Nurses sacrifice themselves for others every shift, enduring long hours on their feet and exposure to deadly pathogens. However, working unusual shifts may pose even more of a danger to the health of nurses, as well as other professionals that don’t work a standard day shift.

The Nurses’ Health Study

The Nurses’ Health Study has been one of the longest and most comprehensive studies of women’s health, researching the impact of different variables since 1976. Almost a quarter of a million nurses took part in this research, providing information on a variety of lifestyle and health variables while letting researchers track their health.

Among other things, the shifts these nurses work were tracked, turning this huge research project into an unintended study of chronobiology and the effects of shift work on the circadian rhythm. Some nurses work nights consistently, others at least three times a month and the last group hardly ever. Researchers began to notice a trend: Nurses who worked night shifts were at higher risk of death from a variety of seemingly unrelated causes.

Night Shifts and the Life Span

Nurses who worked the night shift were 19 percent more likely to die of heart disease and more than 25 percent more likely to die of lung cancer. These nurses were also more likely to have accidents that negatively affected both themselves and patients. This increased risk of disease and accidents adds up to a shortened life span for nurses who work nights, and likely other night shift workers as well.

How can working a night shift affect your life expectancy? People who work nights suffer disruptions to the circadian rhythm that prevent effective DNA repair while disrupting the balance of important neurochemicals such as serotonin and melatonin. Maintaining a healthy circadian rhythm is essential to both brain and cardiovascular health, but almost impossible for people who work odd hours. The World Health Organization has actually labeled night shift work a carcinogen due to the effects on DNA repair and cancer risk.

What Does This Mean for Other Shift Workers?

Nursing is not the only profession where night work is often necessary. Almost 20 percent of workers around the globe work nights. These workers are subject to the same biological stressors of night shift work: disruptions to the circadian rhythm, impairment in decision-making and reaction times and heightened risk of a wide range of chronic, life-threatening diseases.

While this may seem dire for people who have to work nights, understanding the problem is the first step in solving it. Strategies such as light therapy, melatonin supplementation and diet changes may help to reduce the effects of night work and help people maintain a healthy circadian rhythm regardless of their schedule. Researchers in chronobiology are actively looking for ways to restore a healthy biological rhythm in people who cannot avoid night shifts.

Studies are showing medical professionals how important sleep and a healthy circadian rhythm are to overall health. More importantly, they are shedding light on the cellular processes that make up a healthy circadian rhythm and ways that sleep-deprived people of all kinds can achieve the good health they deserve.