Omega-3 fatty acids are frequently in the news for their proposed myriad health benefits—everything from reducing risk of heart disease and cancer to alleviating symptoms of arthritis. The two omega-3 fatty acids most often mentioned are EPA and DHA, which are found in certain types of fatty fish. A third omega-3 fat, alpha-linolenic acid (ALA), makes the news much less frequently, but is, in fact, the omega-3 fatty acid that is actually an essential nutrient. That is, it’s the only one of the omega-3 fats that is required in the diet. EPA and DHA are not considered essential since humans can make them from ALA. Soybean oil is the major source of ALA in American diets.
While much research has focused on heart healthy benefits of DHA and EPA, a new study from the Harvard Medical School, provides support for the coronary benefits of ALA.
Led by Dr. An Pan, the research team conducted an analysis involving 27 studies that included 251,049 subjects and 15,327 cardiovascular disease events, such as heart attacks. Results showed that greater intake of ALA, as determined by dietary intake or blood ALA levels, was associated with a 14% reduction in risk. Furthermore, each 1 gram per day increment of ALA intake was associated with a 10% lower risk of coronary heart disease death. An easy way to increase ALA is to eat soyfoods. Just two servings of full-fat soyfoods can provide as much as one gram of ALA. Soyfoods can help to reduce heart disease risk in other ways, as well. As recognized by the US Food and Drug Administration, soy protein directly lowers blood cholesterol levels.
Pan A, Chen M, Chowdhury R, et al. alpha-Linolenic acid and risk of cardiovascular disease: a systematic review and meta-analysis. Am J Clin Nutr 96:1262-73, 2012.