The largest ever study of the hazards of smoking amongst women has revealed that those who give up by middle age can extend their lives by more than a decade.
The research, published in the medical journal The Lancet today, shows that women who stop smoking before the age of 30 slash their chances of a smoke-related death by 97%.
In one of the biggest studies of its kind more than 1.3m women were recruited between 1996 and 2001.
Those who were still smokers after three years were nearly three times as likely as non-smokers to die over the next nine years, the study revealed.
Professor Sir Richard Peto from the University of Oxford, who co-wrote the report, said: "If women smoke like men, they die like men.
"But whether they are men or women, smokers who stop before reaching middle age will, on average, gain about an extra 10 years of life."
Leanne Dixon, 21, a customer service assistant from Manchester, started smoking when she was 13.
"These statistics really make me think," she told Sky News.
"I've thought about giving up for ages but never have. But it makes you think that you have to stop while you're young."
Alyson Aston and her friend Lyn Faulkner started smoking at the age of 15. Now in their 40s, they say giving up is not an option.
"It's not these statistics that make me want to give up, it's the cost," said Ms Aston.
Ms Faulkner added: "I think a lot about giving up but I don't have the willpower.
"But when you think about living an extra 10 years, it really is a long time."
Those who have had a brush with cancer have a cautionary tale to tell.
June Atherton, 66, used to smoke 60 cigarettes a day. She gave up at the age of 50 but was diagnosed with lung cancer 10 years later.
She said: "I stop young women in the street and tell them that they're killing themselves by smoking. They think I'm mad but it's an important message."
Paula Chadwick, chief executive of the Roy Castle Lung Cancer Foundation, told Sky News: "This is important research and tells us that stopping as early as you can will prolong your life.
"More women are being diagnosed with lung cancer and we need to bring those figures down by supporting those who want to give up and making sure the young don't start."