An apple a day may keep the doctor away for the general population. But menlooking to avoid serious types of prostate cancer, a cup of coffee a day could be a good option.

A recent major study by Harvard researchers published in The Journal of the National Cancer Institute found that men who drink six or more cups of coffee each day have a 60 percent lower chance of contracting lethal cases of prostate cancer. Those who drink 3 or more cups a day have a 30 percent lower risk. In general, heavy coffee consumption lowers men’s risk of developing any type of prostate cancer by 20 percent over 20 years.

Insulin might play a role in prostate cancer formation. Coffee is high in antioxidants and also regulates glucose metabolism and insulin levels. This could be the correlation between high quantities of coffee and low occurrences of prostate cancer and other cancers.

The cause-and-effect component of coffee and prostate cancer is still hard to identify completely. The insulin factor and coffee’s effect on type 2 diabetes could be just one component. But compounds in coffee also have effects on sexual hormones that may also play a role in prostate health.

This study comes on the heels of a Swedish study that found women who drank five or more cups of coffee per day decreased their risk for a particularly aggressive form of breast tumor.

CORE Oncology reports that prostate cancer is the second-leading cause of cancer deaths among American men. The National Prostate Cancer Coalition says that prostate cancer represents 30 percent of all new cancer cases in American men, while the Canadian Cancer Society says that, in 2011, an estimated 25,500 Canadian men will be diagnosed with prostate cancer and 4,100 will die of it. It is the most common form of cancer cases among men in Canada.

Although the detriments and benefits of coffee have long been debated, more and more scientists and medical professionals are touting the medical benefits of coffee. Along with its link to warding off certain cancers, coffee has been associated with lower risk of Parkinson disease, type 2 diabetes, gall stones, and even depression. Coffee may also help prevent muscle pain and weakness associated with vigorous athletic workouts.

More research needs to be conducted to further strengthen the link between coffee and reduced risk for prostate cancer. Although medical professionals have yet to advocate increasing coffee consumption, researchers say that moderate coffee drinking is likely not a contributor or harmful in terms of prostate cancer development.