The comprehensive study, published in The Lancet medical journal and unveiled at the ongoing World Health Summit in Berlin, analysed health data from 204 countries and 660 subnational locations between 1990 and 2023. It found that global life expectancy has rebounded to pre-pandemic levels, averaging 76.3 years for females and 71.5 years for males—an increase of more than 20 years since 1950.
However, the report highlighted deep regional inequalities. Life expectancy in high-income regions stands at about 83 years, compared to just 62 years in sub-Saharan Africa. While most parts of the world have recorded longer and healthier lives, the study warned of an emerging crisis among adolescents and young adults, driven largely by suicide, substance use, and infectious diseases.
Between 2011 and 2023, deaths among people aged 20 to 39 surged in high-income North America, mainly due to drug overdoses, suicide, and excessive alcohol consumption. The trend also extended to Eastern Europe and the Caribbean, where deaths among those aged five to 19 increased within the same period.
The findings show that the global mean age at death rose from 46.4 years in 1990 to 62.9 years in 2023. Yet, vast disparities remain: while women in high-income countries live up to 80.5 years on average, women in sub-Saharan Africa have a mean age of death of just 37.1 years.
In sub-Saharan Africa, the study also uncovered new data suggesting that mortality among girls and young women aged 15 to 29 was 61 per cent higher than previously estimated, mainly due to maternal deaths, road accidents, and meningitis.
In Nigeria, the report showed remarkable improvements in longevity and health. The country’s age-standardised mortality rate (ASMR) fell sharply from 1,722 deaths per 100,000 people in 1990 to 1,085 in 2023. Male mortality declined from 1,846 to 1,182 per 100,000, while female mortality dropped from 1,599 to 1,003—indicating better access to healthcare and a gradual rise in life expectancy.
The GBD report also identified non-communicable diseases (NCDs) as the dominant cause of death globally, accounting for nearly two-thirds of all deaths and disabilities. Ischemic heart disease, stroke, and diabetes topped the list, with half of the world’s disease burden deemed preventable. The report named high blood pressure, air pollution, and smoking as the three leading modifiable risk factors.
It further noted that mental health disorders—particularly anxiety and depression—continue to surge worldwide, increasing related deaths and disabilities by 63 per cent and 26 per cent, respectively.
The study was led by Professor Christopher Murray, Director of the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, with contributions from the GBD Collaborator Network. Researchers analysed data on 375 diseases and injuries and 88 risk factors to assess the world’s health trajectory over three decades.
Despite the global gains, the report warned that reductions in development assistance for health could threaten recent progress, especially in low-resource countries still battling infectious diseases, poor healthcare access, and a growing NCD burden.