LONDON, Dec 30: A new study has revealed that smoking shortens life expectancy more than previously believed, urging smokers to quit in 2025. Researchers at University College London (UCL) discovered that each cigarette smoked reduces a person's life expectancy by approximately 20 minutes. This means that a pack of 20 cigarettes can shorten life by nearly seven hours.

The analysis also showed that quitting smoking could significantly improve life expectancy. For example, a smoker who quits after 10 cigarettes a day would save a full day of life by January 8. Quitting until February 5 could add a week to their life, and quitting by August 5 would extend life by a month. By the end of the year, a smoker could potentially save 50 days of life.

Dr. Sarah Jackson, principal research fellow at UCL’s Alcohol and Tobacco Research Group, emphasized the underestimated impact of smoking on life expectancy. “On average, smokers who don’t quit lose around a decade of life. That’s 10 years of precious time with loved ones,” she said.

Smoking remains a leading preventable cause of disease and death worldwide, accounting for up to two-thirds of long-term users and causing about 80,000 deaths each year in the UK. It is also responsible for a quarter of all cancer deaths in England. The study, commissioned by the Department of Health, draws on data from the British Doctors Study, which began in 1951, and the Million Women Study, which tracks women’s health since 1996.

An earlier study in 2000 estimated that smoking a single cigarette reduced life expectancy by about 11 minutes, but the latest findings, published in the Journal of Addiction, nearly double that figure to 20 minutes — 17 minutes for men and 22 minutes for women.

Dr. Jackson explained that smoking doesn’t just shorten the final years of life, which are often marked by illness or disability. “It primarily affects the relatively healthy years in midlife, bringing forward the onset of illness. A 60-year-old smoker typically has the health profile of a 70-year-old non-smoker,” she said.

Although some smokers live long lives, others develop smoking-related diseases and may die in their 40s. This variation is due to factors such as the number of cigarettes smoked, the type of cigarettes, how deeply smokers inhale, and individual susceptibility to the toxic substances in cigarette smoke.

The authors stressed that quitting completely is the only way to reap the full health and life expectancy benefits. Research has shown there is no safe level of smoking. For instance, those who smoke one cigarette a day have about 50% of the heart disease and stroke risk compared to heavy smokers. "Stopping smoking at any age is beneficial, but the sooner smokers quit, the longer and healthier their lives will be," the study concludes.

The Department of Health has urged smokers to use the NHS Quit Smoking app and Personal Quit Plan for advice and support tailored to individual needs.

Prof. Sanjay Agrawal, a tobacco specialist at the Royal College of Physicians, added, “Every cigarette smoked costs precious minutes of life. The cumulative impact is devastating, not only for individuals but also for the healthcare system and economy. This research is a powerful reminder of the urgent need to address cigarette smoking as the leading preventable cause of death and disease in the UK.”