Watching Too Much TV May Actually Rot Your Brain After All, Study Finds - ScienceAlert

What the report says

ScienceAlert reported on a new study linking frequent television viewing in midlife with later brain differences associated with dementia risk, particularly among men. The research, published in Alzheimer’s and Dementia: Journal of the Alzheimer’s Association, analyzed more than 1,700 adults followed for nearly 24 years as part of the Atherosclerosis Risk in Communities study.

According to the report, participants were in their early 50s when they described how often they watched TV during leisure time and how much they sat at work. About two decades later, when they were in their mid-70s, MRI scans were used to examine brain areas known to be affected early in Alzheimer’s disease and related dementias, as well as white matter hyperintensities, which are linked to small-vessel brain disease and cognitive decline.

The study found that men who often watched television in midlife had smaller volumes in vulnerable brain regions and more brain damage markers, while the same association was not seen in women. By contrast, people who reported sitting for much of the workday tended to show larger cortical volumes and fewer white matter lesions. Researchers said the findings suggest the activity performed while sitting may matter: watching TV is generally passive, whereas desk work can involve reading, planning, writing and problem-solving.

The article noted important limits. The study relied on self-reported habits, cannot prove TV viewing caused the brain changes, and may not account for other behaviors such as alcohol use, snacking or napping. Still, the long follow-up period and MRI-based measures add weight to the finding that mentally passive sedentary time may differ from more cognitively engaged sitting.