Researchers report on a newly-found perk of desk jobs: better cognition in later life.
People who work at jobs that require less physical activity such as desk jobs tend to perform better on mental tasks later in life. The authors explain that this comes down to the greater cognitive challenge of such jobs compared to more physical ones, but note that further research is needed to fully understand this effect.
"The often used mantra 'what is good for the heart, is good for the brain' makes complete sense, but the evidence on what we need to do as individuals can be confusing," said Shabina Hayat from the Department of Public Health and Primary Care at the University of Cambridge. "With our large cohort of volunteers, we were able to explore the relationship between different types of physical activity in a variety of settings."
Lack of physical activity and exercise are known contributors to major health conditions. These include heart disease as well as mental effects, such as poor cognition. But the authors note that we don't yet have reliable poof that physical activity actually protects against cognitive decline.
They worked with data from roughly 8,500 adults aged 40-79 gathered as part of The European Prospective Investigation of Cancer in Norfolk (EPIC-Norfolk) cohort study. The participants each received a baseline general assessment between 1993-1997 and a cognitive assessment between 2004 and 2011. This tested their abilities in areas such as memory, attention, visual processing, speed reading, and cognitive capacity. As part of this questionnaire, they also described their health and lifestyle, and underwent a health examination.
The data structure allowed the team to categorise levels of physical activity during leisure and work, and see if they had different effects on cognition later in life. The long span of the study made it possible to tease out other long-term biases where poor cognition would be the cause of physical inactivity (such as early dementia), not the effect.
All in all, the team reports that physically-inactive jobs were associated with a lower risk of poor cognition at all levels of education. People who worked such a job throughout the study period were most likely to be in the top 10% of performers among the participants. People with no qualifications were more likely to work physically-intensive jobs, but they were less active in their leisure time and had almost three times the chance of poor cognition compared to the first group.
"Our analysis shows that the relationship between physical activity and cognitive is not straightforward," explained Hayat. "While regular physical activity has considerable benefits for protection against many chronic diseases, other factors may influence its effect on future poor cognition.
"People who have less active jobs -- typically office-based, desk jobs -- performed better at cognitive tests regardless of their education. This suggests that because desk jobs tend to be more mentally challenging than manual occupations, they may offer protection against cognitive decline."
However, for now, the team can't definitively say that either desk jobs or physical activity in our free time ward off cognitive decline. Furthermore, there's also the question of how socioeconomic backgrounds influence cognitive performance and employment opportunities. It does however seem that putting our mind to work at work and keeping our bodies moving during play is the best combination for our health.
The paper "Cross-sectional and prospective relationship between occupational and leisure-time inactivity and cognitive function in an ageing population: the European Prospective Investigation into Cancer and Nutrition in Norfolk (EPIC-Norfolk) study" has been published in the journal International Journal of Epidemiology.