Jan. 20: Sleeping well could help to protect men from aggressive prostate cancer, according to scientists.
High levels of the so-called “sleep hormone” melatonin were linked to a 75 per cent reduced risk of the advanced form of the disease, the study found.
Melatonin, which triggers feelings of drowsiness, is crucial for regulating circadian rhythms. Low levels of the hormone are typically associated with disrupted sleep. Now scientists think that melatonin could also help regulate other hormones that are known to play a role in breast and prostate cancers.
In the future, testing patients’ melatonin could help to identify men at greater risk of the disease progressing rapidly.
Sarah Markt, who led the study by Harvard University, said: “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, or disruption of the circadian rhythm are broad, including a potential risk factor for cancer.”
The study involved 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 had difficulty falling and staying asleep, had significantly lower amounts of the melatonin marker.
Over a period of seven years, 111 of the men had prostate cancer diagnosed, including 24 whose cancer was advanced. Men whose melatonin marker levels were higher than average were 75 per cent less likely to develop advanced prostate cancer than those with lower values.
The research was presented at the American Association for Cancer Research-Prostate Cancer Foundation conference in San Diego yesterday. More than 40,000 men have prostate cancer diagnosed each year in Britain, and 10,000 die of the disease.
Prostate cancer can occur in a slow-growing benign form, but once the disease spreads to other tissue it is more likely to prove fatal.
At the moment there is no reliable way to distinguish between slow-growing prostate cancer and aggressive forms, meaning that men have a difficult decision over whether to “watch and wait” or have treatment and risk serious side-effects.