Researchers have found no statistically significant association between omega-3 fatty acid supplementation and decreased risk for major cardiovascular disease events, despite receiving FDA approval for lowering triglycerides in patients with overt hypertriglyceridemia.
“Our findings to do not justify the use of omega-3 as a structured intervention in every day clinical practice or guidelines supporting dietary omega-3 PUFA administration,” the researchers wrote.
Using MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials up to August 2012, Evangelos C. Rizos, MD, PhD, from the University Hospital of Ioannina, Greece and colleagues extracted data, assessed methodological quality and conducted main, subgroup and statistical analyses. Trials were only eligible if they were randomized, controlled using another diet or placebo, and utilized in primary or secondary cardiovascular disease (CVD) prevention settings, the researchers wrote.
Twenty studies; some of which were published as early as 1989, included 68,680 patients. According to data, 7,044 deaths, 3,993 cardiac deaths, 1,150 sudden deaths, 1,837 MIs, and 1,490 strokes were recorded.
Within the studies, the mean omega-3 polyunsaturated fatty acids (PUFAs) dose was 1.51 g per day, and others used 1 g or greater per day, with the exception of two trials where the dose was based on dietary counseling, (with a median treatment of 2 years), the researchers wrote.
Seventeen studies were included for all-cause mortality, which reported that 6,295 events were recorded among 63,279 patients. Overall, the researchers found that omega-3 PUFA supplements were not statistically significantly linked to a reduced all-cause mortality (RR=0.96; 95% CI, 0.91-1.02; P=.17).
From 13 studies, researchers found there were 3,480 cardiac deaths among 56,407 patients. After a correction for multiple comparisons, no statistically significant reduced risk was found (RR=0.91; 95% CI, 0.85-0.98).
Further data showed seven studies which recorded 1,031 sudden death events among 41,751 patients. Again, omega-3 supplementation was not statistically significant in reducing this outcome (RR=0.87; 95% CI, 0.75-1.01), the researchers wrote.
For the outcome of MI, 13 studies were included, which accounted for 1,755 events among 53,875 patients. No evidence found omega-3 supplementation to reduce this risk (RR=0.89; 95% CI, 0.76-1.04), researchers wrote. And for the nine studies examining the instance of stroke, there were 1,490 events out of 52,589 patients; showing once more there was no evidence of reduction in risk.
Although omega-3 supplements were not significantly linked to these outcomes, researchers wrote that individualized patient data meta-analysis would be an appropriate measure in refining associations related to dose, adherence, baseline intake and CVD risk groups.
Disclosure: Elisaf reported having given talks, attended conferences, and participated in trials sponsored by industry not associated with those that manufacture or market omega-3 supplements. Bika, Kostapanos, Ntzani and Rizos report no relevant financial disclosures.