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

Which Foods Affect Stroke Risk?

March 24, 2020 by Dr. Steve Chaney

Why Is Diet And Stroke Risk So Confusing?

One 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?

This 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?

For 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.

However, 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?

As 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.

2) 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?

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.”

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.

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.

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.

Is Fish Oil Really Snake Oil?

February 11, 2014 by Dr. Steve Chaney

Does Fish Oil Reduce Heart Disease Risk?

Author: Dr. Stephen Chaney

One of my readers recently sent me a video titled “Is Fish Oil Just Snake Oil?” and asked me to comment on it. The doctor who made the video claimed that the most recent studies had definitively shown that omega-3 fatty acids, whether from fish or fish oil, do not decrease the risk of heart attack, stroke or cardiovascular death. He went on to say that the case was closed. There was no point in even doing any more studies.

My reader, like many of you, was confused. Wasn’t it just a few years ago we were being told that clinical studies have shown that omega-3 fatty acids significantly reduce the risk of heart disease? Hadn’t major health organizations recommended omega-3 fatty acids as part of a heart health diet? What has changed?

The answer to the first two questions is a resounding YES, and “What has changed?” is THE story. Let me explain.

Fish Oil And Heart Disease Risk In Healthy People

If we look at intervention studies in healthy people (what we scientists refer to as primary prevention studies) the results have been pretty uniform over the years. In a primary prevention setting, fish oil cannot be shown to significantly reduce the risk of heart disease (Rizos et al, JAMA, 308: 1024-1033, 2012).

That’s not unexpected because it is almost impossible to show that any intervention significantly reduces the risk of heart disease in healthy populations. For example, as I pointed out in recent Health Tips From the Professor (“Do Statins Really Work?” and “Can An Apple A Day Keep Statins Away?”) you can’t even show that statins significantly reduce heart attack risk in healthy populations.

If you can’t prove that statins reduce the risk of heart attacks in a healthy population, it should come as no surprise that you can’t prove that fish oil reduce heart attacks in a healthy population. To answer that question we need to look at whether fish oil reduces the risk of heart attacks in high risk populations.

Fish Oil And Heart Disease Risk In Sick People – The Early Studies

Most of the early studies looking at the effect of fish oil in patients at high risk of cardiovascular disease (what we scientists refer to as secondary prevention studies) reported very positive results.

For example, the DART1 study (Burr et al, Lancet, 2: 757-761, 1989) and the US Physician’s Health Study (Albert et al, JAMA, 279: 23-28, 1998) reported a 29% decrease in total mortality and a 52% decrease in sudden deaths related to heart disease in patients consuming diets rich in omega-3 containing fish.

Even more striking was the GISSI-Prevenzione study (Marchioli et al, Lancet, 354: 447-455, 1999; Marchioli et al, Eur. Heart J, 21: 949-952, 2000; Marchioli et al, Circulation, 105: 1897-1903, 2002). This was a very robust and well designed study. It looked at the effect of a fish oil supplement providing 1 g/day of omega-3 fatty acids on the risk of a second heart attack in 11,323 patients who had survived a non-fatal heart attack within the last 3 months – a very high risk group.

The results were clear cut. Over the next 3.5 years supplementation with fish oil reduced overall death by 15% and sudden death due to heart disease by 30% compared to a placebo. And, if you looked at the first 4 months, when the risk of a second heart attack is highest, the fish oil supplement reduced the risk of overall death by 41% and sudden death by 53%.

The authors estimated that treating 1,000 heart attack patients with 1 g/day of fish oil would save 5.7 lives per year. That is almost identical to the 5.2 lives saved per 1,000 patients per year by the statin drug pravastatin in the LIPID trial (NEJM, 339: 1349-1357, 1998).

No wonder the American Heart Association said that patients “could consider fish oil supplementation for heart disease risk prevention.”

Fish Oil And Heart Disease Risk In Sick People – The Latest Studies

However, the most recent studies have been uniformly negative. For example, the ORIGIN trial (Bosch et al, NEJM, 367: 309-318, 2012) treated 12,536 patients who were considered at high risk of heart disease because of diabetes or pre-diabetes with either 1 g/day of fish oil or a placebo. This was also a robust, well designed study, and it found no effect of the fish oil supplement on either heart attacks or deaths due to heart disease.

