Depression is a major health issue for breast cancer survivors, but new research hints that regular exercise and drinking green tea may help.

Exercising regularly and drinking green tea “may play an important role in the prevention of depression among breast cancer survivors,” report Dr. Xiao Ou Shu, at Vanderbilt University Medical Center, in Nashville, Tennessee, and colleagues.

They examined depression-related factors in 1,399 Chinese women who were 54 years old on average and treated for breast cancer in Shanghai, China between April 2002 and December 2006. Six months after their diagnosis, the researchers assessed the women’s physical activity levels; food, tea, and alcohol consumption; cigarette smoking; and use of herbal medicines and supplements.

In depression evaluations at 18-months post-diagnosis, the investigators noted distinct benefits among the women who reported some sort of exercise (62 percent of the total). At this time, exercisers were about 20 percent less likely to be either mildly or clinically depressed, the researchers report in the Journal of Clinical Oncology.

They noted just 84 cases of mild or clinical depression among 437 vigorous exercisers (19.2 percent), but 161 cases among the 528 non-exercisers (30.5 percent).

Plus, compared with non-exercising women, the likelihood of depression was 28 percent lower among women who exercised more than 2 hours a week and 42 percent lower among those who increased their post-diagnosis exercise time.

Tea drinking also seemed to lessen depression. Compared with the 1,216 women who did not drink tea, among the 183 women who did, depression risk was about 36 percent lower. The vast majority of the tea drinkers - 90 percent - drank green tea.

The exercise and tea-drinking benefits remained when Shu’s group allowed for multiple other risk factors for depression.

No other factors seemed to alter depression risk.

Although exercise and drinking green tea seemed to lower depression in this group of Chinese women, breast cancer survivors “should not overdose themselves,” Shu cautioned in an email to Reuters Health.

He noted that excessive exercise and tea drinking may not have the same benefit on mood. Also, further investigations are necessary to clarify these findings since women in other countries, who may undergo different breast cancer treatment regimens, may react differently.

SOURCE: Journal of Clinical Oncology, online January 4, 2010