Women who work night shifts may have a 60 percent greater risk of breast cancer. This finding may be due to the body?s response to light, according to researchers at the Fred Hutchison Cancer Research Center in Seattle.
A gland in the brain known as the pineal gland produces the hormone melatonin when the body is exposed to sunlight or artificial light. This production is disrupted when people are up at night with the lights on.
?Exposure to light at night may increase the risk of breast cancer by suppressing the normal nocturnal production of melatonin by the pineal gland which, in turn, could increase the release of estrogen by the ovaries,? the researchers say. Breast cancer is linked with production of the female hormone estrogen.