Having a higher level of melatonin, the sleep hormone, may protect you from prostate cancer

Having a higher level of melatonin, the sleep hormone, may protect you from prostate cancer

     Sarah C. Markt, MPH, of Harvard School of Public Health's Department of Epidemiology presented her team’s findings connecting melatonin to prostate protection at The American Association for Cancer Research-Prostate Cancer Foundation Conference on Advances in Prostate Cancer Research, held January 18 to 21, 2014 in San Diego.
Melatonin is released in response to darkness, and is involved in the regulation of the body's circadian rhythm (internal clock). The study included 928 men who were a part of the AGES-Reykjavik cohort in Iceland. When you release melatonin at night, it is broken down in the body into 6-sulfatoxymelatonin. Checking the level of this metabolite in the urine gives a good indication of the level of melatonin activity in your body. Morning urinary samples were evaluated for 6-sulfatoxymelatonin at the beginning of the study in 2002 to 2006. Questionnaire responses provided information on sleep patterns and other factors.
Through 2009, 111 men developed prostate cancer, and 24 of these were diagnosed with advanced, life threatening disease. Participants who reported sleep problems had lower melatonin levels than those who slept well. Among those whose urine melatonin (6-sulfatoxymelatonin) levels were above the median (halfway point) of all subjects, there was a 31% lower risk of developing prostate cancer and a 75% lower risk of having advanced disease in comparison with men whose melatonin levels were below the median.
"Sleep loss and other factors can influence the amount of melatonin secretion or block it altogether, and health problems associated with low melatonin, disrupted sleep, and/or disruption of the circadian rhythm are broad, including a potential risk factor for cancer," Markt stated. "We found that men who had higher levels of melatonin had a 75 percent reduced risk for developing advanced prostate cancer compared with men who had lower levels of melatonin."
"Our results require replication, but support the public health implication of the importance of maintaining a stable light-dark and sleep-wake cycle," she added. "Because melatonin levels are potentially modifiable, further studies of melatonin and prostate cancer risk and progression are warranted."