This is an odd admission for a psychiatrist to make, but I’ve never been very good at sitting still. I’m antsy in my chair and jump at any opportunity to escape it. When I’m trying to work out a difficult problem, I often stand and move about the office.
We’ve known for a while that sitting for long stretches of every day has myriad health consequences, like a higher risk of heart disease and diabetes, that culminate in a higher mortality rate. But now a new study has found that sitting is also bad for your brain. And it might be the case that lots of exercise is not enough to save you if you’re a couch potato.
A study published last week, conducted by Dr. Prabha Siddarth at UCLA, showed that sedentary behavior is associated with reduced thickness of the medial temporal lobe, which contains the hippocampus, a brain region that is critical to learning and memory.
The researchers asked a group of 35 healthy people, ages 45 to 70, about their activity levels and the average number of hours each day spent sitting and then scanned their brains with MRI. They found that the thickness of their medial temporal lobe was inversely correlated with how sedentary they were; the subjects who reported sitting for longer periods of time had the thinnest medial temporal lobes.
The implication is that the more time you spend in a chair the worse it is for your brain health, resulting in possible impairment in learning and memory.
Of course, the study cannot prove that this link is causal. It’s possible that people with pre-existing cognitive problems might just be more sedentary. Still, the researchers screened the subjects to rule out major medical and psychiatric disorders, so this explanation is unlikely.
What’s also intriguing is that this study did not find a significant association between the level of physical activity and thickness of this brain region, suggesting that exercise, even strenuous exercise, may not be enough to protect you from the harmful effects of being sedentary.
This all puts me in mind of the ancient Greek Peripatetics, followers of Aristotle, who conducted their philosophical inquiries while strolling about the Lyceum. Sounds like they were on to something.
But what is it about walking — besides increased blood flow to the brain — that might facilitate thinking? Perhaps it’s the fact that you are constantly bombarded by new stimuli and inputs as you move about, which helps derail linear thinking and encourages a more associative unfocused thought process.
Dr. Friedman is a contributing opinion writer and the director of the psychopharmacology clinic at the Weill Cornell Medical College.