(CBS) Is green tea the elixir of immortality? The brew has long been thought to have health benefits ranging from improving mental alertness to treating stomach disorders to preventing various cancers. A new study looked at whether green tea consumption minimizes frailty and disability in the elderly.
Green tea has been linked to a lower risk for diseases that cause functional disability, including stroke, cognitive impairment, and osteoporosis. The new study examined the direct connection between green tea consumption and functional disability in elderly people.
A functional disability is essentially a limitation or inability to perform a physical activity related to daily and long-term care, such as dressing or bathing.
For the study - published in the American Journal of Clinical Nutrition - researchers at the Tohoku University Graduate School of Medicine in Miyagi, Japan, looked at nearly 14,000 Japanese individuals ages 65 years and older. Participants filled out a questionnaire about their daily green tea consumption and other lifestyle factors. Researchers then used corresponding data on functional disability from the public Long-term Care Insurance database, following the patients for 3 years.
Those who drank the most green tea were found least likely to develop functional disability. Among participants who consumed less than one cup of green tea per day, the incidence of functional disability was almost 13 percent. But for those who consumed at least five cups of green tea a day, only about 7 percent had a functional disability.
What makes green tea healthy? It is minimally processed and rich in antioxidants that may protect against cell damage, specifically a catechin called epigallocatechin-3-gallate, or EGCG.
More frequent consumption of green tea was also associated with better cognitive activity, greater social support and participation in community activities, and a better diet (more fish, fruits and vegetables).
Study authors noted that they found an association, but not a casual relationship. Green tea has been found to have a preventive effect on disabling diseases that cause frailty, and these diseases are a major cause of functional disability in Japan.
The authors did confirm that green tea polyphenols improved leg strength and lowered risk for depression, a common cause of functional disability in the elderly.
Said the study, "All of these findings provide a biological basis for the effect of green tea in preventing or postponing the onset of functional disability in the elderly."