t need the recommended RDAs for calcium to build strong bones. The recommended RDAs for calcium are 1,000 mg/day for adults 19-50, 1,000 mg/day for men and 1,200 mg/day for women 51-70, and 1,200 mg/day for both men and women over 70. But do we really need that amount of calcium to build healthy bones?

I have discussed this topic in detail in a previous issue of “Health Tips From the Professor”. Here are the key points:

- The current RDAs are based on calcium needs for people consuming the typical American diet and following the typical American lifestyle. If that is you, the current RDAs probably apply.

- However, strong bones are absolutely dependent on three things, adequate calcium, adequate vitamin D, and adequate weight-bearing exercise. Most recent studies of calcium supplementation and bone density include adequate vitamin D, but almost none of them include exercise. Previous studies have been inadequate.

- The best calcium supplements contain certain nutrients besides vitamin D that optimize bone formation. I have listed those nutrients in the article cited above.

- Our ability to use calcium to build strong bones is dependent on diet (something I call a bone-healthy diet) and lifestyle (something I call a bone-healthy lifestyle).

- For more information on each of these points, read the article I referenced above.

In short, I agree that the current calcium RDAs may be too high for individuals consuming a bone-healthy diet and following a bone-healthy lifestyle. But the current calcium RDAs are likely accurate for people consuming the typical American diet and following the typical American lifestyle.

- While we do not have a calcium RDA for populations following a bone healthy diet lifestyle, some studies suggest that 700-800 mg of calcium/day may be sufficient for this group.

3) Calcium from supplements is absorbed faster and gives higher blood level spikes than calcium from foods. That could be a problem because high blood levels of calcium are associated with calcification of our arteries, which is associated with increased heart disease risk.

This is a theoretical concern, because high blood calcium levels from supplementation are transitory, while it is continuous high blood calcium levels that are associated with calcification of our arteries.

However, it is a plausible concern because most supplement companies design their calcium supplements based on how quickly they get calcium into the bloodstream rather than how effectively the calcium is utilized for bone formation. Here are my recommendations:

- Choose a calcium supplement that provides RDA levels of vitamin D plus other nutrients shown to support strong bone formation.

- Choose a calcium supplement supported by clinical studies showing it is effectively utilized for bone formation.

4) We should be getting our calcium from foods rather than supplements.

While it is always easy for doctors to recommend that we get our nutrients from food rather than supplements, they need to ask whether we are getting those nutrients from our diet. For calcium the data are particularly sobering.

- The average American gets around 740 mg of calcium/day from their diet. That is probably enough for the small percentage of Americans following a bone healthy diet and lifestyle. But it is 260-460 mg short of the 1,000-1,200 mg/day recommended for older adults with the typical American diet and lifestyle.

- - And for the average American, around 70% of their calcium intake comes from dairy foods.
  - So, Americans who are following a typical American diet and lifestyle and are restricting dairy may require 800-1,000 mg/day of supplemental calcium unless they carefully plan their diets to optimize calcium intake.
  - Finally, vegans average about 550 mg/day from their diet. That might be borderline even if they were following a bone healthy lifestyle.

- In short, we cannot assume our diet will provide enough calcium for strong bones unless we include dairy foods and/or plan our diet very carefully. Some degree of supplementation may be necessary.

How Much Calcium Do You Need?

I have covered a lot of territory in this article, so let me summarize the four concerns of the medical community and answer your most important question, “Should you take calcium supplements?”

1) Calcium supplements may increase the risk of heart disease for some people.

That is true, but we have no idea at present who is at increased risk and who isn’t. So, we should minimize our risk by taking the precautions I describe below.

2) We don’t need RDA levels of calcium to build strong bones. That is probably true if you are one of the few people who follows a bone healthy diet and lifestyle, but it isn’t true if you follow the typical American diet and lifestyle.

The current RDAs of 1,000 – 1,200 mg/day are a good guideline for how much calcium you need if you follow the typical American diet and lifestyle.

If you a one of the few people who follow a bone healthy diet and lifestyle (For what that involves, read this article) you may only need 700-800 mg/day. But we don’t have clinical studies that can tell us what the actual RDA for calcium should be under those circumstances.

3) Calcium from supplements is absorbed faster and gives higher blood calcium spikes than calcium from foods. You may remember that the theoretical concern is that even short-term spikes of high blood calcium may lead to calcification of your arteries, which increases your risk of heart disease. So, the important question becomes, “What can we do to minimize these spikes in blood calcium levels?”

