Drinking six cups of coffee a day could leave a man pretty wired, but it may also help lower his risk of fatal prostate cancer, according to a new study from the Harvard School of Public Health.
The study is the largest to examine the link between coffee and prostate cancer, involving about 48,000 men who took part in the long-running Health Professionals Follow-Up Study, which evaluated the relationship between diet and diseases like cancer and heart disease. Every four years between 1986 and 2006 participants reported how much coffee they drank per day (along with other dietary information); they were then tracked for prostate cancer through 2008. Overall, 5,035 men were diagnosed with prostate cancer, and 642 of those cases were deadly.
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The researchers found that the reduction in prostate cancer risk linked to coffee consumption was most pronounced for lethal cancers: men who drank at least six cups a day were 60% less likely to develop deadly cancer, compared with men who drank none. Those who drank one to three cups a day had a 30% lower risk of lethal cancer.
The effect was the same whether men drank regular coffee or decaf, suggesting that caffeine isn’t the key factor in cancer risk. “Coffee has a lot of different biological effects and several of them seem like they might be relevant for prostate cancer,” lead author, Kathryn Wilson, a research fellow in epidemiology at Harvard, told Health.com. “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.”
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The study does not prove that drinking coffee directly prevents prostate cancer; it suggests only an association between consumption and a lower risk. But it adds to the existing evidence that coffee may be linked to a host of health benefits, including lower risks of Type 2 diabetes, Parkinson’s disease, liver cancer and an aggressive type of breast cancer.
That’s good news for people who are already coffee junkies, though the authors of the current study do not recommend that middle-aged men start downing loads of coffee to try to prevent prostate cancer.
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The new study was published in the Journal of the National Cancer Institute.
Read the full Health.com piece here.