Scientists: Excessive TV watching leads to brain shrinkage

TV enthusiasts risk aging their brains prematurely — this is the conclusion reached by scientists who published a large-scale study in the journal Alzheimer's & Dementia.

A team of researchers examined data from approximately 1,700 adults with an average age of 53 who participated in the major American ARIC project. Back in the late 1980s, the volunteers reported how often they spent their free time in front of the TV screen. More than two decades later, each of them underwent a brain MRI — and the results proved quite alarming.

In those who watched television "very often," a number of brain regions were found to be noticeably smaller in volume compared to those who turned it on rarely or didn't watch at all. The structures responsible for memory, as well as the frontal and occipital lobes, were the most affected.

In addition, white matter damage in the brain was found significantly more often among avid TV viewers — changes that are directly associated with aging, increased risk of stroke, dementia, and cognitive decline. These changes were particularly pronounced in men.

Notably, the link between TV watching and deteriorating brain health persisted even after the scientists accounted for the influence of other risk factors: physical activity, smoking, alcohol consumption, diabetes, and body mass index.

Interestingly, people who spent just as much time sitting but doing work did not show a similar association. Moreover, the condition of certain brain regions in these individuals turned out to be even better than average. According to the authors, the issue is not with the sedentary position itself, but rather with what exactly a person is doing: intellectual engagement during work can offset the negative consequences of prolonged inactivity.

The scientists note a caveat: the study does not prove a direct causal relationship. Nevertheless, its results clearly indicate that for brain health, it is important not simply to sit less, but to pay attention to what exactly a person is doing during that time.