- Feb 3, 2009
Watching two to three hours of television a day increases the risk of an early death, type 2 diabetes and heart disease, according to a new study.
Watching television is the most common daily activity apart from work and sleep in many parts of the world. Europeans and Australians spend an average of three to four hours a day in front of the television, and Americans around five hours, researchers at Harvard School of Public Health (HSPH) said.
But this comes at a cost, as it increases the chances of developing heart disease and type 2 diabetes.
"The message is simple. Cutting back on TV watching can significantly reduce risk of type 2 diabetes, heart disease, and premature mortality," said Frank Hu, professor of nutrition and epidemiology at HSPH.
"We should not only promote increasing physical activity levels but also reduce sedentary behaviours, especially prolonged TV watching," he added.
The researchers reached their conclusion after analysing data from eight studies carried out in the US, Europe and Australia that tracked more than 200,000 people for an average of seven to ten years.
More than two hours watching television per day increased the risk of type 2 diabetes and heart disease, and more than three hours a day increased the risk of an early death, the study found.
Every two hours of television time per day increased the risk of type 2 diabetes by 20 per cent, while the risk of heart disease was increased by 15 per cent. The risk of dying before the age of 65 was raised by 13 per cent.
The effect from watching too much television could be due to people tending to eat unhealthy snacks as they sit in front of the box. Time spent watching television also means people are getting less physical activity. Both factors increase the risk of obesity, a major risk factor for type two diabetes and heart disease.
"Sedentary lifestyle, especially prolonged TV watching, is clearly an important and modifiable risk factor for type 2 diabetes and cardiovascular disease," said study co-author Anders Grøntved.
"Future research should also look into the effects of extensive use of new media devices on energy balance and chronic disease risk."
The study findings are published in the Journal of the American Medical Association (JAMA).