Study Finds Long-Term Shift Work Can Impair Brain Function


Various studies have proven that shift workers face a higher risk of being injured on the job than those who work days and that such work can impact employees’ health in various ways. But what about its impact on their brain function?

A study published in the journal Occupational & Environmental Medicine in Nov. 2014 looked at the impact of shift work on workers’ cognitive abilities and found that shift work significantly impacted cognitive performance of workers who did such work for 10 years or more.

The study was based on data taken from the VISAT study (Marquié et al., 2002), which was designed to study the relationship between aging, health and shift work. The initial sample was composed of 3,232 present and former workers of both genders and ages 32 to 62 years in 1996. Researchers followed up with the subjects in 2001 and 2006.

Workers’ cognitive functioning was assessed at all three stages through neuropsychological tests on processing speed, selective attention and verbal episodic memory.

When examining the effect of shift work duration on cognitive performance, the study  found that the effect was significant for workers who experienced shift work for more than 10 years, with a cognitive loss equivalent to 6.5 years of age-related decline.

The good news is that this impact could be reversed by returning to normal day work hours. For example, workers who’d quit shift work for more than five years exhibited higher cognitive performances—at the same level as those of people who were always day workers.

To reduce the impact of shift work on workers’ physical and psychological health, the study has these recommendations for employers:

  • Move people from shiftwork after 10 years of exposure
  • Plan shifts as far in advance as possible
  • Keep schedules flexible by letting workers trade shifts
  • Schedule time off over weekends
  • Provide workshops and information sessions on stress management
  • Make sure demands on workers are reasonable
  • Maximize worker autonomy
  • Include a mental health component to employee assistance programs
  • Consider offering facilities for social activities, such as recreation and staff social gatherings
  • Provide exercise facilities on site
  • Schedule regular meals
  • Provide a 24-hour cafeteria where night workers can obtain a hot, nutritious meal and appropriate dining facilities that allow a meal to be eaten away from the workplace, with colleagues, in as pleasant a surrounding as possible
  • Provide a variety of food choices: complete or vegetarian meals and high-quality snacks are recommended
  • Try to meet food guide nutrition requirements, such as by reducing the provision of highly salted foods and foods high in fat (Learn how to implement a healthy food and beverage policy in your workplace.)
  • Limit caffeine and alcohol consumption
  • Provide regular (e.g. annual) health checks for shift workers and transfer them to day work if required.

Learn more about the risks related to shift work: