This recent study found that women who successfully quit smoking before the age of 40 avoided 90% of the added risk of early death caused by smoking, while stopping before 30 helped women avoid 97% of the added risk. Women smokers who passed away in their 50s, 60s, and 70s did so due to smoking-related illness two-thirds of the time. Data was culled from the Million Women Study, which has followed women in the United Kingdom over the age of 50 since the late 1990s.
