Skip to Content

Lancet Study Reveals a Remarkable 6.2-Year Surge in Global Life Expectancy

An increase in global life expectancy of 6.2 years was documented in a recent study published in The Lancet spanning from 1990 to 2021. This advancement can be attributed to the decline in fatalities from enteric infections, lower respiratory infections, ischemic heart disease, and strokes worldwide. However, the emergence of COVID-19 acted as a setback in numerous countries.

Enteric illnesses, which encompass bacterial, parasitical, and viral diseases transmitted through food and water, notably typhoid and diarrhea, played a pivotal role in the substantial reduction of deaths. The decrease in mortality due to these diseases contributed to an extension of life expectancy by 1-1 years during the period from 1990 to 2021, with a more pronounced increase observed in the decade between 1990 and 2000 compared to subsequent decades.

The significant drop in deaths caused by enteric infectious diseases led to a remarkable gain of 3.1 years in life expectancy in South Asia.

Mohsen Naghavi, the Director of Subnational Burden of Disease Estimation at the Institute for Health Metrics and Evaluation (IHME), emphasized the progress made in combating children’s fatalities from enteric infections, stating, “We already know how to save children from dying from enteric infections including diarrheal diseases, and progress in fighting this disease has been tremendous.”

Naghavi, the lead author of the study, further stressed the importance of focusing on disease prevention and treatment, enhancing immunization programs, and developing novel vaccines targeting pathogens like E. coli, norovirus, and Shigella.

The researchers highlighted that the second most significant factor contributing to the rise in life expectancy was the decrease in deaths from lower respiratory infections, resulting in a 0.9-year extension of life expectancy from 1990 to 2021.

Similarly, a reduction in fatalities from chronic respiratory diseases led to an additional 0.5 years gained in life expectancy. Notably, East Asia, particularly China, played a crucial role in this improvement in mortality rates.

Regional disparities in life expectancy were evident, with Southeast Asia, East Asia, and Oceania experiencing the highest overall gain of 8.3 years in life expectancy globally, while also enduring the smallest reduction in life expectancy due to COVID-19 at 0.4 years.

Eve Wool, a senior research manager at IHME, emphasized the necessity of ensuring equitable access to life-saving interventions for diseases like ischemic heart disease, stroke, and other non-communicable diseases across all countries, irrespective of resource constraints.

The study underscored the progress in reducing mortality rates from vaccine-preventable diseases such as measles, which exhibited widespread declines in mortality rates primarily concentrated in western and eastern sub-Saharan Africa.

However, the study also identified persistent threats from digestive diseases, cirrhosis, diabetes, and kidney diseases, with a lack of improvement noted from 2010 to 2019, resulting in a global decrease of 0.1 years in life expectancy.

Impact of COVID-19

COVID-19 significantly impacted global life expectancy estimates, causing a decline of 1.6 years between 2019 and 2021, marking the most substantial reduction in recent years.

The severity of the impact varied across regions, with Andean Latin America experiencing a significant loss of 4.9 years, while East Asia witnessed minimal changes. Sub-Saharan Africa faced challenges exacerbated by high mortality rates from HIV/AIDS during the pandemic.

The study highlighted the influence of advanced healthcare facilities in containing COVID-19 cases, emphasizing that robust health systems alone did not determine the outcome of the pandemic.

Although the leading causes of death remained unchanged between 1990 and 2019, the rankings were reshuffled by the COVID-19 pandemic in 2021. COVID-19 emerged as the second leading cause of age-standardized deaths, replacing stroke with 94 deaths per 100,000 population, while chronic obstructive pulmonary disease shifted to the fourth-leading position.

The researchers expanded the Global Burden of Diseases 2021 report to include 12 additional causes of death, encompassing COVID-19, pulmonary arterial hypertension, and various cancer types. They plan to streamline the estimation of COVID-19-related deaths by eliminating the category of ‘other pandemic-related mortality (OPRM)’ from the GBD 2021.

Successes in disease mitigation programs can serve as a blueprint for future policy-making in heavily burdened countries, offering valuable insights for addressing healthcare challenges effectively.