Drinking green tea may help fight heart disease, a study of more than 40,000 Japanese men and women suggests.

Researchers examined data on 40,530 healthy adults aged 40 to 79 in northeastern Japan, where 80 per cent of the population drinks green tea and more than half have three or more cups daily.

Laboratory and animal studies have suggested green tea protects health, but the results of smaller studies in people have been inconsistent.

Earlier this year, a U.S. Food and Drug Administration review concluded there is no credible evidence to support manufacturers' claims that green tea can reduce the risk of cardiovascular disease.

In the Japanese study, 892 people died of cardiovascular disease and 1,134 died of cancer between 1995 and 2001, the researchers said.

Women who drank five or more cups of green tea had a 31 per cent lower risk of dying from cardiovascular compared with those who drank less than one cup daily. For the heaviest male drinkers, the risk was 22 per cent lower.

Women who drank five cups had a 62 per cent lower risk of dying from stroke compared with women who drank the least. The reduced stroke risk in men who consumed similar amounts of tea was 42 per cent.

There was also no beneficial link found between drinking black tea and the risk of dying from cardiovascular disease.

No link was found between green tea consumption and dying from cancer, Dr. Shinichi Kuriyama of Tohoku University in Sendai, Japan, reported in Wednesday's issue of the Journal of the American Medical Association.

Healthy lifestyles

"Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer," the study's authors concluded.

A type of antioxidants called polyphenols is found in green tea and may help protect health, the study said.

The research suggests an association between green tea consumption and longer life but clinical trials are needed to test if it is the tea itself that it is protective.

Consumption of green tea is highest among Japanese of normal weight who also eat a healthy diet of fish, rice, tofu, fruit and vegetables, dieticians said, noting the benefits may not translate to those with a Western diet.

In previous studies, people who drink green tea tended to have higher incomes and be more health-conscious, but the Japanese paper included people from different lifestyles and economic groups.

With files from the Associated Press