A new analysis suggests each cigarette smoked reduces life expectancy by approximately 20 minutes—17 minutes for men and 22 minutes for women.

The findings, published in Addiction, update the previous estimate of 11 minutes per cigarette from 2000. Researchers utilized data from the British Doctors Study’s 50-year follow-up through 2001 and the Million Women Study through 2011. These studies revealed that smokers who did not quit lost approximately 10 years (men) to 11 years (women) of life expectancy, even after adjusting for socioeconomic factors.

Average daily cigarette consumption has decreased from 15.8 to 11.5 cigarettes for men and from 13.6 to 9.5 for women. However, the Health Survey for England (1993-2019) found only modest changes in saliva cotinine concentration per cigarette, suggesting no substantial reduction in toxicant exposure.

Projections indicate that for a 10-cigarette-per-day smoker who quits on January 1, 2025:

• One day of life could be saved by January 8.

• One week by February 20.

• One month by August 5.

• 50 days by year-end.

The study noted that smoking primarily affects healthy middle years rather than end-of-life periods. For example, a 60-year-old smoker typically has the health profile of a 70-year-old non-smoker. Individual outcomes, however, vary due to differences in smoking patterns, type of cigarette, and susceptibility to toxicants. Importantly, the findings highlight that total cessation, not just reduction, is essential for maximizing health benefits. 

Key Caveats and Assumptions

• The study assumes consistent cigarette consumption and toxicant exposure over a smoker’s lifetime.

• Changes in tar-to-nicotine ratios may impact toxicity, but this was not addressed in detail.

• Early smoking initiation may further increase health risks.

The research was funded by the Department for Health and Social Care and conducted at University College London’s Department of Behavioural Science and Health.