Dietary supplements rich in omega-3 fatty acids do not have major activity against atherosclerosis and cardiovascular risk, according to a new study.
In a new study, published in the journal JAMA Cardiology, the researchers analyzed data from 10 clinical trials totaling 77,917 patients who had had a heart attack or stroke or other health problems such as diabetes. Most of the patients had been drawn at random to take either supplementation with omega-3 fatty acids or a placebo for at least a year.
The analysis of these studies does not show any significant beneficial effect of omega-3 fatty acid supplementation with respect to the prevention of complications of cardiovascular diseases in general or with respect to a subtype of cardiovascular disease or a subset of patients.
No obvious benefit
Overall, participants were on average 64 years old at entry into the trials and were followed for an average of 4.4 years. Most of the trials in this review involved different doses and combinations of two omega-3 acids: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which were taken for one to six years.
During follow-up, 2,695 people (3.5%) died of heart disease, 2,276 (2.9%) had a non-fatal heart attack, 1,713 (2.2%) had stroke, and 6,603 (8.5%) were treated with angioplasty to re-open the blocked arteries.
Although taking omega-3 supplements appeared to be associated with a slightly lower risk of death from heart disease, non-fatal infarctions, and coronary heart disease, the differences between the supplemented and non-supplemented groups for all of these events were too small to rule out the possibility. that they are due to chance.
To eat or not to eat omega-3s
The American Heart Association recommends eating at least two servings of fish per week or considering omega-3 fatty acid supplementation when this is not possible.
Previous studies had linked omega-3 intake to a reduced risk of heart rhythm disturbances, high cholesterol, atherosclerosis and high blood pressure. In this study, the risks are therefore the same whether people take omega-3 fatty acid supplements or not and it does not support the current recommendations of the American Heart Association.
One limitation of this new study, however, is the great heterogeneity of the types of studies analyzed and the little data available on the factors that can modify the cardiovascular risk: smoking, associated diseases and especially intercurrent treatments.
In particular, the absence of data on the treatments taken by patients is very troublesome because it is clear that if the effect of omega-3 acids is modest, it will be completely invisible in the event of association with the intake of very effective drugs such as statins or antihypertensives.
In the end, although in this study, the evidence is lacking to claim that omega-3 fatty acid supplementation protects against cardiovascular disease, these are inexpensive, without serious side effects and may have other health benefits. (memory, cognition…). They can therefore be used as an adjunct to cardiovascular treatments.
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