Poverty should be regarded as a major risk factor for premature death, scientists have concluded after analysing data on 1.7 million people.
The study is the first to compare the impact of low socio-economic status with other threats to health such as lack of exercise, smoking, diabetes, high blood pressure, obesity and alcohol consumption.
Poorer people were found to be almost 1.5 times more likely to die before the age of 85 than their wealthier counterparts.
Low socio-economic status was associated with a 2.1 year reduction in life expectancy - similar to the effect of being inactive which cut 2.4 years off average life span.
High blood pressure, obesity and heavy alcohol consumption all had much less of an impact on life expectancy than poverty. The biggest life-shortening factors were smoking (4.8 years) and diabetes (3.9 years).
The researchers combined data from 48 studies involving more than 1.7 million participants from the UK, France, Switzerland, Portugal, Italy, the US and Australia.
People’s job titles were used to assess socio-economic status.
Writing in The Lancet medical journal, the scientists estimated that 41% of men and 27% of women in the study fell into the “low” category.
Among people in this group, 55,600 died before the age of 85 compared with 25,452 of those considered to have high socio-economic status.
Lead researcher Dr Silvia Stringhini, from Lausanne University Hospital in Switzerland, said: “Given the huge impact of socio-economic status on health, it’s vital that governments accept it as a major risk factor and stop excluding it from health policy.
“Reducing poverty, improving education and creating safe home, school and work environments are central to overcoming the impact of socio-economic deprivation. By doing this, socio-economic status could be targeted and improved, leading to better wealth and health for many.”
British author Professor Paolo Vineis, from Imperial College London, said: “Socio-economic status is important because it is a summary measure of lifetime exposures to hazardous circumstances and behaviours, that goes beyond the risk factors for non-communicable diseases that policies usually address..
“Our study shows that it should be included alongside these conventional risk factors as a key risk factor for ill health.”