Omega-3 and Heart Disease Risk

Written by Dr. Steve Chaney on . Posted in Omega-3s and Heart Disease

Why Is There So Much Confusion About Omega-3 and Heart Disease Risk?

Author: Dr. Stephen Chaney

 

omega-3 heart diseaseConcerning omega-3 and heart disease, the pendulum keeps swinging. In the 1990’s several strong clinical studies showed that omega-3s reduced heart disease risk. In fact, a major clinical study in Italy, (Lancet 354: 447 – 455, 1999 , Circulation 105 : 1897 – 1903, 2002 ), found omega-3s to be just as effective as statin drugs for preventing heart attacks, but without any of the side effects of statins.

At that time, everyone was talking about the benefits of omega-3s in reducing heart disease risk. The American Heart Association recommended an intake of 500-1,000 mg/day of omega-3s for heart health. Some experts were recommending even more if you were at high risk of heart disease.

In the 2000’s the pendulum swung in the other direction. Several clinical studies found no benefit of omega-3s in reducing heart disease risk. Suddenly, experts were telling us that omega-3s were overrated. They were a waste of money. The American Heart Association kept their omega-3 recommendations for heart health, but put more emphasis on omega-3s for people with elevated triglycerides (where the benefits of omega-3s are non-controversial).

Suddenly regarding omega-3 and heart disease, the pendulum is swinging back again. A recent meta-analysis (Alexander et al, Mayo Clinic Proceedings, 92: 15-29, 2017) reported that omega-3s do appear to be beneficial at reducing heart disease risk. An editorial accompanying that article (O’Keefe et al, Mayo Clinic Proceedings, 92: 1-3, 2017) called the meta-analysis “the most comprehensive of its kind to date…” Those experts went on to say “…omega-3-fatty acid intake of at least 1 gram of EPA + DHA per day, either from seafood or supplementation (as recommended by the American Heart Association) continues to be a reasonable strategy.”

This was followed by publication of three clinical studies that came to essentially the same conclusion (Kieber et al, Atherosclerosis, 252: 175-181, 2016 ; Sala-Vila et al, Journal of the American Heart Association, In Press ; and Greene et al, American Journal of Cardiology, 117: 340-346, 2016 ).

Why is there so much confusion about omega-3 and heart disease? Let’s start by reviewing the recently published meta-analysis.

 

Do Omega-3s Lower Heart Disease Risk?

omega-3 lowers heart disease riskThis study (Alexander et al, Mayo Clinic Proceedings, 92: 15-29, 2017) combined the data from 18 randomized controlled trials with 93,000 patients and 16 prospective cohort studies with 732,000 patients. This was the largest meta-analysis on omega-3s and heart health performed to date. The results were as follows:

  • The combined data from the randomized controlled studies showed that omega-3 supplementation resulted in a non-significant 6% reduction in heart disease risk. This is similar to other recently published studies (more about that later).
  • However, when the investigators looked at high risk populations within the randomized controlled studies, the results were strikingly different.
    • In patients with elevated triglycerides, omega-3 supplementation caused a significant 16% reduction in heart disease risk.
    • In patients with elevated LDL cholesterol, omega-3 supplementation caused a significant 18% reduction in heart disease risk.
  • In addition, the combined data from the prospective cohort studies showed that omega-3 supplementation resulted in a significant 18% decrease in heart disease risk.

The authors concluded “[Our] results indicate that EPA + DHA may be associated with reducing heart disease risk, with greater benefits observed among higher-risk populations…”

 

Why Is There So Much Confusion About Omega-3s and Heart Disease Risk?

confusionThere are several major clinical studies in progress looking at the effect of omega-3s on heart health. Some experts predict that the confusion will be cleared up once they are published. I predict they will only add to the confusion. Let me explain why.

You’ve heard the old saying “Garbage in – garbage out.”  Proper design of clinical studies is essential. If a study is poorly designed, it provides incorrect information. When you analyze the previous clinical studies carefully, you find that many of them are flawed. Their results are, therefore, incorrect. My fear is that many of the ongoing clinical studies will contain the same flaws and will provide the same incorrect information.

Let’s look at the flaws, and why they provide incorrect information.

