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Melatonin may reduce the risk of prostate cancer

Prostate cancer: melatonin may reduce its occurrence

Melatonin level may influence the likelihood of being affected by prostate cancer. In fact, a high concentration of this hormone, known for its effects on the regulation of sleep-wake cycles, appears to be able to reduce the risk of developing advanced prostate cancer by 75 percent.


The finding was presented during the AACR- Prostate Cancer Foundation Conference on Advances in Prostate Cancer Research, the conference held in San Diego Jan. 18-21, by Sarah Markt, of the Harvard School of Public Health's Department of Epidemiology in Boston, U.S.



The actions of melatonin

Melatonin is a hormone produced by the epiphysis, a small gland attached to the encephalon, The substance is synthesized at night in response to darkness and is an important regulator of sleep-wake cycles In addition to its ability to regulate, improve sleep and mood, with recent studies, melatonin has shown numerous other properties, including high antioxidant power and the ability to regulate the cyclic production of other hormones that in turn may influence the occurrence of certain types of cancer 



High levels of the hormone protect against cancer

The study, conducted between 2002 and 2009, involved 928 Icelandic men. In the initial phase, urine samples were collected from each and the concentration of 6-sulfatoxymelatonin, the main metabolite of melatonin in urine, was assessed. In addition, each subject filled out a questionnaire highlighting any sleep difficulties From the data collected, it was found that 1 in 7 had difficulty falling asleep, 1 in 5 had difficulty continuing to sleep, and 1 in 3 had taken medication in order to sleep. In these subjects, urinary levels of 6-sulfatoxymelatonin were significantly lower than in those who had not manifested any sleep-related problems.


 In the final stage of the research, it was found that 111 men out of the 928, had developed prostate cancer and that 24 of them were in an advanced stage of the disease. Men who had higher-than-average levels of 6-sulfatoxymelatonin (17.14 ng/ml urine) showed a 31 percent lower risk of developing prostate cancer than those with levels below the average value, while the risk of having advanced disease was as much as 75 percent lower.



The importance of circadian rhythms

According to Sarah Markt and her colleagues, sleep loss could reduce melatonin secretion or block it completely, causing a range of dysfunctions, Health issues associated with low levels of the hormone, interrupted sleep or circadian rhythm dysfunction may also include cancer. 


As the researchers explained, it will be necessary to replicate their findings and conduct further research on the link between prostate cancer and melatonin, especially since melatonin levels are potentially modifiable. Still, the study testifies to the importance for health of maintaining a stable light-dark and sleep-wake cycle.  


Source: Sarah C. Markt "Urinary melatonin levels, sleep disruption, and risk of prostate cancer" AACR- Prostate Cancer Foundation Conference on Advances in Prostate Cancer Research. January,18-21, 2014. San Diego, CA