Health Tips From The Professor Are Omega-3 Supplements Good For You?

Posted December 4, 2018 by Dr. Steve Chaney

Do Omega-3s Reduce Risk Of Heart Disease & Cancer?

Author: Dr. Stephen Chaney

 

Are omega-3 supplements good for you?

are omega-3 supplements good for you fish oilYou have every right to be confused. In the late 1990s and early 2000s several major clinical studies showed that omega-3 supplements reduced the risk of heart attacks and stroke. In contrast, a few months ago a major study called ASCEND was published that failed to find any benefit of omega-3s at reducing heart disease risk. The headlines said “Omega-3 Supplements Don’t Protect Against Heart Disease”. You were told that omega-3 supplements were worthless. I pointed out the weakness of that study in a previous issue  of “Health Tips From the Professor”.

In mid-November two more major clinical studies were published. However, if you rely on the media for your information on supplementation, you are probably still confused. Headlines ranged from “Omega-3 Supplements Do Not Prevent Cancer Or Heart Disease” to “Eating More Fish Or Taking Omega-3 Fish Oil Supplements Can Cut Heart Attack Risk.” What is the truth?

The problem is that reporters aren’t scientists. They don’t know how to interpret clinical studies. What they report is filtered through their personal biases. That is why I take the time to carefully evaluate the clinical studies, so I can provide you with accurate information. Let me sort through the dueling headlines and give you the truth about omega-3s.

Note: One of the clinical studies looked at the effect of omega-3s on both cancer and heart disease risk. I will discuss the cancer results briefly, but most of my focus will be on the heart disease findings.

 

How Were The Studies Designed?

are omega-3 supplements good for you heart disease

The VITAL STUDY (JE Manson et al, New England Journal of Medicine, DOI: 10.1056/NEJMoa1811403 )in the United States. The study participants were 50% female, 50% male, and 20% African American. None of the participants had pre-existing heart disease. The characteristics of the study group were typical of the American population at that age, namely:

  • The average BMI was 28, which means that most of the participants were significantly overweight.
  • 7% of them had diabetes.
  • 38% were on cholesterol-lowering medications.
  • 50% had high blood pressure treated by medication.

Study participants were given questionnaires on enrollment to assess clinical and lifestyle factors including dietary intake. Blood samples were taken from about 50% of the participants to determine omega-3 index at baseline and at the end of the first year. The participants were given a high purity omega-3 supplement (1 gram capsules containing 840 mg of total omega-3s, 460 mg of EPA, and 380 mg of DHA as the ethyl esters) or a placebo and followed for an average of 5.3 years.

There were two important characteristics of this study that distinguished it from the negative ASCEND study.

  • This study specifically excluded cardiovascular drugs other than statins and blood pressure medications because many of those drugs provide the same benefits as omega-3s. Patients in the ASCEND study were on 3-5 heart medications
  • The omega-3 status of participants at the beginning of this study was very low. The omega-3 status of participants in the ASCEND study was near optimal at the beginning of the study.

The REDUCE-IT study (DL Bhatt et al, New England Journal Of Medicine, DOI:10.1056/NEJMoa1812792 ): This study enrolled 8,179 participants (average age = 64) from several countries. The study participants were 70% male and 90% white. The average BMI was 31, which is considered obese. This study differed from the VITAL study in that all the patients were at high risk of heart disease.

  • 70% of them had preexisting heart disease.
  • The remaining 30% had diabetes plus at least one additional risk factor for heart disease.
  • In addition, all of them had elevated triglycerides, which is an independent risk factor for heart disease.

The participants were given a high purity EPA supplement (4 grams of EPA as the ethyl ester) or a placebo and followed for an average of 4.9 years.

 

Do Omega-3s Reduce The Risk Of Heart Disease?

 

are omega-3 supplements good for you heart attackThe VITAL Study: The primary end point for this study was something called “major cardiovascular events”, which was a composite every cardiovascular end point measured in the study. For this end point the results were negative. Omega-3 supplementation did not cause a significant decrease in major cardiovascular events compared to the placebo.

