Sit less to live longer

[Posted: Tue 10/07/2012 by Gillian Tsoi www.irishhealth.com]

Cutting down on time spent sitting down could lengthen your life by two years, according to US researchers.

They suggest that reducing sitting time to under three hours every day will add a whole two years to your lifespan.

Furthermore, watching TV for less than two hours a day might add an extra 1.4 years.

Spending long periods of time sitting down and/or watching TV has long been linked to poor health (including conditions such as diabetes), and death from heart disease or stroke.

To further examine this, researchers in the US trawled through published studies on sitting time and deaths from all causes. These studies involved almost 167,000 adults.

Included in this was data collected for the National Health and Nutrition Examination Survey (NHANES) to calculate the amount of time US adults spent watching TV and sitting down on a daily basis.

NHANES regularly surveys a large representative sample of the US population on various aspects of their health and lifestyle.

They used these figures to calculate the number of deaths associated with time spent sitting down and discovered that deaths from all causes linked to sitting time and TV viewing were 27% and 19%, respectively.

The results of life table analyses indicates that cutting the amount of time spent sitting down every day to under three hours would add an extra two years to life expectancy.

Similarly, restricting time spent watching TV to under two hours daily would extend life expectancy by an extra 1.38 years.

The experts believe that the evidence demonstrated the detrimental effect of a sedentary lifestyle on health.

And they caution that their findings should not be interpreted as meaning that someone who leads a more sedentary lifestyle can expect to live two or 1.4 years less than someone who is more active.

"Given that the results from objective monitoring of sedentary time in NHANES has indicated that adults spend an average of 55% of their day engaged in sedentary pursuits, a significant shift in behaviour change at the population level is required to make demonstrable improvements in life expectancy," they conclude.

Further research will be required before recommendations on safe levels of sedentary behaviour can be made, they added.

The research was carried out by Dr Peter Katzmarzyk and Prof I-Min Lee from the Pennington Biomedical Research Centre in Baton Rouge, Louisiana.

It was published in the online journal BMJ Open.