In 1944, towards the end of World War II, Dr. Hugh Sinclair, a young graduate of Oxford, was stationed in northern Canada among the Inuit. Doing eye exams, he observed that the Inuit did not have cholesterol deposits in their retinas that most of the British airmen had. This was surprising to him, since the Inuit diet consisted mostly of coldwater marine life, namely fish, seal, and whale, which are very high in fat.
In 1976 Dr. Sinclair teamed up with two Danish scientists, Dr. Jorn Dyerberg and Dr. Hans Olov Bang, in an expedition by dogsled to North Western Greenland. They found that the Greenland Inuit had very low rates of heart disease despite high fat intakes. This work was the foundation of research that showed that while some fats—saturated fats—cause heart disease, other fats—omega-3 fatty acids—prevent heart disease.
There are basically 3 different omega-3 fatty acids that people eat. They are called alpha-linolenic acid, EPA*, and DHA†. Most alpha-linolenic acid in the American diet comes from vegetable oils, especially canola oil and soybean oil. Most EPA and DHA come from fish.
Both the plant-derived omega-3 fatty acids (alpha-linolenic acid) and the marine-derived omega-3 fatty acids (EPA and DHA) reduce the risk of heart disease. The amount of omega-3 fatty acids in different foods in listed in the tables below.
Realize that fatty fish has more omega-3 fatty acids than lean fish. Yes, fatty fish has a higher caloric density than lean fish, but even fatty fish has a relatively low caloric density and will help you lose weight.
Avoid fried fish, since the frying process changes the fatty acids in fish. Fried fish are high in unhealthy trans-fats and low in healthy omega-3 fatty acids.
*Short for eicosapentaenoic acid.
†Short for docosahexanenoic acid.
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