This was the result that was reported in the abstract and was what lazy journalists, who never read past the abstract, reported.

However, the rest of the study was very positive. For example, 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 for heart disease.
  • 19% in patients with low fish intake.

In other words, omega-3 supplementation caused a significant decrease in heart disease risk for high risk patients and for patients with a poor diet (low intake of omega-3s).

In addition, several individual cardiovascular events were significantly reduced by omega-3 supplementation. For example:

  • Heart attacks were reduced by 28% in the general population and by 70% for African-Americans.
  • Death from heart attacks was reduced by 50%.
  • Total coronary heart disease was reduced by 17%.
  • Death from coronary heart disease was reduced by 24%.

In short, headlines saying that omega-3 supplementation can decrease heart attack risk appear to be accurate. Saying that eating more fish can reduce heart attack risk is stretching it a bit. The study was not done with fish, and you would need to eat 2-4 servings of omega-3-rich fish a week to get an equivalent amount of omega-3s. That’s a lot of fish.

The authors attributed the positive results obtained in this study compared to the negative results obtained in several recent studies to four factors:

  • Many of the previous studies had fewer participants, used lower doses of omega-3s, and were shorter. There may not have been enough statistical power to demonstrate a benefit of omega-3s in those studies.
  • Participants in many of the previous studies were on multiple medications that mimicked the beneficial effects of omega-3s, making it more difficult to show a positive effect of omega-3 supplementation.
  • Most of the previous studies either did not measure the omega-3 status of participants or had a study population that started the study with near optimal omega-3 status. The VITAL study showed that omega-3s had a stronger beneficial effect for people who seldom ate fish.
  • African-Americans were underrepresented in most previous studies. The VITAL study showed that omega-3s were more beneficial for African-Americans than for other ethnic groups.

As for side effects, there was no increased risk of bleeding or any other serious side effect from omega-3 supplementation.

The REDUCE-IT Study: This study of high-risk patients was even more positive than the VITAL study.

  • The composite of all cardiovascular end points was reduced by 25%.
  • The risk reduction was greatest for men, non-whites, and people over 65.
  • The risk reduction was also greatest for people with pre-existing heart disease, very high triglyceride levels, and people who required high-dose statin therapy to keep their cholesterol under control.

In other words, everyone benefited from omega-3 supplementation in this study because they were all at high risk, but those at the highest risk benefitted the most.

When they looked at individual cardiovascular events:

  • Fatal and non-fatal heart attacks were reduced by 31%.
  • Cardiovascular death was reduced by 20% and death from any cause was reduced by 23%.
  • Fatal and non-fatal stroke was reduced by 28%.
  • Hospitalization for unstable angina was reduce by 32%.

However, this very high dose of EPA was not completely without risk:

  • 1% of patients in the EPA group were hospitalized for atrial fibrillation versus 2.1% in the placebo group.
  • 7% of patients in the EPA group experienced a serious bleeding event compared to 2.1% in the placebo group.

 

Do Omega-3s Reduce The Risk Of Cancer?

 

are omega-3 supplements good for you cancerThe VITAL Study: The VITAL study also looked at the effect of omega-3s on cancer risk. The results from this study were uniformly negative. There was no effect of omega-3 supplementation on invasive cancer of any type, breast cancer, prostate cancer, colon cancer, or death from cancer. Does that mean omega-3s have no role in reducing cancer risk? That’s not clear.

If we look at previous animal studies and human association studies, reduced cancer risk is seen when omega-3s replaced saturated fats, trans fats, and/or omega-6 fats in the diet. The subjects in the VITAL study ate a typical American diet, and the study made no effort to change what they were eating. It just added an omega-3 supplement. There is relatively little evidence that you can eat burgers and fries and expect omega-3s to reduce cancer risk.

