By Colleen Doyle, MS, RD

I admit it; I'm a java junkie. I LOVE my morning (and mid-morning) cups of coffee.  So any study that looks at the potential health benefits of coffee gets my adrenaline pumping, whether I'm revved up on caffeine or not.

A study just published in the Journal of the National Cancer Institute looked at whether or not coffee consumption was related to prostate cancer risk. The researchers were particularly interested in whether or not coffee consumption reduced the risk of advanced prostate cancer (by advanced, they mean that the cancer has spread beyond the prostate at the time of diagnosis).  As a matter of fact, this study is the first of its kind looking specifically at the relationship between coffee consumption and advanced prostate cancer.  While prostate cancer is one cancer I don't need to personally worry about, on behalf of all the men in my life, I took a look.

Researchers at the Harvard School of Public Health collected data on about 48,000 men who participated in the Health Professionals Follow-Up Study. Every 4 years between 1986 and 2008, the men reported how much coffee they drank, and researchers determined the risk for prostate cancer related to the amount of coffee consumed. Compared to the men who didn't drink any coffee, they found that drinking 6 or more cups of joe each day may be linked to a slightly lower risk of developing prostate cancer, and the odds of developing advanced prostate cancer dropped by more than 50%.

"Six cups a day?!" you may ask. Yet even men who drank "only" 1 to 3 cups a day had a 22% lower risk of developing advanced prostate cancer. Decaf or caffeinated didn't seem to make a difference.

I was talking about this study to someone at lunch today, and she asked "What on earth would make them think coffee consumption might be related to prostate cancer?" Good question. According to the researchers, while they don't know specific mechanisms, they suggested a few things about coffee which may have an impact: it could be the antioxidants found in coffee; it could be compounds that reduce inflammation, which may be related to prostate cancer risk; it could be that coffee seems to have an effect on insulin - and it's possible that high insulin levels may increase prostate cancer risk. Bottom line: the researchers are not sure how coffee may impact risk, but in their study, consumption of coffee was related to a reduced risk of prostate cancer, including advanced prostate cancer.

So - what does this mean for men? Start downing six cups of coffee a day?

Not necessarily. For one thing, while this was a large, well-designed study, more studies like it need to be done to see if the same impact is found.  This single study doesn't prove that drinking coffee will protect a man from prostate cancer - advanced, or otherwise. And if someone is sensitive to caffeine, it's probably a good idea to not drink more than 2-3 cups of caffeinated coffee per day.

Prostate cancer remains the most common cancer diagnosed and the second leading cause of cancer death in men in the United States. While we still don't know exactly what causes prostate cancer, we DO know steps men - and all of us - can take to reduce our overall risk of cancer: don't smoke, eat well and be physically active. 

While the science on coffee and cancer risk continues to percolate, THAT'S the advice I'll give the men in my life.