Shift work harmful, but small changes can help

Knowing how much a few sleepless nights can throw off my concentration, it’s not surprising to learn that for those who routinely do shift work— nurses, doctors, firefighters and, increasingly in our more 24-hour society, retail workers—lack of consistent sleep can throw off natural sleep-wake rhythms playing havoc with health and personal life. Two recent studies highlight new research on shift work. One looks at potential serious effects on organs, while the other provides simple strategies for creating shift schedules that are less harmful.

The human body works according to a natural 24-hour sleep-wake cycle, also referred to as a circadian rhythm, which controls body temperature, sleep/wake timing, and the way the organs and body systems work together. Past research has shown that irregular sleep patterns and shift work take a toll on even the healthiest person over an extended period. At the University of Toronto, researchers found that disruption of this natural sleep-wake cycle is a contributing factor in the development of organ disease. The findings were recently published in the Journal of American Physiology.

“We knew that circadian rhythm disruption had been linked with reduced longevity so we decided to try and find out where, why and how longevity is compromised,” said researcher Martin Ralph, a professor out of the Department of Psychology at U of T and one of the lead researchers on the project, in a press release. The research team found that co-ordination of the many circadian clocks throughout the body is critical for normal healthy organs and that long-term disruption of normal circadian rhythms can ultimately result in heart and kidney disease.

But simple work schedule changes may promote health and help shift workers strike a better balance between work and personal life, according to a new review of studies in this area from researchers at Durham University in England, published in the May issue of the American Journal of Preventive Medicine and reported by Health Behavior News Service.

The study looked at 26 studies of shift workers, including traffic controllers, autoworkers, police officers, nurses and chemical plant employees, and found that many have frequently changing schedules. Instead of a permanent night shift, some workers work at night for several days and then rotate to afternoons for several days.

According to the review, forward-rotating shifts that follow the logical order of the day seem to be less damaging to health and easier on the body. A forward rotation would be a shift in the morning, then the afternoon and then maybe a night shift later. That is less harmful to people’s health than starting at night, It also found that rotating workers through shift changes more quickly—perhaps every three or four days versus every seven days—is better for health and work-life balance. These changes didn’t have big costs associated with them and they were not particularly disruptive.