Omega-3 fatty acids and cardiovascular protection
| Author : Pierre Allain
||Date : 2010-10-25
The Lancet August 14, 2010 published a review from 106 bibliographical references concerning the cardiovascular effects of omega-3 fatty acids, eicosapentaenoic acid, EPA, and docosahexaenoic acid, DHA. Omega-3 fatty acids are regarded as having beneficial effects and their intake from food (fish for example) or supplementation is recommended. However, according to this review, the benefits of omega-3 fatty acids appear rather modest: beside studies showing of very favourable effects, others did not obtain convincing results, especially regarding cardiac rhythm disorders and sudden death.
The NEJM published "online first" in August 2010 the results of a clinical study comparing in people from 60 to 80 years having as case history a myocardial infarction, the effects of a supply of omega-3 fatty acids for 40 months, according to the 4 following conditions: − 400 mg of EPA plus DHA, −2 g of alpha-linoleic acid, ALA, − EPA, DHA and ALA, and margarine taken as reference. The supplementation in EPA + DHA or ALA did not modify in a statistically significant way the occurrence of cardiovascular events nor overall mortality of these patients having had a myocardial infarction and for most treated by antihypertensives, statins and antithrombotic agents. According to this study, the supplementation with EPA and DHA or ALA does not seem to give a significant benefit to people already treated in a conventional way.
These discordant results call the following remarks: − the "doses" of fatty acids used in supplementation differ according to the trials, − dietary supply is variable and difficult to quantify, − the eating habits of a population are difficult to quantify and change over time, influenced by advertising, − in parallel the use of drugs likely to reduce the cardiovascular risks is current.