Study of offshore oil workers links night shift to prostate cancer risk

Oslo, Norway — Offshore petroleum workers engaged in rotating shift work may face increased risk of prostate cancer, according to the results of a recent study.

Researchers from the University of Oslo and the Cancer Registry of Norway examined data from about 25,000 men in the Norwegian Offshore Petroleum Workers cohort. The team compared offshore petroleum workers who rotated between day and night shifts with those who worked only day shifts.

Findings show that the participants who worked on a rotating shift schedule for more than 19 years faced an 86% higher risk of developing aggressive prostate cancer. However, occupational exposure to chlorinated degreasing agents – as endocrine-disrupting agents – wasn’t considered a risk for aggressive prostate cancer.

The researchers noted how shift work is frequently associated with disrupting a worker’s internal body clock, which can compromise hormones and throw a worker out of line with the normal cycle of light and darkness.

“It is often difficult to adapt to light at night,” lead study author Leon Berge, a postdoctoral fellow in the university’s Department of Biostatistics and at the Cancer Registry of Norway, said in a press release. “People who work nights often suffer from acute disruption of the sleep and wake cycle, sleep deprivation, increased stress, and a variety of other health problems.

“When this balance between light and dark is continually disturbed, it may also increase the risk of cancer, as experiments in animals have shown.”

The study was published online in the International Journal of Epidemiology.