Long working hours could have more than just a negative impact on health; they may also change the brain’s structure, according to new research.
The study, released Tuesday, identified “significant changes” in the brains of those who are overworked. This condition is characterized by physical and emotional strain, along with insufficient rest.
Conducted by researchers from Chung-Ang University and Yonsei University in South Korea, the study examined a group of 110 healthcare professionals, dividing them into “overworked” and “non-overworked” categories.
In South Korea, where the maximum workweek is legally set at 52 hours, overworking has emerged as a pressing public health issue.
The overworked group, comprising 32 individuals, worked 52 hours or more weekly. They tended to be younger, newly employed, and possess higher education levels compared to their counterparts who kept standard hours.
By comparing other study data and utilizing MRI scans, researchers applied neuroimaging methods to investigate changes in brain volume among the workers.
This technique enabled them to assess and identify variations in gray matter across different brain regions, utilizing atlas-based analysis to label structures within the scans.
Researchers noted that “those working 52 or more hours a week exhibited significant changes in areas linked to executive function and emotional control, unlike those working standard hours.”
Specific brain regions that increased in volume included the middle frontal gyrus, influential in cognitive functions like attention and memory, and the insula, which handles emotional processing and social awareness.
The findings imply a “potential relationship” between higher workloads and alterations in these regions, indicating a biological basis for the cognitive and emotional difficulties faced by overworked individuals.
Joon Yul Choi, a co-author and assistant professor at Yonsei University’s Biomedical Engineering Department, remarked that these alterations could be “at least partly reversible” if stress-inducing factors are alleviated. However, reverting to a baseline brain state might take longer than expected.
Previous studies have underscored the negative health effects tied to extensive working hours. For instance, a 2021 joint study by the International Labour Organization (ILO) and the World Health Organization (WHO) linked overworking to over 745,000 fatalities in one year. Excessive hours have also been associated with increased risks of diabetes among women and a decline in cognitive capabilities.
While the psychological and behavioral effects of overwork are well recognized, the neurological mechanisms and anatomical changes remain less clear, according to the study.
Frank Pega, who led the WHO-ILO report in 2021, indicated that these fresh findings provide “important new evidence” that can enhance understanding of how extended working hours significantly affect workers’ physical health.
Pega, a WHO technical officer not involved in the current study, emphasized that the research reaffirms previous assertions that “long working hours are the primary risk factor for disease.”
However, the study’s limited sample size and its focus solely on healthcare workers in South Korea make generalization difficult. “More studies across various populations are essential,” remarked Pega.
“Although the results should be interpreted with caution due to the exploratory nature of this pilot study, they represent a relevant initial step in grasping the link between overwork and brain health,” noted the researchers.
For those caught in lengthy work hours, this study might just provide a scientific justification for reducing time spent at work.
“To safeguard workers’ health against long hours, actions from governments, employers, and individuals are crucial,” Pega advised, referencing laws and policies that can ensure healthier work patterns.
“The results emphasize the need to address overwork as a significant occupational health issue,” stated the authors of the study.
Jonny Gifford, a principal research fellow at the Institute for Employment Studies in Brighton, England, who was not part of the research, said the findings “validate the physiological impacts that extended working hours have on our wellbeing.”
He added, “By employing brain scanning technology to reveal neurological explanations, this study offers compelling evidence connecting overwork to structural brain changes related to executive function and emotional regulation.”
“Though it’s a small study involving 110 healthcare professionals in Korea, the strength of its neurological measurements and the fundamental nature of the issues of overwork and fatigue make its conclusions broadly applicable,” Gifford concluded.
The study appeared in the journal of Occupational and Environmental Medicine.
