Beijing: Men, take note! Working night shifts, skipping day-time naps or sleeping for more than ten hours every night may significantly increase your risk of cancer, a new study has warned.
Scientists from Huazhong University of Science and Technology in China reviewed data obtained via interviews with middle-aged and older Chinese in a cohort of about 27,000 retired workers.
The researchers sought to investigate the independent and combined effects of three sleep habits on cancer incidence; night shift work, daytime napping, and night time sleep. Through a questionnaire they ascertained individuals who had worked night shifts for over 20 years, had a habit of taking day time naps and when they usually went to sleep at night and woke up in the morning.
The researchers found that men who had worked night shifts for over 20 years had a 27 per cent increased risk of cancer incidence, and that men that did not nap in the day time had double the risk of cancer of those who took a one to 30-minute nap.
They also found that men who slept for more than ten hours per night had an increased risk of cancer. However, no such relationship was observed in women.
The researchers also found that male participants with at least two of these sleep habits (long-term night shift work, lack of daytime napping, or sleeping over ten hours per night) had a 43 per cent increased risk of cancer incidence and a two-fold increase in cancer mortality compared to those who exhibited none of the sleep habits. The study was published in the journal Annals of Medicine.