Many people grew up hearing that watching too much television would ‘rot your brain.’ While that saying is exaggerated, a new study suggests there may be some truth behind the warning.
Researchers found that people who watched television very often during middle age were more likely to show changes in brain structure years later. The study was published in Alzheimer’s & Dementia.
The research was carried out by scientists at the USC Dornsife College of Letters, Arts and Sciences. They wanted to know whether different kinds of sitting affect the brain in different ways. Most earlier studies focused only on how long people sat each day rather than what they were doing while sitting.
The team analyzed information from about 1,700 adults who joined the long-running Atherosclerosis Risk in Communities study in the late 1980s.
Participants were around 53 years old when they answered questions about how often they watched television and how much time they spent sitting at work. More than 20 years later, they underwent detailed brain MRI scans.
People who reported watching television very often had smaller brain areas linked to memory, planning, and visual processing. They also had more white matter damage, which has been linked to aging, stroke, dementia, and declining thinking skills. These differences remained even after researchers considered exercise, smoking, alcohol use, diabetes, and body weight.
One surprising finding was that sitting itself did not appear to explain the results. People who spent long hours sitting at work often showed healthier brain measurements than those who spent large amounts of time watching television. Researchers believe mentally demanding work may keep the brain more active than passive television viewing.
The scientists also noticed that the associations were stronger in men than in women, although they are not yet sure why. They caution that the study cannot prove television directly caused the brain changes because TV viewing was self-reported and participants did not have brain scans at the beginning of the study.
Overall, the findings suggest that the quality of sedentary activities may matter as much as the amount of time spent sitting.
Reading, learning, puzzles, creative hobbies, or other mentally engaging activities may be healthier choices than spending many hours watching television. More research is needed, but this study provides another reason to balance screen time with activities that challenge both the body and the mind.
Study analysis: This was a large, long-term study with careful statistical adjustment, making the findings important.
However, because it was observational, it shows a link rather than cause and effect. Future studies using baseline brain scans and objective measures of screen time will help confirm whether reducing television viewing can protect brain health.
If you care about dementia, please read studies about Vitamin B9 deficiency linked to higher dementia risk, and flavonoid-rich foods could help prevent dementia.
For more health information, please see recent studies that cranberries could help boost memory, and how alcohol, coffee and tea intake influence cognitive decline.
Source: University of Southern California (USC).
