Title: Association Between Omega-3 Fatty Acid Supplementation and Risk of Major Cardiovascular Disease Events: A Systematic Review and Meta-Analysis
Date Posted: September 11, 2012
Authors: Rizos EC, Ntzani EE, Bika E, Kostapanos MS, Elisaf MS.
Citation: JAMA 2012;308:1024-1033. [JAMA abstract]
What is the effect of omega-3 fatty acid supplementation on major cardiovascular outcomes?
A systematic review and meta-analysis
was conducted using MEDLINE, EMBASE, and the Cochrane Central Register
of Controlled Trials through August 2012. Criteria for inclusion
included randomized controlled clinical trials evaluating the effect of
omega-3 on all-cause mortality, cardiac death, sudden death, myocardial
infarction, and stroke. Subgroup analyses were performed for the
presence of blinding, and whether primary or secondary prevention.
Meta-regression analyses were performed for the omega-3 dose. A
statistical significance threshold of 0.0063 was assumed after
adjustment for multiple comparisons.
Of the 3,635 citations retrieved, 20
studies of 68,680 patients were included, reporting 7,044 deaths, 3,993
cardiac deaths, 1,150 sudden deaths, 1,837 myocardial infarctions, and
1,490 strokes. No statistically significant association was observed
with all-cause mortality, cardiac death, sudden death, myocardial
infarction, and stroke when all supplement studies were considered.
Overall, omega-3 polyunsaturated
fatty acid supplementation was not associated with a lower risk of
all-cause mortality, cardiac death, sudden death, myocardial infarction,
or stroke based on relative and absolute measures of association.
Among the known and putative
benefits of dietary and supplemental omega-3 PUFAs include their ability
to lower triglyceride levels (at the expense of raising low-density
lipoprotein cholesterol), prevent atrial fibrillation and sudden death,
decrease platelet aggregation, lower blood pressure, reduce depression,
and improve cognitive function. The inability to demonstrate a clear
benefit despite the large clinical trials is similar to the anti-oxidant
vitamin supplements. Despite the attempts to neutralize differences in
study designs, a neutral meta-analysis does not establish lack of
benefit, albeit it blunts the enthusiasm. Among the concerns drawing
conclusions from this report are that of the 20 studies included, only
eight had 3 or more years of follow-up and four included primary and
secondary prevention. Would anyone accept this design in a statin or
Melvyn Rubenfire, M.D., F.A.C.C. (Disclosure)
Prevention/Vascular, General Cardiology
© 2012 American College of Cardiology Foundation