We should avoid calcium supplements that brag about how quickly and efficiently the calcium is absorbed. That could lead to calcium spikes. Instead, we should look for calcium supplements that are backed by clinical studies showing they are efficiently utilized for bone formation.

We should look for calcium supplements that include RDA levels of vitamin D and other nutrients that optimize bone formation. You will find more information on that in the same article I referenced above.

Some experts recommend that calcium supplements be taken between meals. But it is probably better to take them with meals because foods will likely slow the rate at which calcium is absorbed and reduce calcium spikes in the blood.

We are told to limit calcium supplements to less than 500 mg at any one time because calcium absorption becomes inefficient at higher doses. It might be even better to limit calcium to 250 mg or less at a time to reduce calcium spikes in the blood.

4) We should get calcium from foods rather than supplements.

Many Americans do not get enough calcium from diet alone, especially if they avoid dairy foods. So, some degree of calcium supplementation may be necessary. I have given some guidelines depending on your diet and lifestyle above.

The amount of supplemental calcium needed is relatively small. I do not recommend exceeding the RDA unless directed to by your health professional.

The Bottom Line

Some studies say that calcium supplements increase heart disease risk while others say they decrease heart disease risk. The headlines veer between “killer calcium” and “beneficial calcium”.

A recent meta-analysis of 12 double-blinded randomized clinical trials with 87,899 participants comparing the effect of a calcium supplement versus a placebo on heart disease outcomes has just been published. This study found no effect of calcium supplementation on:

Heart attack.
Stroke.
Heart failure.
Cardiovascular mortality.
All-cause mortality.

The authors of the study concluded, “Calcium supplementation was not associated with myocardial infraction [heart attack], stroke, heart failure, and cardiovascular/all-cause mortality.

For more details and advice on whether you should follow your doctor’s recommendations for calcium supplementation read the article above.

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

_____________________________________________________________________________

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

The Omega-3 Pendulum

April 12, 2022 by Dr. Steve Chaney

Who Benefits Most From Omega-3s?

Author: Dr. Stephen Chaney

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

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

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

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

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

Summarize what you should know about omega-3 intake and your risk of heart disease.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

- An omega-3 index of 4% or less is associated with high risk of heart disease, and…

- An omega-3 index of 8% or more is associated with a low risk of heart disease.

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

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

The Omega-3 Pendulum

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

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

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

The GISSI Study:

The patients enrolled in this study all had suffered a heart attack in the previous 3 months. They were at very high risk of suffering a second heart attack within the next couple of years.

Omega-3 intake was not measured in this study. But it was uncommon for Europeans to supplement with omega-3s in the 90’s. And European studies on omega-3 intake during that period generally found that omega-3 intake was low.

Patients enrolled in this study were generally taking only 2 heart disease drugs, a beta-blocker and a blood pressure drug.

The ASCEND Study:

The patients enrolled in this study had diabetes without any evidence of heart disease. Only 17% of the patients enrolled in the study were at high risk of heart disease. 83% were at low risk. Remember, it is difficult to show a benefit of any intervention in low-risk patients.

The average omega-3 index of patients enrolled in this study was 7.1%. That means omega-3 levels were near optimal at the beginning of the study. Adding additional omega-3s was unlikely to show much benefit.

Most of the patients in this study were on 3-5 heart drugs and 1-2 diabetes drugs which duplicated the effects of omega-3s.

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

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

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

The VITAL Study:

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

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

This study excluded omega-3 supplement users The average omega-3 index of patients enrolled in this study was 2.7% at the beginning of the study and increased substantially during the study. This enhanced the ability of the study to show a benefit of omega-3 supplementation.

Participants in this study were only using statins and blood pressure medications. People using more medications were excluded from the study. This also enhanced the ability of the study to show a benefit of omega-3 supplementation.

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

However, the authors designed the study so they could also:

Look at the effect of omega-3s on heart disease risk in high-risk groups. They found that major cardiovascular events were reduced by:

- 26% in African Americans.

- 26% in patients with diabetes.

- 17% in patients with a family history of heart disease.

- 19% in patients with two or more risk factors of heart disease.

Look at the effect of omega-3s on heart disease risk in people with low omega-3 intake. They found that omega-3 supplementation reduced major cardiovascular events by:

- 19% in patients with low fish intake.

