There is enough evidence to show that physical inactivity increases the risk of many adverse health conditions, including major non-communicable diseases such as coronary heart disease, type 2 diabetes, breast and colon cancers and shortens life expectancy.
Physical inactivity affects health worldwide. But decrease in or removal of this unhealthy behaviour may improve health substantially, according to a latest study ‘Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of disease and life expectancy’ published in the latest edition of The Lancet .
Physical inactivity causes 6 per cent (ranging from 3.2 per cent in Southeast Asia to 7.8 per cent in the eastern Mediterranean region) of the burden of disease from coronary heart disease, 7 per cent (3.9—9.6) of type 2 diabetes, 10 per cent (5.6—14.1) of breast cancer, and 10 per cent (5.7—13.8) of colon cancer, according to the study.
A sedentary lifestyle causes 9 per cent (range 5.1 – 12.5) of premature mortality. More than 5.3 million of the 57 million deaths that occurred worldwide in 2008 have been attributed to inactivity.
If inactivity were not eliminated, but instead decreased by 10 per cent or 25 per cent, more than 533 000 and more than 1.3 million deaths, respectively, could be averted every year, according to The Lancet .
“We estimated that elimination of physical inactivity would increase the life expectancy of the world's population by 0.68 (range 0.41—0.95) years,” the authors conclude.
The study aims to quantify the effect of physical inactivity on these major non-communicable diseases by estimating how much disease could be averted if inactive people were to become active and to estimate gain in life expectancy at the population level.
The study has been done by I-Min Lee, Eric J Shiroma, Felipe Lobelo, Pekka Puska, Steven N Blair, and Peter T Katzmarzyk.
If all inactive people take to activity, the results of the research suggest that 6 per cent of the burden of disease worldwide due to coronary heart disease could be done away with. It further pointed out that sedentary behaviour had the largest effect on colon cancer, and the smallest on coronary heart disease, in terms of percentage reduction.
However, in case of the number of cases that could potentially be averted, coronary heart disease would have a far larger effect than would colon cancer due to the higher incidence of the disease.
The study provides a window of perspective by sighting 2008 statistics where 7.25 million people worldwide died from coronary heart disease versus 647 000 from colorectal cancer.
According to estimates, in Africa 15,000 deaths from coronary heart disease could have been averted in 2008 if more physical activity had taken place, 60 000 could have been avoided in the Americas, 44,000 in the eastern Mediterranean region, 1,21,000 in Europe, 59 000 in south east Asia, and 100 000 in the western Pacific region.
In the case of deaths from breast cancer, 3,000 could have been averted in Africa, 11 000 in the Americas, 4000 in the eastern Mediterranean, 14 000 in Europe, 5000 in Southeast Asia, and 10,000 in the western Pacific.
Inactivity was also the cause of 9 per cent of premature mortality, or more than 5.3 of the 57 million deaths in 2008. If inactivity could be done away with, life expectancy of the world's population might be expected to increase by 0.68 years.
These findings make inactivity similar to the established risk factors of smoking and obesity.
For perspective, other research done in the USA estimated that inactive people would gain 1.3 - 3.7 years from age 50 years by becoming active.
In an East Asian population, life expectancy from age 30 years in active people was 2.6 - 4.2 years greater than that in inactive people.
