Duffy MacKay N.D., vice president, scientific and regulatory affairs, CRN, argued that the study did not change the current recommendations by authoritative bodies such as the World Health Organization, American Heart Association and the U.S. National Academies of Science, and advised consumers not to discount the “proven benefits of omega-3 fatty acids. “There is extensive scientific evidence demonstrating the importance of omega-3 fats during pregnancy/lactation, breastfeeding and childhood,” he said. “Furthermore, omega-3 fats have a role in maintaining the health of adults as well as in the prevention of age-related chronic diseases (e.g., cardiovascular disease and cognitive decline).”
Mr. MacKay went on to add that he was worried that the study’s results would be taken out of context. “The attraction of doing a meta-analysis is to combine comparable smaller clinical studies to assess whether similarities in the combined results exist,” he said. “The problem is that this meta-analysis combined studies that were not comparable in their design (e.g., studies on healthy individuals were combined with those targeting diseased individuals), which makes the results more skew.
“Second, omega-3 fatty acids are vital nutrients and not drugs,” he continued. “Many of the studies included in the meta-analysis were conducted on diseased individuals already undergoing treatment with one or more drugs (e.g., statins), which may mask the less potent and more long-term effects of omega-3 fats.”
Mr. MacKay also questioned the why the researchers apparently did not examine whether or not study subjects had sufficient dietary intake of omega-3 fats. “Without that information, they could not have controlled for this variable,” he said. “In this regard, studies on drugs are far simpler than those of nutrients (the treatment group gets the drug and the placebo group does not); with nutrients, if participants in the control group already have a diet sufficient in that substance, then it will be that much harder to demonstrate any benefit among the treatment participants. It is impossible for five researchers to control the diet of almost 70,000 patients over several years (particularly as a retrospective meta-analysis), as omega-3 fats are widespread throughout a variety of foods.”
In conclusion, he said, consumers should not be swayed by these results. “While people should be eating a diet high in fatty fish which contain these nutrients, the reality is that people are simply not doing this. Omega-3 supplements serve as an affordable, convenient and safe way to obtain omega-3 fatty acids and the array of health benefits they offer.”
The Global Organization for EPA and DHA (GOED) also issued a statement disputing the meta-analysis. "Given the flawed design of this meta-analysis, bypassing the advice of the American Heart Association or the 2010 Dietary Guidelines for Americans by stating that omega-3s are not cardioprotective, could be harmful to public health," said Adam Ismail, GOED executive director. “GOED disputes the findings and urges consumers to continue taking omega-3 products if they are concerned about their heart.”
This meta-analysis looked at people who have already suffered heart attacks or strokes rather than the general healthy population, and like some other recent studies, failed to account for the effect of cardiovascular disease medications consumed by subjects in the studies analyzed. Harry B. Rice, PhD, vice president-regulatory and scientific affairs for GOED, commented, "Consider that cardiac patients today are prescribed multiple cardio drugs (such as cardiac glycosides, antiarrhythmics, antihypertensives, hypolipidemics, antianginals, anticoagulants, beta-blockers, calcium channel blockers, diuretics and/or vasodilators). There is a significant challenge in trying to determine if omega-3s can reduce cardiovascular disease risks if you are already giving patients a handful of other drugs that contribute to achieving that objective.
"We know from the studies that have shown a benefit that future research in this area should only analyze studies that do not include confounding medications, are longer than two years in duration, and use dosages greater than 1-2 grams of omega-3s per day," Dr. Rice continued. "Very few of the studies included in this meta-analysis met these criteria."
GOED said it’s important for doctors and consumers to understand that the totality of the scientific evidence justifies the use of omega-3s for both people with diagnosed cardiovascular disease and those trying to prevent cardiovascular disease. Researchers from Harvard University have estimated that 84,000 deaths a year could be prevented by adequate omega-3 consumption and governments and scientific groups around the world have established minimum recommended intakes based on this evidence.
Loren Israelsen, executive director, United Natural Products Alliance fully agreed with GOED's analysis of the major problems with the meta-analysis, specifically that studies involving heart attack or stroke patients were confounded by current cardiovascular treatment plans which include multiple medications to control heart beat, heart rate, blood pressure, vasodilation, etc.
"In order to understand the contribution of Omega-3s to cardiovascular health in that patient population, you must take into account the effects of those medications," he said. "The average consumer will not understand this critical distinction and may be discouraged from continuing Omega-3 consumption, both through consumption of fish or use of supplements. It is disheartening (literally) that a meta-analysis of this sort and subsequent media news surrounding it would fail to provide the essential background story so that the public is able to make informed and smart choices with respect to their heart health."