Shift work could harm mental abilities

Shift work could harm mental abilities

Shift work imageLong-term shift work could be linked to impaired brain power, according to a study by scientists from Swansea University and other European researchers.

Shift work, like chronic jet lag, is known to disrupt the body’s internal clock and has been linked to ulcers, cardiovascular disease, metabolic syndrome and some cancers. But little is known about its potential impact on brain functions such as memory and processing speed.

The study, published in Occupational and Environmental Medicine, suggests the impact is most noticeable after 10 years and could take five years to reverse.

Swansea Associate Professor of Psychology Dr Philip Tucker said: “Long-term effects of shift work on the body clock not only harm workers’ physical health, but also their mental abilities. Such cognitive impairments may have consequences for the safety of shift workers as well as their quality of life.”  

Researchers tracked the cognitive abilities of more than 3,000 people who were working or had recently retired. Just under half had worked shifts for at least 50 days of the year.

  • Shift workers had lower scores on memory, processing speed, and overall brain power than others.  
  • People with 10 or more years of shift work had lower global cognitive and memory scores equivalent to 6.5 years of age-related cognitive decline.

No definitive conclusions can be drawn but the disruption of the body clock could generate physiological stressors which may affect the functioning of the brain.

 “The cognitive impairment observed may have important safety consequences for the individuals concerned and society as a whole, given the increasing number of jobs in high hazard situations that are performed at night,” warned the researchers, including Swansea Emeritus Professor Simon Folkard.

They recommend that the health of people who have worked shift patterns for 10 years should be monitored.

Swansea University Department of Psychology