Researchers in Taiwan have uncovered evidence to support the controversial claim, ‘sitting is the new smoking’.
In a new study, looking at the health outcomes of nearly 500,000 people over a 20-year period, scientists found those who spent prolonged periods sitting down at work were 16 percent more likely to die early, compared to those who didn’t.
Prolonged sitting at work was also seen to raise a person’s risk of death from cardiovascular disease by 34 percent.
The harms of a lifetime of inactivity have been highlighted by numerous experts over the last two decades, with many comparing the life-limiting effects to that of smoking.
For the new study, investigators examined 481,688 people and gathered data on their health in relation to occupational sitting, physical activity, and other lifestyle factors.
Those defined as spending most of their time sitting down had a 16 percent higher risk of death from all causes compared to those who mostly did not sit.
They tracked health outcomes over the two decades, and adjusted for sex, age, smoking, drinking, and body mass index (BMI).
People who led a combination lifestyle – who alternated between sitting and ‘non-sitting’ at work – did not experience an increased risk of death.
And those who had sedentary work lives but also engaged in exercise during their free time displayed a reduced risk of mortality, from all causes and from cardiovascular disease.
The increased risk of death and heart disease could be offset by 15 to 30 minutes of vigorous exercise a day.
Throughout the study, researchers documented a total of 26,257 deaths, with 15,045 – about 57 percent – occurring in individuals predominantly engaged in sitting at work.
Among them, there were 5,371 deaths related to cardiovascular disease (CVD), and 60 percent (3,234) of them were in the predominantly sitting group.
The study’s findings suggest that the risks associated with prolonged occupational sitting can be mitigated by incorporating regular breaks and engaging in additional physical activity.
The authors said: ‘Systemic changes, such as more frequent breaks, standing desks, designated workplace areas for physical activity, and gym membership benefits, can help reduce risk.’
Lead author Dr Wayne Gao from Taipei Medical University, Taiwan, said: ‘As part of modern lifestyles, prolonged occupational sitting is considered normal and has not received due attention, even though its deleterious effect on health outcomes has been demonstrated.
‘Our findings suggest that reducing prolonged sitting in the workplace and/or increasing the volume or intensity of daily physical activity may be beneficial in mitigating the elevated risks of all-cause mortality and cardiovascular disease associated with prolonged occupational sitting.’
Study co-author Dr Min-Kuang Tsai added: ‘The fact that there is no increased risk for those who alternate between sitting and non-sitting at work suggests that incorporating regular breaks in work settings can be beneficial.
‘The increased risks for those who are mainly sedentary can be offset by an extra 15 to 30 minutes per day of exercise per day, or by participating in more physically intense activities.’
The study also offered several explanations which could lie behind the dangers of prolonged sitting.
These included a lack of exercise of the large muscles in the lower limbs, possibly causing reduced blood flow to the extremities.
Also, sitting for long periods increases the risk of obesity – as fewer calories are burned, leading to diabetes and reduced kidney function, as well as heart problems.
Dr Min-Kuang Tsai said: ‘Employers can play a role in facilitating this by providing designated areas for leisure time physical activity or offering company-sponsored group activities.
‘Overall, our findings from this large prospective cohort help to strengthen the increasingly accumulating evidence linking a sedentary lifestyle and health risks.’
Their findings were published in the journal JAMA Network Open.