The VITAL study merely confirms what previous studies have suggested. You can’t continue to eat a typical American diet and expect omega-3s to make cancer go away. Omega-3s should be thought of as part of a holistic approach to reducing cancer risk. If they have any role in reducing cancer risk, it is likely to be as part of a primarily plant-based diet that substitutes omega-3s for the bad fats in the American diet.

For example, the Mediterranean diet is primarily plant-based and is rich in healthy oils like olive oil and omega-3s. It is associated with reduced risk of several cancers, especially cancers of the breast and colon.

 

Are Omega-3 Supplements Good For You?

are omega-3 supplements good for you truthThere is a lot of confusion around the question of whether omega-3s are good for the heart. Some studies say yes. Others say no. If you average all the studies together, as some recent meta-analyses have done, it is easy to throw up your hands and conclude there is no definitive evidence that omega-3s reduce heart disease risk. However, if you look at why the studies differ a clear pattern emerges.

  • If the study subjects are on multiple heart medications that duplicate the beneficial effects of omega-3s, the studies tend to be negative. If the subjects are only on one or two medications, the studies tend to be positive. Since most people I know would prefer to minimize the number of medications they are on, the negative studies with multiple medications are simply not relevant to them.
  • If the study subjects are at low risk of heart disease, the studies tend to be negative. If the subjects are at high risk, the studies tend to be positive. This does not mean that omega-3s are of no benefit if you are at low risk of heart disease. It simply reflects the fact it is easier to show a beneficial effect of any intervention when you have a pool of high-risk patients who are likely to experience some sort of cardiovascular event during the time-period of the study.

For example, as discussed in my recent book, “Slaying The Supplement Myths,” this the same pattern you see with statin clinical studies. If patients are at high risk, statin drugs clearly save lives. If they are at low risk, it is almost impossible to show any benefit of statin drugs. Cardiologists extrapolate from the high-risk studies and prescribe statins to low-risk patients. I think it is time to take a similar approach with omega-3s.

  • If the subjects have a good omega-3 status at the beginning of the study, additional omega-3 supplementation usually has no benefit. If their omega-3 status is poor at the beginning of the study, the results of omega-3 supplementation tend to be positive. This is just common sense. Supplementation is meant to fill gaps in the diet – not to provide a surplus of nutrients. Of course, the reality is many Americans do not get enough omega-3s in their diet.

 

What Do These Studies Mean For You?

are omega-3 supplements good for you healthy heartOmega-3s Are Good For Your Heart: When you combine the latest studies with what we already know about omega-3s and heart disease, the results are clear-cut.

  • If you are at high risk of heart disease, don’t eat many omega-3-rich fish, and/or don’t want to be on a handful of heart medications, the evidence is strong that omega-3s reduce your risk of heart disease.
  • On the other hand, if you are at low risk of heart disease, eat 2-4 servings of omega-3-rich fish a week, and/or are happy taking multiple heart medications with all their side effects, it is difficult to prove that omega-3s have any benefits. That doesn’t mean that omega-3s don’t have benefits. It just means we can’t prove they do.

If you are still having trouble making up your mind whether omega-3 supplements are the right choice for you, I might remind you:

  • If you are like millions of Americans, the first sign you are at risk of heart disease might be sudden death.
  • If you are like most Americans, you are probably not getting enough omega-3s in your diet.
  • If you prefer taking drugs, you are probably not interested in supplements anyway.

Holistic Is Best: When you combine the VITAL study results with what we already know about omega-3s and cancer, it appears that adding omega-3s to a bad diet is unlikely to reduce your risk of cancer. However, a holistic approach that starts with a healthy, primarily plant-based diet and substitutes omega-3s for the bad fats in the American diet is likely to substantially reduce your cancer risk. The Mediterranean diet might be considered an example of that approach.

The same is likely true for heart health. While the latest two studies suggest that adding omega-3 supplements to your regular diet reduces your heart disease risk, those omega-3 supplements are likely to be even more effective if you also adopt a heart-healthy diet and lifestyle.