Flaw #1: Omega-3 supplementation will only be beneficial for people who are omega-3 deficient. The authors of the Mayo Clinic Proceedings editorial provided a useful analogy. They said: “Vitamin C bestows dramatic and lifesaving benefits to persons with scurvy, but is no better than placebo for persons who are replete with vitamin C.”

That means a well-designed study should measure omega-3 levels in red blood cells both prior to and at the end of the clinical study. The data analysis should focus on those individuals who started the study with low omega-3 status and whose omega-3 status improved by the end of the study. Unfortunately, few of the previously published studies have done that, and I am not confident that the ongoing studies have incorporated that into their experimental design.

Flaw #2: Omega-3 supplementation will be of most benefit for those people who are at highest risk for heart disease. This has been a recurrent pattern in the literature. Many of the clinical studies focusing on high-risk individuals have shown a beneficial effect of omega-3 supplementation on heart disease risk. Most of the studies focusing on the general population (most of which are of low risk for heart disease) have failed to show a benefit of omega-3 supplementation. The current meta-analysis is no exception. When they looked at the general population, there was a non-significant reduction in heart disease risk. However, when they looked at high-risk populations the beneficial effect of omega-3s was highly significant.

I can’t predict how the ongoing studies will analyze their data. If they focus on high-risk groups they are more likely to report a beneficial effect of omega-3s on heart health. If they only report on the results with the general population, they are likely to conclude that omega-3s are ineffective.

I do need to make an important distinction here. The inability to demonstrate a beneficial effect of omega-3 supplementation in the general population does not mean that there is no effect. It turns out to be incredibly difficult to demonstrate a beneficial effect of any intervention, including statins , in a healthy, low-risk population. Because of that, we may never know for sure about the relationship between omega-3 and heart disease. Do omega-3s reduce heart disease risk for the young and healthy. At the end of the day, you will need to make your own decision about whether omega-3s make sense to you.

omega-3 supplementationFlaw #3: Heart medications mask the beneficial effects of omega-3 supplementation. When the public hears about the results of a randomized controlled study they assume that the placebo group received no treatment and the omega-3 group was only receiving omega-3s. That is not how it works.  Medical ethics guidelines require that the placebo group receive the standard of care treatment – namely whatever drugs are considered appropriate for that population group.

That means that it has become very difficult to demonstrate that high-risk populations benefit from omega-3 supplementation. Back in the 90s, the standard of care for high risk patients was only one or two drugs. In those days, many studies were reporting beneficial effects of omega-3 supplementation in high risk populations. However, for the past 5-10 years the standard of care for high risk patients is 4-5 medications.

These are medications that reduce cholesterol levels, lower triglyceride levels, lower blood pressure, reduce inflammation, and reduce clotting time. In other words, the drugs mimic all the beneficial effects of omega-3s. (The only difference is that the drugs come with side-effects. The omega-3s don’t.) It is no coincidence that many of the recent studies have come up empty-handed.

The current studies are asking a fundamentally different question. In the 90s, clinical studies asked whether omega-3s reduced heart disease risk in high-risk patients. Today’s clinical studies are asking whether omega-3s provide any additional benefits for patients who are already taking multiple drugs. Personally, I think my readers are more interested in the first question than the second.

Once again, the current meta-analysis is perfectly consistent with this interpretation. The high-risk groups who clearly benefited from omega-3 supplementation were not ones with pre-existing heart disease or who had previously had a heart attack. They were the ones with elevated LDL cholesterol or triglycerides. They were patients who were, either not taking drugs for those risk factors, or patients for whom the drugs were ineffective.

Because subjects in future studies will be taking multiple medications, I predict that even those ongoing studies focusing on high-risk populations will come up empty-handed.

Now you understand why I started this section by saying that I predict many of the ongoing studies will provide incorrect results. I predict that you will see more headlines proclaiming that omega-3s don’t work. However, you won’t be swayed by those headlines because you now know the truth about the flaws in the clinical studies behind the headlines!

What Does This Mean For You?

omega-3 fish oilThe most recent meta-analysis and a careful evaluation of previous studies make two things clear:

  • If you are at high risk of heart disease, omega-3 supplementation is likely to reduce your risk.

We can divide risk factors for heart disease into those we know about, and those we don’t.

