Low socio-economic status is the third most powerful risk factor for premature death after smoking and physical inactivity, a large international study has found.
The study, published in The Lancet, 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 leading a sedentary lifestyle, 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 people from the UK, France, Switzerland, Portugal, Italy, the US and Australia.
People's job titles were used to assess socio-economic status.
An estimated 41 per cent of men and 27 per cent 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.
The link between low socio-economic status and poor health is widely known but is often overlooked in health policies.
Lead author Dr Silvia Stringhini from Lausanne University Hospital, Switzerland, says its vital governments accept low socio-economic status 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," Dr Stringhini said.
Australian research recently highlighted the impact of education on health.
The Sax Institute study, published in the International Journal of Equity in Health last December, found those with no tertiary education qualifications had more than double the rates of heart attack (150 per cent) relative to those with a university degree.
"We know that a good education impacts long-term health by influencing what type of job you have, where you live and what food choices you make," commented Kerry Doyle, CEO of the Heart Foundation of New South Wales.