The Global Burden of Disease Study (GBD) 2021, published in The Lancet, predicts that global life expectancy will increase by 4.9 years in males and 4.2 years in females between 2022 and 2050. This increase is expected to be largest in countries with lower life expectancies, leading to a convergence of increased life expectancy worldwide. Public health measures that have prevented and improved survival rates from various diseases such as cardiovascular diseases, COVID-19, and communicable, maternal, neonatal, and nutritional diseases are driving this trend.
The study highlights the ongoing shift in disease burden to non-communicable diseases (NCDs) such as cardiovascular diseases, cancer, chronic obstructive pulmonary disease, and diabetes, as well as exposure to NCD-associated risk factors like obesity, high blood pressure, non-optimal diet, and smoking. This shift will have the greatest impact on the disease burden of the next generation, with more people expected to live longer but with more years spent in poor health. Global life expectancy is forecasted to increase from 73.6 years in 2022 to 78.1 years in 2050, while global healthy life expectancy is projected to increase from 64.8 years to 67.4 years during the same period.
To arrive at these conclusions, the study forecasts cause-specific mortality, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life years (DALYs), life expectancy, and healthy life expectancy (HALE) from 2022 through 2050 for 204 countries and territories. The study’s lead author, Dr. Chris Murray, noted that while health inequalities between regions will remain, the gaps are shrinking, with the biggest increases anticipated in sub-Saharan Africa. The study emphasizes the importance of policy interventions aimed at preventing and mitigating behavioral and metabolic risk factors to reduce the global disease burden.
The GBD 2021 risk factors study, released alongside the main findings, reveals that the total number of years lost due to poor health and early death attributable to metabolic risk factors has increased by 50% since 2000. The study also explores various alternative scenarios that compare potential health outcomes if different public health interventions could eliminate exposure to key risk factor groups by 2050. The ‘Improved Behavioral and Metabolic Risks’ scenario is highlighted as having the strongest impact, with a 13.3% reduction in disease burden compared to the reference scenario. Additional scenarios focusing on safer environments and improved childhood nutrition and vaccination also show potential for reducing the disease burden.
The authors stress the need for continued progress and resources in the areas of safer environments, improved nutrition, and vaccination to accelerate progress and reduce the disease burden further. Dr. Murray emphasizes the importance of addressing rising metabolic and dietary risk factors related to behavioral and lifestyle choices such as high blood sugar, high body mass index, and high blood pressure. The study underscores the opportunity to influence the future of global health by implementing interventions to mitigate these risk factors and improve health outcomes worldwide.
In conclusion, the GBD 2021 study predicts significant increases in global life expectancy between 2022 and 2050, driven by improvements in public health measures and reductions in disease burden from communicable to non-communicable diseases. The study highlights the importance of addressing metabolic and dietary risk factors through policy interventions to reduce the global disease burden further and improve healthy life expectancy. By focusing on key risk factors and implementing targeted interventions, there is a potential to accelerate progress and positively impact the future of global health.