Green tea linked to long life in Japanese study-part 2

[Guest guest]

This perspective mentions that the heavy green tea drinkers in the

study mentioned previously also ate more fruits and vegetables. It

points to the fact that human studies often have too many variables! -

Diane

http://apnews.excite.com/article/20060912/D8K3HHV00.html

CHICAGO (AP) - Can drinking green tea really protect against two big

killers, strokes and cancer? A huge study in Japan suggests yes and

no: It might lower your stroke risk but won't save you from cancer.

The study's authors say their findings might explain why the Japanese

are less likely than Americans to die of heart disease and stroke.

Even so, the answers aren't clear. Green tea has been researched a

lot, and many of the studies have come up with conflicting results.

Earlier this year, the U.S. Food and Drug Administration said an

analysis found no credible scientific evidence to support

manufacturers' claims that green tea can cut cardiovascular disease risks.

The National Cancer Institute says human studies on tea and cancer

prevention have had contradictory results. But there's still hope and

the institute is funding rigorous studies testing whether tea extract

can help prevent several kinds of cancer.

Tea contains substances called antioxidants that can help keep cells

healthy. Green tea has more of them than black tea, and studies in

animals have shown that tea antioxidants called catechins seem to

shrink cancerous tumors. Some studies in humans have suggested tea can

also help keep arteries and cholesterol healthy.

The current study was funded by the Japanese government and is

published in Wednesday's Journal of the American Medical Association.

Dr. Shinichi Kuriyama of Tohoku University in Sendai, Japan is the

lead author.

It's different from many previous studies because it involved so many

people - 40,530 Japanese adults. Those who drank lots of green tea

were less likely than those who drank only a little tea to die from

cardiovascular disease and other causes, but not cancer.

Because tea-drinking is popular among Japanese people from all

lifestyles and economic groups, the research seems to refute a

criticism of previous studies - that people who drink green tea are

higher income and more health-conscious and thus apt to be healthier

anyway.

However, heavy tea drinkers in the study also tended to eat more

fruits and vegetables, and such a diet also might reduce

cardiovascular disease and cancer risks, said Folts, a professor

of medicine at the University of Wisconsin.

Study participants were generally less overweight than Americans, and

it's unknown if similar results would be found in a more diverse group

of people, said Alice Lichtenstein, a Tufts University nutrition

professor and spokeswoman for the American Heart Association.

The results from this study, which observed people and their habits

over several years, " point you in a direction " but aren't conclusive,

she said.

The Japanese volunteers filled out questionnaires on tea-drinking and

other habits including diet, alcohol and tobacco use, weight, job and

education status, and physical activity.

During seven years of follow-up, 1,134 participants died of cancer and

892 died from cardiovascular disease.

Women who drank five or more cups of green tea daily had a 31 percent

lower risk of dying from cardiovascular disease than women who drank

less than one cup daily; in men, the comparable reduced risk was 22

percent.

Cardiovascular disease includes heart disease and stroke. While heavy

tea drinkers had less heart disease than those who drank little tea,

the results suggest the difference for heart disease alone might have

been due to chance.

Green tea appeared to work best against clot-related strokes. Among

the five-cup-a-day group, women had a 62 percent lower risk of dying

from these strokes than women who drank little tea, and for men the

reduced risk was 42 percent.

The researchers said more men were smokers, and that might have

explained the gender differences since smoking affects cardiovascular

disease risks.

There were no significant differences in cancer death rates among

heavy and light tea drinkers of either sex.

While the study isn't the last word on whether tea-drinking is good

for you, tea is generally harmless and has no calories, so if you like

the taste, most researchers would probably say go ahead and drink it.

" The point is, if you're drinking green tea, that's fine. It's

premature to recommend that somebody start drinking " it to protect

their health, Lichtenstein said.