Working Nights Linked To Risk of Colon Cancer

According to a new study:

Harvard Nurses who work regular night shifts have a higher risk of colon cancer, U.S. researchers reported. The study by researchers at Harvard Medical School and Brigham and Women's Hospital in Boston, published in the Journal of the National Cancer Institute, supports earlier research that found women who work night shifts have a higher risk of breast cancer.

The U.S. Bureau of Labor Statistics estimates that about 4 percent of adults work rotating night shifts. Shift work disrupts melatonin production and increases levels of other hormones such as estrogen.

Women's cancers are often linked with estrogen, but Eva Schernhammer, who led the study, said melatonin may play a more important role.

The summary is here (Scroll Down) and a longer article here.