While numerous studies suggest prolonged sitting is bad for your health, a new study suggests that what we do while sitting also matters.
According to a US study published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, watching a lot of television in middle age was linked to greater shrinkage in brain regions involved in memory and thinking.
The findings were based on 1,712 adults with an average age of 53. Participants reported how often they watched television during their free time and how much time they spent sitting at work.
More than 20 years later, brain scans revealed striking differences. Compared with people who said they watched television “never” or “seldom”, those who reported watching it “very often” showed broad structural differences throughout the brain.
They tended to have smaller volumes in brain areas involved in memory, thinking, decision-making, and visual processing, as well as more signs of damage in the brain’s white matter. These changes have been associated with ageing, stroke risk, cognitive decline, and dementia
Interestingly, sitting itself was not linked to poorer brain health. People who spent a lot of time sitting at work showed better brain health, with larger brain volumes and less white matter damage than those who sat and watched TV.
Researchers suggest that many seated jobs involve problem-solving, concentration, and other forms of intellectual stimulation, which may affect the brain differently from passive television viewing.
MRI scans also showed that brain changes associated with TV watching were more pronounced in men.
"We frequently encourage the public not to spend too much time sitting down,” the study author said, “but experts may want to expand that recommendation to encompass the activities done while sitting, since those seem to have distinct impacts on brain health.”
