Lasting nearly eight years study by the Harvard School of Public Health in Boston covered 928 men. During the study, prostate cancer developed in 12% of men. The study showed that undisturbed and restful sleep, and related with it melatonin level in the body affects the risk of cancer.
The study showed that in men who had no trouble sleeping level of melatonin remained high. What is more, men with melatonin concentration of 17.1 ng / ml had a 31% lower risk of prostate cancer and a 75% lower risk of an advanced form of the cancer.
The greatest impact on the melatonin production has light. This is the reason why everyone should sleep in the dark.