Research published online in the British Journal of Sports Medicine suggests, watching television for approximately six hours daily could shorten the viewers life expectancy by almost five years. Competing with other well known behavioral risk factors, such as smoking and not enough exercise, the investigation indicates.
Sedentary behavior (as distinct from too little exercise) is linked with a increased risk of death, especially from heart attack or stroke. Watching TV makes up for a huge amount of sedentary activity, but its impact on life expectancy has not been evaluated, say the researchers.
To assemble a lifetime risk framework, researchers used previously published information on the connection between TV viewing time and death from analyses of the Australian Diabetes, Obesity and Lifestyle Study (AusDiab), together with Australian national population and mortality figures for 2008.
Including over 11,000 adults aged 25 or older, and beginning in 1999-2000, AusDiab is a national survey of a representative sample of the population.
The researchers then created a risk framework for the Australian population in 2008, based upon answers those participating in the survey had provided, when questioned about the total time they spent in the previous week watching TV or videos.
In 2008 it was estimated that Australian adults (25 years and over) watched 9.8 billion hours of TV, which led them to calculate that each hour of TV watched after the age of 25 reduced the life expectancy of the viewer by just under 22 minutes.
The researchers calculated based on these figures, that in comparison to someone who does not watch TV, those who spend a lifetime average of over six hours daily watching television can expect to live just under 5 years less.
These figures compare with additional well known lifestyle risk factors of death from cardiovascular disease after the age of 50, including physical activity and obesity.
According to the researchers risk framework other investigations, for example, have shown the lifelong smoking is connected with the shortening of life expectancy by over 4 years after the age of 50, with the average loss of life from each cigarette calculated to be 11 minutes - the same as half an hour of watching TV.
The researchers say their findings indicate that substantial loss of life may be linked with prolonged TV viewing. Also adding,
"While we used Australian data, 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."
"If these [figures] are confirmed and shown to reflect a causal association, TV viewing is a public health problem comparable in size to established behavioral risk factors."
Written by Grace Rattue