OH NOOOOooooooooo my medial temporal lobe* may have shrunk to the size of a pea from all the sitting I’ve done since fracturing my ankle.
“A team of researchers from UCLA and the University of Adelaide studied 35 non-demented adults who were from 45 to 75 years old. They gave each study participant the International Physical Activity Questionnaire to determine how many hours on average they spent sitting and how much physical activity they got each day. Each study participant also underwent a high-resolution MRI scans of his or her brain.”
The researchers found that the more hours the subjects sat the thinner the medial temporal lobes of their brains tended to be. (Each hour of additional sitting correlated with a medial temporal lobe that’s 2% thinner.) This was regardless of how much physical activity they engaged in when not sitting.
Some of the possibilities of how sitting impacts your brain include:
- Your blood may not be circulating as much throughout your body and therefore your brain. This could mean that your brain is not getting as much oxygen or the waste products in your brain aren’t being cleared out as effectively.
- You don’t burn as many calories, which could lead to weight issues, which then alter a wide variety of mechanisms in your body.
- Your body’s metabolic machinery and hormones may be impacted so that your brain is not getting as many nutrients or is being exposed to other conditions such as higher blood sugar.
Correlations and associations do not mean cause-and-effect.
A study with only 35 people has many limitations and does not prove that sitting will make part of your brain thinner. “Maybe in this study, the people who were more likely to sit more each day also were more likely to be less active socially, have less stimulating jobs, or have other circumstances that could be affecting their brains. Alternatively, could thinning medial temporal lobes somehow be affecting their behaviors so that they sat more? More studies are needed to figure out what is actually happening.”
*The medial temporal lobe is part of the brain responsible for forming longer term memories. It tends to thin as you age to begin with!
“Nonetheless, this study does add to the concern that “sitting is the new smoking”, which by the way nothing to do with “cigarette butts.” Other studies have associated regularly sitting for lengthy periods of time with increased risks of obesity, diabetes, muscle and back problems, cancer, and other health problems.”