BOSTON – Higher exposure to alpha-linolenic acid (ALA), an omega-3 fatty acid found in walnuts and flaxseed, was associated with a moderately lower risk of cardiovascular disease, according to a meta-analysis that appeared on-line Oct. 17 in The American Journal of Clinical Nutrition.
The study involved researchers from the Harvard School of Public Health, the National University of Singapore, the University of Cambridge in the United Kingdom and the University of Western Australia in Perth, Australia. They identified 27 original studies, including 251,049 people and 15,327 cardiovascular disease events. The association between ALA and reduced cardiovascular disease risk was significant in 13 comparisons that used dietary ALA as the exposure.
An unrestricted educational grant from the California Walnut Commission, Folsom, Calif., supported the meta-analysis as did two grants from the National Institutes of Health.
The Food and Drug Administration has a qualified health claim for two other kinds of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), but not for ALA. The F.D.A. has a qualified health claim for walnuts that states, “Supportive but not conclusive research shows that eating 1.5 oz of walnuts per day, as part of a low saturated fat and low cholesterol diet, and not resulting in increased caloric intake may reduce the risk of coronary heart disease.”