TV Viewing Habits in Midlife Could Exacerbate Cognitive Decline

Bingeing new Netflix series, movie trilogies, or reality shows has become nothing short of an American pastime. But what effect does so much TV time have on our cognitive health?

Sedentary behavior has been linked to such health complications as poor sleep, compromised bone health, heart disease, stroke, cancer, diabetes, and even early death. And new research shows that middle-aged to older adults reporting high levels of television viewing experience greater cognitive decline.

People are more likely to become sedentary as they age. So it's important to understand the potential consequences of this kind of behavior and take the necessary steps to promote cognitive health and function.

The Research

Three studies were presented at the American Heart Association’s virtual Epidemiology and Prevention—Lifestyle and Cardiometabolic Health conference held in late May 2021. Each explored the negative effects high levels of television viewing can have on the brain in middle-aged to older adults.

One study focused specifically on cognitive decline and risk of dementia in relation to how much leisure time was spent watching television.

Participants self-reported their television-viewing habits in two separate assessments between the years 1987 and 1995. Then, participants underwent cognitive tests of language, working memory and executive function, and processing speed in two separate assessments between 1996 and 2013.

Researchers found that individuals who reported moderate or high levels of TV watching experienced nearly 7% greater decline in cognitive function over the course of 15 years compared to individuals that reported low levels of TV watching. However, the findings also showed no notable association between high amounts of television viewing and heightened dementia risk.

In a second study, participants also self-reported their television-watching habits on five separate occasions. Participants who reported persistent television viewing then underwent magnetic resonance imaging (MRI) scans to determine whether this behavior affected brain structure measures.

Researchers focused on the brain's gray matter, or the darker tissue of the brain and spinal cord that contributes to muscle control, decision making, seeing, hearing, and other important functions. Typically, a higher volume of gray matter indicates better cognitive skills.

The scans showed that individuals who reported moderate to high viewing levels had lower volumes of gray matter a decade after reporting compared to individuals who reported low levels of viewing. This indicates greater brain deterioration.

The third study presented at the conference used data from a 20-year longitudinal study. Researchers analyzed MRI scans from the study to discover lower gray matter volume in participants who reported more television viewing early to mid-adulthood.

"This sedentary behavior may impart a unique risk with respect to brain and cognitive health,” said the study's lead researcher, Ryan Dougherty, PhD, in a statement. “This is an important finding since it is now well accepted that the neurobiology of dementia, including brain atrophy, begins during midlife. That’s a period where modifiable behaviors such as excessive television viewing can be targeted and reduced to promote healthy brain aging.”

Your Brain on Television

Watching television doesn't require much thought, which is why it's such a popular activity when we're bored, tired, or looking for easy entertainment. But, as these studies illustrate, cognitively passive activities like this aren't the best for our brains.

"As soon as you put a screen in front of [your] face, you’re setting a fixed visual patterning," says neuroanatomist Jill Bolte Taylor, PhD. "You can train your brain to learn new behavior and new things, but if we keep doing the same routinized patterning over and over again, then those cells adapt to whatever that stimulation is. And the other cells get the message, ‘Well, I’m not needed.’"

Taylor, a stroke survivor herself and author of the book "Whole Brain Living: The Anatomy of Choice and the Four Characters That Drive Our Life," notes that our brains do best when they have opportunities to learn and take on new challenges. Without this, the brain lacks stimulation. While mindless television might not benefit your brain health, not all TV is created equal. Intentionality in what you're watching can help.

When looking for something to scratch the TV itch, opt for documentaries on subjects you're interested in, YouTube videos that teach you something new, or game shows that test your knowledge. These provide more stimulation than, say, a reality show or action movie.

"Don’t be a couch potato unconsciously," Taylor says. "That's where we work into really bad habits, and we let ourselves deteriorate.” 

Stay Stimulated

Your cognitive health is of the utmost importance, so it's important to keep the billions of cells in your brain active and stimulated. Limiting the amount of time you spend binge-watching and instead prioritizing trying new activities and challenging yourself is key.

Spending time outdoors, taking walks through neighboring towns, or trying a new recipe are great alternatives. Taylor recommends diving into a familiar or unfamiliar art practice (she paints along with famed TV art teacher Bob Ross) or spending time on sites like Brain HQ that offer gamified brain exercises and trainings to continue to challenge the mind regardless of your age or physical abilities.

"We become what we feed ourselves," Taylor says. "If we feed ourselves exciting, interesting curiosity, then the brain tunes itself to be adventurous and open to possibilities. We have so much more power over what’s going on inside our heads than we have ever been taught. And to really pay attention to new possibilities is a great way to fuel your mind toward health.”