Research published in Scientific Reports suggests that television viewing for more than 3.5 hours per day could contribute to cognitive decline in over 50s.
Prof Tara Spires-Jones, UK Dementia Research Institute Programme Lead and Deputy Director, Centre for Discovery Brain Sciences, University of Edinburgh, said:
“This paper from Fancourt and Steptoe at UCL examined data from over 3,500 people to determine whether there were associations between watching TV and declining cognitive function people over the age of 50. They observed that people who watched more than 3.5 hours of TV per day were more likely to have a decline in memory over six years compared to people who watched less TV. The researchers made efforts to figure out whether this was due other factors like being less active by taking these into account in their analyses. The data from this study suggest that the observed association of watching a large amount of TV was not entirely explained by other factors including being less physically active.
“Despite these solid efforts to control for level of exercise and other lifestyle factors, this type of study cannot prove that watching TV was the cause of cognitive decline. Some of the people in the study could for example be in the very early undetectable stages of dementia which might influence behaviour. Some aspects of memory decline slightly in people as a normal part of ageing, which is very different from the memory decline caused by diseases like Alzheimer’s disease. So while this is a very interesting and well conducted study, more work will need to be done to fully understand whether watching television is truly the culprit in contributing to memory decline as we age. Having said that, the evidence that remaining active and engaged is good for cognition during ageing is overwhelming, so being active instead of watching TV is likely to be good for us all.”
Dr Rosa Sancho, Head of Research, at Alzheimer’s Research UK, said:
“There isn’t much existing evidence exploring whether TV consumption has any bearing on dementia risk. While this study found watching TV for longer than three and a half hours each day was linked to poorer memory performance on word tasks, it didn’t look to see if people went on to develop dementia or include people already living with a dementia diagnosis.
“It’s important that we understand how our lifestyle choices affect our memory and thinking but this study only observed a link between the two and further research is needed to investigate the causes underlying this association in more detail.
“We do know that what is good for our heart is also good for our brain health. The best current evidence shows that staying physically fit and mentally active, eating a healthy balanced diet, not smoking, drinking only within the recommended limits and keeping weight, cholesterol and blood pressure in check are all good ways to support a healthy brain as we age.”
Prof Andrew Przybylski, Associate Professor and Director of Research at the Oxford Internet Institute, University of Oxford, said:
“This is an interesting paper that puts fears about technology and young people on the back burner for once. The main strengths are the sample quality and a range of task-based outcomes including memory and speech fluency instead of relying on surveys alone.
“The results provide food for thought but caution is merited because a relatively high number of statistical tests mean that the chance of a false positive is high. It might be the case that those predisposed to memory and verbal problems simply use self-report questionnaires of screen time differently than those without these problems.”
Prof Dame Til Wykes, Professor of Clinical Psychology and Rehabilitation, Institute of Psychiatry Psychology & Neuroscience, King’s College London, said:
“What this scientifically sound study tells us is that being a couch potato is bad for the over-50s because it is associated with poorer verbal memory but not language fluency. This association was found after accounting for lots of other potential explanations including how much time you spend on the internet. Being a passive observer may be a potential explanation.
“There is still a lot we don’t know, such as whether memory reductions are affected by what we watch, whether we watch alone or whether you interact with the TV like those on Gogglebox. We also don’t know whether changing behaviour would improve memory.
“Although this result will cause us to think carefully about screen time, a lot more research is needed before we panic and closely measure TV time like a step counter.”
Dr Bob Patton, Lecturer in Clinical Psychology, University of Surrey, said:
“This well conducted research explored the association between television viewing and cognitive decline in a large group of older adults by testing the same participants at two points in time. The study found that even after accounting for things like age, sex, exercise and other potential confounding factors, that watching an average of 3.5 hours or more of television per day was associated with a significant decrease in verbal memory (ability to remember a list of words) six years later, compared to those who watched fewer hours. This was dose specific: the more television watched, the greater the decline in verbal memory.
“Other research has previously demonstrated that television watching can cause changes in brain structure, specifically in the parts responsible for learning and memory. So it’s not surprising to find that over time, learning and memory can decline among those who watch a lot of television. Of course these abilities do decline naturally as part of the ageing process, and the researchers did note that there was a reduction among those who watched little or no television, however the rate of decline was significantly greater among those who watched 3.5 hours or more a day suggesting that there was something about this activity which accelerated this process.
“Of course there are several ways that watching television may impact upon cognitive function – apart from changes in brain structure, the content of the shows themselves can have an effect – we tend to demonstrate different emotional responses to comedy, drama and documentary, and each of those responses stimulates different brain regions and produces different neuro-chemical reactions. And like any sedentary, perhaps isolated activity, time spent watching television displaces time that could be spent on other activities such as reading, socialising and sleep, all of which we know are associated with healthy ageing.
“The research sends a clear message that while there are positive benefits to television viewing, that older adults (and their carers) should be mindful that too much may have negative consequences. While TV may not rot the brain as traditional wisdom may suggest, even moderate watching is associated with some very real changes among viewers aged over 50.”
‘Television viewing and cognitive decline in older age: findings from the English Longitudinal Study of Ageing’ by Daisy Fancourt et al. was published in Scientific Reports at 14:00 UK time on Thursday 28 February 2019.
Dr Rosa Sancho: “No conflicts.”
Prof Andrew Przybylski: “None.”
Prof Dame Til Wykes: “I don’t have any conflicts of interest.”
Dr Bob Patton: “No conflicts of interest.”
None others received.