How Does Shift Work Impact Your Health?

Health Professional

According to the U.S. Bureau of Labor Statistics, 15 million people work evening shift, night shift, rotating shifts or other schedules outside the traditional 9 AM to 5 PM work day. These non-traditional hours are called shift work.

Shift workers include nurses, doctors, firefighters, police officers, flight attendants, pilots, waitresses, and truck drivers.

Shift work had been linked to various health conditions.

Health effects of shift worardiovascular disease: Shift work increases cardiovascular disease 40 percent, on average. The longer you perform shift work, the greater your risk.

Diabetes: According to a 2014 meta-analysis published in Occupational & Environmental Medicine, shift work is associated with increased diabetes risk. Risk is significantly increased for men and those who work rotating shifts.

Depression: Shift workers tend to have lower serotonin levels. Serotonin is a central nervous system hormone and neurotransmitter. Low serotonin levels are connected to sleep issues, anger, depression, and anxiety.

Cancer: In 2007 the International Agency for Research on Cancer declared the circadian rhythm disruption linked to shift work as probably carcinogenic. A study published in 2013, meanwhile, found women who work night shifts for 30 or more years to be at higher risk for breast cancer.

Metabolic syndrome: Evidence suggests shift work may impact metabolic balance and obesity. A study conducted on individuals between 2002 and 2007 found shift workers with one or two risk factors for metabolic syndrome initially were 4.6 and 12.7 times more likely to develop metabolic syndrome. (Lin Y-C, Hsiao T-J, Chen P-C. "Persistent rotating shift-work exposure accelerates development of metabolic syndrome among middle-aged female employees: a five-year follow-up." Chronobiol Int.2009;26:740–55. doi: 10.1080/07420520902929029.) luck finding confirmation on this.

Gastrointestinal disorders: Conditions connected to shift work range from upset stomach, nausea, diarrhea, constipation, heartburn, peptic ulcers, and irritable bowel syndrome. A 1998 cohort study from 1998 that reviewed literature studies from 1966-2009 found night-shift workers to have twice the risk for developing a peptic ulcer compared to daytime workers. (Sugisawa A, Uehata T. Onset of peptic ulcer and its relation to work-related factors and life events: a prospective study. J Occup Health. 1998;40:22-31)

Cognitive declines: A study published in Occupational & Environmental Medicine found shift workers scored lower on memory tests, processing speed, and overall brain power. Researchers found the level of cognitive decline seen in shift works to be equivalent to a 6.5-year age-related decline. (On a positive note, cognitive abilities returned to normal when shift work was stopped for five years.)

Infertility and pregnancy complications: Shift work has been connected to increased miscarriages, complications during delivery, premature births, low-birth weight infants, infertility, endometriosis, and irregular menstruation. (Numinen T. Shift work and reproductive health. Scand J Work Environ Health 1998;24 Suppl 3:28-34)

Steps for counteracting the risks

There are numerous reasons people engage in shift work, from its necessity for furthering one's career, from income pressures and childcare logistics to the simple reality that it is part and parcel of one's chosen field. Whatever the reason, for most workers no longer taking part in shift work is not a realistic plan. But because shift work is just one of many risk factors for various diseases, taking some basic steps to promote good health can help most people maintain fairly low risk while doing shift work. For example:

  • Get adequate sleep. Be aware of the impact light has on sleep quality. Limit your exposure to daylight as you come off a night shift. Consider driving home in sunglasses to reduce morning light exposure and wear a sleep mask to block light when sleeping.
  • Maintain a stable schedule. If possible, work consistent hours versus a rotating schedule.
  • Eat a healthy diet, exercise, and maintain a healthy weight. Maintaining a healthy weight, eating a well-balanced diet, and exercising regularly will reduce your risk for many of the conditions linked to shift work.
  • Consult your doctor. If you’ve noticed changes in your health or have concerns about the impact of shift work on your health, contact your doctor.

If you are working to implement positive changes in your life, but struggle to maintain healthy habits, take a look at How _to Make Heart Healthy Changes I_nto Lifelong Habits.

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Lisa Nelson is a dietitian/nutritionist with a genetic predisposition for high cholesterol and heart disease. She guides clients to lower cholesterol and blood pressure levels through practical diet and lifestyle changes. Learn more and sign up to receive How to Make Heart Healthy Changes into Lifelong Habits at