Does shift work impair workers’ memory?

People exposed to night shifts and rotating shift work are more likely to experience cognitive impairment in later life, according to a new study from York University, Canada.

The findings, based on self-reported data and cognitive function tests from almost 50,000 people participating in the Canadian Longitudinal Study, adds to a growing body of evidence on the health impacts of irregular work schedules.

Overall, one in every five individuals (21%) reported having been exposed to some kind of shift work over their career. Higher rates of cognitive impairment were found among participants exposed to night shift work during their current job or night shift work during their longest job when compared to those who only reported daytime work.

Within subdomains of cognition, night shift work was associated with memory function impairment and rotating shift work was associated with impairment of executive function.

In a paper published in the journal PLOS ONE, the authors conclude that circadian rhythm disruption due to shift work could have a negative impact on cognitive function in middle-aged and older adults, which warrants further investigation.

‘The study findings suggest a potential link between shift work exposure and cognitive function impairment,’ the authors said. ‘We speculate that disruptive circadian stimuli may play a role in neurodegeneration contributing to cognitive impairment.’

However, they said additional studies are needed to confirm the association between shiftwork and cognitive impairment as well as any physiological pathways that underlie the mechanism.