Omega 3 Supplementation And Heart Disease Risk

How Can You Reduce Your Risk Of Heart Disease?

I understand your confusion. One month the headlines say that omega 3 supplementation reduces the risk of heart disease. The next month headlines claim that omega 3 supplements are worthless. What is the truth about omega 3 supplementation and heart disease risk?

Let me start by sharing the two of the most recent studies on the topic. They are both very large, well designed studies. However, the reason I selected these two studies is that they approached the relationship between omega 3 supplementation and heart disease risk in very different ways but came to the same conclusion.

The first study (Y Hu et al, Journal of the American Heart Association, Volume 8, Issue 19, 1 October 2019) was a meta-analysis of 13 randomized controlled clinical studies looking at the relationship between omega 3 supplementation and heart disease risk.

The second study (Z-H Li et al, British Medical Journal, BMJ2020;368:m456) looked at the association between habitual omega 3 supplementation and heart disease risk.

Each of these studies had strengths and weaknesses, but they complemented each other. The weaknesses of one study were the strengths of the other study.

How Were The Studies Done?

Study #1: The 13 studies included in the meta-analysis had a total of 127,477 participants (mean age 64, 60% male, mostly overweight) who were given either an omega-3 supplement or a placebo.

40% of the participants had diabetes.

72% of the participants were on cholesterol lowering drugs and a variety of other medications.

Participants were followed for between 3 and 7.4 years (average follow-up period was 5 years).

The dose of omega 3s ranged between 376 and 4,000 mg/day.

The major strengths of this study were:

All 13 studies included in the meta-analysis were randomized, placebo controlled clinical trials.

The meta-analysis had a very large number of participants (nearly 130,000), so it was possible to accurately measure even small effects of omega 3 supplementation on heart disease risk.

The major weaknesses of this study were:

Most of the participants were already on multiple drugs that provided many of the same benefits as omega 3s, so it was impossible to assess the full effect of omega 3 supplementation on heart disease risk.

The duration of the clinical trials included in this meta-analysis was short compared to the decades required for heart disease to develop.

Most of the participants already had heart disease or were at high risk of developing heart disease. The people in these studies were not representative of the general population.

Study #2: The data for this study were obtained from the UK Biobank study which enrolled 427,678 participants (mean age 56, 45% male) from 22 medical centers across England, Scotland, and Wales. None of the participants had been diagnosed with heart disease or cancer at the time of enrollment.

At enrollment the participants filled out a detailed online questionnaire concerning their lifestyle, diet, diseases, medications, and supplement use. Among the questions was whether they habitually used fish oil supplements (Yes or No).

The participants were enrolled between 2006 and 2010 and followed for an average of 9 years.

31% of the participants were already taking omega 3 supplements on a regular basis at the time they enrolled in the study. This was the omega 3 supplementation group. The remaining 69% was the control group.

Only 10% of the participants were taking statin drugs or aspirin, probably because none of them had been diagnosed with heart disease.

Around 10% of the participants had high blood pressure and were taking blood pressure medications.

Most of the participants were slightly overweight but only 4% had diabetes.

The main strengths of this study were:

Very few of the participants were on medications. That means that medications did not interfere with the effect of omega 3 supplementation.

The participants were already using omega 3 supplements at the time of enrollment and were followed for an additional 9 years. That means that the duration of omega 3 supplement use was much longer than in the first study.

The participants were healthy and free of heart disease at the beginning of the study. That means that the results of this study focused more on prevention than on treatment. It also means the results are more applicable to the general population.

The main weakness of this study was:

It was an association study, which cannot prove cause and effect. In contrast, the first study was based on randomized, placebo controlled clinical trials, which can prove cause and effect.

In short, the weaknesses of the first study were strengths of the second study and vice-versa.

Study #1: The results from the meta-analysis of randomized, placebo-controlled clinical trials were that omega 3 supplementation:

Reduced heart attacks by 12%.

Reduced overall heart disease risk by 7%.

Reduced deaths from heart disease by 8%.

Because of the large number of participants included in the meta-analysis, all these reductions were highly significant.

The risk reduction was linearly related to the dose of omega-3s, but the study did not allow estimation of an optimal omega-3 dose.

The authors concluded: “Marine [fish oil] omega-3 supplementation lowers risk for heart attack, overall heart disease risk, and heart disease death…Risk reductions appear to be linearly related to marine omega-3 dose.”

Study #2: This study showed that regular use of omega-3 supplements:

Reduced deaths from all causes by 13%.

Reduced deaths from heart attacks by 20%.

Reduced deaths from all types of heart disease by 16%.

Because of the large number of participants, all these reductions were highly significant.

This study did not collect data on omega-3 dose, so the study did not allow estimation of an optimal omega-3 dose.

The authors concluded: “Habitual use of fish oil seems to be associated with a lower risk of all cause mortality and heart disease mortality…,supporting their use for the prevention of mortality from all causes and heart disease. Future studies are needed to examine the extent to which the dose of fish oil supplements influences the ability to achieve a clinically meaningful effect.”

While these studies did not provide information on the optimal omega 3 dose, a previous study concluded that an omega-3 intake of 835 mg/day or higher is needed to achieve clinically meaningful reductions in heart disease risk.

How Can You Reduce Your Risk Of Heart Disease?

These two studies support the value of omega 3 supplementation for reducing heart disease risk. However, while risk reductions were highly significant, the magnitude of risk reduction was relatively small. That means we should think of omega-3 supplementation as part of a holistic approach to reducing our health disease risk. It is just one piece of the puzzle.

With that in mind, here is what the American Heart Association recommends for reducing your risk of heart disease:

If you smoke, stop.

Choose good nutrition.

- Choose a diet that emphasizes vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, nontropical vegetable oils, and nuts.

- Choose a diet that limits sweets, sugar-sweetened beverages, and red meats.

Reduce high blood cholesterol and triglycerides.

- Reduce your intake of saturated fat, trans fat and cholesterol and get moving.

- If diet and physical activity don’t get those numbers under control, then medication may be the next step.

Lower High Blood Pressure.

Be physically active every day.

- Aim for at least 150 minutes per week of moderate-intensity physical activity per week.

Aim for a healthy weight.

Manage diabetes.

Reduce stress.

Limit alcohol.

Add in omega-3 supplementation to these recommendations and you have a winning combination.

The Bottom Line

Two major studies have recently been published on the relationship between omega 3 supplementation and heart disease. I felt it was important to evaluate these studies together because:

They are both very large, well designed studies.

They approached the relationship between omega 3 supplementation and heart disease risk in very different ways but came to the same conclusion.

They complemented each other. The weaknesses of one study were the strengths of the other study.

These studies showed that omega 3 supplementation:

Reduced heart attacks by 12-20%.

Reduced overall heart disease risk by 7%.

Reduced deaths from heart disease by 8-16%.

Reduced deaths from all causes by 13%

While these studies did not provide information on the optimal omega 3 dose, a previous study concluded that an omega-3 intake of 835 mg/day or higher is needed to achieve clinically meaningful reductions in heart disease risk.

For more details and the American Heart Association recommendations on what else you can do to reduce your risk of heart disease, 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.