By Amanda Gardner

TUESDAY, May 17, 2011 ( — Men who drink a lot of coffee might feel a bit jittery or high-strung, but those side effects may come with a hidden benefit: prostate health. According to a new study, drinking six or more cups of coffee per day can lower a man's risk of fatal prostate cancer by up to 60%.

A decreased risk of cancer was seen in men regardless of whether they drank decaf or caffeinated, which suggests that the benefit may come from a property in coffee other than caffeine, researchers say.

"Coffee has a lot of different biological effects and several of them seem like they might be relevant for prostate cancer," says the lead author of the study, Kathryn Wilson, a research fellow in epidemiology at the Harvard School of Public Health, in Boston. "It's an important source of antioxidants and also has positive effects on glucose metabolism and insulin levels, and it's thought that insulin plays a role in the progression of prostate cancer."

Coffee also appears to influence levels of testosterone and other sex hormones, which "clearly play a role in prostate cancer," Wilson adds.

The potentially beneficial effects of coffee have received a slew of attention from researchers in recent years. Coffee consumption has been linked to a lower risk of type 2 diabetes, Parkinson's disease, and liver cancer, among other conditions, and just last week, researchers in Sweden reported that women who drank at least five cups a day were at lower risk of developing a certain aggressive type of breast cancer.

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