Not all sitting is the same, according to a new study from Spain that found adults who watch three or more hours of TV per day may double their risk of early death compared to those who watch less.
Similar amounts of time spent sitting while driving or using a computer did not have the same associations, according to the researchers, who focused on people with an average age of 37 to eliminate old age as a factor.
“We did this study because there were some previous reports of a higher mortality among subjects with a higher TV viewing time, but they had been done in elderly people in other countries,” Dr. Miguel Martinez-Gonzalez told Reuters Health in an email.
“We were interested in knowing whether or not this association also was present in younger subjects,” said Martinez-Gonzalez, a researcher with the Department of Public Health at the University of Navarra in Pamplona, who is the study's senior author.
His team’s results are in line with past studies that found a 13 percent higher risk of death for each additional two hours per day of television-watching time, and a sharper risk increase when daily TV time went above three hours, he said.
And no study has ever reported lower mortality among those with higher TV viewing time, he noted.
The researchers analyzed data gathered from 13,284 adults who had graduated from the university beginning in 1999. They wanted to examine any associations between three types of sedentary behavior and risk of death from any cause.
The study team followed the participants for an average of eight years and found 97 deaths, 19 of them from cardiovascular causes, 46 from cancer and 32 from other causes.
Compared to the people who sat watching an hour or less of television a day, those who watched two hours a day had a 40 percent higher risk of death. For those who watched three or more hours, the risk was two-fold higher.
For drivers, two hours a day came with a 14 percent higher risk of death compared to one hour or less. And two hours of computer use daily was linked to a 4 percent lower risk than one hour or less. Spending three or more hours at either task was not linked to any further risk changes.
These results took into account other lifestyle factors like diet, age, weight, smoking and other physical activity, the researchers note in the Journal of the