South Africa was one of 11 countries world-wide that saw a decline in average life expectancy since 1990, a study published on Thursday said.
The average life expectancy for women was 63 years in 2013, with men living on average 57.7 years.
By contrast, in 1990 women lived on average 68.9 years and men had a life expectancy of 60.5 years, according to research co-ordinated by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in the US.
Out of the 188 countries included in the study South Africa ranked 162nd for women and 169th for men for the longest life expectancies.
According to the study, globally, people lived on average 6.2 years longer than they did in 1990, with life expectancy rising to just under 72 in 2013.
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The leading killers in South Africa were HIV/Aids, stroke, and pneumonia, accounting for 51 percent of all deaths in 2013.
This compared to 15 percent in 1990.
In 1990 pneumonia was the first cause of death in South Africa (26 614 deaths) and stroke the 5th leading cause of death (21 360 deaths), while HIV accounted for about 415 deaths. Altogether, the three conditions accounted for less than 15 percent of all deaths recorded in the country in 1990.
In 2013 HIV/Aids and interpersonal violence were the top two causes of death for people between the ages of 15 and 49, resulting in 191 792 lives lost.
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In 1990 HIV/Aids and violence accounted for about 2 460 deaths in the age group 15 to 49 years (with HIV/Aids claiming only about 200 lives in this age group in that year).
"We have achieved great progress in reducing mortality from a number of diseases, reflecting our country's investments in improving health for its citizens," University of Cape Town professor of medicine Dr Bongani Mayosi said.
"But we are still seeing children dying and deaths from other conditions are rising."
He said the data was critical to understanding how to save more lives in the future.
Read the full study published in the journal Lancet.
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