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
American Heart Association.
The study doesn't prove that watching TV directly leads to premature death, it
only shows a correlation, Martinez-Gonzalez and his colleagues point out,
adding that more research is necessary to learn more about the possible
mechanisms behind the links.
It's also possible that other factors, such as illness, could explain both the
higher mortality and greater amounts of sedentary time watching TV, for
example.
However, Martinez-Gonzalez said that inactivity and a sedentary lifestyle
increase resistance to insulin, reduce lean body mass and increase fat mass.
"These mechanisms are related to a higher risk of diabetes, cardiovascular
disease and some cancers, such as colon, rectum, and breast."
Martinez-Gonzalez added that links between a sedentary lifestyle and a
greater risk of depression and suicidal ideation may also be involved.
"What we realize is that the study stresses the importance of decreasing our
sedentary time and then also increasing our moderate intensity physical
activity as recommended by the American Heart Association guidelines," Dr.
Heather Johnson told Reuters Health.
"There have been multiple very large studies demonstrating an association
with higher levels of physical activity and lower rates of mortality and lower
rates of cardiovascular disease," said Johnson, a cardiologist at the University
of Wisconsin School of Medicine and Public Health. She was not involved in
the study.
Johnson said that aerobic physical activity helps to lower so-called bad
cholesterol, helps to lower blood pressure and improves the health of blood
vessels.
"The American heart association stresses 150 minutes per week of moderate
intensity aerobic exercise," she said. "So about 30 minutes five days a week
or some people prefer 40 minutes four days per week."
Johnson added that people who don't currently have an exercise regimen
should start slowly � about 15 minutes per day and should check with their
physician before starting a new exercise program.





m.financialexpress.com/news/too-much-tv-tied-to-premature-death/1265980?rhnews/