Working the overnight shift has been linked to an increased risk of developing cancer. Though the association may seem a bit far fetched, research has found that men who work the overnight shift have higher rates of prostate cancer, while women have higher rates of breast cancer. The overnight shift – cancer link is strong enough that the International Agency for Research on Cancer, the cancer arm of the World Health Organization (WHO), recently added the graveyard shift to its list of probable carcinogens.
The night shift – cancer link was first brought to light in 1987, when Richard Stevens, a cancer epidemiologist and professor at the University of Connecticut Health Center, published a paper suggesting the connection. Stevens speculated that a sudden rise in breast cancer rates in the 1930s was somehow connected to the increased prevalence of night shift work brought on by industrialization. Most other scientists, however, scoffed at Stevens’ assertions. But over the years, more and more research has pointed to a connection between overnight work and cancer rates. Also, lab animals that have their light and dark schedules switched have been shown to develop more tumors and die earlier.
