A meta-analysis published online late yesterday by the Archives of Internal Medicine has been panned as “limited” and “inaccurate” by industry trade associations. The study, titled “Efficacy of Omega-3 Fatty Acid Supplements (Eicosapentaenoic Acid and Docosahexaenoic Acid) in the Secondary Prevention of Cardiovascular Disease” suggested there is insufficient evidence to prove that omega-3 fatty acid supplements offer secondary prevention of cardiovascular events in patients with heart disease. 

The Natural Products Association (NPA) and the Council for Responsible Nutrition (CRN) each took issue with the study.
 
In comments issued via press release, Dr. Cara Welch, NPA’s vice president of scientific and regulatory affairs, pointed to the “wealth of evidence” that demonstrated omega-3’s benefits on cardiovascular disease. “This conclusion is not one that the scientific community has rushed to make. Rather, it is based on epidemiological and observational studies as well as clinical trials looking at a variety of cardiovascular disease outcomes,” she said, and pointed to two large trials that were not included in the AIM meta-analysis which documented the benefits of fish oil supplementation. “The GISSI-Prevenzione trial and the Japan EPA Lipid Intervention Study demonstrated that omega-3 supplements reduced the risk of death, nonfatal myocardial infarction, and nonfatal stroke, as well as major coronary events. A third trial, the GISSI-Heart Failure trial, found that fish oil supplementation reduced fatal cardiovascular disease,” she said  
 
Dr. Welch also cited the American Heart Association’s recommendation of a diet high in omega-3s. “The authors of this study concede that their analysis is limited, especially in that they only analyzed trials with small populations and short durations. Combining these limited trials does not give an accurate picture of omega-3 fatty acids,” she said. “We strongly believe that this meta-analysis is an inaccurate depiction of the benefits of omega-3 on cardiovascular health. Research on omega-3s will continue, as well as meta-analyses of published research, but for now, a diet high in omega-3s should continue to be recommended for all Americans.”  
 
Like Dr. Welch, Taylor Wallace, Ph.D., senior director, scientific and regulatory affairs, CRN, zeroed in on the study’s limited scope. “Physicians and consumers should not be swayed by the results of this meta-analysis as it conflicts with the totality of scientific evidence which finds benefit for omega-3 EPA and DHA for heart health,” he said. “Further, this meta-analysis cherry-picked 14 randomized clinical trials (RCTs), most of which were small, short-term studies (less than one year of follow-up), leaving out other RCTs of longer length and greater relevance, all observational studies, and three[1]-3 well-respected systematic reviews designed to look specifically at CVD outcomes.”
 
He went on to point out that study’s guest commentary paid homage to the extensive study of omega-3s and the accompanying body of evidence showing the potential benefits of fish oil in cardiovascular health. “The commentary authors note the fact that the authors of the meta-analysis left out two large studies that could have altered their conclusion,” he said. “While we agree with the guest commentary that people should eat a diet high in fatty fish, the reality is that people are simply not doing this and should have other options for obtaining omega-3s.
 
“The irony is that the guest commentators advise physicians that while waiting for more ‘…conclusive evidence to recommend fish oil supplements for primary or secondary prevention of CVD’ they are quick to suggest fatty fish, which has no more (and some may say less) conclusive evidence than fish oil supplements in this area,” he continued. “Fish oil supplements are an affordable, convenient way to get omega-3 fatty acids, and CRN suggests that the evidence is strong enough for physicians to suggest the option of fish oil supplements, while still recommending the benefits of salmon, sardines and other fatty fish.” 
 
Dr. Wallace concluded by saying that although scientific research often opens doors to new discoveries, “one research team’s analysis of a subset of the available evidence does not discount previous study results, analysis, and recommendations made by authoritative scientific bodies such as the American Heart Association.”
 
The AIM omega-3 meta-analysis, he said, should be “looked at as a piece of the evidence—and given its flaws, not necessarily a very good one—certainly not one on which physicians—or consumers—should change their mind with regard to fish oil supplements.”