As a nurse on the Labor and Delivery Unit, you have worked your whole career on the night shift. For the most part, you sleep soundly but on occasion your husband cannot sleep when you toss and turn in your battle with insomnia. And then to boot he has also reached over to wake you when you snore. Your health has been sound, nothing out of the ordinary except when you went in for your annual mammogram. You just learned that you have breast cancer. Could working the night shift, disturbances in sleep and developing cancer be related? Do shift-workers have an increased risk for cancer?
The answer is yes. With study results published in the British Medical Journal, researchers in Canada discovered that there was a connection between shift-work and cancer incidence, specifically breast cancer. The results demonstrated that the longer the test subject was a shift-worker, the higher the incidence of cancer. Specifically, those individuals who worked the night-shift for more than 30 years doubled their development of breast cancer. Under 30 years, the incidence was not statistically significant.
The Canadian investigators believed that artificial lighting negatively impacted melatonin production. Melatonin is a hormone produced by the body and helps to initiate sleep as well as thought to protect a person against cancer. So during the day, the gland that secrets melatonin is on pause but at night, it kicks into high gear. With artificial lighting being what it may be at night, shift-workers’ bodies think it is daytime and they produce a lower quantity of melatonin. And thus sleep is adversely affected. With that being said, not reaping the benefits of restorative sleep, the health of shift-workers place them at higher risk for diseases such as cancer.
But why breast cancer specifically? The researchers of this study theorized that with lower levels of melatonin being produced an increase in estrogen occurs, which may cause breast cancer to develop in these female shift-workers involved in various occupations. This study confirmed previous research that discovered a link between night nurses and breast cancer.
Shift-Workers and Cancer: In the Genes?
With close to an estimated 15 percent of the worldwide population working the night shift, there are quite a number of people who could theoretically be at risk for cancer. Early this year a group at the Sleep Research Centre at University of Surrey disclosed results from a study that will be published in the Proceedings of the National Academy of Science. Researchers found that with shift-work close to 1,500 genes could be damaged. With shift-work, the group said that a person’s natural 24-hour body cycle is disrupted, which prompts the issue with their genes. They believe that certain genes work in sync with circadian rhythm.
For any person who works the night shift, it is important that they take care of their health to help prevent diseases such as cancer. It always a good idea to eat a healthy diet, exercise regularly and adopt sound sleep hygiene practice.
If you have sleep apnea and would like to learn more about available treatment options, we can help. Please contact one of our medical concierges today at 1-855-863-4537 to schedule a free consultation.