Look at the effect of omega-3s on the risk of different forms of heart disease. They found that omega-3 supplementation reduced:

- Heart attacks by 28% in the general population and by 70% for African Americans.

- Deaths from heart attacks by 50%.

- Deaths from coronary heart disease (primarily heart attacks and ischemic strokes (strokes caused by blood clots)) by 24%.

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

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

How is heart disease defined? Studies looking at heart attack and/or ischemic stroke are much more likely to show a benefit of omega-3s than studies that include all forms of heart disease.

Are the patients at low-risk or high-risk for heart disease? Studies in high-risk populations are much more likely to show a benefit than studies in low-risk populations.

What is the omega-3 intake of participants in the study? Studies in populations with low omega-3 intake are more likely to show a benefit of omega-3 supplementation than studies in populations with high omega-3 intake.

How many heart drugs are the patients taking? Studies in people taking no more than one or two heart drugs are more likely to show a benefit of omega-3 supplementation than studies in people taking 3-5 heart drugs.

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

Who Benefits Most From Omega-3s?

The answers to this question are clear:

People at high risk of heart disease are most likely to benefit from omega-3 supplementation.

People with low omega-3 intake are most likely to benefit from omega-3 supplementation.

Omega-3 supplementation appears to have the biggest effect on heart attack and ischemic stroke (stroke due to blood clots). Its effect on other forms of heart disease is less clear.

Omega-3 supplementation appears to be most effective at preventing heart disease if you are taking no more than 1 or 2 heart drugs. It may provide little additional benefit if you are taking multiple heart drugs. However, you might want to have a conversation with your doctor about whether omega-3 supplementation might allow you to reduce or eliminate some of those drugs.

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

If we compare omega-3 studies with statin studies, the answer would be yes. Remember that statins cannot be shown to reduce heart attacks in low-risk populations. However, because they are clearly effective in high-risk patients, the medical community assumes they should be beneficial in low-risk populations. The same argument could be made for omega-3s.

We also need to recognize that our ability to recognize those who are at high risk of heart disease is imperfect. For too many Americans, the first indication that they have heart disease is sudden death!

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

I feel the same way about omega-3s:

Most Americans do not get enough omega-3s in our diet.

Our omega-3 index is usually much closer to 4% (high risk of heart disease) than 8% (low risk of heart disease).

Many of us may not realize that we are at high risk of heart disease until it is too late.

And omega-3s have other health benefits.

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

The Bottom Line

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

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

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

A Diet To Die For

September 14, 2021 by Dr. Steve Chaney

Which Diet Is Best?

Author: Dr. Stephen Chaney

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

Saturated and trans fats are bad for us and monounsaturated and omega-3 fats are good for us.

Sugar and refined carbohydrates are bad for us, but complex carbohydrates are good for us.

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

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

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

It turns out that one of the diets significantly increases your risk of sudden cardiac death. I call that one, “A diet to die for”.

Another diet significantly decreases your risk of sudden cardiac death. I call that one, “A diet to live for”.

The other diets had no significant effect on the risk of sudden cardiac death.

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

How Was The Study Designed?

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

30% of its participants from what is called the “the stroke belt” (North Carolina, South Carolina, Georgia, Tennessee, Alabama, Mississippi, Arkansas, and Louisiana).

20% of its participants from what is called “the stroke buckle” (the coastal plain of North Carolina, South Carolina, and Georgia).

50% of its participants from elsewhere in the continental United States.

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

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

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

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

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

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

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

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

Points are added for beneficial foods (vegetables, fruits, legumes, whole grain cereals, nuts, and fish).

Points are subtracted for detrimental foods (meat and dairy).

Points are added for a high ratio of monounsaturated fats to saturated fats (think diets rich in olive oil).

One point is added for moderate alcohol consumption, Zero or excess alcohol consumption is assigned 0 points.

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

A Diet To Die For

The results were striking.

The Southern Diet increased the 10-year risk of sudden cardiac death 2.2-fold. Basically, it doubled the risk.

- In people with no previous history of heart disease at the beginning of the 10-year study, the Southern Diet increased the risk of sudden cardiac death by 2.3-fold.

- In people with a previous history of heart disease at the beginning of the 10-year study, the Southern Diet increased the risk of sudden cardiac death by 2-fold.

