Shift work linked to brain changes and cognitive decline, study reveals

A new study has found that shift work alters brain structure and function. Researchers observed reduced brain volume and lower cognitive performance in those working irregular hours. However, some recovery was seen in workers who returned to daytime schedules. The study compared shift workers to daytime employees. It revealed symmetrical tissue loss in the left amygdala and right thalamus among those on irregular shifts. White matter microstructure also appeared impaired in this group.

Shift workers scored lower on tests measuring memory, processing speed, and fluid intelligence. The research further showed that the more frequent the shift work, the greater the reduction in amygdala volume. Despite these findings, the changes were described as minor, and not all workers faced severe impairment.

Notably, workers who stopped shift schedules saw a halt in brain volume loss—some even experienced slight recovery. The study’s authors stressed that the design does not prove shift work directly causes these effects. They have, however, called for regular health checks, sleep and stress management support, and more flexible scheduling for shift workers. The findings strengthen arguments for predictable daytime working hours, especially for middle-aged and older employees. While the brain changes are modest, the study highlights the need for better support systems. Employers may now face growing pressure to adjust shift patterns and provide health monitoring for affected staff.