Washington, March 5 (IANS): Significantly higher consumption of omega-3 fatty acids among middle-aged Japanese men appears to impart a protective factor that wards off heart disease, a study has revealed.

"Previous studies investigated substantially lower intake of omega-3 fatty acids than what people in Japan actually get through their diet. Our study indicates that the level of omega-3 fatty acids consumed must be higher than previously thought to impart substantial protection," said Akira Sekikawa, associate professor of epidemiology at the University of Pittsburgh's Graduate School of Public Health.

Marine-derived omega-3 fatty acids in fish, especially oily fish as well as in squid and krill, may help to reduce inflammation and slow the formation of fatty plaques in arteries.

Researchers partnered with scientists in Japan, Hawaii and Philadelphia to follow nearly 300 men for five years.

They tracked multiple factors that affect cardiovascular health, including cigarette smoking, cholesterol levels, alcohol consumption, diabetes and high blood pressure.

After accounting the risk factors for heart disease, US men had three times the incidence of coronary artery calcification as compared to Japanese men.

Meanwhile, the levels of marine-derived omega-3 fatty acid in the blood were more than 100 percent higher in the Japanese men.

The average dietary intake of fish by people living in Japan is nearly 100 grams each day.

The average American eats about 7 to 13 grams of fish a day, or about one serving a week.

"I am not encouraging Americans to start consuming massive amounts of fish, which may have harmful contaminants such as mercury in their flesh," added Sekikawa.

It is worthwhile to take another look at the effect of marine-derived omega-3 fatty acids on heart disease particularly when consumed at higher rates than previously investigated, suggested the study published in the journal Heart.