The health benefits of drinking tea have been well publicized lately, and recent studies point to two newly discovered advantages to consuming this beverage. One shows that drinking tea can help prevent death after a heart attack. The other reports that tea may increase bone mineral density, which helps prevent fractures and osteoporosis.
In the first study, published in Circulation, researchers questioned 1,900 patients hospitalized for heart attacks about the amount of caffeinated tea they drank in the past year. After adjusting for age, gender, and other variables, researchers found that those who drank 14 or more cups of tea per week were 39% less likely to die of cardiovascular disease in the 3.8 years following their heart attack than non-tea drinkers. Patients who consumed 114 cups of tea per week were 31% less likely to die from cardiovascular causes during that period than non-tea drinkers.
When researchers further looked into subjects' caffeine intake, they found that caffeine from sources other than tea did not affect death rates.
In the second study, published in the Archives of Internal Medicine, researchers surveyed 1,037 men and women age 30 and older about their tea consumption. Subjects who drank tea at least once a week for the preceding six months were labeled "habitual tea drinkers." This group was asked about their tea-drinking history, the kind of tea they drank, how often they drank it, and how much they drank in each sitting.
Researchers then measured the bone mineral density (BMD) of the lumbar spine, hip, neck, and total body of both the habitual tea drinkers and the non-drinkers.
The researchers found that people who consumed tea regularly for more than 10 years had the highest BMD scores compared to the other groups, after they adjusted for sex, age, weight, and lifestyle variables that may affect BMD. Those who drank tea regularly for the past 610 years also had significantly higher lumbar spine BMDs than the nonhabitual tea drinkers. People who consistently drank tea for the past 15 years did not have any significant differences in BMD score compared to the nonhabitual drinkers.
It didn't seem to matter what type of tea the person drank, and neither did the amount of tea consumed each time. Only duration of habitual tea consumption was an independent predictor of BMD score. Tea contains several components, including fluoride and flavonoids, which may work separately or in concert to maintain or restore bone density.
Although BMD score is often a good gauge of the risk of fracture from osteoporosis, this study did not actually test the link between tea consumption and bone fracture.
July 2002 Update