The Mediterranean Diet decreased the 10-year risk of sudden cardiac death 41%.

- In people with no previous history of heart disease at the beginning of the 10-year study, the Mediterranean Diet decreased the risk of sudden cardiac death by 51%. Basically, it cut the risk in half.

- In people with a previous history of heart disease at the beginning of the 10-year study, the Mediterranean Diet decreased the risk of sudden cardiac death by 23%, but that decrease was not statistically significant.

None of the other diets had a significant effect on the 10-year risk of sudden cardiac death.

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

Which Diet Is Best?

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

This should come as no surprise:

I have reported on a previous study showing that the Mediterranean diet decreases the risk of heart disease by 47%.

In the Woman’s Health Study the Mediterranean diet decreased the risk of sudden cardiac death by 36%.

In the Nurses’ Health Study there was an inverse association between the Mediterranean Diet Score and sudden cardiac death.

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

It starts with a breakfast of fried eggs, grits with “red-eye gravy” (a mixture of ham drippings and coffee), ham or sausage, and biscuits made with lots of lard and sugar.

When I was growing up, a snack might be an RC cola and moon pies (look that one up).

Dinner might be fried chicken and hushpuppies or fried fish and hushpuppies.

Instead of picnics we have pig pickins (which is pretty much what it sounds like).

And we boil our vegetables with fatback (pig fat) and sugar.

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

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

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

As described, this is a semi-vegetarian diet, while the best results for reducing heart disease risk are seen with strict vegetarian and lacto-ovo-vegetarian diets.

However, my biggest concern is that we don’t know what other foods they were consuming. Were they also consuming convenience foods? Were they consuming sweets? We don’t know.

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

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

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

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

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

The Bottom Line

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

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

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

It turns out that the Southern diet doubles your risk of sudden cardiac death. I call that one, “A diet to die for”.

In contrast, the Mediterranean diet cuts your risk of sudden cardiac death in half. I call that one, “A diet to live for”.

The other diets had no significant effect on the risk of sudden cardiac death.

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

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

What Is The Truth About Eating Eggs And Heart Disease?

July 30, 2020 by Dr. Steve Chaney

Have The Dangers Of Eggs Been “Eggagerated”?

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

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

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

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

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

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

They only measured egg consumption at the beginning of the study. This fails to account for the fact that egg consumption has waxed and waned over the years as eggs have gone from enemy to friend and back to enemy.

They did not assess how the overall diet influences the effect of egg consumption on heart disease. If we believe the previous studies, eggs lower the risk of heart disease and hemorrhagic stroke in China and increase the risk of both in the United States and Europe. This suggests that overall diet is important, but this hypothesis has not been tested.

They also did not address the question of whether eggs, because of their cholesterol, might have a more adverse effect on heart disease in individuals who already have high blood cholesterol and have difficulty controlling their cholesterol levels.

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

How Was The Study Done?

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

The first Nurse’s Health Study, which ran from 1980 to 2012,

The second Nurse’s Health Study, which ran from 1991-2013, and

The Health Professional’s Follow-Up Study, which ran from 1986-2012.

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

A detailed food frequency questionnaire was administered every 2-4 years. This allowed the investigators to calculate cumulative averages of all dietary variables, including egg intake. This assured that the effects of egg consumption and diet represented the participant’s diet over the 32-year duration of the study.

Participants also filled out questionnaires that captured information on disease diagnosis, disease risk factors, medicines taken, weight, and lifestyle characteristics every 2 years with follow-up rates >90%. This allowed the investigators to measure the onset of disease and medicine use for each participant during the study. More importantly, 32 years is long enough to measure the onset of diseases like heart disease, diabetes, and cancer – diseases that require decades to develop.

The endpoint of the study was “incident heart disease”, which the investigators defined as non-fatal heart attack, death from heart disease, and fatal and non-fatal stroke. During this study, 14,806 participants developed incident heart disease. This was a large enough number for a detailed statistical analysis of the data.

For example, statistical analysis showed that the participants with the highest egg intake also were more likely to be obese and more likely to consume red meat, bacon and other processed meats, refined grains, French fries, and sugar-sweetened beverages. These are what we refer to as “confounding variables” because they also increase the risk of heart disease and are likely to confound (confuse) the analysis. Therefore, the investigators statistically corrected the data on egg consumption for these confounding variables. Many previous studies did not have the data or statistical power to correct their egg consumption data for these confounding variables.

