By Daniel Machin
Women smokers who kick the habit before they reach middle age can add an extra 10 years to their life, according to scientists.
A total of 1.3 million women aged 50 to 65 were studied from 1996 to 2001, and researchers found that those who smoked tripled their chances of dying over nine years compared with non-smokers.
Smoking-related diseases such as lung cancer, chronic lung disease, heart disease or stroke were largely responsible for the increased death rate, with the risk increasing steeply with the quantity of tobacco smoked.
Even light smokers who puffed fewer than 10 cigarettes a day doubled their likelihood of dying.
The authors of the Million Women Study found that people who quit smoking around the age of 30 avoided 97 per cent of their excess risk of premature death.
"Smokers lose at least 10 years of lifespan," they wrote in the Lancet medical journal.
"Although the hazards of smoking until age 40 years and then stopping are substantial, the hazards of continuing are 10 times greater."