Omega-3 Supplements vs Omega-3 Drugs: The Omega-3 preparations used in this study are pharmaceutical-grade omega-3 preparations and are marketed as drugs. Thus, it is likely that many doctors will recommend them rather than less expensive omega-3 supplements. Which choice is best for you?

The preparation used in the VITAL study is similar in composition to many commercially available omega-3 supplements. The main difference is that it is high purity and is subject to the quality control standards required for pharmaceutical drugs. Many omega-3 supplements do not meet these standards, but some do. If you wish to use an omega-3 supplement, do your research. Inquire about their quality control standards and only buy high purity supplements.

The preparation used in the REDUCE-IT study used ultra-pure EPA only. That preparation did not contain any other omega-3s, so a commercially available omega-3 supplement would not be comparable. However, I do not recommend an EPA-only supplement for three reasons.

  • The results for high risk patients in the REDUCE-IT study were similar to those for high risk patients in the VITAL study. This suggests that removing DHA and other omega-3s may not provide additional protection against heart disease. A head to head comparison of the two supplements would be required to prove the superiority of an EPA-only supplement.
  • I have the same concern for this high-dose EPA supplement as I have for any high-dose single nutrient supplement. DHA and other omega-3s provide benefits such as cognitive health that EPA does not. Very high dose EPA is likely to interfere with the uptake and utilization of the other omega-3s.
  • The EPA only supplement used in the REDUCE-IT study had side effects that were not seen with the mixed omega-3 supplement used in the VITAL study. It is not clear whether those side effects were due to differences in dose or differences in formulation.

Omega-3 Ethyl Esters vs Omega-3 Triglycerides: There has been a lot of hype about the superiority of omega-3 triglyceride preparations recently. These studies were both done with omega-3 ethyl esters and proved to be very effective. Until someone shows that omega-3 triglyceride preparations provide better results at reducing heart disease risk than omega-3 ethyl esters, I would leave omega-3 triglyceride supplements on the shelf.

How Much Omega-3s Do You Need? We have too few dose-response studies to reliably predict how much omega-3s are optimal for reducing heart disease risk. The 1 gram/day dose used in the VITAL study gave good results, so that is an excellent starting point. The 4 gram/day dose used in the REDUCE-IT study seemed to provide little additional benefit.

Of course, the optimal dose is likely to be different for each of us. Once the omega-3 index blood test becomes more widely available I would recommend getting your omega-3 index determined on an annual basis and aiming for an omega-3 index of 8 or above, since that is the level associated with a low risk of heart disease.

 

The Bottom Line

 

There is a lot of confusion around the question of whether omega-3s are good for the heart. Some studies say yes. Others say no. If you average all the studies together, as some recent meta-analyses have done, it is easy to throw up your hands and conclude there is no definitive evidence that omega-3s reduce heart disease risk.

However, two recent studies support the effectiveness of omega-3s for reducing heart disease risk. When you combine the latest studies with what we already know about omega-3s and heart disease, the results are clear-cut.

  • If you are at high risk of heart disease, don’t eat many omega-3-rich fish, and/or don’t want to be on a handful of heart medications, the evidence is strong that omega-3s reduce your risk of heart disease.
  • On the other hand, if you are at low risk of heart disease, eat 2-4 servings of omega-3-rich fish a week, and/or are happy taking multiple heart medications with all their side effects, it is difficult to prove that omega-3s have any benefits. That doesn’t mean that omega-3s don’t have benefits. It just means we can’t prove they do.

If you are still having trouble making up your mind whether omega-3 supplements are the right choice for you, I might remind you:

  • If you are like millions of Americans, the first sign you are at risk of heart disease might be sudden death.
  • If you are like most Americans, you are probably not getting enough omega-3s in your diet.
  • If you prefer taking drugs, you are probably not interested in supplements anyway.

