Omega-3 Fatty Acids May Explain the 'Japanese Paradox' Regarding Low Rates of Heart Disease

Why is it that Japanese men have half the mortality from heart disease as American Caucasian men in spite of smoking and having high cholesterol, diabetes and hypertension? The September 2008 Fats of Life and PUFA Newsletter electronic publications suggest why, summarizing new research about long-chain omega-3 fatty acids.

When Japanese men migrate to America, they develop atherosclerosis as readily or more so than their Caucasian compatriots, according to a recent study. The reason is likely dietary.

"This study suggests that the long-term habit of eating plenty of fish rich in long-chain omega-3s tends to counteract the development of atherosclerosis," said Editor Joyce Nettleton, D.Sc. "The findings are consistent with other evidence that the consumption of long-chain omega-3s is associated with having less carotid artery plaque and low incidence of nonfatal heart events among the Japanese."

Another paradox is why mothers who eat plenty of fish, and have higher levels of mercury as a result, have children without adverse effects. According to new research, beneficial nutrients counter-act and protect against potential harm from mercury. In fact, children whose mothers eat more than 12 ounces of fish/week outperform those whose mothers avoid eating fish.

In other reports, the long-chain omega-3 eicosapentaenoic acid (EPA) in seafood was linked to fewer nonfatal heart events in women and eating tuna or other non-fried fish more than three times/week was associated with fewer tiny hemorrhages in the brain. People without these brain lesions are less likely to have a stroke or impaired cognition. Another study showed that EPA supplementation reduced the likelihood of having a second stroke in those who had already had one.

New research also demonstrated that a 200 mg daily supplement of the long-chain omega-3 docosahexaenoic acid (DHA) taken during pregnancy improved the DHA status of mothers and their infants and doubled the mothers' DHA milk content. In people with major depression, EPA was significantly lower compared with non-depressed individuals. Another study showed that low-dose DHA improved the symptoms of depression.

"Omega-3 fatty acids appear integral to the healthy performance of nearly all of the body's major systems," Nettleton said.