Smoking may lead to more belly fat; new study suggests - here’s why

Madeline Holcombe, CNN | 3/21/2024, 1:56 p.m.
Mark another point against smoking: It may cause an increase in a type of body fat linked to serious disease, …

Mark another point against smoking: It may cause an increase in a type of body fat linked to serious disease, according to a new study.

Both starting smoking and spending a lifetime smoking cigarettes was associated with an increase in abdominal fat, according to a study published Thursday in the journal Addiction.

And further analysis showed that the increase may be in visceral fat, said lead study author Dr. Germán Carrasquilla, an epidemiologist and assistant professor at Karolinska Institute in Sweden.

Visceral fat isn’t visible — it surrounds your organs within your abdomen. It’s normal and healthy for visceral fat to make up about 10% of your body weight, according to the Cleveland Clinic. Too much visceral fat, however, can create inflammation, contributing to chronic disease.

“Its location and the way it interacts with our body’s functions make it particularly dangerous,” Carrasquilla said in an email. “This type of fat is strongly linked to heart disease, type 2 diabetes, and other metabolic conditions.”

The results show the need for large-scale efforts to prevent and reduce smoking, he said.

“Reducing one major health risk in the population will, indirectly, reduce another major health risk,” Carrasquilla said in a statement.

Bad habits travel together

The research team conducted a statistical analysis called Mendelian randomization, which uses genetic differences to study how behaviors or environments lead to different health outcomes.

“By examining genetic data we can infer whether a relationship is causal, going beyond associations,” Carrasquilla said.

The study is well done, and though it provides strong evidence that smoking and increased abdominal fat have a causal, not just correlational, relationship, it is not quite definitive, said Naveed Sattar, professor of cardiometabolic medicine at the University of Glasgow in Scotland. He was not involved in the research.

There could be some confounding elements that make the link between smoking and belly fat stronger, added Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver.

“Bad habits also tend to travel together,” said Freeman, who was not involved in the research. For example, people may reach for a pack of cigarettes when stressed or may be smoking alongside a beer, he said.

Are you ready to quit?

One big question that remains is whether stopping smoking can reverse the development of abdominal fat, Carrasquilla said.

But that does not mean that smokers should hesitate to start their journey to quitting, he said.

“We all know that smoking is bad,” he said. “Public health interventions should continue to emphasize the overall health improvements associated with smoking cessation.”

Even outside of cigarettes, breathing in substances — such as marijuana, air pollution and cooking smoke — has been associated with an increase in cardiovascular and lung disease, Freeman added.

“Any inhaled substance is bad news,” he said. “Getting rid of it is always a plus.”

Quitting smoking is famously hard, however.

Freeman recommends his patients utilize support programs such as the helpline 1-800-QUIT-NOW and find ways to remove the temptation, particularly if you have loved ones who smoke as well.

“If you have a significant other in the household or another person in the household who smokes, it’s going to be really hard to quit smoking,” he said. “I always tell people, if you have friends that smoke and you’re trying to quit, tell them you’ll see them in a few months — as awful as that sounds.”

It can also be helpful to find new ways of coping with stress, since that is often a big trigger driving people to smoke, he said.

Exercise is not only a good stress reducer but has also been shown to be a potent aid in quitting smoking, Freeman added.

“Getting in 30 minutes a day of good breathless activity is really important,” he said.

However you approach quitting, the first step is to get to the place where you are ready and eager to rid yourself of the habit, Freeman said. That could be a desire to be stronger, healthier or even just to save money.

“If you’re not ready to quit smoking, I could cover you head to toe in patches and give you your body-weight drugs to help you quit smoking and you’re not going to quit,” he said.

“Do you want to be Grandpa Joe or Grandma Jean who is suffering the ills of cardiovascular disease that would have been progressed by cigarette smoking and having a miserable time in old age, or do you want to be dancing with your great-grandchildren?” Freeman said. “That’s really the motivating factor.”