In addition, one of the studies confirmed what we already know about omega-3s and cancer. Adding omega-3s to a bad diet is unlikely to reduce your risk of cancer. However, a holistic approach that starts with a healthy, primarily plant-based diet and substitutes omega-3s for the bad fats in the American diet is likely to substantially reduce your cancer risk. The Mediterranean diet might be considered an example of that approach.

The same is likely true for heart health. While the latest two studies suggest that adding omega-3 supplements to your regular diet reduces your heart disease risk, those omega-3 supplements are likely to be even more effective if you also adopt a heart-healthy diet and lifestyle.

For more details read the article above. In addition, the article covers topics like omega-3 supplements versus omega-3 drugs, omega-3 ethyl esters versus omega-3 triglycerides, and how much omega-3s we need. It also discusses why several recent studies have failed to find a benefit of omega-3s for reducing heart disease risk.

 

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

Health Tips From The Professor Are High Fat Dairy Foods Good For You?

Posted November 13, 2018 by Dr. Steve Chaney

Can You Have Your Cream And Eat It Too?

Author: Dr. Stephen Chaney

 

are high fat dairy foods good for youDairy foods can play an important role in helping us get enough calcium in our diet and may provide some other benefits (discussed below). However, many dairy foods contain a lot of saturated fat. Thus, we have been told to select low-fat dairy foods. So, what should we make of the recent headlines and blogs telling us that high-fat dairy foods are good for us?

Are high fat dairy foods good for us?

To answer that question, I picked a recent article (F. Imamura et al, PLOS Medicine, doi: 10.1371/journal.pmed.1002670 ) claiming that dairy fats lower the risk of type 2 diabetes and did an in-depth analysis of the data behind the headlines.

Fat Chemistry 101

 

Before I get started, let me cover what I call “Fat Chemistry 101”. Sorry, professors never fully retire.

are high fat dairy foods good for you professorFat Nomenclature: Let me briefly describe some of the nomenclature that chemists and biochemists use when they describe fats. Fats, or triglycerides, are generally defined as three fatty acids attached to a molecule of glycerol. The chemical nomenclature for fatty acids consists of a “C” followed by the number of carbons in that fatty acid. That, in turn, is followed by a colon (:) and the number of doubles bonds (0 for a saturated fatty acid, 1 for a monounsaturated fatty acid, and 2 or more for a polyunsaturated fatty acid). Let me give some examples, specifically the examples I will refer to in this article.

Saturated fatty acids:

  • C15:0 (pentadecanoic acid)
  • C16:0 (palmitic acid)
  • C17:0 (heptadecanoic acid)
  • C18:0 (stearic acid)

Monounsaturated fatty acids:

C16:0, and C18:0 are referred to as even-chain fatty acids (They have an even number of carbon atoms). C15:0 and C17:0 are referred to as odd-chain fatty acids (They have an odd number of carbon atoms).

C16:0 (palmitic acid) is the most abundant saturated fatty acid in meats and dairy food. C18:0 (stearic acid) is the second most abundant saturated fatty acid in these foods. The odd-chain fatty acids C15:0 and C17:0 are primarily found in dairy fat although small amounts can also be found in meat and fish.

All saturated fats raise LDL cholesterol. However, the effect is not equally strong for all saturated fats. The effect on LDL cholesterol is strongest for palmitic acid (C16:0). It is weaker for stearic acid, possibly because stearic acid (C18:0) can be metabolized to oleic acid (C18:1), which has no effect on LDL cholesterol.

Foods Are A Complex Mixture Of Fats: We generally think of saturated fats coming from meat and dairy, monounsaturated fats coming from olive oil and avocados, and polyunsaturated fats as coming from vegetable oils, seeds, and nuts. However, that is an oversimplification. Meats also contain monounsaturated and polyunsaturated fats. Olive oil contains some saturated and polyunsaturated fats. Vegetable oils also contain monounsaturated and saturated fats.

Why do I even mention this? It is important because we tend to label a food “good” or “bad” based on its most abundant fat. Perhaps we would be better served if we considered all the major fats in that food before deciding whether it is good or bad for us.

