Working the Night Shift May Cause Colon Cancer

A study published in the Journal of the National Cancer Institute found that nurses who worked the night shift on a regular basis were at increased risk for colorectal cancer.

Specifically, researchers found that nurses who worked the night shift at least three times a month for 15 years or longer, had a 35% greater risk of developing cancer of the colon or rectum.

Why? Researchers aren't sure, but they think that lack of exposure to natural light may be to blame. Artificial light supresses melatonin production and melatonin is a well-established cancer-fighting compound.

_{Source: Schernhammer, E. and Laden, F. "Night-Shift Work and Risk of Colorectal Cancer in the Nurses' Health Study." Journal of the National Cancer Institute 95.11 (Jun. 2003): 825-828. 26 Aug. 2006 [http://jncicancerspectrum.oxfordjournals.org/cgi/content/full/jnci;95/11/825].}