To the Editor.
—The study by Dr Siscovick and colleagues1 shows that increased levels of n-3 polyunsaturated fatty acids (PUFAs) are associated with reduced risk of cardiac arrest. Unfortunately, the authors misstate the sources of n-3 PUFAs. Contrary to popular belief, fish is not the primary dietary source of the long-chain n-3 PUFAs eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3). The approximate percentage of total fat as n-3s from samples of common foods (which depend on growing methods, processing, and geographic location) I analyzed are as follows: egg yolk, 1% to 4%; fresh liquid lecithin, 7%; chicken thighs, 3% to 4%; tofu, 7%; soybean oil, 7%; flax oil, 54%; and wheat grass, 53%. Other sources of n-3 include soybeans, flax seeds, canola oil, foods cooked with canola or soybean oil, and green vegetables. Vegetarians and many other people get most of their n-3 PUFAs from
Siguel EN. Dietary Sources of Long-Chain n-3 Polyunsaturated Fatty Acids. JAMA. 1996;275(11):836. doi:10.1001/jama.1996.03530350018016