Higher sedentary behaviour is linked to greater neurodegeneration and poorer cognitive outcomes in older adults, even among those who are physically active.
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Many believe that performing daily workouts is sufficient enough to protect the brain from dangers of leading a sedentary lifestyle. However, contemporary studies suggest that even those people who do regular exercises can be affected negatively by spending time sitting.
During a 7-year study, 404 adults aged 50 years and older who participated in the Vanderbilt Memory and Ageing Project were followed by researchers. Participants were wearing devices measuring their sedentary time and physical activity level.
They also passed repeated MRI scans and cognitive assessments for the brain examination. The study results showed that those participants who spent more time sitting had a greater decrease in brain volume as compared to those who spent less time sitting. Thus, it was shown that the more time people were sitting, the more decline showed in their cognitive abilities.
It should also be noted that the study proved that the associations remained even after including the results of moderate physical activities. This means that performing different exercises cannot totally reduce the negative effect of prolonged sitting.
However, it did not prove that prolonged sitting causes brain shrinkage or Alzheimer's disease because it was observational. The study showed an association between sedentary behaviour and brain health changes but did not establish proof of any cause-and-effect relationship.
Reference:
Gogniat, M. A., et al. (2025). Increased sedentary behavior is associated with neurodegeneration and worse cognition in older adults over a 7-year period despite high levels of physical activity. Alzheimer’s & Dementia, 21(5), e70157. https://doi.org/10.1002/alz.70157
