If you’re a woman who smokes, you could potentially add 10 years to your life by quitting before you hit middle age, according to a new study conducted by researchers at the University of Oxford in the U.K. Women in the quitting smoking benefits study who smoked until reaching middle age, or age 40, were approximately 20% more likely to die than those who never smoked over the 12 years in which the study was conducted. However, women who smoked throughout their entire lives tripled their chances of dying over the same 12-year period.

While 10 years might be a surprisingly long extension to one’s life, the benefits of quitting smoking are well documented. Aside from longevity, kicking the habit can greatly reduce the chances of getting cancer, heart disease, and many other conditions affecting the respiratory system.

Major Quitting Smoking Benefits Before 40

According to the researchers, women who managed to kick the smoking habit before the age of 40 effectively avoided 90% of the risk of a smoking-related death. For those who quit smoking by age 30 instead of 40, a whopping 97% of the risk was avoided. The study was very large, comprising over 1 million women in their 60s and 70s. Previous studies involving men have come to similar conclusions.

Sir Richard Peto, one of the lead researchers behind the study, said that the generation born around the year 1940 was the first in which many individuals smoked cigarettes throughout their entire adults lives. According to Peto, modern studies are the only ones truly able to examine the long-term of effects of smoking and smoking cessation. Older studies are outdated or simply incomplete in comparison because they don’t include lifelong smokers who are now reaching the age of mortality.

About the Study

The study participants, who were approximately 55 years of age at the time of enrollment, were studied between the years of 1996 and 2011. The participants were asked to respond to questions about their social activity, medical history and lifestyle habits approximately every 3 years. Approximately 66,000 of the participants died from various causes over the study’s 12 years.

Roughly 52% of the participants in the study never smoked, while 28% were former smokers and 20% were current smokers. The women who reported smoking after the first 3 years of the study had passed increased their risk of dying during the following 9 years three-fold in comparison to women who never smoked.

The higher mortality rates among smokers were largely attributed to smoking-related diseases, such as lung cancer and emphysema.

The Bottom Line

If you’re a woman, you can gain approximately 10 years of life by quitting smoking before you reach the age of 40, according to a new study by the University of Oxford. Of course, quitting sooner would be even more beneficial. Overall, quitting smoking is one of the single best decisions you can make for your health.

The full text of the study is available online in the medical journal The Lancet.