  • Risk factors we know about include previously diagnosed heart disease or heart attack, genetic predisposition, age, elevated LDL cholesterol levels, high triglycerides, high blood pressure, inflammation, obesity, metabolic syndrome and diabetes.
  • Unfortunately, there are also risk factors we don’t know about. For too many Americans the first sign of heart disease is sudden death – sometimes just after receiving a clean bill of health from their doctor.
  • If you are not getting enough omega-3s in your diet, omega-3 supplementation is likely to reduce your heart disease risk.

If you are young and healthy, the unfortunate truth is that we may never completely understand the relationship between omega-3 and heart disease. We may not know whether omega-3 supplementation reduces your risk of heart disease. However, I think the overall evidence is strong enough that you should consider adding omega-3s to your diet.

In short, I agree with the authors of the Mayo Clinic Proceedings editorial and the American Heart Association that omega-3-fatty acid intake of at least 1 gram of EPA + DHA per day, either from seafood or supplementation, is a prudent strategy for reducing heart disease risk.

 

The Bottom Line

  • There has been a lot of confusion about the role of omega-3s in reducing heart disease risk.
  • In the 90s, several clinical studies reported that omega-3 supplementation reduced heart disease risk. Most experts, including the American Heart Association, were recommending that most Americans would benefit from adding 500-1,000 mg of omega-3s to their daily diet.
  • In recent years, several clinical studies have reported that omega-3 supplementation has no effect on heart disease risk. [There were some important flaws in those studies, which I discuss in the article above]. Experts started saying that omega-3s were overrated. They were a waste of money.
  • The largest meta-analysis ever undertaken in this area of research has recently reported that omega-3 supplementation decreases risk of heart disease in high-risk population groups. Three subsequent clinical studies have come to essentially the same conclusion.
  • Other studies suggest that omega-3 supplementation is also likely to reduce heart disease risk in individuals with poor omega-3 status, and most Americans have poor omega-3 status.
  • We may never know whether omega-3 supplementation reduces heart disease risk if you are young and healthy. Simply put, not enough young & healthy people develop heart disease within the time-frame of a clinical study for the results to be statistically significant. For this group, the old saying about “An ounce of prevention…” just makes sense.
  • I agree with those experts who recommend at least 1,000 mg/day of omega-3s as a prudent strategy for reducing heart disease risk.
  • There are several major clinical trials in progress studying the efficacy of omega-3s for reducing heart disease risk. Some experts predict that the confusion will be cleared up once they are published. I predict they will only add to the confusion. I predict that many of those studies will show no benefit of omega-3 supplementation, and you will see more headlines proclaiming that omega-3s play no role in heart health. If you have read the article above, you won’t be swayed by those headlines because you will know the truth about the flaws in the studies behind the headlines.

 

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.

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What Is The Best Diet For You?

Posted May 23, 2017 by Dr. Steve Chaney

Sorting Through The Dueling Diets

Author: Dr. Stephen Chaney

battle over best dietDiets are a lot like politics in today’s world. Everyone is absolutely convinced their diet is the best and absolutely convinced the other diets are terrible.

Remember the nursery rhyme: “Jack Sprat could eat no fat. His wife could eat no lean…”? Today’s diets remind me of that. They run the gamut from no fat to no carbohydrates. Surely, both extremes couldn’t be healthy. Or could they?

Some diets eliminate whole food groups. That couldn’t be a good thing. Or, could it?

So, what is the best diet for you?

In today’s article, I will give you the pros and cons of these dueling diets. Before I do that, however, let me give you some principles to put things into perspective.

General Principles For Evaluating Diets

How do you sort out the claims and counterclaims associated with the various diets? More importantly, how do you know which of the claims are true and which are misleading? Here are some general principles to help you separate the wheat from the chaff.  What’s the right diet for you?

We are omnivores. We can adapt to a wide variety of diets and do reasonably well. That means most people will do well on any of these diets short term.

wings proteinAnything is better than the standard American diet (SAD). It is high in sugar and refined carbohydrates. It is also high in saturated and trans fats. That is why proponents of every diet can claim that you will feel better and be healthier when you switch to their diet.

