It's widely known that the effects of smoking start to fade as soon as a smoker quits.
However, new research suggests the effects of the habit can persist for a decade or more after quitting.
People who smoke a pack a day for 20 years are at higher risk of heart disease for 10 to 15 years after quitting than those who never smoked.
UPI reports that as of 2017, just 14% of Americans were smokers.
That's a significant decrease from just over 42% in 1965 -- but that means well over 30 million people still smoke.
Nevertheless, data shows the decline in smokers in the U.S. has plateaued somewhat, and is increasing in some other countries.