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Turning off your TV may help you live longer, study suggests

Each hour we adults spend in front of a television shortens our life expectancy by an average of about 22 minutes, an Australian study found.
REUTERS/Mario Anzuoni
Each hour we adults spend in front of a television shortens our life expectancy by an average of about 22 minutes, an Australian study found.

Maybe our TVs, like our cigarette packages, need health-warning labels.

On the heels of a Harvard study that linked TV watching with an increased risk of diabetes, heart disease and premature death comes a new Australian study that quantifies the premature-death risk in even blunter terms:

Each hour we adults spend in front of a television shortens our life expectancy by an average of about 22 minutes, the study found.

Since the average American adult spends 35.5 hours a week watching TV, that means we’re shaving almost 13 hours from our lives each week.

OK. OK. The study did not find that TV viewing actually caused a decrease in life expectancy. It found only an association between the two. Still, these findings add to a growing body of research that suggests being sedentary (sitting too much) is a major risk factor for a shortened life span.

In fact, the current study found that TV viewing may be as detrimental to your life expectancy as some well-known risk factors, such as smoking and not exercising.

The study’s details
For this study, which appeared online Tuesday in the British Journal of Sports Medicine, researchers from the University of Queensland used published data from the large (11,000 participants) and ongoing Australian Diabetes, Obesity and Lifestyle Study (AusDiab). That data had previously revealed an association between TV viewing (participants had been surveyed about their TV habits) and an increased risk of premature death from all causes — even after adjusting for such things as smoking, exercise habits, diet, high blood pressure and cholesterol levels.

According to the data, Australian adults aged 25 and older watched 9.8 billion hours of television in 2008. Using Australian mortality figures from that same year, the authors of Tuesday’s study estimated the extent to which TV viewing reduced life expectancy.

They calculated that individuals who spend a lifetime average of six hours per day watching TV can expect to live 4.8 years less than those who watch no TV.

To put it another way: Every single hour of TV viewed after the age of 25 reduces the viewer’s life expectancy by 21.8 minutes.

If no one watched TV, according to the mathematical modeling used in the study, the 2008 life expectancy at birth would have been 1.8 years longer for Australian men and 1.5 years longer for Australian women.

It’s unlikely these findings are unique to Aussies. “While we used Australian data,” write the study’s authors, “the effects in other industrialized and developing countries are likely to be comparable, given the typically large amounts of time spent watching TV and similarities in disease patterns.”

Comparing the risk
The negative impact on health associated with TV viewing in this study is similar to that of other well-known lifestyle factors. As the authors of this study point out, other risk models have estimated that each cigarette smoked reduces an individual’s life expectancy an average of 11 minutes, and that lifelong smoking is associated with a loss of life after age 50 of 4.3 years for men and 4.1 years for women — the equivalent of 6.0 and 6.4 daily hours of TV watching.

Other research has shown that low physical activity after age 50 reduces life expectancy by about 1.4 years compared with moderate physical activity and about 3.6 years compared with high physical activity — the equivalent of watching 2.1 and 5.4 hours, respectively, of TV a day.

“TV viewing time may have adverse health consequences that rival those of lack of physical activity, obesity and smoking,” conclude the study’s authors. “… A public health case could be made that adults [as well as children] need to limit the time spent watching TV.”

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Comments (8)

  1. Submitted by Gregory Lang on 08/17/2011 - 11:11 am.

    The “math” on this gets curiouser and curiouser. Just yesterday there was something about how fifteen minutes of “exercise” a day does wonders and just last week geneitic factors were the largest factor in longivity.

    My ather smoke a pack of day of Pall Mall straight since WWII. He died a month short of age 85. Had he lead a “healthy” life would he have become the world’s oldest person?

    I’ll concede that smoking is bad for you and exercise is good for you but this sound like “junkscience” research. Heavy TV viewing in the US has been the norm since the mid 1950’s.

    The “lost lifetime” might have more to do with class and income rather than TV viewing itself.

    Basically, if you have money you do not have time. I’d bet you would find that TV causes more “lost lifetime” to those who do not have “cable”. The key reason being lower demographics of broadcast only because they can’t afford cable.

  2. Submitted by Ray Schoch on 08/17/2011 - 11:24 am.

    It’s just a guess, but I’ll be surprised if this story leads the evening news on WCCO.

    One quibble: while there are surely health clubs with giant flat-screen TVs to entertain the patrons while they put in their hour on the stationary bike or the treadmill, or whatever, it seems more likely that the statement leading the last paragraph (“TV viewing time may have adverse health consequences that rival those of lack of physical activity…”) ranks as among the more redundant of the year, since TV viewing, at least in most people’s homes, generally equates to a “…lack of physical activity…”

    In general, and without some definitive evidence that television is emitting some sort of “death ray,” the culprit here seems to be the lack of physical activity, not just the fact that television is being watched. People who spend hours in front of a computer screen every day are equally sedentary, and probably are having the same sort of negative effect on their health and lifespan.

    Take this far enough, and it suggests that we should all abandon civilization and return to our hunter-gatherer roots, where we’ll all live well into our active 90s before being recycled, as it were, by a resurgent mountain lion population.

  3. Submitted by Gregory Lang on 08/17/2011 - 11:29 am.

    In the early 1970’s I took psychology courses. They expected the nest big market to be “leisure counseling”. They envision that people who presumably had the money to pay for this leisure counseling.

    I tried tell them that people with money wouldn’t have spare time. A very neurotic psych grad student who was co-teachingthe course told me “I don’t see how you can possibly know anything about human behavior if you do not have a psychology degree!

    Leisure counseling never took off. Again demographics/money is probably the greatest determiner of TV viewing time.

  4. Submitted by Susan Perry on 08/17/2011 - 12:16 pm.

    As I pointed out in my post,this study only shows an association between TV viewing and early death, which means, of course, that other not-yet identified factors could explain the results. (Observational studies are notoriously unreliable.) The data this study is based on was adjusted, however, for a variety of risk factors, including not exercising. By the way, don’t confuse sedentary behavior (sitting a lot) with not exercising. Recent research suggests they are separate risk factors for disease. In other words, sitting eight hours at a desk may harm your health even if you run 5 miles every evening.

    One thing I didn’t mention in my post is that the confidence intervals in this study’s
    findings were very wide. That raises concerns about the validity of the findings. The authors acknowledge this, but point to two comparable studies (one Scottish, one English)that had similar results to theirs. One found a 7% increase in mortality risk per daily hour of TV viewing; the other found a 4% increased risk.

  5. Submitted by NIcole Masika on 08/17/2011 - 02:06 pm.

    22 min lost for each hour watched? sounds like about the amount of time commercials use in each hour of TV,hmm

  6. Submitted by Soapy Johnson on 08/17/2011 - 08:54 pm.

    If cigarettes need graphic warning labels, so does everything …

  7. Submitted by Susan Lesch on 08/18/2011 - 11:10 am.

    How does reading a good book compare to watching television? We are having trouble taking this one seriously.

  8. Submitted by ian brennan on 02/06/2013 - 11:08 am.

    Five days out of the week I sit in school for about seven hours; about an hour for each class.I spend 2 minutes between each class walking to the next one. So does that mean that students like myself who are in school, are loosing life-span due to sitting still in a desk for 6 hours and 46 minutes a day?

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