If you quit smoking and gain weight, it may seem like you're trading one set of health problems for another. But a Harvard University-led study found that you're still better off in the long run. Compared with smokers, even the quitters who gained the most weight had at least a 50% lower risk of dying prematurely from heart disease and other causes, the San Francisco Chronicle reports.
The study is impressive in its size and scope and should put to rest any myth that there are prohibitive weight-related health consequences to quitting cigarettes, said Dr William Dietz, a public health expert at George Washington University. "The paper makes pretty clear that your health improves, even if you gain weight," said Dietz, who was not involved in the research. "I don't think we knew that with the assurance that this paper provides."
The nicotine in cigarettes can suppress appetite and boost metabolism. The report says many smokers who quit and don't step up their exercise find they eat more and gain weight – typically less than 10 pounds (4.5kg), but in some cases three times that much.
A lot of weight gain is a cause of the most common form of diabetes, a disease in which blood sugar levels are higher than normal. Diabetes can lead to problems including blindness, nerve damage, heart and kidney disease and poor blood flow to the legs and feet.
The report says in the US study, researchers tracked more than 170,000 men and women over roughly 20 years, looking at what they said in health questionnaires given every two years. The people enrolled in the studies were all health professionals, and did not mirror current smokers in the general population, who are disproportionately low-income, less-educated and more likely to smoke heavily.
The researchers checked which study participants quit smoking and followed whether they gained weight and developed diabetes, heart disease or other conditions.
Quitters saw their risk of diabetes increase by 22% in the six years after they kicked the habit. An editorial in the journal characterised it as "a mild elevation" in the diabetes risk.
Studies previously showed that people who quit have an elevated risk of developing diabetes, said Dr Qi Sun, one the study's authors. He is a researcher at the Harvard-affiliated Brigham and Women's Hospital. But that risk doesn't endure, and it never leads to a higher premature death rate than what smokers face, he said.
"Regardless of the amount of weight gain, quitters always have a lower risk of dying" prematurely, Sun said.
Abstract
Background: Whether weight gain after smoking cessation attenuates the health benefits of quitting is unclear.
Methods: In three cohort studies involving men and women in the United States, we identified those who had reported quitting smoking and we prospectively assessed changes in smoking status and body weight. We estimated risks of type 2 diabetes, death from cardiovascular disease, and death from any cause among those who had reported quitting smoking, according to weight changes after smoking cessation.
Results: The risk of type 2 diabetes was higher among recent quitters (2 to 6 years since smoking cessation) than among current smokers (hazard ratio, 1.22; 95% confidence interval [CI], 1.12 to 1.32). The risk peaked 5 to 7 years after quitting and then gradually decreased. The temporary increase in the risk of type 2 diabetes was directly proportional to weight gain, and the risk was not increased among quitters without weight gain (P<0.001 for interaction). In contrast, quitters did not have a temporary increase in mortality, regardless of weight change after quitting. As compared with current smokers, the hazard ratios for death from cardiovascular disease were 0.69 (95% CI, 0.54 to 0.88) among recent quitters without weight gain, 0.47 (95% CI, 0.35 to 0.63) among those with weight gain of 0.1 to 5.0 kg, 0.25 (95% CI, 0.15 to 0.42) among those with weight gain of 5.1 to 10.0 kg, 0.33 (95% CI, 0.18 to 0.60) among those with weight gain of more than 10.0 kg, and 0.50 (95% CI, 0.46 to 0.55) among longer-term quitters (>6 years since smoking cessation). Similar associations were observed for death from any cause.
Conclusions: Smoking cessation that was accompanied by substantial weight gain was associated with an increased short-term risk of type 2 diabetes but did not mitigate the benefits of quitting smoking on reducing cardiovascular and all-cause mortality. (Funded by the National Institutes of Health.)
Authors
Yang Hu, Geng Zong, Gang Liu, Molin Wang, Bernard Rosner, An Pan, Walter C Willett, JoAnn E Manson, Frank B Hu, Qi Sun
[link url="https://www.sfgate.com/news/medical/article/Study-Smokers-better-off-quitting-even-with-13159006.php"]San Francisco Chronicle report[/link]
[link url="https://www.nejm.org/doi/full/10.1056/NEJMoa1803626"]New England Journal of Medicine abstract[/link]
[link url="https://www.nejm.org/doi/full/10.1056/NEJMe1809004?query=recirc_curatedRelated_article"]New England Journal of Medicine editorial[/link]