Similarly, a recent meta-analysis looking at the combined effects of 14 randomized, double-blind, placebo-controlled trials in patients at high risk of heart disease found no significant effect of fish oil supplements on overall deaths, sudden death due to heart disease, heart attacks, congestive heart failure or stroke (Kwak et al, Arch. Int. Med., 172: 686-694, 2012).

No wonder you are confused by all of the conflicting studies. You must be wondering: “Is the American Heart Association wrong?” “Are fish oil supplements useless for reducing heart disease risk?”

What Has Changed Between The Early Studies & The Latest Studies?

When a trained scientist sees the outcome of well designed clinical studies change over time, he or she asks: “What has changed in the studies?” It turns out that a lot has changed.

1) In the first place the criteria for people considered at risk for heart attack and stoke have changed dramatically. Not only has the definition of high cholesterol” been dramatically lowered, but cardiologists now treat people for heart disease if they have inflammation, elevated triglycerides, elevated blood pressure, diabetes, pre-diabetes or minor arrythmia.

For example, the GISSI-Prevenzione study recruited patients who had a heart attack within the past three months, while the ORIGIN study just looked at people who had diabetes or impaired blood sugar control. While both groups could be considered high risk, the patients in the earlier studies were at much higher risk for an imminent heart attack or stroke – thus making it much easier to detect a beneficial effect of omega-3 supplementation.

2) Secondly, the standard of care for people considered at risk for heart disease has also changed dramatically. In the earlier studies patients were generally treated with one or two drugs – generally a beta-blockers and/or drug to lower blood pressure. In the more recent studies the patients generally receive at least 3 to 5 different medications – medications to lower cholesterol, lower blood pressure, lower triglycerides, reduce inflammation, reduce arrhythmia, reduce blood clotting, and medications to reduce the side effects of those medications.

Since those medications perform many of the beneficial effects of omega-3 fatty acids, it is perhaps no surprise that it is now very difficult to show any additional benefit of omega-3 fatty acids in patients on multiple medications.

The bottom line is that we are no longer asking the same question. The earlier studies were asking whether fish oil supplements reduce the risk of heart attacks or cardiovascular death in patients at high risk of heart disease. The more recent studies are asking whether fish oil supplements provide any additional benefits in a high risk population that is already on 3-5 medications to reduce their risk of heart disease.

However, the people who are writing the headlines you are reading (and the videos you are watching) are not making that distinction. They are pretending that nothing has changed in the way the studies are designed. They are telling you that the latest studies contradict the earlier studies when, in fact, they are measuring two different things.

Is Fish Oil Really Snake Oil?

Was the doctor who made the video “Is Fish Oil Just Snake Oil?” correct in saying that omega-3 fatty acids are ineffective at reducing the risk of heart disease? The answer is yes and no.

If you take the medical viewpoint that the proper way to treat anyone at the slightest risk of heart disease is with 3-5 medications – with all of their side effects, the answer seems to be pretty clear cut that adding fish oil to your regimen provides little additional benefit.

However, that is not the question that interests me. I’d like to know whether I can reduce my risk of heart attack and cardiovascular death by taking omega-3 fatty acids in place of those drugs – as the original studies have shown.

I’m sure many of my readers feel the same way.

The Bottom Line

Studies performed prior to 2000 have generally shown that fish oil supplements reduce the risk of a second heart attack in patients who have previously had a heart attack. One study even suggested that they were as effective as statin drugs at reducing heart attack risk in this population.

Recent studies have called into question the beneficial effects of fish oil supplements at reducing the risk of heart disease. However, these studies were performed with lower risk patients and the patients were on 3-5 medications to reduce their risk of heart attack or stroke.

The recent studies are no longer evaluating whether fish oil supplements can reduce the risk of heart disease. They are asking whether they have any additional beneficial effects for people taking multiple medications. That’s a totally different question.

So ignore the headlines saying that fish oil is snake oil. If you are content taking multiple medications to reduce your risk of heart disease, it is probably correct to say that omega-3 fatty acids provide little additional benefit.

However, if you are interested in a more holistic, drug-free approach to reducing your risk of heart disease, I still recommend omega-3 fatty acids as part of a heart healthy diet, as does the American Heart Association.

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.

