Irregular sleep patterns can lead to a higher risk of breast cancer

Consistently disrupting your body clock can lead to a higher risk of breast cancer, a study published in the British Journal of Cancer has found.

A/Prof Deborah Glass (DEPM)  was among a group of researchers headed by Professor Lin Fritschi (UWA)  who examined a large group of female shift workers from 2009 – 2011, and found that night shift work can lead to a greater chance of contracting the disease.

However, it is not working nights itself that is the carcinogen, but constant changes in sleep patterns.

For example, a woman that worked a stable midnight – 8am shift every night would not have an increased risk of breast cancer. However, a woman who started at midnight on Monday, 2am on Tuesday, 3am on Wednesday and 6am on Thursday would be more likely to see adverse health effects.

A shift which involves a disruption in the regular sleep cycle is known as a “phase shift.” There was a 22% increase in breast cancer risk for the women in the study who work phase shifts.

This is because the body finds it harder to control certain functions, most importantly cell proliferation, under these conditions.