Global Life Expectancy May Increase By 2050

This study is the latest findings from the Global Burden of Disease Study (GBD) 2021 which was published in The Lancet, and it forecasts that global life expectancy will increase by 4.2 years by 2050 despite geopolitical, metabolic, and environmental threats. These increases are predicted to be the largest in countries where life expectancy is lower, and this will contribute to a convergence of increased life expectancy across geographics. The trend will be driven by improvements in public health measures designed to prevent and improve survival rates from cardiovascular diseases, and a range of communicable, maternal, neonatal, and nutritional diseases (CMNNs).

This study indicates that there is an ongoing shift in disease burden to non-communicable diseases (NCDs) such as cardiovascular diseases, cancers, diabetes, and chronic obstructive pulmonary diseases, as well as exposure to NCD-associated risk factors such as obesity, high blood pressure, sub-par diet, and smoking which have the greatest impacts in the disease burden of the next generation. As the burden continues to shift from CMNNS to NCDs and from years of life lost (YLLs) to years lived with disability (YLDs), more people are projected to live longer, however, this increase is with more years being spent in poor health.

According to the study, global life expectancy is forecasted to increase from 73.6 years of age in 2022 to 78.1 years of age in 2050 (a 4.5-year increase). Global healthy life expectancy (HALE) -- the average number of years a person can expect to live in good health -- will increase from 64.8 years in 2022 to 67.4 years in 2050 (a 2.6-year increase). In order to come to these conclusions, the study forecasts cause-specific mortality; YLLs; YLDs; disability-adjusted life years (DALYs, or lost years of healthy life due to poor health and early death); life expectancy; and HALE from 2022 through 2050 for 204 countries and territories.

"In addition to an increase in life expectancy overall, we have found that the disparity in life expectancy across geographies will lessen," said Dr. Chris Murray, Chair of Health Metrics Sciences at the University of Washington and Director of the Institute for Health Metrics and Evaluation (IHME). "This is an indicator that while health inequalities between the highest- and lowest-income regions will remain, the gaps are shrinking, with the biggest increases anticipated in sub-Saharan Africa."

These findings build upon the results of the GBD 2021 risk factors study, which has also been published in The Lancet, and this accompanying study found that the total number of years lost due to poor health and early death (measured in DALYs) attributable to metabolic risk factors has increased by 50% since 2000. It also suggests alternate scenarios to compare potential outcomes if different public health interventions were to be put in place to help eliminate exposure to several key risk factors by 2050. 

"We forecast large differences in global DALY burden between different alternative scenarios to see what is the most impactful on our overall life expectancy data and DALY forecasts," said Dr. Stein Emil Vollset, first author of the study who leads the GBD Collaborating Unit at the Norwegian Institute of Public Health. "Globally, the forecasted effects are strongest for the 'Improved Behavioral and Metabolic Risks' scenario, with a 13.3% reduction in disease burden (number of DALYs) in 2050 compared with the 'Reference' (most likely) scenario."

Two scenarios were put forth that had more favorable outcomes, one focused on safer environments, and the other focused on improved childhood nutrition. Dr. Murray explains that the biggest opportunity to accelerate reductions in the global disease burden anywhere in the World is through public policy interventions designed with the goal of preventing and mitigating lifestyle behavioral and metabolic risk factors.

"There is immense opportunity ahead for us to influence the future of global health by getting ahead of these rising metabolic and dietary risk factors, particularly those related to behavioral and lifestyle factors like high blood sugar, high body mass index, and high blood pressure," concluded Dr. Murray.