How Was The Study Designed?

are high fat dairy foods good for you studiesWith that background in mind, let us turn our attention to the current study. The authors wished to test the hypothesis that high-fat dairy foods might decrease the risk of type 2 diabetes. The results of previous studies had been mixed, but the authors hypothesized that might have been due to the limitations of using dietary recalls to assess intake of high-fat dairy foods. Specifically, they theorized that dietary recalls tend to underestimate the less apparent sources of dairy fats such as creams, sauces, cheeses, and butter used as part of meal preparation or in prepared foods.

They postulated that blood and tissue concentrations of the odd-chain fatty acids (C15:0 and C17:0) would be a much better biomarker of dairy fat consumption than dietary recalls. They performed a meta-analysis of all studies that measured blood or tissue levels of odd-chain fatty acids and looked at type 2 diabetes as an outcome.

Their meta-analysis included 16 studies from 12 countries with a total of 63,682 participants (age range: 49 to 76 years). The participants were slightly overweight, but none of them had type 2 diabetes at the beginning of the studies. The participants were followed for an average of 9 years. By the end of the studies 15,180 (24%) had developed type 2 diabetes.

 

Are High Fat Dairy Foods Good For You?

 

are high fat dairy foods good for you milk cheeseWhen the authors compared the highest versus the lowest levels of odd-chain fatty acids in the subjects, the results of the study were as follows:

  • The highest level of C15:0 fatty acids was associated with a 20% lower incidence of type 2 diabetes.
  • The highest level of C17:0 fatty acids was associated with a 35% lower incidence of type 2 diabetes. This is consistent with several previous studies that have suggested C17:0 fatty acids are a better predictor of type 2 diabetes than C15:0 fatty acids.
  • When these data were combined the overall effect was a 29% lower incidence of type 2 diabetes.

The authors concluded: “These novel findings support the need for additional clinical and molecular research to elucidate the potential effects of [odd-chain] fatty acids on glucose-insulin metabolism and the potential role of selected [high-fat] dairy products for the prevention of type 2 diabetes.”

What Does This Study Mean For You?

are high fat dairy foods good for you what does it meanOn the surface, this looks like a very strong study. It is, after all, a meta-analysis with over 68,000 subjects. It also used biomarkers for dairy fat consumption rather than relying on less accurate dietary recalls. Finally, it is consistent with several earlier studies suggesting that high-fat dairy foods decrease the risk of type 2 diabetes and heart disease. What could go wrong?

The answer is “Plenty.”

  • Studies looking at the effect of high-fat dairy foods on the risk of heart disease and type 2 diabetes have been inconsistent. Some have shown benefit, but others have come up empty. Despite the inconsistent results, the idea that high-fat dairy foods might be good for us has gotten a lot of media attention. I suspect that is because this is the kind of news we really want to be true. After all, wouldn’t it be great news if we could eat all the cheese, cream, and butter we wanted?
  • Some studies have concluded that high-fat and low-fat dairy products were equally effective at decreasing the risk of heart disease and type-2 diabetes. If these studies are correct, they would suggest something else in dairy foods is protective, not the kind of fat.
  • The odd-chain saturated fatty acids are very minor constituents of dairy fat. Together, they represent 1.3% of the fatty acids in dairy fat. In contrast, even-chain saturated fatty acids make up 68% of the fatty acids in dairy fat. Palmitic acid (C16:0) makes up 30% or 23 times the concentration of odd-chain fatty acids. Stearic acid (C18:0) makes up 12% or 9 times the concentration of odd-chain fatty acids.
  • This study, and most previous studies, have just looked at the association between odd-chain fatty acids and type 2 diabetes. They do not prove cause and effect.
  • No mechanism has been proposed that would account for the proposed beneficial effects of odd-chain saturated fatty acids, especially in the presence of much higher concentrations of even-chain saturated fatty acids.
  • A study published last year (BJ Jenkins et al, Scientific Reports, 7:44845, doi: 10.1038/srep44845 ) reported that blood levels of C15:0 were dependent on intake of dairy foods, but that blood levels of C17:0 were independent of dairy intake. These authors presented evidence showing C17:0 in the human body resulted from metabolism of C18:0 (stearic acid) in our diet rather than coming from dairy fats.

