Does less sleep equal greater risk of dying from prostate cancer? Let’s look at the numbers revealed in a recent study by epidemiologists at the American Cancer Society. A news release from the American Association for Cancer Research reports that epidemiologists analyzed data from two large, long-term cohort studies, one that followed 407,649 men from 1950 through 1972, and one that followed 416,040 men from 1982 through 2012. All men were cancer free at the beginning of the studies. When the researchers analyzed self-reported sleep duration in relation to deaths from prostate cancer, they found that during the first eight years of follow-up, among men under the age of 65, men who got three to five hours of sleep per night had a 55 percent greater risk of dying of prostate cancer than men who got seven hours of sleep per night. Men who got six hours of sleep per night had a 29 percent higher risk than those who got seven hours. The good news? Men who were 65 or older showed no difference in the risk of death from prostate cancer, no matter how much sleep they got. What’s that about? The researchers don’t really know, but they suggest that sleep deprivation and the presence of light at night can inhibit the production of melatonin, a hormone that affects sleep cycle. Low melatonin production can spark increased genetic mutations, greater oxidative damage, reduced DNA repair, and immune suppression. Also, short sleep duration may also contribute to the disregulation of a number of genes involved in tumor suppression.