For decades, parents everywhere have told their children that watching too much television will rot their brains (in a manner of speaking, of course). And if you’re of a certain age, you’ll recall your folks calling it the “boob tube.” Ever wonder why?
The word “boob,” according to the Oxford English Dictionary, once commonly referred to “a stupid, inept, or blundering person; a fool.” So, the cheeky nickname alluded to the fact that “boobs” were content to sit in front of the TV set, filling their brains with simple-minded drivel.
But how damaging is television to the human brain, really? The latest science is worth checking out.
A recent study from Johns Hopkins Bloomberg School of Public Health in Baltimore examined the effects of television on the brain. And these findings are proving those parental television naysayers right.
Examining the viewing habits of 599 American adults between 1990 and 2011, Dr. Ryan Dougherty and his team found that watching television impacts the structure of the human brain. For example, Dr. Dougherty found that those who watched an above average amount of television showed reduced volume in their frontal cortex and entorhinal cortex. So, basically, television really does rot your brain.
Dr. Dougherty and his team concluded that the more television you watch in middle age, the more gray matter you lose.1 Gray matter is the brain’s center for decision-making, hearing and vision, and muscle control. Gray matter volume, studies show, is low in those people who have suffered memory loss and diminished cognitive function.2
TV Watching as a Sedentary Behavior Measure
Despite the fact that lots of bright people watch quality content on TV these days, researchers say television is still a passive activity and this can spell trouble for brain health.
Kelley Pettee Gabriel, Ph.D., lead author of another recent study into television watching, explains that while much research has shown the benefits of exercise to support brain health, less is known about the potential consequences of prolonged sedentary habits, such as television viewing, on brain health.3
“This is important to look at because other studies have shown that physical activity and sedentary behaviors may have different effects on health and disease,” Dr. Gabriel says.
“Engaging in healthy behaviors during midlife, between ages 45 to 64 years in the context of our study, may be important factors to support a healthy brain later in life.”
The lead author of a third study, Priya Palta, Ph.D., adds that while there are no medications to cure or stop dementia, “nearly 40 percent of worldwide dementia diagnoses may be prevented or delayed by modifying twelve risk factors including exercise.”
Television Linked to Diminished Cognitive Function
In Professor Palta’s study, participants were asked how much television they watched in their leisure time. The participant responses were not based on specific hours or amounts of time, but were divided into three categories: never or seldom watched TV (low), sometimes watched TV (medium/moderate), or often/very often watched TV (high).
Professor Palta’s study included 10,700 adults with an average age of 59 years. Each participant offered self-reported assessments of television viewing between 1987 and 1995. Later, researchers measured brain health by asking participants questions about their viewing habits, and supplying cognitive tests and brain MRI scans.
These researchers found that those who watched the most TV had a 6.9 percent greater dip in cognitive function over a 15-year period.4
In the study that Dr. Gabriel led, researchers used a similar self-reporting model. They analyzed 1,601 adults with a mean age of 76.2 years.
Those participants who reported high TV viewing during midlife also had lower volumes of gray matter more than a decade later.
But here’s the most interesting conclusion. These researchers calculated that each 1-hour increase in a person’s daily average TV viewing time was linked to a 0.5 percent reduction in gray-matter volume.
First, let’s discuss the research limitations. When studies use self-reported data, their findings have to be taken with a grain of salt.
Also, I believe additional research is needed to determine if there’s something specific about watching TV or, rather, if the detrimental effects on brain health are due to less physical activity.
I’ve never been a fan of television. I much prefer to read a book, and research from recent years has done little to change my mind about the benefits of TV (or lack thereof). My advice is if you’re going to watch television, watch sparingly and don’t forget to exercise. From time to time, ditch the remote and opt for more cognitively stimulating activities, including reading, knitting, board games, or simply talking to a friend.