In other words, the odd-chain fatty acid (C15:0) that comes from dairy foods is the one that has only a weak association with the risk of developing type 2 diabetes. The odd-chain fatty acid with a strong association with diabetes risk is synthesized in our bodies from stearic acid (C18:0), a fatty acid that is also found at high levels in meat.

So, are high fat dairy foods good for you?  More studies are needed.

 

The Bottom Line

 

A recent study has reported that high-fat dairy products may reduce the risk of type 2 diabetes. This is consistent with a few other studies that have suggested high-fat dairy products may reduce the risk of diabetes and heart disease.

The idea that high-fat dairy foods might be good for us has gotten a lot of media attention. I suspect that is because this is the kind of news we really want to be true. After all, wouldn’t it be great news if we could eat all the cheese, cream, and butter we wanted?

However, the clinical results have been inconsistent. Some have shown benefit, but others have come up empty. Most of the studies also had significant limitations. I have discussed the limitations of the current study in the article above.

We can remain hopeful that high-fat dairy foods will eventually be shown to be good for us, but until we have stronger evidence for the proposed benefits of dairy fats, my recommendation is to consume high-fat dairy products sparingly.

 

For more details read the article above.

 

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

Health Tips From The Professor Are Eggs Good For You?

Posted June 12, 2018 by Dr. Steve Chaney

Do Eggs Reduce Heart Disease Risk?

Author: Dr. Stephen Chaney

Are eggs good for you?

are eggs good for youIf you are like most Americans, you are probably confused about whether you should eat eggs or not. It’s no wonder. The story about eggs keeps changing.

Just a few years ago we were told that eggs were full of cholesterol. They would increase our risk of heart disease. We should avoid them. If we did eat eggs, it should just be the egg whites because all the cholesterol was in the yolk.

Then we were told that the latest science showed that dietary cholesterol didn’t have much of an effect on serum cholesterol levels. It was saturated fats, trans fats, and obesity that raised serum cholesterol levels. Several major studies found that eggs didn’t increase heart disease risk. But we were told not to overdo it. Two to three eggs a week were probably OK, but more might be risky.

Now the headlines proclaim that eggs are good for our heart. They decrease heart disease risk. You can eat an egg every day and actually reduce your risk of heart disease. What is the truth? Let’s start by looking at the study (C. Qin et al, Heart, doi: 10.1136/heartjnl-2017-312651 ).

How Was The Study Done?

are eggs good for you and your heartThe study was performed in China. 500,000 adults (aged 30-79 years) from 10 diverse sites in China were enrolled in the study between 2004 and 2008. At the beginning of the study, the participants were asked about the frequency of egg consumption. A subset of the participants was asked about egg consumption at regular intervals during the first year to assess whether egg consumption was constant. The participants were followed for 8.9 years and cardiovascular incidents were determined from multiple health registries in China.

In terms of egg consumption:

  • 9% of the population never consumed eggs or consumed them very infrequently.
  • 20% of the population consumed eggs 1-3 days/month.
  • 47% of the population consumed eggs 1-3 days/week.
  • 11% of the population consumed eggs 4-6 days/week.
  • 13% of the population consumed eggs daily (average = 0.76 eggs/day).

 

Are Eggs Good For You?

 

are eggs good for you and reduce heart diseaseWhen the scientists conducting the study compared participants reporting daily egg consumption with those who never or rarely consumed eggs:

  • Overall risk of cardiovascular disease was lowered by 11%
  • Risk of heart attacks was lowered by 12%
  • Risk of major cardiovascular events was lowered by 12%.
  • Risk of hemorrhagic stroke (stroke caused by bleeding in the brain) was lowered by 26%
  • Risk of ischemic stroke (stroke caused by a blood clot) was lowered by 10%.

