Here’s how much one cigarette drastically shortens your life expectancy

Smoking a single cigarette is enough to take 20 minutes off your life expectancy, almost double the figure previously thought, according to a medical study.

This means a typical pack of 20 cigarettes can shorten a person’s life by nearly seven hours, according to researchers at University College London. 

If smokers on 10 cigarettes a day use 1 January to kick the habit, they could add a day to their life expectancy by 8 January, according to the study. 

This increases to a week if they quit until 5 February, a whole month if they stop until 5 August, and 50 days of life if they quit until the end of the year. 

Dr Sarah Jackson, a principal research fellow at UCL’s alcohol and tobacco research group, told the Guardian: “People generally know that smoking is harmful but tend to underestimate just how much.”

The data is different for men and women, with men losing 17 around minutes per cigarette and women losing 22 minutes, which averages at 20. 

The findings in the Journal of Addiction are nearly double what was previously published in the BMJ in 2000, which found a single cigarette takes 11 minutes off a person’s life expectancy.

Jackson added that smoking doesn’t just cut off the unhealthy end-years of our lives, but cut shorts the healthy ones, which means “a 60-year-old smoker will typically have the health profile of a 70-year-old non-smoker”.

The study notes “some smokers live long and healthy lives while others succumb to smoking-related diseases and even death in their 40s”. 

This variation can be downe to differences in smoking patterns, such as the depth of inhalation and the type of cigarette, as well as individual susceptibility to the toxins in cigarette smoke.

It summarises that it is not enough just to reduce consumption – total cessation is required to achieve the maximum benefits for health and life. 

According to the NHS, Smoking is the biggest cause of preventable deaths in England, accounting for more than 80,000 deaths each year. It says one in two smokers will die from a smoking-related disease.

The study was commissioned by the Department of Health and drew on data from two major sources: the British Doctors Study, launched in 1951 as one of the world’s first large-scale investigations into the effects of smoking, and the Million Women Study, which has been monitoring women’s health since 1996.