Stay switched on by switching off

3 minute read


Your parents were right. Watching too much TV really is bad for you. 


The Back Page is the bearer of bad tidings for folks whose idea of a fun weekend is to binge-watch two series of Bridgerton from the comfort of a La-Z-Boy recliner.  

All that sitting about is not only bad for your body, it may also increase your risk of developing dementia, especially if you are member of the boomer demographic and beyond.  

Recent research published in the journal Proceedings of the National Academy of Sciences suggests that watching television for extended periods is worse for long-term cognitive outcomes than many other common leisure activities. 

Using data from UK Biobank, which provides anonymous biomedical data to researchers, US-based researchers examined more than 145,000 participants aged 60 and older.  

At the beginning of the project in 2006, none of the subjects had been diagnosed with dementia.  

The researchers used touchscreen questionnaires so the participants could self-report information about their levels of sedentary behaviour over four years. 

They then conducted a follow-up after 12 years using hospital inpatient records to determine dementia diagnoses. After adjusting for demographics and lifestyle characteristics that could affect brain health, the researchers determined that more than 3500 of the study group had developed dementia. 

More tellingly, what they also found was a measurable link between time spent watching television and the likelihood of a diagnosis. In particular, it was not just the sitting down that was having an impact (although that too has been found to be a dementia link) but it was the television watching that was critical. So folks who sat down a lot but were doing other things, such as using a computer or reading a book, were less affected.    

“It isn’t the time spent sitting per se, but the type of sedentary activity performed during leisure time that impacts dementia risk,” lead author Professor David Raichlen said in the statement.

“We know from past studies that watching TV involves low levels of muscle activity and energy use compared with using a computer or reading. The relatively greater intellectual stimulation that occurs during computer use may counteract the negative effects of sitting.” 

To be fair to fans of the Idiot Box, the findings merely show a correlation rather than causation. But educated speculation would suggest that actively using the brain, even when sitting down, is going to be healthier than passive use, such as watching reruns of Midsomer Murders.    

“What we do while we’re sitting matters,” Professor Raichlen said. “This knowledge is critical when it comes to designing targeted public health interventions aimed at reducing the risk of neurodegenerative disease from sedentary activities through positive behaviour change.” 

So next time you can’t find the remote control, maybe that’s your brain trying to tell you something. 

If you see something that makes you want to chuck stuff at the telly, toss it on over to penny@medicalrepublic.com.au instead. 

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