In addition, daily egg consumers lowered their risk of:

  • Cardiovascular death by 18%.
  • Hemorrhagic stroke death by 28%.

The reduction in hemorrhagic stroke risk is particularly significant for the Chinese. In China stroke is the leading cause of death and disability. The reasons for the high stroke risk in China are not well understood. However, the smoking rate and the incidence of high blood pressure are both higher in China than in the United States.

 

What Does This Study Mean For You?

There are some weaknesses to this study. For example, participants reporting daily egg consumption had a higher level of education and household income, were more likely to take a multivitamin supplement, and less likely to have high blood pressure than participants reporting little or no egg consumption. The authors did their best to compensate for these differences statistically, but there is always the concern that they might have introduced bias into the conclusions.

More to the point, diet and lifestyle are very different in China than in the United States. That also could have influenced the results. Thus, it is, perhaps, premature to claim the eggs reduce the risk of heart disease. However, several major studies performed in the United States have shown that eggs do not increase heart disease risk. That means eggs can be part of a heart healthy diet. According to the Mayo Clinic : “Most healthy adults can eat up to seven eggs a week with no increase in their risk of heart disease.”

That is fortunate because eggs are a very healthy food. According to the authors of this study:

  • Studies have shown that egg protein results in better blood sugar control, better satiety (feeling of fullness), and reduced subsequent food intake in healthy and overweight individuals. In layman’s terms that means egg protein can help you achieve and maintain a healthy weight.
  • Egg yolks are a good source of lutein and zeaxanthin. We think of lutein and zeaxanthin as good for eye health. But, they also play an important role in protecting against oxidation, inflammation, and atherosclerosis.
  • Egg yolks also contain choline. We think of choline as good for brain and nerves. But, choline and other phospholipids in the yolk also raise HDL levels and enhance HDL function.
  • Eggs are a good source of vitamin A, vitamin D, vitamin B12, riboflavin, selenium and iron.
  • Eggs contain almost twice as much monounsaturated and polyunsaturated fats as saturated fats.

are eggs good for you but not sausage and baconThere is one other possible takeaway from this study. Let’s return to the differences between the Chinese study and US studies. There is one other major study showing that daily egg consumption reduces heart disease risk, and it was performed in Japan. What is different between Japan, China, and the United States you might ask. The answer is simple. They consume primarily plant-based diets.

That suggests eggs may be healthier as part of a primarily plant-based diet than they are as part of the typical American diet. In short, eggs are healthy. It’s the sausage, bacon, ham, breakfast muffin, and biscuits that are the problem.

Are eggs good for you? Yes.

For more information on heart healthy diets, read my book “Slaying The Food Myths.”

 

The Bottom Line:

A recent study looked at the effect of egg consumption on heart disease risk in China. It found that people who consumed one egg per day had significantly lower risk of heart disease risk than people who seldom or never consumed eggs.

This study has some shortcomings and may not be directly applicable to those of us in the United States. However, several major studies in the United States have concluded that egg consumption does not increase heart disease risk. That means eggs can be part of a heart healthy diet. According to the Mayo Clinic: “Most healthy adults can eat up to seven eggs a week with no increase in their risk of heart disease.” That is fortunate because eggs are a very healthy food.

There is one other major study showing that daily egg consumption reduces heart disease risk, and it was performed in Japan. What is different between Japan, China, and the United States you might ask. The answer is simple. They consume primarily plant-based diets.

That suggests eggs may be healthier as part of a primarily plant-based diet than they are as part of the typical American diet. Are eggs good for you? Yes, eggs are healthy. It’s the sausage, bacon, ham, breakfast muffin, and biscuits that are the problem.

For more information on heart healthy diets, read my book “Slaying The Food Myths.”

For more details on this study, read the article above:

 

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