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

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

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

Biochemistry 101: Cholesterol Metabolism

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

Our body makes vitamin D and coenzyme Q10 from cholesterol.

Our body makes steroid hormones such as cortisol, estrogen, and testosterone from cholesterol.

Cholesterol is a vital component of the myelin sheath that coats our nerve cells.

And that is just the beginning.

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

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

When we get little cholesterol from our diet, our body makes more and excretes less.

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

Obesity

Type 2 diabetes

Diets high in saturated fats

Diets high in sugar and refined carbohydrates

Genetics

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

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

What Is The Truth About Eating Eggs And Heart Disease?

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

There was no difference in heart disease outcomes for participants consuming an average of one egg/day and participants consuming less than one egg/month.

When the investigators examined heart attack and stroke separately, there was no difference in either outcome for participants consuming an average of one egg/day and participants consuming less than one egg/month.

As mentioned above the participants who consumed the most eggs weighed more; were less physically active; were more likely to be current smokers; and were more likely to consume red meat, processed meats, refined grains, potatoes (think French fries and potato chips), full fat milk, and sugar-sweetened beverages.

- Without correcting for these factors eating one egg/day resulted in a 10% increase in heart disease risk.

- After correcting for these factors, eating one egg/day resulted in a 7% decrease in heart disease risk.

- In both cases the differences were statistically non-significant. However, they were in line with the previous studies mentioned above.

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

There was no association between heart disease risk and egg consumption.

- In Asian countries where the diet was primarily unrefined, plant-based foods, egg consumption decreased heart disease risk.

- In people with type 2 diabetes, egg consumption increased heart disease risk.

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

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

Have The Dangers Of Eggs Been “Eggagerated”?

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

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

If you are consuming a primarily plant-based diet, your body is fully able to regulate your blood cholesterol levels. Then, you can reap the full benefits of the egg, namely the protein, iron, unsaturated fats, lecithin, choline, and carotenoids it provides. Under these conditions, eating up to one egg/day reduces your risk of heart disease.

If you are consuming a diet that contains primarily chicken or fish and unprocessed plant foods, egg consumption is neutral. It neither increases nor decreases your risk of heart disease.

If you are consuming a diet that contains sugar-sweetened beverages, red and processed meats, high fat dairy products, refined grains, and junk foods (ie, the typical American diet), your body is no longer able to regulate blood cholesterol levels well. Now the cholesterol content of eggs becomes an issue and consuming one egg/day slightly increases your risk of heart disease.

If you are overweight and have developed type 2 diabetes, your body has become insulin resistant. This also interferes with your body’s ability to regulate blood cholesterol levels. In this situation, consuming one egg/day also increases your risk of heart disease.

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

The Bottom Line

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

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

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

If you are consuming a primarily plant-based diet, your body is fully able to regulate your blood cholesterol levels. Then, you can reap the full benefits of the egg, namely the protein, iron, unsaturated fats, lecithin, choline, and carotenoids it provides. Under these conditions, eating up to one egg/day reduces your risk of heart disease.

If you are consuming a diet that contains primarily chicken or fish and unprocessed plant foods, egg consumption is neutral. It neither increases nor decreases your risk of heart disease.

If you are consuming a diet that contains sugar-sweetened beverages, red and processed meats, high fat dairy products, refined grains, and junk foods (ie, the typical American diet), your body is no longer able to regulate blood cholesterol levels well. Now the cholesterol content of eggs becomes an issue and consuming one egg/day slightly increases your risk of heart disease.

If you are overweight and have developed type 2 diabetes, your body has become insulin resistant. This also interferes with your body’s ability to regulate blood cholesterol levels. In this situation, consuming one egg/day also increases your risk of heart disease.

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

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

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

Do Vegetarians Have A Higher Risk Of Stroke?

December 10, 2019 by Dr. Steve Chaney

What Are The Benefits And Risks Of A Vegetarian Diet?

Vegetarian diets are thought to be very healthy. Clinical studies show that vegetarian diets are associated with decreased risk of heart disease, diabetes, cancer, Alzheimer’s disease, and much more. What’s not to like?

That’s why the recent headlines claiming that vegetarian diets may increase the risk of stroke were so surprising. Advocates of meat-heavy diets like the Paleo and Keto diets were overjoyed. These results fit in with their view that we should be eating more meat protein and less plant protein. Nutrition experts, on the other hand, were asking: “What’s going on?” “How can this be?”