Processed and convenience foods are part of the problem. Most diets recommend “clean eating” (elimination of processed and convenience foods). Any diet that eliminates processed and convenience foods is likely to help you lose weight and get healthier. Caution: As soon as a diet becomes popular, food manufacturers rush in to provide pre-packaged, convenience foods to support that diet. Avoid the temptation to use those foods. Big Food Inc. does not have your best interests in mind. They are not your friends.

Most diets lead to a fairly rapid initial weight loss. This is because they restrict food choices and eliminate processed foods. When you eliminate familiar foods from someone’s diet, they instinctively eat less without even thinking about it. This rapid initial weight loss is part of the allure of almost every diet program. However, over time most people start adding back some of their favorite foods or find new foods they like, and the weight comes back.

Weight loss leads to improved blood parameters irrespective of diet composition. That is why every diet, no matter how bizarre, can claim it lowers your blood pressure, improves your blood sugar, lowers your cholesterol, and lowers your triglycerides.

Long term weight loss is virtually identical on every diet. Numerous clinical studies have compared long term weight loss on low fat diets, low carbohydrate diets, and virtually everything in between. Initial weight loss is more rapid on the low-carbohydrate diets. However, at the end of one or two years there is not a dime’s worth of difference in weight loss between any of the diets. The exception is the Vegan diet. Long term Vegans typically weigh less than their meat-eating counterparts, probably because the foods in the Vegan diet have low caloric density (fewer calories per serving).

Healthy carbs and healthy fats are more important than low carb or low fat diets. Ignore the claims and counter claims about low fat and low carb diets. Focus instead on diets that provide moderate amounts of whole grains instead of refined grains & sugar. Also focus on diets that provide moderate amounts of monounsaturated and polyunsaturated fats, especially the omega-3 polyunsaturated fats, instead of saturated and trans fats.

Focus on well balanced meals rather than individual foods. For example, moderate amounts of healthy carbohydrates will have relatively little effect on blood sugar and triglyceride levels as part of a plant-based meal that provides plenty of fiber and protein. However, those same carbohydrate-rich foods by themselves may cause a spike in both blood sugar and triglycerides.

best diet for youPlant-based diets rule. The Ornish diet (a very restrictive form of the Vegan diet) is the only diet that has been shown to reverse atherosclerosis in some people. The Vegan diet and the Mediterranean diet, which is largely plant-based, have been shown to be healthy long term. On the other hand, we simply don’t know whether low carbohydrate diets are healthy long term. Those clinical studies have not been done.

Saturated and trans fats are not your friends. They increase inflammation, which can have many serious long-term health consequences. In addition, the foods that are rich in saturated fats are often acid-forming foods, which can upset your acid-base balance.

We have 5 food groups for a reason. Each food group provides valuable nutrients (vitamins a & minerals) and phytonutrients. You may be able to replace the missing nutrients with supplementation, but you are unlikely to replace the phytonutrients with supplements – even those supplements that claim to be made from whole foods. You should be concerned about the long-term health consequences of any diet that eliminates whole food groups.

Low fat diets aren’t necessarily healthy. Whole food, low-fat diets like the Vegan diet are extremely healthy. However, as soon as health experts started recommending low-fat diets, Big Food Inc. stepped in to offer convenient low fat options. They simply replaced the fat with refined carbohydrates, sugar, and a witch’s brew of chemicals (Remember the part about Big Food Inc. not being your friend?). As a result, the low-fat diet consumed by most Americans is anything but healthy.

The supposed advantages of low carbohydrate diets are misleading. Low carbohydrate diets look very good when you compare them to the Big Food Inc version of the low-fat diet. However, when you compare them to something like the Vegan diet the advantages disappear.

Avoid sugar-sweetened and diet beverages. This should go without saying. Choose water instead. Add carbonation and/or a little lemon or lime juice for flavoring if necessary. Fortunately, most of the major diets exclude sugar-sweetened and diet beverages.

 

The Pros and Cons Of The Major Diets

It is not possible to cover each diet in depth in a single article, so this is meant to be a very brief overview of the major diets.

Low Fat Diets

The Dean Ornish Diet. This is a variation of the Vegan Diet that eliminates all oils, even vegetable oil.

Pros:

  • Whole food, plant-based diet.
  • All the advantages of the Vegan diet, plus it is the only diet shown to reverse atherosclerosis.

