…according to an article in MedPageToday.
Yet another reason to work out
In a forward-looking study, white men suspected of prostate cancer and scheduled for biopsy were less likely to have the disease if they were at least moderately active, according to Lionel Bañez, MD, of the Durham Veterans Affairs Medical Center in Durham N.C., and colleagues.
If they did have cancer, they were significantly less likely to have high-grade disease if they had been working out regularly, Bañez and colleagues reported in Cancer.
Another way to reduce your risk of prostate cancer is to follow the Mediterranean diet. Other cancers reduced by the Mediterranean diet are breast, colo-rectal, and uterus.
The association of exercise and lower prostate cancer risk was not noted in black men, for unclear reasons.
Paleo Diabetic 
Hi
But this is a logical finding because exercise upregulates antioxidant enzyme systems in the body and helps the elimination/detoxification sytems to function optimally. It also switches on AMPK pathway which upregulates the innate immune system and switches off growth and growth mediated metabolic activity.