Sun Exposure by Marc Sorenson, EdD, Sunlight Institute…
A recent study from Canada produced some intriguing information regarding the influence sun exposure may have on prostate cancer (PC). A total of 1,638 men with prostate cancer and 1,697 without, were assessed between 1994 and 1997 to determine the amount of time each spent outdoors exposed to ultraviolet light (UV). The men were a mixture of Indians, Asians, and Caucasians.
The men were assessed for their sun habits by determining how many hours per day they spent in the sun, whether sun exposure was moderate (2-6 hours per day) or high (>6 hours per day). Interestingly, men who were in the highest level of sun exposure had a reduced risk of PC of about 32% compared to unexposed men (the control group). There was no difference when moderate levels of sun exposure were compared to risk of PC. This would indicate that more sun is better, at least in this single study
The men who were of Asian and Indian descent started out with a profoundly reduced risk of PC, having only a 17% risk or 25% risk of PC, respectively. I opine that because those two ethnic groups consume much higher levels of vegetation than Caucasians, they are more protected.
There are probably 20 studies that show a protective effect of sun exposure on PC. Early research by Dr. Esther John and here colleagues is only one of many that reported a dramatic protective influence of sun exposure on prostate cancer. They compared the lifetime sun exposure of 450 white men with advanced prostate cancer to that of 455 white men who did not have cancer. The men were divided into quintiles (fifths) according to the amount of exposure they had received. Subjects in the highest fifth of sun exposure had only 51% of the risk of prostate cancer as did those in the lowest quintile.
So, most research shows an impressive association between higher sun exposure and lower risk of prostate cancer. Men, remember to be safe as you soak up that glorious sun. Don’t burn, and be sure to develop a good tan if you can. If you don’t tan, then a very short time in the sun is sufficient, after which you should wear a big hat and long-sleeved shirt. And please don’t use cancer-causing sunscreens.
 Peters CE, Demers PA, Kalia S, Hystad P, Villeneuve PJ, Nicol AM, Kreiger N, Koehoorn MW. Occupational exposure to solar ultraviolet radiation and the risk of prostate cancer. Occup Environ Med. 2016 Jul 27. [Epub ahead of print]
 John EM, Schwartz GG, Koo J, Van Den Berg D, Ingles SA. Sun exposure, vitamin D receptor gene polymorphisms, and risk of advanced prostate cancer. Cancer Res 2005;65(12):5470-79.