Research shows that working at night can impair memory by 79% in middle-aged and older adults. Those who work late into the night have a higher incidence of cognitive disorders due to disruptions in their circadian rhythms, which act as the body’s biological clock.
Night Shifts Are Harmful to the Brain
Previous studies have established that shift work significantly impacts health. This includes any work schedule that falls outside the traditional 9-to-5 hours.
The research team analyzed data from 47,811 adults, which included information about their jobs, work schedules, and cognitive function test results. One in five participants reported experiencing some form of shift work during their careers.
Those currently working night shifts exhibited a 79% higher rate of cognitive disorders compared to those who only worked during the day. Furthermore, individuals who worked nights for the longest duration showed a 53% increase in cognitive issues. The study’s authors told the Daily Mail that these results may stem from disruptions in circadian rhythms, the body’s internal clock.
Night Work Disrupts Daily Cues
A team of Canadian researchers says their findings suggest a link between shift work and cognitive dysfunction. They propose that disruption to daily environmental cues may play a role in neurodegeneration, contributing to cognitive impairments.
Professor of Circadian Neuroscience Russell Foster says the finding that night-shift work raises the risk of cognitive disorders is significant. He says it aligns with lab and field studies — including research on long-haul airline pilots — that link sleep and circadian-rhythm disruptions with declines in emotional and cognitive functioning.
Not Just Memory Decline, But Heart Issues Too
Previous studies have shown that night shift work is also significantly linked to irregular and rapid heartbeats. A study involving 283,000 people in the UK revealed that women and those who are not physically active may face the highest risk of atrial fibrillation.
Working night shifts is also associated with an increased risk of ischemic heart disease. It’s worth noting that in the UK alone, about 15% of workers are employed at night, often in roles that require overnight work.
