If you’ve quit smoking, how long will it take for your risk of cardiovascular disease (CVD) to return to “normal”—that is, as if you never smoked? Between 10 and 15 years, according to a study in the Journal of the American Medical Association that looked at data from 8,770 participants in the long-running Framingham Heart Study.
Over an average follow-up of 26 years, former heavy smokers who had quit within the last five years were significantly less likely than current smokers to have a first cardiovascular event (defined as a heart attack, stroke, heart failure, or death due to CVD). But compared to people who never smoked, former smokers’ CVD risk remained elevated for another five to 10 years (or 10 to 15 years total) before falling to nonsmokers’ levels. The finding is important because some cardiovascular risk calculators consider former smokers’ CVD risk to be identical to that of people who never smoked after just five years.
Heavy smoking was defined in the study as at least 20 “pack-years”—for example, smoking a pack a day for 20 years, or two packs a day for 10 years.
Also see Light Smoker? You’re Still at Risk.