Women can add nine years to their lives by quitting smoking before the age of 40, according to a new study by the University of Oxford, published in The Lancet.
The study surveyed nearly 1.2 million women in Britain. For those who quit smoking before 30, they gained 30 years.
Study co-author Richard Peto of the University of Oxford said in a press release: “Whether they are men or women, smokers who stop before reaching middle age will on average gain about an extra 10 years of life."
The study warned this did not mean that it was safe to continue smoking until age 40: “Women who do so have throughout the next few decades [of their lives] a mortality rate 1.2 times that of never-smokers. This is a substantial excess risk, causing one in six of the deaths among these ex-smokers.”
It also cautioned against so-called light cigarettes, smoked by most of the women in the study: “Low-tar cigarettes are not low-risk cigarettes and… more than half of those who smoke them will eventually be killed by them."