A good night’s sleep ‘can ward off cancer’

Scientists linked higher levels of the night-time hormone melatonin with a 75 per cent reduced risk of advanced disease.

Melatonin is produced in the dark at night. It plays a key role in regulating the body’s sleep-wake cycle and influences many other functions associated with the body’s 24-hour clock, or circadian rhythm.

Low levels of the hormone are typically associated with disrupted sleep.

Scientists studied 928 Icelandic men who were questioned about their sleep patterns and had urine samples tested for levels of a melatonin breakdown product.

Men who reported taking medication for sleep problems, and difficulty falling and staying asleep, had significantly lower amounts of the melatonin marker.

Over a period of seven years, 111 of the men were diagnosed with prostate cancer including 24 with advanced disease. Men whose melatonin marker levels were higher than the middle of the range were 75 per cent less likely to develop advanced prostate cancer than those with lower values.

“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,” said study leader Sarah Markt, from the Harvard School of Public Health in Boston, US.