The Effect of Nicotine on IBD

Smoking worsens Crohn's disease but not ulcerative colitis

Research has shown that there is a connection between nicotine and inflammatory bowel disease (IBD). However, what is puzzling is that smoking seems to have opposite effects on the two main forms of IBD—ulcerative colitis and Crohn's disease.

Woman smoking a cigarette
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Nicotine and Ulcerative Colitis

Ulcerative colitis is largely referred to as a disease of non-smokers. Former smokers are at the highest risk for developing ulcerative colitis, while current smokers have the least risk. This tendency indicates that smoking cigarettes may prevent the onset of ulcerative colitis.

Researchers have discovered that it is the nicotine in tobacco cigarettes that have a positive influence on symptoms of ulcerative colitis. Nicotine is a naturally occurring substance in tobacco that has a complex effect on many organs and systems in the body. Nicotine is also highly addictive, and many people who smoke cigarettes have difficulty quitting despite serious health risks.

It is theorized that the nicotine in cigarettes affects the smooth muscle inside the colon. This effect may alter gut motility (the rate at which food material moves through the GI tract).

Nicotine and Crohn's Disease

Smoking cigarettes actually has a detrimental effect on Crohn's disease. People who smoke, or who have smoked in the past, have a higher risk of developing Crohn's disease than non-smokers.

Crohn's disease patients that smoke has an increased number of relapses and repeat surgeries and may require aggressive immunosuppressive treatment. People with Crohn's disease are strongly encouraged by their physicians to stop smoking in order to prevent flare-ups of the disease.

The Effect of Secondhand Smoke

Secondhand smoke in children does have an effect on the course of IBD. Children exposed to secondhand smoke have a decreased risk of ulcerative colitis and an increased risk of developing Crohn's disease.

Former Smokers With Ulcerative Colitis Experience Fewer Symptoms When Lighting Up Again

Some studies have shown that former smokers who develop ulcerative colitis and then go back to smoking experience fewer symptoms. However, smoking itself carries other serious health risks: it is a major cause of vascular disease, cancer, and chronic obstructive pulmonary disease. Cigarette smoking also causes other respiratory symptoms, adversely affects reproductive outcomes, and is a cause of diminished health status. Furthermore, exposure to second-hand smoke is an established cause of coronary heart disease and lung cancer, as well as a host of other adverse health effects.

Physicians would not advise that a patient start smoking to benefit UC, as the risks of smoking far outweigh any possible benefit.

Nicotine Patches Come With Bothersome Side Effects

Now that nicotine patches (also known as transdermal nicotine) are available for smoking cessation, it is possible to study the effects of nicotine alone without exposing the body to the other health risks of smoking.

The effect of a drug is often studied by researchers in a type of experiment known as a double-blind placebo-controlled study. In this type of study, some patients are given the new drug while others are given a dummy preparation (placebo). Neither the patients nor the physicians studying them know who is receiving the actual drug and who is receiving the placebo until the study is completed.

In two double-blind placebo-controlled studies, nicotine patches were found to be better than placebo at inducing remission in active ulcerative colitis. Unfortunately, side effects in the nicotine group were common and included nausea, lightheadedness, and headache. Study participants who had never smoked found the side effects particularly bothersome.

In another study, people with left-sided ulcerative colitis who were no longer responding to treatment with oral mesalamine were given transdermal nicotine and mesalamine enemas. This new combination was effective in inducing remission in 12 of the 15 study participants.

Nicotine does not appear to be beneficial as maintenance therapy; it may not help patients stay in remission. Rather, it seems to have a positive effect on the active disease (flare-ups). To prevent the side effects from the patch, researchers are developing ways to release nicotine directly to the colon. In one study, a nicotine capsule was created to act directly on the colon over a period of 6 hours.

What This All Means for People With Ulcerative Colitis

The total effect of nicotine on ulcerative colitis is still unclear, but it does present a promising direction for the development of new treatments. As nicotine's role in the colon is better understood, patients with ulcerative colitis may someday benefit from new treatments based on this effect.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Pullan RD, Rhodes J, Ganesh S, et al. Transdermal nicotine for active ulcerative colitis. N Engl J Med Mar 1994;330:811-815. doi:10.1056/NEJM199403243301202

  2. Sandborn WJ, Tremaine WJ, Offord KP, et al. Transdermal nicotine for mildly to moderately active ulcerative colitis. Transdermal nicotine for mildly to moderately active ulcerative colitis. a randomized, double-blind, placebo-controlled trial. Ann Intern Med Mar 1997;126:364-371. doi:10.7326/0003-4819-126-5-199703010-00004

  3. Mahid SS, Minor KS, Stromberg AJ, Galandiuk S. Active and passive smoking in childhood Is related to the development of inflammatory bowel disease. Inflamm Bowel Dis. 2007;13(4):431-8. doi: 10.1002/ibd.20070.

  4. Bastida G, Beltrán B. Ulcerative colitis in smokers, non-smokers and ex-smokers. World J Gastroenterol. 2011;17(22):2740-7. doi:10.3748/wjg.v17.i22.2740

Additional Reading

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.