Kids are often cautioned against watching too much TV, but maybe older adults should be too.

A recent study in Alzheimer’s and Dementia: Journal of the Alzheimer’s Association finds that people who reported watching TV “very often” in midlife later exhibited reduced volume in some areas of the brain. They also showed damage in the brain’s white matter associated with aging, stroke risk, cognitive decline and dementia.

“For years we’ve focused on how much people sit. Our findings suggest we should also pay attention to what they’re doing while they’re sitting,” says David Raichlen, professor of biological sciences and anthropology at the USC Dornsife College of Letters, Arts and Sciences and a senior author of the study.

The study also looked at other sedentary activities, but they didn’t have the same associations.

So it seems sitting isn’t the problem, but what you do while sitting.

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