Holistic Health
Occupational sitting less harmful to heart
than sitting at home
Scientists are learning more about the cardiovascular risks of a desk job
I
t’s been commonly known that people with lifetime
desk jobs show higher rates of heart disease and
related death compared to more active colleagues.
But now evidence is starting to show that a
desk-bound lifestyle, while not optimal, is still not as
dangerous as one anchored to the couch at home.
Empirical evidence showing the health effects of
occupational sitting dates back to 1953, when a study
of workers in the London public transport sector
showed that drivers who sat for most of their working
lives were more likely to suffer a heart attack than their
more active colleagues working as conductors.
These early results, suggesting an association
between occupational sitting and cardiovascular
disorders, have also been supported by more recent
research, although the evidence is mixed.
That’s because while studies from the last decade
have even suggested a reduced risk of heart failure in
those with sitting occupations compared with those
whose jobs have moderate and high physical activity,
other research has found the opposite.
But a new study published in the Journal of the
44
MAY 2020
American Heart Association has some encouraging
findings for the desk-bound.
Sitting at work, it says, may not be as bad for the
heart and lifespan as sitting and watching television
during your free time.
After adjusting for health and lifestyle factors, the
researchers found that “often or always” sitting at work
was not associated with a heightened risk of death and
heart disease. But those watching four or more hours of
television per day had a 50 percent higher risk of heart
issues and death, compared to those watching two
hours or less per day.
Demographic factors did play a part in the study,
though, namely with regards to the type of person who
has a desk job versus a more active job.
Compared to those who rarely sat at work, people
in the study with sedentary jobs were more likely to
exercise outside the office regularly, have a high school
degree, make more money, and eat a healthy diet. They
were also less likely to drink heavily and smoke.
Exercise outside of work is nearly always good for
health, so people who spend much of their free time
watching television probably do so at the expense of
exercising.
Doing more exercise can mediate some of the
harmful effects of a sedentary lifestyle. In the new
study, for example, those who got at least 150 minutes
of moderate or vigorous physical activity per week
had a lower risk of health problems, even if they also
watched a lot of TV.
A separate recent study also found that replacing
just 30 minutes of daily sitting with any other activity
reduced mortality risk by 17 percent.
The new study adds to the body of work, but for
now, evidence for the health effects of occupational
sitting exposure is not as strong as that for overall
sedentary behaviour, according to Dr Leon Straker,
a professor of physiotherapy and exercise science at
Curtin University.
“Notably, few studies have captured occupational
sitting exposure objectively,” he told Global Health
Asia-Pacific.
“It’s generally been assessed through categorical
measures of occupational activity, such as comparing
‘mostly sitting’ occupations to ‘mostly standing’ or
‘heavy physical labour’ ones,” he added.
Dr Straker also noted that few studies had quantified
the number of hours or proportion of work time spent
sitting, so the lack of evidence of an association
between occupational sitting exposure and various
outcomes might be due to lack of precision in
measuring occupational exposure.
A separate
recent study
also found that
replacing just
30 minutes of
daily sitting
with any
other activity
reduced
mortality risk
by 17 percent
GlobalHealthAndTravel.com