Watching This Much TV Per Day Could Cause Dementia

If you’re anything like me, you’ll find nothing more soothing than settling in to watch your favourite series after a long day (Ugly Betty, I owe you my life).

But it turns out that watching too much telly can not only be bad for your physical health – it could affect your long-term brain health too.

A study named Television Viewing and Cognitive Decline in Older Age: Findings from the English Longitudinal Study of Ageing looked into the links between settling down with a good box set and dementia. After all, “there has been significant interest in the effects of television on cognition in children, but much less research has been carried out into the effects in older adults,” they said.

The researchers set out to “explore longitudinal associations between baseline television watching and cognition 6 years later while controlling for demographic factors, socio-economic status, depression, physical health, health behaviours and a range of other sedentary behaviours.”

And I’m warning you: if you’re a telly lover, you might want to adjust your set right about now.

The study referenced other work which suggested that younger people who watched three hours of telly a day or more went on to have decreased semantic fluency, but not memory, over the next 25 years.

Another study examined how watching TV for four or more hours a day affected 37-73-year-olds, finding that it “has been longitudinally linked over 4 years with poorer short-term memory and fluid intelligence (but not clearly with visual-spatial memory)”.

And “television viewing in older adults has been associated with cognitive impairment up to 6 years later using the Mini Mental State Examination (MMSE).”

In this study, the researchers looked at 3,590 initially dementia-free adults over 50 in the UK. They observed their TV-watching habits over six years and monitored their effects on the participants’ cognition. The majority of the group (69.8%) were retired or otherwise unemployed.

“This study showed that watching television for more than 3.5 hours per day is associated with poorer verbal memory but not semantic fluency six years later, independent of demographic factors, physical activity, health-related factors or sedentary behaviours and even amongst those with no mobility problems or dementia diagnoses at or shortly following baseline,” the researchers found.

So, even considering the participants’ activity level, wealth, health, and approach to exercise, it seemed that more than three-and-a-half hours of telly watching increased their risk of cognitive decline.

Of course, this was a group of 50+-year-olds – but if you fall beneath that age bracket, the other study on 37-75-year-olds set the brain health tipping point at in and around four hours.

I don’t know about you, but I think I’m about to take those “are you still watching?” Netflix prompts a bit more seriously…