Quitting Smoking Benefits Health Despite Weight Gain

The benefits to cardiovascular health that are associated with quitting smoking aren’t blunted by the modest weight gain, according to a new study. The findings underscore the benefits of putting a stop to smoking.

Cigarette smoking causes about 1 in every 5 deaths in the United States each year. Smoking harms nearly every organ in the body, including the heart, lungs, blood vessels, eyes, reproductive organs, bones, bladder and digestive organs. Smoking cessation greatly lowers the risk of many diseases and conditions, including cardiovascular disease.

About 80% of smokers who quit gain weight. Obesity is a risk factor for cardiovascular disease, so health professionals have wondered whether this weight gain might counter the health benefits of quitting. A team of researchers that included Dr. James B. Meigs of Harvard Medical School, Dr. Carole Clair — now at the University of Lausanne, Switzerland — and Dr. Caroline S. Fox of NIH’s National Heart, Lung and Blood Institute (NHLBI) set out to investigate.

The researchers analyzed data collected between 1984 and 2011 from over 3,000 adults in the community-based Framingham Heart Study. The participants underwent physical examinations every 4 years, including measures of weight, blood pressure and diabetes status.

Participants were categorized as smoker, recent quitter (4 years or less), long-term quitter (more than 4 years) or nonsmoker, based on their reported smoking status at each exam. The presence of cardiovascular disease (including heart attack, angina, stroke, peripheral arterial disease and heart failure) was assessed over approximately 6 years. The study was supported in part by NHLBI and NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Results appeared in the March 13, 2013, issue of the Journal of the American Medical Association.

The researchers found that, among participants without diabetes, those who quit smoking had about half the risk of cardiovascular problems as those who smoked. A similar benefit was found among those with diabetes, but the number of participants with diabetes wasn’t large enough to ensure this result wasn’t due to chance.

Participants without diabetes who were recent quitters gained about 6 pounds over the 4 year period since their last exam visit. Long-term quitters gained about 2 pounds, which was similar to that gained by smokers and nonsmokers. The researchers found that, despite gaining weight, the participants who stopped smoking maintained their lower risk of cardiovascular disease.

“Our findings suggest that a modest weight gain, around 5-10 pounds, has a negligible effect on the net benefit of quitting smoking,” Fox says. “Being able to quantify to some degree the relationship between the benefits and side effects of smoking cessation can help in counseling those who have quit or are thinking about quitting.”

The researchers plan to conduct follow-up studies to determine whether this finding holds among people with diabetes.