Watching too much TV is linked to a reduction in brain volume, with different effects on the brain than sitting all day at work

A USC-led study of 1,712 adults in the ARIC cohort linked frequent TV watching in midlife to smaller brain volumes and more white matter hyperintensities decades later.

In contrast, long hours of sitting at work were associated with more favorable brain measures, suggesting different types of sedentary behavior may affect the brain differently.

The associations were stronger in men, but the researchers stressed the findings show correlation, not causation.

The results could reshape thinking about screen time, sedentary behavior, and dementia risk, including Alzheimer’s disease.