It added that millions of premature deaths could also be avoided by “bringing an end to smoking.”
The analysis suggested speeding up progress toward ending smoking could deliver substantial population health benefits over the next three decades.
The study’s findings suggested that, based on current trends, global life expectancy will likely rise to 78.3 years by 2050, up from 73.6 years in 2022. However, if tobacco smoking gradually declined from current levels to a rate of five per cent in 2050, this would result in one year of additional life expectancy in males and 0.2 years in females.
If tobacco smoking was eliminated from 2023 onwards, this could result in up to 1.5 additional years of life expectancy among males and 0.4 years among females in 2050.
In both scenarios, millions of premature deaths would be avoided.
Mortality and smoking
Smoking is a leading risk factor for preventable death and ill health globally, accounting for more than one in ten deaths in 2021.
Smoking rates have fallen substantially over the past three decades, but the pace of decline varies and has slowed in many countries. Cancers, ischemic heart disease, and chronic obstructive pulmonary disease (COPD) are the leading causes of premature deaths from smoking. Together, these conditions account for 85 per cent of potentially avoidable years of life lost (YLLs), a measure of premature deaths.
Several countries have set ambitious goals to reduce smoking rates to below five per cent in the coming years. However, the authors said a significant opportunity exists to expand and strengthen proven policies and interventions to achieve these targets.
Stein Emil Vollset, senior author and professor at the Institute for Health Metrics and Evaluation (IHME), said, “We must not lose momentum in efforts to reduce, and ultimately eliminate, smoking around the world. Our findings highlight that millions of premature deaths could be avoided by bringing an end to smoking.”
The authors acknowledged some limitations to their study. Only the direct effects of reductions in tobacco smoking on health were estimated, meaning overall health benefits may be underestimated as the impact of associated reductions in second-hand smoke exposure was not analysed.
The analysis did not account for the possible health effects of e-cigarettes. The estimates also could not account for potential future advancements in healthcare improvements, such as improved lung cancer detection or treatment.
The results
The study found that between 1990 and 2022, age-standardised smoking rates among males aged 10 years and older fell from 40.8 per cent to 28.5 per cent. In the same period, smoking in females aged 10 years and older declined from 9.94 per cent to 5.96 per cent.
Based on current trends, the study estimates smoking rates will continue to decline, albeit at a slower pace than over the past three decades.
In 2050, it is estimated that (after adjusting for age) 21.1 per cent of males and 4.18 per cent of females will smoke, with considerable regional variation. For males, the percentage ranges from 3.18 per cent in Brazil to 63.2 per cent in Micronesia and from 0.5 per cent in Nigeria to 38.5 per cent in Serbia.
However, the findings have indicated that accelerating efforts to eliminate smoking could result in fewer premature deaths.
In a scenario where countries reduce smoking rates to five per cent by 2050, there would be 876m fewer YLLs (a measure of premature deaths) compared to the most likely future scenario.
Life expectancy in 2050 would be 77.1 years in males and 80.8 years in females.
The greatest gains in life expectancy among males would be in East Asia, Central Asia, and Southeast Asia, with between 1.2 and 1.8 extra years of life gained.
Among females, life expectancy would increase the most in East Asia, high-income North America and Oceania, with between 0.3 and 0.5 additional years gained.