The median weight gain for recent quitters over a four-year period was about 6 pounds. Despite this, researchers found quitters had a significantly reduced risk of cardiovascular disease.

Recent smokers who quit were about 53 percent less likely to have cardiovascular disease than those who continued to smoke, Clair said. Long-term quitters had a 54 percent lower risk, despite weight gain.

These results applied to only those in the study without diabetes. While the researchers also looked at data for people WITH diabetes, they did not find a significant association between quitting smoking and a reduced risk of cardiovascular disease. Clair believes the study sample was too small and that more people would reveal results similar to the non-diabetic results.

Caveats

The smoking data in the Framingham study was self-reported, so participants' could have fudged the truth on their smoking habits. And as mentioned earlier, the exact time period for when participants' quit smoking was undetermined.

The study also did not capture any relapses that the smokers may have had. "Smokers generally need several attempts before successfully quitting," the study authors wrote.

One other limitation to the study is its lack of diversity -- the majority of the participants were white, so the authors aren't sure if their results would translate to a wider population.

The takeaway

People who quit smoking can reduce their risk of cardiovascular disease. Period.

"The message of this study is that weight gain following smoking cessation does not offset the benefits of smoking cessation on cardiovascular diseases," Clair said. "Doctors should advise all their patients to quit smoking."