Tobacco use remains a primary contributor to disease, disability, and premature death across the globe. A recent editorial summarizes data demonstrating that smoking reduces life expectancy by approximately 20 minutes per cigarette smoked—17 minutes for men and 22 minutes for women.

The estimate, which drew on data from long-term studies such as the British Doctors Study and the Million Women Study, accounts for factors like smoking rates and early death outcomes over several decades. It’s also grounded in better and more up-to-date data, including studies that tracked the effects of smoking for up to 50 years.

While smoking rates have declined in recent decades, the harm caused per cigarette may not have decreased substantially, as smokers may inhale more deeply or compensate for fewer cigarettes smoked. However, urinary cotinine levels—a marker of toxicant exposure—show only modest changes, suggesting that the risks per cigarette remain consistent with earlier estimates.

These findings emphasize that the harm from smoking is cumulative, and quitting earlier can markedly reduce the risk of early death and disease. Smokers who quit at any age can prevent substantial loss of life expectancy, with each cigarette avoided contributing to a longer, healthier life. Smokers in their 60s, for example, may experience health improvements that narrow the gap between their current health and that of a non-smoker several years younger.

Though individual factors like smoking intensity and age of initiation vary, the general conclusion remains the same: Smoking shortens life at every stage, and cessation at any age offers considerable, tangible health benefits. Like many harmful lifestyle behaviors, smoking accelerates epigenetic aging. Learn more in this clip featuring Dr. Steve Horvath.