Television time might shave years off lifespan
In a first study researchers measured how many years are shaved from life expectancy by watching six hours of television a day.
The finding, if substantiated, could mean television viewing for prolonged periods might be considered a public health hazard, just like smoking, lack of exercise or obesity.
According to the study authors, TV viewing is a sedentary activity, not to be confused with lack of exercise. The impact on life expectancy hasn’t been measured before now.
Researchers came to the conclusion that TV can shorten a person’s life by analyzing the Australian Diabetes, Obesity and Lifestyle Study (AusDiab) that included 11,000 adults over age 25, beginning 1999-2000.
For their study, the scientists constructed a risk factor table, based on how much time survey respondents age 25 and older said they spent watching television. The total was 9.8 billion hours in 2008.
Sitting in front of the TV as risky as smoking
Next they calculated how much time one hour of TV watching shortens lifespan, which is approximately 22 minutes.
Six hours a day of television then translated to dying five years sooner than someone who doesn’t watch television at all.
The authors used the same reference to find other risks for mortality
For instance, a person who smokes cigarettes after age 50 loses four years of life. One cigarette shortens a person’s life by 11 minutes.
The authors say "While we used Australian data, the effects in other industrialised and developing countries are likely to be comparable, given the typically large amounts of time spent watching TV and similarities in disease patterns."
Watching six hours of television a day shortens life expectancy by five years, suggests the study, which is published in the British Journal of Sports Medicine.
Just sitting for prolonged periods has been suggested to boost the chances of dying from any cause, making the new study no surprise.
A January, 2010 study, from the Swedish School of Sport and Health Sciences, also published in the British Journal of Sports Medicine, suggested sitting for too long, even for healthy individuals, can be a health hazard.
The finding doesn't mean don't watch TV. Instead, it means don't sit for long periods of time. Take breaks from sitting to do chores, at work or at home. Moving large muscle groups at least every 30 to 40 minutes can help reverse the negative effects of being still.
Br J Sports Med doi:10.1136/bjsm.2011.085662
"Television viewing time and reduced life expectancy: a life table analysis"
J. Lennert Veerman, et al.
Image credit: morguefile
Updated Mary 12, 2016