Recent research from the UK does show that watching television can have a detrimental effect on the brain in adults age 50 and older. Specifically, the study found that watching more than 3.5 hours of TV daily is associated with a decline in verbal memory – the ability to remember words and language. This was observed in tests conducted six years after the investigators collected information on the amount of time the study participants spent watching television.
The researchers, from Univerity College London, drew information from 3,662 participants in a long-running study of aging. They reported that watching TV less than 3.5 hours a day didn’t seem to affect verbal memory. The most pronounced negative effects occurred in those who watched TV for more than seven hours a day. The study revealed that women watched more TV than men, as did people who weren’t married or living with someone, individuals who weren’t employed, and those who had less formal education and lower incomes.
The investigators noted that many previous studies of television viewing saw it as a proxy for sedentary behavior, which has been linked with cognitive decline in older people. But they made the point that “other sedentary activities such as using the Internet are not associated with cognitive decline and might even contribute to cognitive preservation and reduced dementia risk.” This suggests that the sedentary nature of watching television doesn’t fully account for its effects on cognition.
The researchers also wrote that despite a long-standing assumption that spending a lot of time watching TV can contribute to the development of dementia, this hasn’t been proved. There are no guidelines in the UK (or the U.S.) about recommended daily limits for TV watching among seniors.
Despite the downside of watching television seen in this study, the investigators acknowledge that there are benefits. Research with adults has suggested that TV dramas can enhance understanding of others, and that educational television “can be an efficient way of learning when programs are designed appropriately.”
This isn’t the first study to demonstrate that watching too much TV can be bad for the brain. In 2015 researchers at the University of California, San Francisco reported on the effects of watching three or more hours of TV daily on young adults they followed for 25 years. Those who watched that much television and did little exercise were twice as likely as others to score poorly on tests designed to evaluate information processing, verbal memory and executive function – the skills that help us plan, organize and solve problems.
Andrew Weil, M.D.
Daisy Fancourt & Andrew Steptoe, “Television viewing and cognitive decline in older age: findings from the English Longitudinal Study of Ageing.” Scientific Reports, February 28, 2019.