18 September 2017
Every hour you spend sitting watching TV makes you more likely to die from inflammation-related diseases, Melbourne researchers have found.
And it’s not just those watching more than four hour-long episodes in a row at risk.
Baker Heart and Diabetes Institute researchers have found that even moderate viewing of between two and four hours daily was risky, with very extra hour of seated TV viewing per day associated with a 12 per cent higher risk of inflammation-related death.
Researchers analysed the lifestyles, hours of daily TV viewing, inflammatory markers, and causes of death of almost 9000 adults, who were followed up 13 years after first taking part in the Australian Diabetes, Obesity and Lifestyle Study.
After excluding cancer and cardiovascular-related deaths, they found that every extra hour of TV time increased the risk of inflammatory-related death.
The risk was similar, but smaller, in nonsmokers in the study.
Lead author and senior researcher at the Baker Institute’s physical activity research unit, Dr Megan Grace said while the damaging mechanisms of sedentary behaviour like TV watching were still being uncovered, there was growing evidence that it was linked to inflammation.
“We know sitting involves reduced muscle activity, and therefore reduced blood flow. We think this stagnation in the blood vessels may be leading to an accumulation of inflammatory markers in the blood and muscles”, Dr Grace said.
“Inflammation is a normal response in the body when there’s an injury or infection.
“When the inflammation isn’t cleared away and it hangs around, we think this long-term low-level inflammation is actually causing damages to tissues that lead to diseases like diabetes, lung diseases and cognitive disorders like Alzheimer’s and Parkinson’s.”
Dr Grace said she hoped the findings, published in the journal Medicine and Science in Sports and Exercise, would help drive new guidelines to include advice on reducing sitting time in addition to physical activity.
“This data was collected in 2000, before many of these on-demand TV technologies existed. We think the problem is probably even worse now than what we recognised”, she said.
“The literature is really becoming stronger that even for those who do meet the daily exercise guidelines, if they go and sit for the rest of the day they are still at risk of these inflammatory diseases.”
“Some sitting is good for you, but too much is bad. We need to move around as much as possible.”