Reducing this behaviour could decrease the risk of dementia.
Too much sitting down is linked to a thinner brain in regions critical to memory formation.
Reducing sedentary behaviour could also decrease the risk of dementia.
Even high levels of physical activity were not enough to offset the damaging effects of sitting down for long periods, the researchers found.
The study’s authors conclude:
“In this preliminary study of middle-aged and older adults, self-reported hours per day spent sitting, but not physical activity level, was associated with less thickness in the MTL [the medial temporal lobe] substructures.
These findings are novel and require further exploration in longitudinal studies and analysis of mediating mechanisms.
Better understanding the effects of sedentary behavior on our brains is important given the global epidemic of physical inactivity and sedentary lifestyles.”
For the study, 35 middle-aged people were asked about their physical activity and had their brains scanned.
More sedentary people had thinner medial temporal lobes.
The medial temporal lobe is involved in the formation of new memories.
The authors write:
“Several lines of evidence suggest that sedentary behavior may be a risk factor for the development of age-related cognitive impairment.
A detailed projection of the effect of risk factors on Alzheimer’s disease (AD) prevalence suggests that approximately 13% of AD cases worldwide may be attributable to sedentary behavior.
A 25% reduction in sedentary behavior could potentially prevent more than 1 million AD cases globally.”
The study was published in the journal PLOS ONE (Siddarth et al., 2018).
