What effect does working the night shift have on health?

By Dr Pushpa Chandra

Apr 07
Working the night shift

Millions of people work the night shift, including first responders, medical professionals, military, truck drivers, and more. Although working the night shift may have some personal benefits, medical and scientific research continues to show that this type of shift work has the potential to affect the health of workers negatively. Here's a closer look at the potential health effects of working nights.

1. Increases the Risk of Diabetes

Working nights could increase your risk of diabetes, and research has shown that men are especially prone to developing diabetes if they have irregular working hours. Shift work also has the ability to impact insulin activity, which increases the risk of Type 2 diabetes in individuals who work at night.

Shift work has the ability to impact insulin activity, increasing the risk of Type 2 diabetes

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2. Raises Obesity Risk

Individuals who work nights find themselves sleeping against the natural biological clock of the body, and sleeping too little is also a common problem. Both of these issues have the ability to raise the risk of becoming obese according to a study published in Science Translational Medicine. Night workers often have a difficult time sleeping during the day, which often results in insufficient sleep and a disruption in their circadian rhythm. Evidence shows that getting enough sleep and getting it at night is essential for overall well-being.

3. Higher Risk of Heart Attack

Working the night shift may also increase the risk of having a heart attack according to recent information published in the British Medical Journal. Dr. Daniel Hackman, who led authored this information, looked at 34 different studies that included over two million people. He and his co-authors concluded that individuals that work the night shift have an increased rate of vascular events, including heart attacks and ischemic strokes. Shift workers must take care of their cardiovascular heart and pay close attention to cardiovascular risk factors, such as glucose levels, cholesterol levels, waist circumference, and blood pressure.

Night shifts may increase the risk of having a heart attack: British Medical Journal

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4. Increased Risk for Breast Cancer

Several studies have also shown that women who work the night shift have a higher risk of developing breast cancer. One study showed that Danish women working nights had a 40% higher likelihood of developing breast cancer. Working nights for more than six years and three times or more per week specifically raised the risk of developing this type of cancer. Another Canadian study showed that women who worked the night shift for over 30 years doubled their risk of breast cancer.

5. Higher Risk of Depression

Those working nights also increase their risk of depression, since studies show that working at night may have impact mental health negatively. According to the International Journal of Occupational and Environmental Health, depression is more common among shift workers. Another study published in the International Journal on Disability and Human Development noted that individuals who work night shifts have an increased risk of aggravating or developing mood disorders.

Depression, mood disorders more common among shift workers

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6. Gastrointestinal Problems

Shift work also appears to increase the risk of developing serious gastrointestinal issues, such as peptic ulcers. General GI symptoms, such as constipation, diarrhea, and nausea are also seen more commonly in individuals working at night. Working the night shift may even increase the risk of developing irritable bowel syndrome, GERD, and chronic heartburn.

7. Issues with Pregnancy and Fertility

Women who work at night may also have issues with pregnancy and fertility, since the disruption in circadian rhythm may affect the reproductive system in women. Common fertility problems among women working at night include irregular periods, painful periods, and endometriosis. Pregnant women working nights were more likely to deal with miscarriages, low-weight babies, and complications during delivery.

Pregnant women working nights more likely to have miscarriages, complications in delivery

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8. Workplace Injuries are More Likely

Studies show that working at night increases the risk of workplace injuries according to researchers from the University of British Columbia. Shift work disrupts normal sleep patterns, which often results in fatigue and drowsiness on the job. This increases the risk of suffering an injury on the job, and individuals working night shifts are more likely to deal with an injury on the job than those working day shifts.

Working the night shift has the potential to cause significant health problems, and the longer individuals work nights and deal with circadian disruption, the more severe those health problems may be. From increasing the risk of heart disease to increasing the risk of certain types of cancers, shift work poses some serious risks that must be addressed.

Photo courtesy The Financial Times


About the Author

Dr. Pushpa Chandra is a Vancouver-based Naturopathic Physician. She worked for over 27 years as a registered nurse and 22 years at BC's Children's Hospital, working in critical care with the province's sickest children. Her interests include research in circadian rhythm disruption, sports medicine and pediatrics. A competitive sports enthusiast, she has completed ultramarathons and marathons in all 7 continents. As a shift worker she has been using the ingredients of AWAKE and ASLEEP to boost her performance, endurance and overall health.