Cons:

  • Very restrictive.
  • Long-term adherence is low.

 

vegetablesThe Vegan Diet. This is a whole food, plant based diet. It uses plant proteins instead of meat and plant substitutes for dairy and eggs.

Pros:

  • Whole food, plant-based diet.
  • Associated with lower blood pressure, blood sugar, cholesterol, triglycerides, and inflammation.
  • Clinical studies show that the onset of major diseases like heart disease, cancer, and diabetes are delayed by at least 5-10 years. People on this diet live healthier, longer.

Cons:

  • Long-term adherence is relatively low, but some people stick with this diet for a lifetime.

 

Healthy Fat, Healthy Carb Diets

The Mediterranean Diet. This diet emphasizes fresh fruits & vegetables, whole grains, fish, nuts, seeds, legumes and olive oil. It includes cheese, poultry and eggs in moderation.

whole food dietPros:

Cons:

  • Not designed specifically for weight loss. You will need to watch portion sizes and track calories if you want to lose weight on this diet.

 

The DASH Diet. This diet was specifically designed to help reduce the risk of hypertension and stroke. It is similar to the Mediterranean diet except that it restricts sodium and includes a wider range of lean meats and low-fat dairy products. It does not specifically include olive oil.

Pros:

  • Whole food diet.
  • Clinically proven to lower blood pressure  as effectively as some blood pressure medications.
  • Relatively easy to follow. Includes foods familiar to Americans.

Cons:

  • Not designed specifically for weight loss. You will need to watch portion sizes and track calories if you want to lose weight on this diet.

 

Low Carb Diets

meat protein dietThe Paleo Diet. The Paleo diet is supposedly based on the diet of our paleolithic hunter-gatherer ancestors. The diet is high in protein & fat, and low in carbohydrates. The diet eliminates grains, sugars, refined oils, dairy, legumes, and starchy fruits & vegetables. Most of the protein comes from meats, but the animals must be grass-fed. This reduces, but does not eliminate, saturated fat and gives a modest increase in omega-3 polyunsaturated fat. Thus, the meats included in this diet are healthier than the meats in other low carbohydrate diets. However, it does not turn red meats into health foods.

Anthropologists tell us that the premise of the Paleo diet is faulty. The diet of our paleolithic ancestors was highly dependent on the foods available in their environment. Some were hunters and gatherers. Others lived in areas where fruits & vegetables were prevalent and game was scarcer. Still others lived in areas where starchy root vegetables were an important part of their diet. Furthermore, the enzymes required for digestion of starches are inducible. We can easily adapt to the introduction of grains into our diet.

Pros:

  • Whole food diet.
  • The Paleo diet is associated with several short-term benefits including weight loss, improved blood sugar control and reduced cholesterol, triglycerides & blood pressure.

Cons:

The Atkins Diet. The Atkins diet is the granddaddy of the low-fat diets. It is a very low carbohydrate diet that restricts sugars, grains, high carbohydrate fruits and vegetables. The allure of the diet is that it includes as much fatty meats and saturated fats as you want.

Pros:

  • The Atkins diet is associated with several short-term benefits including weight loss, improved blood sugar control and reduced cholesterol, triglycerides & blood pressure.

Cons:

  • There are no studies evaluating the long-term benefits and risks of the Atkins diet.
  • Weight loss at the end of one or two years is no better than for the low-fat diets.
  • The high intake of saturated fat has the potential to increase the risk of heart disease and cancer.
  • It is a very restrictive diet. Long-term adherence to this diet is poor.

The Ketogenic Diet. The Ketogenic diet is even more restrictive than the Atkins diet. I have covered the pros and cons of the Ketogenic diet in a recent post, so I will refer you to that article, Is the Ketogenic Diet Safe for details. In short, the Ketogenic diet has some short-term benefits and some potential long-term risks. Ketone supplements mimic some, but not all, of the short-term benefits of the Ketogenic diet. Their long-term health risks are unknown.

 

What Is The Best Diet For You?

what diet is right for youWe are all different, so there is no perfect diet for everyone. Want to know how to find a diet that works for you?  Here are some things to think about.