Those of you who are regular readers of “Health Tips From the Professor” know that I am an advocate of primarily plant-based diets. Thus, I felt a responsibility to analyze the study (TYN Tong et al, British Medical Journal, 366: 14897, 2019) behind the headlines impartially and give you, my readers, clear guidelines for the healthiest possible diet.

How Was The Study Done?

Let’s start with some background:

· A major study called the “European Prospective Investigation Into Cancer and Nutrition” (EPIC) has been underway since the early 90’s.

· The British component of this study is known as the EPIC-Oxford study.

· While the study has “cancer” in it’s title, it was designed to measure the impact of nutrition on many diseases. In this case, the study focused on heart disease and stroke.

· Finally, enrollment in the EPIC-Oxford study was designed to give a high proportion of vegetarians in the study population.

The EPIC-Oxford study enrolled 48,188 participants with no previous history of heart disease, stroke, or angina between 1993 and 2001. A detailed diet analysis was performed upon enrollment and again in 2010. Based on these data, the participants were divided into three groups:

1) Meat eaters (24,428 participants).

2) Fish eaters (7,506 participants). This group consumed fish but no other meats. People with this eating style are often called pescatarians.

3) Vegetarians (16, 254 participants). This group consumed dairy and eggs, but no meat. People with this eating style are often called lacto-ovo vegetarians.

4) The diet analysis also identified participants who were vegans (no animal foods). However, this group was too small to obtain statistically significant comparisons, so they were included with the lacto-ovo vegetarians in the vegetarian group.

Data on heart disease and stroke were obtained from the UK’s health service records through March 31st, 2016. The average time of follow-up for participants in the study was 18.1 years.

Without going into greater detail, this was a very large, well-designed study.

How Did The Diets Of The Three Groups Compare?

The first step in analyzing this study is to ask how the diets of the three groups compared.

Compared to meat eaters, the fish eaters consumed:

· No meat other than fish.

· Slightly less milk and significantly more cheese.

· Slightly more fruits & vegetables.

· Significantly more legumes & soy foods, nuts & nut butter.

· Slightly more carbohydrate and slightly less protein.

· Slightly less saturated fat and slightly more polyunsaturated fat.

· Around 260 fewer calories per day.

Compared to fish eaters, the vegetarians consumed:

· No meat.

· Slightly less milk & cheese.

· About the same amount of fruits & vegetables.

· Significantly more legumes & soy foods, nuts & nut butter.

· Slightly more carbohydrate and slightly less protein.

· About the same saturated and polyunsaturated fat.

· Around 125 fewer calories per day.

On average, the vegetarians consumed about 1 cup of milk and one ounce of cheese per day. The fish eaters consumed 1.4 ounces of fish per day.

In terms of comparisons:

· The biggest differences were between the fish eaters and the meat eaters. It would be fair to say that the fish eaters consumed a primarily plant-based diet with added fish and dairy.

· The biggest differences between the vegetarians and fish eaters was that the fish eaters got a significant percentage of their protein from fish, while the vegetarians got a significant amount of their protein from plant sources. Otherwise, their diets were fairly comparable.

Finally, the 10-year follow-up diet analysis showed that most participants stuck with their initial diet.

Do Vegetarians Have A Higher Risk Of Stroke?

Now, for the study results:

· Compared to meat eaters, fish eaters had 13% lower risk of heart disease, and vegetarians had a 22% lower risk of heart disease.

o For vegetarians this corresponds to 10 fewer cases of heart disease per 1,000 people over 10 years.

· Compared to meat eaters, vegetarians had a 20% higher risk of stroke, mostly due to an increased risk for hemorrhagic stroke.

o For vegetarians this corresponds to 3 additional cases of stroke per 1,000 people over 10 years.

· The risk of stroke was essentially identical for fish eaters and meat eaters.

In many other aspects, vegetarians were healthier than meat-eaters. For example, they:

· Weighed less.

· Had lower blood pressure.

· Had lower total and LDL cholesterol.

· Were less likely to have developed diabetes during the study.

· Were less likely to have required long-term treatment for other illnesses.

What Are The Strengths And Weaknesses Of The Study?

