Published yesterday in JAMA, data from 70,000 patients indicated that supplementation with omega-3 polyunsaturated fatty acids was not associated with a lower risk of cardiac death, sudden death, heart attack, or stroke.
“Our findings do not justify the use of omega-3 as a structured intervention in everyday clinical practice or guidelines supporting dietary omega-3 PUFA administration,” concluded researchers from the University Hospital of Ioannina in Greece.
Reaction
The conclusions were disputed by Adam Ismail, GOED executive director: "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.
“GOED disputes the findings and urges consumers to continue taking omega-3 products if they are concerned about their heart.”
Ismail added that researchers from Harvard University have estimated that 84,000 deaths a year could be prevented by adequate omega-3 consumption.
The heart health benefits of fish oil, and the omega-3 fatty acids it contains, are well-documented, being first reported in the early 1970s by Dr Jorn Dyerberg and his co-workers in The Lancet and The American Journal of Clinical Nutrition.
To date, the polyunsaturated fatty acids (PUFAs) have been linked to improvements in blood lipid levels, a reduced tendency of thrombosis, blood pressure and heart rate improvements, and improved vascular function.
Confounders
Harry Rice, PhD, VP of regulatory and scientific affairs for GOED, told NutraIngredients-USA that the authors failed to note that, with the passage of time, more and more cardio drugs have come onto the market and as a result a greater number of cardio patients are maintained on drug cocktails that include a greater number of drugs, making it difficult to demonstrate a cardiovascular benefit of yet one more substance (i.e. omega-3s).
"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," he said. "Very few of the studies included in this meta-analysis met these criteria."
Meta-analysis
The Greece-based researchers analyzed data from 68,680 patients. The mean daily dose of omega-3 was 1.51 grams, with a mean EPA and DHA dose of 0.77 and 0.6 grams per day.
Analysis of the 7,044 deaths, 3,993 cardiac deaths, 1,150 sudden deaths, 1,837 heart attacks, and 1,490 strokes indicated that there were no statistically significant associations cardiovascular events or death.
“Randomized evidence will continue to accumulate in the field, yet an individual patient data meta-analysis would be more appropriate to refine possible associations related to, among others, dose, adherence, baseline intake, and cardiovascular disease risk group,” concluded the authors.
Recommendations
Duffy MacKay, ND, vice president, scientific and regulatory affairs for the Council for Responsible Nutrition (CRN) added that 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.
“Along these lines, the researchers apparently did not examine within each individual study included in the meta-analysis whether individuals in the placebo group were sufficient or insufficient in their dietary intake omega-3 fats. Without that information, they could not have controlled for this variable.”
“Consumers should not be swayed by these results,” said Dr MacKay. “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.”
Source: JAMA
Volume 308, Number 10, Pages 1024-1033
“Association Between Omega-3 Fatty Acid Supplementation and Risk of Major Cardiovascular Disease Events - A Systematic Review and Meta-analysis”
Authors: E.C. Rizos, E.E. Ntzani, E. Bika, M.S. Kostapanos, M.S. Elisaf