Watching television for more than three to four hours a day is linked to eight leading causes of death, including cancer, heart disease and diabetes, in the U.S., researchers say.
Previous studies had reported a relationship between TV viewing and an elevated risk of death from cancer and cardiovascular disease. In this study, researchers at the National Cancer Institute in the U.S. looked at more than 2,21,000 individuals in the 50-71 age group who were free of chronic disease at study entry. They confirmed the association with higher mortality risk from cancer and heart disease.
In addition, they identified new associations with higher risk of death from most of the leading causes of death in the U.S., such as diabetes, influenza/pneumonia, Parkinson’s disease and liver disease.
“We know that television viewing is the most prevalent leisure-time sedentary behaviour and our working hypothesis is that it is an indicator of overall physical inactivity,” said lead investigator Sarah K. Keadle from the U.S. National Cancer Institute.
“In this context, our results fit within a growing body of research indicating that too much sitting can have many different adverse health effects,” Ms. Keadle said.
The study found that compared to those who watched less than one hour of TV a day, individuals who reported watching three to four hours were 15 per cent more likely to die from any cause.
Those who watched seven or more hours were 47 per cent more likely to die over the study period. Risk began to increase at three to four hours for most causes they examined.
