Memory decline and dementia risk: how television affects your brain

A large study published in the journal Alzheimer's & Dementia has found a link between prolonged television viewing in middle age and structural brain changes years later. Participants who watched a lot of TV had smaller frontal and occipital lobes, as well as more hyperintense lesions in white matter, which is associated with the risk of cognitive impairment. The association persisted after accounting for smoking, diabetes, and activity levels. Sedentary work did not produce the same effect—the key factor was the passive nature of viewing. Men were found to be more vulnerable.

A large study published in the journal Alzheimer's & Dementia has identified a link between the habit of watching television for long periods in middle age and structural brain changes that appear years later. Scientists analyzed data from approximately 1,700 US residents participating in the long-term ARIC project. When participants were on average about 53 years old, they reported their habits. About two decades later, their brain health was assessed using MRI. Those who frequently watched television had smaller frontal and occipital lobes, as well as structures related to memory. Additionally, they had more hyperintense lesions in white matter, indicating small vessel damage and associated with the risk of stroke and dementia. The association remained after accounting for smoking, alcohol consumption, body mass index, diabetes, and physical activity levels. Notably, participants who spent a lot of time sitting at work on intellectual tasks did not show such changes—on the contrary, they had larger volumes in some brain regions. Researchers attribute this to the passive nature of television viewing, which does not require active intellectual engagement. A separate analysis showed that most structural changes were observed in men. The authors emphasize that the data do not prove that television directly causes dementia, but they serve as an argument in favor of diverse leisure activities that include physical and mental activity.