  • If you are like most Americans, almost any of these diets is better than your current diet.
  • The good thing about all the diets reviewed in this article is:
    • They replace refined carbohydrates & sugars with healthier alternatives (The best of the diets also replace saturated & trans fats with healthier alternatives).
    • They emphasize whole foods rather than processed and convenience foods.
    • They eliminate sugar-sweetened and diet beverages.
    • They emphasize fresh vegetables and most include fresh fruit.
  • If you are looking for rapid initial weight loss:
    • The very restrictive diets at either extreme (very low fat or very low carb) are best because they eliminate familiar foods from the diet.
    • The very low carb diets are slightly more effective than low fat diets initially because of water loss, but weight loss on most low carb and low fat diets is identical after 1-2 years.
    • Because both the Mediterranean and DASH diets involve many familiar foods, you will need to pay more attention to portion sizes and total calories on these diets if your primary goal is to lose weight.
  • If you are looking for long term weight control, the Vegan diet is best, probably because most foods in the Vegan diet have low caloric density. Multiple studies have shown that Vegans weigh less than their meat-eating counterparts.
  • If you are looking for long term health benefits:
    • The Vegan and Mediterranean diets are clearly your best choices. They are backed by multiple clinical studies showing they reduce the risk of heart disease, cancer, diabetes, dementia and other diseases.
    • The DASH diet is probably equally healthy. However, because it was designed to control blood pressure, most clinical studies have focused only on how well it reduces blood pressure.
    • There is no evidence that the low carb diets have any long-term health benefits, and there is reason to suspect they may have some long-term health risks.
  • I have serious concerns about long-term health risks for any diet that:
    • Eliminates whole food groups.
    • Is high in saturated and trans fats.
  • The effectiveness of any diet is dependent on how well you stick with it:
    • The long-term adherence to any of the very restrictive diets (either low carb or low fat) is low, although some people do stick with the Vegan diet for a lifetime.
    • Adherence is best with the Mediterranean and DASH diets, probably because many of the foods are familiar and readily available.

 

The Bottom Line

 

In this article I have reviewed the major low fat diets (the Dean Ornish diet and the Vegan diet), the major healthy carb, healthy fat diets (the Mediterranean diet and the DASH diet), and the major low carb diets (the Paleo diet, the Atkins diet, and the Ketogenic diet). In summary:

 

  • If you are like most Americans, almost any of these diets is better than your current diet.
  • The good thing about all these diets is:
    • They replace refined carbohydrates & sugars with healthier alternatives (The best of the diets also replace saturated & trans fats with healthier alternatives).
    • They emphasize whole foods rather than processed and convenience foods.
    • They eliminate sugar-sweetened and diet beverages.
    • They emphasize fresh vegetables and most include fresh fruit.
  • If you are looking for rapid initial weight loss:
    • The very restrictive diets at either extreme (very low fat or very low carb) are best because they eliminate familiar foods from the diet.
    • The very low carb diets are slightly more effective than low fat diets initially because of water loss, but weight loss on most low carb and low fat diets is identical after 1-2 years.
    • Because both the Mediterranean and DASH diets involve many familiar foods, you will need to pay more attention to portion sizes and total calories on these diets if your primary goal is to lose weight.
  • If you are looking for long term weight control, the Vegan diet is best, probably because most foods in the Vegan diet have low caloric density. Multiple studies have shown that Vegans weigh less than their meat-eating counterparts.
  • If you are looking for long term health benefits:
    • The Vegan and Mediterranean diets are clearly your best choices. They are backed by multiple clinical studies showing they reduce the risk of heart disease, cancer, diabetes, dementia and other diseases.
    • The DASH diet is probably equally healthy. However, because it was designed to control blood pressure, most clinical studies have focused only on how well it reduces blood pressure.
    • There is no evidence that the low carb diets have any long-term health benefits, and there is reason to suspect they may have some long-term health risks.
  • I have serious concerns about long-term health risks for any diet that:
    • Eliminates whole food groups.
    • Is high in saturated and trans fats.
  • The effectiveness of any diet is dependent on how well you stick with it:
    • The long-term adherence to any of the very restrictive diets (either low carb or low fat) is low, although some people do stick with the Vegan diet for a lifetime.
    • Adherence is best with the Mediterranean and DASH diets, probably because many of the foods are familiar and readily available.
  • 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.

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