The latest Global Burden of Disease Study (GBD) 2021, published in The Lancet, predicts a notable increase in global life expectancy. By 2050, life expectancy for males will rise by 4.9 years and for females by 4.2 years. The study highlights significant gains in countries with currently lower life expectancy, contributing to a global convergence in longevity.
DRIVING FACTORS BEHIND INCREASED LONGEVITY
Public health measures have significantly improved survival rates from cardiovascular diseases, COVID-19, and various communicable, maternal, neonatal, and nutritional diseases (CMNNs). These measures are the primary drivers behind the projected increase in life expectancy. As these health interventions continue to evolve and spread, more regions are expected to see substantial improvements in lifespan.
SHIFTING DISEASE BURDENS: FROM CMNNS TO NCDS
The study indicates a shift in the global disease burden from CMNNs to non-communicable diseases (NCDs), such as cardiovascular diseases, cancer, chronic obstructive pulmonary disease, and diabetes. This transition will significantly impact future health challenges, as exposure to NCD-associated risk factors—including obesity, high blood pressure, poor diet, and smoking—becomes more prevalent.
IMPLICATIONS FOR HEALTHY LIFE EXPECTANCY
While global life expectancy is forecasted to rise from 73.6 years in 2022 to 78.1 years in 2050, the number of years spent in good health—known as healthy life expectancy (HALE)—will also increase, though at a slower rate. HALE is expected to grow from 64.8 years in 2022 to 67.4 years in 2050. This suggests that while people will live longer, they may spend more years dealing with health issues and disabilities.
DETAILED FORECASTING AND REGIONAL DISPARITIES
The GBD 2021 study provides comprehensive forecasts for cause-specific mortality, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life years (DALYs), life expectancy, and HALE for 204 countries and territories from 2022 to 2050. Dr. Chris Murray, Chair of Health Metrics Sciences at the University of Washington and Director of the Institute for Health Metrics and Evaluation (IHME), notes a reduction in the disparity of life expectancy across different regions. The greatest improvements are expected in sub-Saharan Africa, where life expectancy gains will help close the gap between high- and low-income regions.
OPPORTUNITIES FOR POLICY INTERVENTIONS
Dr. Murray emphasizes the potential to further reduce the global disease burden through targeted policy interventions. These interventions should aim to prevent and mitigate behavioural and metabolic risk factors. The accompanying GBD 2021 risk factors study reveals that DALYs attributable to metabolic risk factors have surged by 50% since 2000. Addressing these risks is crucial for improving global health outcomes.
EXPLORING ALTERNATIVE SCENARIOS FOR BETTER HEALTH OUTCOMES
The study also examines various alternative scenarios to assess potential health outcomes if different public health interventions were implemented to eliminate key risk factors by 2050. Dr. Stein Emil Vollset, first author of the study, highlights the “Improved Behavioural and Metabolic Risks” scenario as the most impactful. This scenario could reduce the global disease burden by 13.3% in 2050 compared to the “Reference” scenario. Additional scenarios focused on safer environments and improved childhood nutrition and vaccination also show promising reductions in disease burden.
THE PATH FORWARD: ADDRESSING RISING HEALTH RISKS
Amanda E. Smith, Assistant Director of Forecasting at IHME, underscores the need for continued progress and resource allocation in areas like childhood nutrition, vaccination, and environmental safety. Dr. Murray concludes that significant opportunities exist to influence future global health by proactively addressing rising metabolic and dietary risk factors, particularly those related to behavioural and lifestyle choices such as high blood sugar, high body mass index, and high blood pressure.
By adopting comprehensive public health strategies and policies, the global community can look forward to a future where increased life expectancy is matched by a higher quality of health and well-being.
