Smoking and Ulcerative Colitis: What's the Link?

Medically Reviewed by Sabrina Felson, MD on June 01, 2022
4 min read

We know that smoking is bad for your health in many ways, as it’s linked to cancer, heart disease, and other serious medical issues. But experts know it may actually protect you from a small number of health problems, too. Research shows smoking – specifically the chemical nicotine in tobacco – seems to both guard against ulcerative colitis (UC) and help ease symptoms.

In fact, some doctors prescribe nicotine-replacement patches or gums as treatment for UC.

The bottom line is that smokers are less likely to get UC than nonsmokers, whether you’ve never smoked, or you smoked in the past and quit. UC is a type of inflammatory bowel disease (IBD). It happens when your digestive tract, which runs from your mouth to your bottom, is seriously inflamed.

Researchers aren’t sure exactly how smoking works to protect you from UC, but they have some ideas. Experts think that nicotine or other substances in tobacco may keep you from getting UC in several ways, including:

  • Lowering the levels of cytokines, proteins that trigger inflammation
  • Activating immune cells that help tamp down inflammation
  • Producing carbon monoxide, which may work as an anti-inflammatory agent
  • Making more mucus, which forms a protective barrier to support healthier gut bacteria

If you have UC and you smoke, studies show you’re less likely to:

  • Have a UC relapse
  • Need hospitalization due to UC
  • Require stronger drugs for UC
  • Have bowel removal surgery

Experts have used nicotine as a therapy for UC. But the nicotine is in the form of chewing gum, skin patches, or enemas -- not cigarettes. Some of these treatment options have unwanted side effects. They can lead to pancreatitis (swelling and redness in your pancreas), nausea, or headaches. In addition, some studies suggest that nicotine enemas don’t actually help active UC.

It’s not certain how useful these treatments are.

Researchers are unable to do a formal study on the link between UC and smoking for ethical reasons. It would be dangerous to ask a group of people to begin smoking, since there are many serious health risks linked to cigarettes.

So, all that’s known about smoking as a treatment for UC comes from studies with people who already smoked. But the results of these studies are conflicting.

Some people have reported that their UC symptoms come back when they stop smoking. Their symptoms then lessened again once they began smoking again. Some experts have found that male smokers with UC reported less bowel symptoms than male nonsmokers with UC. But in other studies, they found no tie between smoking and UC severity.

It’s important to know the possible ties between smoking and UC, because it can help you make informed lifestyle choices. But, despite any benefits smoking may have on UC, doctors strongly suggest you don’t use cigarettes or other vaping methods to treat UC symptoms.

While you’re less likely to have UC if you smoke, the habit hurts your gastrointestinal (digestive) tract in other ways. That’s because chemicals in cigarette smoke, and the large amounts of pollution breathed in during smoking, can damage your body’s tissues.

If you’ve smoked for more than 2 years, you may also have a higher risk of stomach issues, due to a lower stomach pH (the level of how acidic something is). Smoking can also change how your gut repairs itself.

These factors suggest that, while smoking may protect you from getting UC, it can increase your risks for other inflammatory diseases.

Unlike with UC, smoking makes you more likely to get another inflammatory bowel disease known as Crohn’s disease. While UC and Crohn’s are similar in some ways, their differences include:

Genetics. While UC and Crohn’s have a lot in common, like inflammation, their genetics are different.

Immune system. The two conditions have different immune responses.

Environmental factors. Crohn’s disease and UC may be affected differently by your diet, the medications you take, and other things in your environment, like smoking.

While smoking cigarettes offers some protection against UC, it heightens your risk of Crohn’s disease. With Crohn’s, you’re more likely to have complications, frequent hospitalizations, need surgery, and respond badly to medication if you smoke.

This is the opposite in those with UC. Their hospitalization rates, number of relapses, and need for more drugs or surgery is a lot lower if they smoke.

If you have UC, you may be able to gain the positive aspects of smoking without using cigarettes. Ask your doctor about nicotine options like patches, gum, or other options that may provide you with the benefits, while avoiding the dangers of smoking.

But nicotine replacement isn’t for everyone. You can still become addicted to these products. If you want to find a way to control your UC symptoms without nicotine, talk to your doctor.