CHICAGO (Reuters) - Habitual tea drinking over several years preserves bone
density in both men and women, Taiwanese researchers said Sunday.
"The protective effect of tea on bone
mineral density of the total body, lumbar spine and hip regions was clearly
demonstrated," wrote study authors Chih-Hsing Wu and Chih-Jen Chang of the
National Cheng Kung University Hospital in Tainan, Taiwan.
Their report speculated that the high fluoride content in tea, especially
green tea, as well as flavonoids and phytoestrogen may help, over time, preserve
bone density. Other ingredients in tea may inhibit bone resorption and boost
metabolic creation of bone.
They concluded it was the duration of habitual tea drinking, not the amount
of tea consumed, that conferred the benefit on bones. The effect was most
pronounced in the bones of people who had drank tea regularly for more than a
decade.
Previous studies have credited polyphenols found in tea with helping prevent
cardiovascular disease and cancer, the researchers said. But other studies have
produced contradictory findings on the relationship between tea drinking and
bone formation and bone loss. Ingredients such as caffeine may have a
detrimental effect on bones and overall health.
Green tea, which is unfermented, and oolong, which is partially fermented,
are popular in Asia, while in the West, fermented black tea -- often taken with
milk -- is generally preferred. Tea contains 4,000 chemical compounds that can
have effects on health, the report said.
The study surveyed 497 Chinese men and 540 Chinese women who were at least 30
years old about their tea drinking habits and other lifestyle factors such as
exercise, alcohol consumption and smoking.
Appearing in the Archives of Internal Medicine (news
- web
sites), a journal published by the American Medical Association, the
researchers claimed it was the first study to examine the impact of all three
types of tea on both sexes.
