August 11, 2020

Findings from an updated meta-analysis published in the October 2020 issue of Pharmacological Research support a protective effect for supplementing with omega-3 polyunsaturated fatty acids (PUFA) against heart disease mortality, major adverse cardiovascular events and myocardial infarction (heart attack).

For their analysis, researchers selected 16 randomized, controlled trials that examined the effects of omega 3 fatty acid supplementation among a total of 81,073 participants. Trials were limited to those that included subjects at high cardiovascular risk and/or who had previous cardiovascular events. “The objective of our study was to perform a meta-analysis of all the available randomized controlled trials on cardiovascular secondary prevention and patients at high (and very high) cardiovascular risk to investigate the cardiovascular preventive effect of omega 3 fatty acid administration through supplements (no dietary counselling), with a focus on the role of dose and type of omega 3 PUFA administered, as well as its effects in populations with different cardiovascular risk at baseline,” authors Manuela Casula of the University of Milan and colleagues explained.

During the trials’ follow-up periods, which ranged from one to seven years, the intake of more than one gram per day of omega 3 was associated with a 35% lower risk of dying from cardiovascular causes, a 24% lower risk of experiencing major adverse cardiovascular events and a 33% lower risk of myocardial infarction. Further analysis revealed that a reduction in the risk of cardiac death or myocardial infarction occurred only among trials that included participants who had already experienced major adverse cardiovascular events. Interestingly, a combination of the omega 3 fatty acids eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) was more effective than the use of EPA alone to reduce the risk of dying from cardiac conditions; however, EPA alone, which was evaluated in three trials, appeared to have a greater association with the reduction in the occurrence of major cardiovascular events.

The authors of the report remark that the intake of one to two meals containing oily fish per week for general health as recommended by world health authorities provides only 250 to 500 milligrams per day of EPA plus DHA, and that an intake of omega 3 fatty acids well above this amount has been associated with a reduction in cardiac mortality among healthy individuals, as well as those with pre-existing cardiovascular disease.

“Stratified analyses based on levels of omega 3 PUFA above and below one gram per day highlight a relevant clinical benefit of the supplementation of omega 3 on coronary heart disease outcomes only when administered at high doses,” they observed. “Only the administration of more than one gram per day of omega 3 PUFA seems to be effective in reducing the risk of cardiac death, major adverse cardiac events and myocardial infarction.”