The hormone melatonin is an important part of sleep chemistry. More and more studies are linking higher levels of melatonin with reduced cancer growth and risk. The more you sleep, the more melatonin your body makes.

In a recent study of prostate cancer in sleep (the first such study, really), researchers found that men who slept less than 6 hours a night had a 34% increase in their risk of prostate cancer. The more the men slept, the lower their risk with men who slept more than 9 hours of night having 50% of the risk of those sleeping less than 6 hours a night. The study had over 22,000 Japanese men enrolled between the ages of 40 and 79.

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