Japan's Heart-Healthy Diet: Fish Is Key
Study Shows High Omega-3 Levels in Japanese Diet Cuts Heart Disease Rates
The 'Omega-3 Hypothesis'
In an editorial accompanying the study, Harris writes that what he calls the "omega-3 hypothesis" grew from research on the Inuit Eskimos of Greenland conducted almost four decades ago.
Despite eating a diet low in fruits, vegetables, and complex carbohydrates and high in fat and cholesterol, the Eskimos had very low rates of heart disease. Researchers concluded that the reason was the incredibly high levels of omega-3 in their diets from the consumption of large amounts of fish, whale, and seal.
But recent studies suggest that heart disease rates among Alaskan Eskimos are now higher than among whites in the U.S., even though fish consumption in the population remains high.
"At least part of the problem in Alaska appears to be not a lack of omega-3 but the introduction of massive amounts of shortenings and other saturated fats into their Westernizing diet," Harris writes.
He concludes this and other research suggest that the "cardioprotective punch of the long-chain omega-3 fatty acids may be no match for diets high in fat, particularly saturated fat."
Cardiologist Robert Eckel, MD, who is a past president of the American Heart Association, says studies in heart attack patients treated with very high doses of omega-3 have generally proven disappointing.
Eckel is a professor of medicine at the University of Colorado Denver School of Medicine.
"We have known for some time that people who eat more fish seem to have less heart disease," Eckel tells WebMD. "This study supports that, but more research is needed."