A new study claims that smoking a single cigarette takes 20 minutes off life expectancy

The research from University College London, commissioned by the Department for Health and Social Care, says that on average, one cigarette cuts a woman's lifespan by 22 minutes, whereas it is 17 minutes for men.

Researchers said the effect of smoking is "cumulative", meaning that the sooner someone stops smoking and the more cigarettes they avoid having, the longer they will live.

"Studies suggest that smokers typically lose about the same number of healthy years as they do total years of life," they said.

"Thus smoking primarily eats into the relatively healthy middle years rather than shortening the period at the end of life, which is often marked by chronic illness or disability.

"So a 60-year-old smoker will typically have the health profile of a 70-year-old non-smoker."

They concluded: "We estimate that on average, smokers in Britain who do not quit lose approximately 20 minutes of life expectancy for each cigarette they smoke.

"This is time that would likely be spent in relatively good health.

"Stopping smoking at every age is beneficial but the sooner smokers get off this escalator of death the longer and healthier they can expect their lives to be."