Is it worth spending money on omega-3 supplements?

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

This is one of the most difficult questions in modern evidence-based medicine.

What we know about omega-3

Omega-3 fatty acids are one of the pillars of modern healthy eating.

The usefulness of these compounds has long been beyond doubt: they reduce blood pressure and the risk of heart disease, including heart attacks, normalize metabolism, and fight “bad” cholesterol. In general, they are simply irreplaceable.

And literally. These fatty acids are not synthesized by Omega-3 Fatty Acids by the body on its own. Therefore, it is important to get them from the outside - with food or in the form of dietary supplements.

In such an irreplaceable status, omega-3 acids have taken root in the diet and have even been introduced. A fish a day, keeps the cardiologist away! - A review of the effect of omega-3 fatty acids in the cardiovascular system into international medical guidelines for the prevention and treatment of cardiovascular diseases. There have been dozens of studies supporting the benefits of these fatty acids.

However, it turned out that the research may not be all that accurate. And omega-3 suddenly became a kind of bifurcation point on which all evidence-based medicine stumbled.

What happened to omega-3

It's simple: scientists decided to double-check the results of previous scientific works. For this, the so-called meta-analyzes were carried out - this is when experts take at once a lot of studies related to one topic, and compare their methodology and results. The goal is to eliminate all extraneous factors that could sneak into the original work and influence their conclusions, and to derive some general statistics.

A small digression on how external factors can distort the research results. Many of the studies supporting the cardiovascular benefits of omega-3 have been observational. So, scientists noticed that representatives of the "fish" communities, for example, the Greenlandic Eskimos have a Historical overview of n-3 fatty acids and coronary heart disease. or a number of ethnic groups of Quebec Fish consumption and blood lipids in three ethnic groups of Québec (Canada)., the incidence of heart disease is lower and life expectancy is higher than the human average. The diet of these communities, as is clear from the definition, is based on oily marine fish. Therefore, the researchers suggested that it was all about the omega-3 acids contained in fish. Other possible reasons - the same healthier and more mobile lifestyle that representatives of such communities lead, the absence of bad habits, or just a good environment - were simply discounted.

From 2012 to 2018, the results of at least four such meta-analyzes of Efficacy of Omega-3 Fatty Acid Supplements (Eicosapentaenoic Acid and Docosahexaenoic Acid) in the Secondary Prevention of Cardiovascular Disease, Association between fish consumption, long chain omega 3 fatty acids, and risk were published of cerebrovascular disease: systematic review and meta-analysis, Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk, Associations of Omega-3 Fatty Acid Supplement Use With Cardiovascular Disease Risks. In all cases, the authors came to the same conclusion.

Omega-3 intake does not (or only slightly) affect the health of the cardiovascular system and does not reduce the risk of stroke and myocardial infarction.

The largest meta-analysis on this topic was published by Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease in 2018 on the website of the international research organization Cochrane. It enrolled 79 randomized controlled trials with a total of 112,059 volunteers. Such works are the basis, the gold standard of modern evidence-based medicine. They rule out any overlap. Situations when in one group everyone eats fish and leads an active lifestyle (as in the "fish" communities), and in the other - entirely residents of nervous gas-polluted megacities are impossible. All categories of people - and active, and nervous, and smokers, and fish lovers - are divided into control groups approximately equally.

This review confirmed the findings of previous meta-analyzes that omega-3 fatty acids do not prolong life and do not improve the health of the heart and blood vessels, as previously assumed.

How Omega-3 Triggered the Evidence-Based Medicine Crisis

It should be noted here: Cochrane is so authoritative that WHO is also guided by its data. Therefore, the publication had the effect of an exploding bomb. Scientists from large research centers began their own double-check. And there was a medical scandal.

In 2019, Marine Omega-3 Supplementation and Cardiovascular Disease: An Updated Meta-Analysis of 13 Randomized Controlled Trials Involving 127 477 Participants was released from the Harvard Medical School meta-analysis. 13 randomized controlled trials, over 127 thousand participants. And the result: omega-3 dietary supplements of marine (that is, from oily sea fish) origin still reduce the risk of developing myocardial infarction, coronary heart disease and death from any other cardiovascular problems.

