It’s a phrase that’s reverberated across living rooms for decades: “Turn off that TV!” As a dad to three kids, I need look no further than my own couch to find an abundant and persistent crop of potatoes staring blankly at that siren of a screen. Personally, I try to vary the clause that comes after the main exhortation: “There has to be something better to do,” “It’s too beautiful out to be inside,” or “I swear, I’m taking that thing off the wall” usually do the trick. But often I harken back to my ancestors and deliver the classic parenting chestnut: “That thing will rot your brain!”
I, like many well-intentioned parents before me, levy that particular claim without ironclad scientific evidence supporting its veracity. But now, researchers studying TV watchers—albeit of a slightly older vintage—say viewers may actually suffer some brain ills from the habit.
Publishing their findings in Alzheimer’s and Dementia: Journal of the Alzheimer’s Association earlier this month, a team of scientists analyzed data from more than 1,700 people who were asked, between 1987 and 1989, how frequently they watched television to pass the time. The study subjects averaged 53 years old and were part of a long-running study of cardiovascular and brain health risks in communities across the United States. The authors of the paper followed up with the study participants more than two decades later and scanned their brains using an MRI machine.
The researchers found that people who had indicated they watched TV “very often” showed marked differences in brain anatomy compared to people who reported they watched TV “never” or “seldom.” The brains of the frequent TV watchers had smaller occipital and frontal lobes, which control executive function and visual processing, than their peers. And they also showed reduced volume in brain areas associated with memory and more damage in patches of white matter that are tied to cognitive decline and dementia.
Read more: “Here’s Why Binge-Watching Is Good for You”
“For years we’ve focused on how much people sit,” David Raichlen, University of Southern California anthropologist and a senior author of the study, said in a statement. “Our findings suggest we should also pay attention to what they’re doing while they’re sitting.”
Now, there are limitations to this study, some of which the paper’s authors acknowledge. The findings were based on self-reported behavior rather than direct measurements of subjects’ TV-watching, “which may involve some recall bias,” they wrote. Also, study participants’ brains were not initially MRI scanned, meaning baseline measurements of brain structures were not established. And I feel compelled to note that the pull of TV programming in the 1980s was much less robust than the virtually limitless options available to the modern-day viewer. Also, these people were middle aged at the time they were asked to recount their TV viewing habits. These habits may or may not have differed in their youth.
These caveats aside, the researchers did control for other factors, such as overall physical activity, body mass index, alcohol use, and other potential confounders in their analysis, and the brain differences held. Additionally, they factored in people who were sedentary, but sat at work rather than in front of the boob tube. The brain changes weren’t as drastic in the sedentary workers.
“We frequently encourage the public not to spend too much time sitting down, but experts may want to expand that recommendation to encompass the activities done while sitting, since those seem to have distinct impacts on brain health,” said study coauthor Natan Feter, a USC postdoctoral student.
The authors also note that their findings largely mesh with previous studies conducted in the United Kingdom, where adults who watched more TV tended to have poorer cognitive performance and higher risks of dementia.
These findings are certainly not definitive in supporting my assertion to my children that watching TV is not the best use of their time. But I am grateful that they lend some degree of scientific heft to the suggestion, from me and many parents throughout the past 7 or so decades, that the habit likely does no favors to one’s brain health.
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Lead image: JrCasas / Adobe Stock
