Does Shift Work Increase My Risk of Cancer?

From healthcare workers and plant personnel to law enforcement and truck drivers, nearly 15 million Americans do shift work. And among those who start work between 2-6 a.m., men take the lead. Other than the struggle of trying to sleep when the rest of us are awake, the lack of sleep and sleep disruptions shift workers face can have serious health implications.

A study published in Annals of Medicine found that men who do shift work without napping during the day are 43% more likely to be diagnosed with cancer later and are twice as likely to die as a result. And men who had worked night shifts for over 20 years had a 27% increased risk of cancer incidence.

Multiple studies have looked at the connection between sleep and prostate cancer. One found that men under 65 who reported getting three to five hours of sleep consistently were 55% more likely to die of prostate cancer when compared to men who reported getting seven hours or more a night.

Sleep deprivation and the presence of light at night while working an overnight shift can inhibit the natural production of melatonin, a hormone that affects sleep cycles. Low melatonin production can lead to an increase in genetic mutations, greater oxidative damage, reduced DNA repair and a weakened immune system.

Another study found that men who slept longer and with fewer interruption had increased levels of melatonin in their urine and were 75% less likely to develop advanced prostate cancer than those with less melatonin.

There is a growing body of research looking at factors that disrupt circadian rhythms – like shift work and a lack of sleep. Circadian rhythms are 24-hour cycles that are part of the body’s internal clock, and one of the most important circadian rhythms is the sleep-wake cycle. When running smoothly, that means great nights of sleep. But if your circadian rhythm is thrown off … not so much.

Getting adequate sleep is key to your overall health, with a slew of benefits – a better mood, immune system, memory and weight, to name a few. For shift workers, consistency is key. If you can, stay on the same sleep schedule every day of the week. This means night shift workers, for example, shouldn’t switch to sleeping at night on their off days. Keeping a regular schedule helps align your body clock with your sleep pattern, increasing the quality of your sleep.