Elderly people who drink several cups of green tea a day are less likely to suffer from depression, probably due to a "feel good" chemical found in this type of tea, Japanese researchers said.

日本研究人员日前称，老年人每天喝几杯绿茶可降低患抑郁症的风险，这可能是因为绿茶中含有一种能让人“感觉良好”的化学物质。

Elderly people who drink several cups of green tea a day are less likely to suffer from depression, probably due to a "feel good" chemical found in this type of tea, Japanese researchers said.

Several studies have linked drinking green tea to lessening¹ psychological心理的 problems and Kaijun Niu, of Tohoku University Graduate School, and colleagues found people aged² 70 and older who drank four or more cups of green tea daily were 44 percent less likely to experience depression.

Green tea is widely consumed in many Asian countries, including China and Japan.

Niu's team investigated 1,058 relatively³ healthy elderly men and women. About 34 percent of the men and 39 percent of the women had symptoms症状 of depression, according to the study that was published in the the American Journal of Clinical Nutrition.

A total of 488 participants said they drank four or more cups of green tea a day, 284 said they downed two to three cups daily and the rest reported having one or fewer cups daily.

According to the researchers, the apparent effect of drinking more green tea on alleviating⁴减轻，缓和 symptoms of depression did not fade after they factored in social and economic status, gender⁵, diet, history of medical problems and use of antidepressants抗抑郁药.

There was no association between consumption of black or oolong tea乌龙茶, or coffee, and lower symptoms of depression.

A green tea component⁶成分，元件, the amino acid氨基酸 theanine茶氨酸, which is thought to have a tranquillising effect on the brain, may explain the "potentially beneficial effect" shown in the current study, Niu noted⁷, adding that more study is needed.