Could Shift Work Contribute to Cognitive Decline?

Shift work over a period of 10 or more years significantly contributed to cognitive loss, and while the negative impact can be reversed, it could take up to 5 years to achieve full recovery, according to a recent study.

“Shift work, like chronic jet lag, is known to disrupt workers’ normal circadian rhythms and social life, and to be associated with increased health problems (eg, ulcers, cardiovascular disease, metabolic syndrome, breast cancer, reproductive difficulties) and with acute effects on safety and productivity,” said the study’s authors.
_________________________________________________________________________________________________________________________________________________________________

RELATED CONTENT
Shift Work May Increase Risk of Diabetes
Working Longer Hours Increases CHD Risk
_________________________________________________________________________________________________________________________________________________________________

“However, very little is known about the long-term consequences of shift work on cognitive abilities. The aim of this study was to assess the chronicity and reversibility of the effects of shift work on cognition,” they said.

For the study, researchers evaluated 3232 employed and retired participants who were 32, 42, 52, and 62 years of age during their first assessment, with 5-year and 10-year follow-up assessments.

Of the participants, 1484 had shift work experience (current or past) while 1635 of the individuals did not. Researchers conducted tests of the participants’ speed and memory during all of the 3 evaluation periods.

The study showed that cognitive impairment was more common in individuals that had worked 10 years of shift work or more than in those with less or no time working shift work.

Investigators noted that the cognitive loss was equivalent to 6.5 years of age-related decline. Once participants retired from shift work, full cognitive recovery took up to 5 years.

The complete study is published in the November issue of Occupational and Environmental Medicine.

-Michelle Canales

Reference:

Marquie JC, Tucker P, Folkard S, et al. Chronic effects of shift work on cognition: findings from the VISAT longitudinal study: findings from the VISAT longitudinal study. J Occup Environ Med. 2014 November [epub ahead of print] doi: 10.1136/oemed-2013-101993