The strength of this study is obvious. It was a very large, well-designed study. The study also lasted a long time. Participants in the study were followed for almost 20 years.

There are two clear weaknesses, however:

1) Numerous previous studies have confirmed that vegetarian diets decrease heart disease risk by about 20%. However, none of those previous studies have reported an increase in stroke risk. This study is an outlier.

2) There is no clear mechanism that explains why a vegetarian diet might increase stroke risk. Based on previous observations that statin drugs increase the risk of hemorrhagic stroke, the authors suggested the increased stroke risk might be due to lowered LDL cholesterol levels.

This mechanism is speculative at present. Furthermore, if true, it would suggest that any intervention (drug or nutritional) that lowers LDL cholesterol would increase stroke risk.

In the words of the authors:

· “The present study has shown that British adults who were fish eaters or vegetarians had lower risks of heart disease than meat eaters, but that vegetarians had higher risks of stroke.

· Future work should include further measurements…to identify which factors may cause the observed associations. [In plain English: We need to understand how vegetarian diets might increase stroke risk before we put too much weight on the results of this study.]

· Additional studies in other large-scale cohorts with a high proportion of non-meat eaters are needed to confirm the generalizability of these results and assess their relevance for clinical practice and general health.” [In plain English: More studies are needed to confirm this observation before we start changing our recommendations about what constitutes a healthy diet.]

What Are The Benefits And Risks Of A Vegetarian Diet?

Let’s assume for a minute that the results of this study are accurate and take a closer look at the benefits and risks of a vegetarian diet. Here is my assessment:

1) This report is troubling, but it may not be correct. The association of vegetarian diets with a slight increase in stroke risk has only been seen in a single study. This study needs to be confirmed before we become too concerned about vegetarianism increasing stroke risk.

2) On the balance, vegetarian diets should still be considered very healthy. They lower the risk of heart disease, high blood pressure, diabetes, some cancers, inflammatory diseases and possibly even Alzheimer’s disease.

3) However, I have often said that we have 5 food groups for a reason, and it is not a good idea to eliminate whole food groups. In the past, I have used that statement to critique diets that leave out important plant food groups like fruit, whole grains, and legumes.

If the data on stroke risk in this study are true, it suggests it might also not be a good idea to leave out meat. However, you don’t need a lot of meat. The fish eaters in this study were consuming 1.4 ounces of fish per day. That was enough to eliminate the increased risk of stroke.

4) In addition, you don’t have to be a vegan purist to enjoy the health benefits of a primarily plant-based diet. As I describe in my book, “Slaying The Food Myths”, primarily plant-based diets ranging from vegan through pescatarian and semi-vegetarian to Mediterranean and DASH are all incredibly healthy.

I personally follow a semi-vegetarian diet but often recommend Mediterranean and DASH diets to others because they are the easiest primarily plant-based diets for the average American to follow.

5) Finally, if you have a family history, or are at high risk, of stroke, I recommend prudence until we know more. You may wish to adopt a version of primarily plant-based diets that incorporates some meat (That would be in the pescatarian to DASH range of primarily plant-based diets). Your heart will thank you, and you won’t increase your risk of stroke.

The Bottom Line

A recent study enrolled 48,188 British adults; divided them into meat eaters, fish eaters, and vegetarians; followed them for 18.1 years; and looked at their risk for heart disease and stroke. The results were:

· Compared to meat eaters, fish eaters had 13% lower risk of heart disease, and vegetarians had a 22% lower risk of heart disease.

o For vegetarians this corresponds to 10 fewer cases of heart disease per 1,000 people over 10 years.

· Compared to meat eaters, vegetarians had a 20% higher risk of stroke, mostly due to an increased risk for hemorrhagic stroke.

o For vegetarians this corresponds to 3 additional cases of stroke per 1,000 people over 10 years.

· The risk of stroke was essentially identical for fish eaters and meat eaters.

Here is my perspective:

4) In addition, you don’t have to be a vegan purist to enjoy the health benefits of a primarily plant-based diet. As I describe in my book, “Slaying The Food Myths” (https://slayingthefoodmyths.com), primarily plant-based diets ranging from vegan through pescatarian (the fish eaters in this study) and semi-vegetarian to Mediterranean and DASH are all incredibly healthy.

I personally follow a semi-vegetarian diet but often recommend Mediterranean and DASH diets to others because they are the easiest primarily plant-based diets for the average American to follow.

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.