This was followed by a meta-analysis of Effect of Omega-3 Dosage on Cardiovascular Outcomes conducted by experts from the American medical organization Mayo Clinic. 40 randomized controlled trials, involving over 135 thousand people. Once again, a finding that contradicts the Cochrane data is that omega-3 supplements reduce the risk of cardiovascular disease. Moreover, the higher the daily dose that the study participants received, the more pronounced the effect was. The meta-analysis looked at dosages of up to 5,500 mg of omega-3 per day.

Russian researchers have gone so far as to call the Cochrane publication On Repression of ω -3 Polyunsaturated Fatty Acids by Evidence-Based Medicine Adherents "repression" of omega-3 polyunsaturated fatty acids. And at the same time - a vivid example of the crisis in modern evidence-based medicine.

Why the results are inconsistent and who is right after all

This is a complex issue that requires additional in-depth study.

It is very possible that one of the parties again did not take into account all the factors and came to the wrong conclusions. This version is quite reasonable, for example, for the meta-analysis of Harvard Medical School.

The inclusion of some studies in the Harvard Review of Marine Omega-3 Supplementation and Cardiovascular Disease: An Updated Meta-Analysis of 13 Randomized Controlled Trials Involving 127 477 Participants was not entirely correct. They (for example, in the large study VITAL Marine n − 3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer) involved only people over 50 years old - the average age of the volunteers was 67.1 years. Or (in another large study, ASCEND Effects of n − 3 Fatty Acid Supplements in Diabetes Mellitus) - only people with diabetes, including those who used additional drugs to control the underlying disease. In both cases, the participants took only prescription omega-3 preparations with a precisely adjusted dosage of 840 mg of omega-3 marine fatty acids.

This selectivity in the selection of participants and drugs may have influenced the results of the meta-analysis. For example, maybe omega-3 supplements play a role in people taking diabetes medications. But this does not mean at all that for the rest, such supplements are not dummies.

So drink or not drink omega-3 supplements

The most authoritative Cochrane continues to insist on its own. On the official website of the organization, despite the published meta-analyzes from Harvard and the Mayo Clinic, the Scientific expert reaction to Cochrane Review on omega-3 fatty acids is still available, an article with the reaction of the world's largest experts to the news that omega-3 acids turned out to be a dummy. Some of the quotes are impressive.

Tim Chico Professor of Cardiovascular Medicine and Emeritus Consultant Cardiologist at the University of Sheffield (UK)

Omega-3 supplements cost quite a lot. My advice to anyone who buys them in the hopes of reducing the risk of heart disease: Better spend your money on vegetables.

In addition, even if you disbelieve Cochrane and side with Harvard Medical School and others like them, another controversial issue arises. The lion's share of the evidence in the conclusion about the benefits of omega-3 is based on the use of prescription drugs, not conventional dietary supplements. Omega-3 Fatty Acids, on the other hand, can differ significantly from drugs in composition and have a much lesser effect.

American Heart Association warns Omega-3 Fatty Acids for the Management of Hypertriglyceridemia: A Science Advisory From the American Heart Association: Omega-3 supplements should not be used in place of prescription drugs.

However, you shouldn't write off omega-3 fatty acids.

First, the current scientific debate concerns only the link between omega-3 and cardiovascular health. Other potential health benefits of the 17 Science-Based Benefits of Omega-3 Fatty Acids of these fatty acids have not been studied as extensively.

Today it is believed that taking omega-3s relieves depression, reduces the risk of mental disorders, fights inflammation and autoimmune diseases. Perhaps it is so. Until proven otherwise.

Secondly, it is normal for the emergence of new data to force physicians to revise old recommendations. And even if scientists have not agreed yet, no one will forbid you to take omega-3, even if not in the form of dietary supplements with dubious value, but, for example, in the form of fatty sea fish.

Moreover, you do not need a lot of fish: to get a dose of omega-3, which is considered healthy, one serving of Fish and shellfish (about 140 g) per week is enough.

This content was last updated on March 31, 2021.