Physical Work Demands May Influence Memory Decline in Older Age
A new study suggests that a physically demanding job is associated with occupational stress and may lead to faster brain aging and poorer memory.
In the research, Colorado State University investigators connected occupational survey responses with brain-imaging data from 99 cognitively normal older adults, age 60 to 79. They found that those who reported high levels of physical stress in their most recent job had smaller volumes in the hippocampus and performed more poorly on memory tasks.
The hippocampus is the part of the brain that is critical for memory and is affected in both normal aging and in dementia.
The study, performed by Dr. Aga Burzynska, an assistant professor in the Department of Human Development and Family Studies, and her team appears in Frontiers in Human Neuroscience.
“We know that stress can accelerate physical aging and is the risk factor for many chronic illnesses,” Burzynska said. “But this is the first evidence that occupational stress can accelerate brain and cognitive aging.”
She added that it is important to understand how occupational exposures affect the aging of our brains.
“An average American worker spends more than eight hours at work per weekday, and most people remain in the workforce for over 40 years,” Burzynska said. “By pure volume, occupational exposures outweigh the time we spend on leisure social, cognitive and physical activities, which protect our aging minds and brains.”
Burzynska explained that the association between “physical stress” and brain/memory were driven by physical demands at work. These included excessive reaching, or lifting boxes onto shelves, not necessarily aerobic activity.
This is important because earlier work by Burzynska and her colleagues showed that leisure aerobic exercise is beneficial for brain health and cognition, from children to very old adults. Therefore, the researchers controlled for the effects of leisure physical activity and exercise.
As expected, leisure physical activity was associated with greater hippocampal volume, but the negative association with physical demands at work persisted.
“This finding suggests that physical demands at work may have parallel yet opposing associations with brain health,” Burzynska explained. “Most interventions for postponing cognitive decline focus on leisure, not on your job. It’s kind of unknown territory, but maybe future research can help us make some tweaks to our work environment for long-term cognitive health.”
She added that the results could have important implications for society.
“Caring for people with cognitive impairment is so costly, on economic, emotional and societal levels,” Burzynska said. “If we can support brain health earlier, in middle-aged workers, it could have an enormous impact.”
The researchers considered and corrected for several other factors that could be related to work environment, memory and hippocampus, such as age, gender, brain size, educational level, job title, years in the occupation and general psychological stress.
“The research on this topic is so fragmented,” Burzynska said.
“One previous study linked mid-life managerial experience with greater hippocampus volume in older age. Another showed that taxi drivers had larger hippocampi than a city’s bus drivers, presumably due to the need to navigate.
In our study, job complexity and psychological stress at work were not related to hippocampal volume and cognition. Clearly, our study is just one piece of the puzzle, and further research is needed.”
Source: Colorado State University
Nauert PhD, R. (2020). Physical Work Demands May Influence Memory Decline in Older Age. Psych Central. Retrieved on November 24, 2020, from https://psychcentral.com/news/2020/07/23/physical-work-demands-may-influence-memory-decline-in-older-age/158333.html