Can Soft Drinks Cause Heart Disease?

October 17, 2013September 2, 2013 by Steve Chaney

Put Down That Soda

Author: Dr. Stephen Chaney

Can Soft Drinks Cause Heart Disease? For today’s “Health Tip” I’m going to paraphrase a quote from your some of your favorite action flicks: “Put down that soda and back away and nobody gets hurt.”

You see, the news about soft drinks keeps getting worse and worse! You’ve probably already heard that soft drink consumption leads to weight gain, pre-diabetes and possibly even diabetes because calories in liquid form do not affect appetite to the same extent as calories in solid form.

Soft Drink Consumption increases the risk of heart attack and stroke in women:

As if that weren’t bad enough, three recent studies suggest that soft drinks consumption is also associated with increased risk of heart attacks and stroke.

The first study looked at sweetened beverage consumption and risk of coronary heart disease in women (Fung et al, Am. J. Clin. Nutr., 89: 1037-1042, 2009).

This study followed 88,520 women enrolled in the Nurses Health Study for 24 years. Consumption of sugar-sweetened beverages (either sodas or non-carbonated sugar-sweetened beverages such as Hawaiian Punch, lemonade and other non-carbonated fruit drinks) was assessed from food-frequency questionnaires administered 7 times during the 24 years. And the total incidence of coronary events (both fatal and non-fatal) was recorded.

The results were striking. When they compared women who consumed as little as one sugar-sweetened beverage per day with women who consumed those beverages less than once per month, the increased risk of coronary heart disease was 23%. And when they compared women who consumed more than two sugar-sweetened beverage per day with women who consumed those beverages less than once per month, the increased risk of coronary heart disease was a whopping 35%.

Sodas are just as harmful for men:

And, in case you guys thought you were off the hook, a study has just been published showing similar results in men (de Koning et al, Circulation, March 12, 2012, Epub ahead of print). This study was a 22 year follow up of 42,883 men enrolled in the Men’s Health Professional study. The study design and results were very similar to the ones obtained previously in the Nurses Health Study except that this study did not distinguish between subjects consuming one sugar sweetened beverage a day and those consuming more than one each day.

When they compared men who consumed one or more sugar sweetened beverage a day to men who never consumed sugar-sweetened beverages, the increased risk of coronary heart disease was 20%.

Diet sodas are just as bad as regular sodas:

Finally, you may be saying that this information doesn’t apply to you because you only consume diet sodas or artificially sweetened non-carbonated beverages.

Unfortunately, you may not be off the hook either!

Another study published in January 2012 reported that diet soft drink consumption is also associated with increased risk of coronary heart disease – including strokes (Gardener et al, J. Gen. Intern. Med., DOI: 10.1007/sl11606-011-1968-2). This study followed 2564 men and women enrolled in the Northern Manhattan Study for 10 years.

The people in this study who consumed more than one diet soda or artificially sweetened beverage/day were 43% more likely to have a vascular event (heart attack or stroke) then the people consuming less than one diet beverage/month. This study is in line with previous studies showing that diet soda consumption is associated with increased risk of pre-diabetes and type 2 diabetes.

And, as I have pointed out in my previous “Health Tips”, there is no convincing evidence that diet sodas actually help prevent weight gain. Sure there are several published studies showing that when dietitians supervise the diets of the study participants, you can achieve weight loss by substituting diet beverages for sugar containing beverages.

However, two major studies have shown that when you look at free-living populations, consumption of diet beverages is associated with just as much weight gain as consumption of sugar containing beverages (Dhingra et al, Circulation,116: 480-488, 2007; Fowler et al,

Obesity, 16:1894-1900, 2008). Apparently, without a dietitian looking over our shoulder, we manage to make up for those lost calories somewhere else!

The Bottom Line:

So what’s the bottom line for you?

You should be aware that these studies just look at associations – not cause and effect – and they can be skewed by the characteristics of the study populations. For example, there were some striking inconsistencies between the 3 studies I cited that are likely due to differences in the population groups that they sampled. However, despite some differences from one study to the next, the weight of accumulating evidence seems to suggest that sodas – both sugar containing and diet – are really not good for us.

So it’s back to my original advice: “Just put down that soda and nobody gets hurt.” Water is sounding better and better!

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.