The hazards of smoking and the benefits of cessation: a critical summation of the epidemiological evidence in high-income countries.

Prabhat Jha

doi:10.7554/elife.49979

Abstract

In high-income countries, the biggest cause of premature death, defined as death before 70 years, is smoking of manufactured cigarettes. Smoking-related disease was responsible for about 41 million deaths in the United States, United Kingdom and Canada, cumulatively, from 1960 to 2020. Every million cigarettes smoked leads to one death in the US and Canada, but slightly more than one death in the UK. The 21st century hazards reveal that smokers who start smoking early in adult life and do not quit lose a decade of life expectancy versus non-smokers. Cessation, particularly before age 40 years, yields large reductions in mortality risk. Up to two-thirds of deaths among smokers are avoidable at non-smoking death rates, and former smokers have about only a quarter of the excess risk of death compared to current smokers. The gap between scientific and popular understanding of smoking hazards is surprisingly large.

Highlights

Tobacco use is well established as a major cause of death worldwide, accounting for about five to six million deaths per year worldwide (Jha and Peto, 2014)
The loss of a full decade of life is seen, surprisingly, among male cigarette smokers in India, despite the later age of uptake and generally fewer cigarettes smoked (Jha et al, 2008). These findings further suggest that 3-fold higher death rates among persisting smokers represents that of a fully-mature smoking epidemic, given the fact that the late 20th century risk among women reached 3-fold of that versus non-smokers, as observed for men two decades earlier
I have drawn on existing epidemiological evidence, with careful re-interpretation of risks in individuals and rates among populations

Summary

Introduction

Tobacco use is well established as a major cause of death worldwide, accounting for about five to six million deaths per year worldwide (Jha and Peto, 2014). The National Cancer Institute review concluded: “Epidemiological and other scientific evidence, including patterns of mortality from smoking caused diseases, does not indicate a benefit to public health from changes in cigarette design and manufacturing over the last 50 years.” Lower-tar cigarettes do appear to result in lower lung cancer deaths.

Results

Conclusion