Watching television for more than three-and-a-half hours a day in later life is associated with a decline in verbal memory, according to research from University College London (UCL).
The study analysed data from 3662 adults aged 50 and over, and found that watching TV for more than three-and-a-half hours per day was associated with a decline in memory of words and language over the following six years.
The association was independent of other individual socio-economic, behavioural and lifestyle factors, including time spent sitting down.
Participants from the English Longitudinal Study of Ageing (ELSA) were asked in 2008/09 and in 2014/15 about how much television they watched daily, and they also took part in verbal memory and fluency tests.
Researchers found that adults who watched television for more than three-and-a-half hours a day experienced, on average, an eight to 10 per cent decrease in verbal memory, while those who watched less than three-and-a-half hours of television per day experienced, on average, a decrease in verbal memory of around 4 to 5 per cent over the same period.
“There has been interest for over a decade in the effect of television-viewing behaviours on cognition, but much of this literature has concentrated on children,” explained Dr Daisy Fancourt from UCL.
“Much less attention has been paid to the effects of television viewing at the other end of the lifespan, despite it being hypothesised for over 25 years that watching excessive television could contribute to the development of dementia.
“While watching television may also have benefits such as educational benefits from watching documentaries and relaxation benefits as a way of reducing stress, overall, this suggests that adults over the age of 50 should try to ensure television viewing is balanced with other contrasting activities.”
Dr Fancourt also suggested that watching television could reduce the amount of time that people spend on activities that could contribute to cognitive preservation, such as reading.
Additionally, interactive screen-based activities, such as video gaming and using the internet, can have cognitive benefits, such as improved problem-solving skills, whereas the alert-but-passive nature of watching television may create cognitive stress that could contribute to memory decline.