Does Smoking Have Harmful Effects on Digestive System? Dr Badran Answers

Smoking has been shown to have harmful effects on all parts of the digestive system, contributing to such common disorders as heartburn and peptic ulcers. It also increases the risk of Crohn’s disease and possibly gallstones. Smoking seems to affect the liver, too, by changing the way it handles drugs and alcohol. Smoking can also make pancreatitis worse.

In addition, smoking is a risk factor for mouth, lip, and voice box cancer, as well as cancer of the esophagus, stomach, pancreas, liver, colon, and rectum.

In fact, there seems to be enough evidence to stop smoking solely on the basis of digestive distress.

Smoking and Heartburn

Heartburn happens when acidic juices from the stomach splash into the esophagus. Normally, a muscular valve at the lower end of the esophagus, the lower esophageal sphincter, keeps the acid solution in the stomach and out of the esophagus. Smoking decreases the strength of the esophageal valve, thereby allowing stomach juice to reflux, or flow backward into the esophagus.

Smoking also seems to promote the movement of bile salts from the intestine to the stomach, which makes the stomach juice more harmful. Finally, smoking may directly injure the esophagus, making it less able to resist further damage from refluxed material.

Smoking Makes Saliva Potentially Lethal

Smoking tobacco reduces the amount of bicarbonate present in the saliva. Bicarbonate is an acid-neutralizing compound. Smoking cigarettes can turn saliva in the mouth into a potentially lethal cocktail that promotes cancer. Normally saliva acts as a buffer that protects the lining of the mouth from harmful substances. Research shows that spit can be poisoned by chemicals in cigarette smoke. They destroy its protective components, leaving a corrosive mix that damages cells in the mouth and can lead to cancer. The mixture of saliva and smoke is actually more lethal to cells in the mouth than cigarette smoke alone.

Once exposed to cigarette smoke, the normally healthy saliva not only loses its beneficial qualities but it turns traitor and actually aids in destroying the cells of the mouth and oral cavity. Cigarette smoke is not only damaging on its own, it can turn the body against itself. Saliva contains natural antioxidants, molecules that neutralise harmful free radicals - unstable groups of atoms capable of damaging DNA and triggering cancer. Cigarette smoke not only destroyed the antioxidants, but created a potentially deadly free radical cocktail.

Approximately 90% of people with oral cancer are tobacco users, and smokers are six times more likely than non-smokers to develop oral cancer. Additionally, users of smokeless tobacco, commonly known as chewing tobacco, have a 50 times more likely chance of developing mouth cancer.

Smoking and excess drinking in combination can significantly increase your risk of oral cancer. Some studies suggest that heavy drinkers who are also smokers are up to 100 times more likely to be diagnosed with oral cancer than those who don’t drink or smoke.

Smoking and Peptic Ulcers

Cigarette smoking appears to be a risk factor for the development, maintenance, and recurrence of peptic ulcer disease. Smoking has an inconsistent effect on gastric acid secretion, but it does have other effects on upper gastrointestinal function that could contribute to the pathogenesis of peptic ulcer disease. These include interference with the action of histamine-2 antagonists, acceleration of gastric emptying of liquids, promotion of duodenogastric reflux, inhibition of pancreatic bicarbonate secretion, reduction in mucosal blood flow, and inhibition of mucosal prostaglandin production.

Smoking also raises the risk for infection from Helicobacter pylori. This is bacteria commonly found in ulcers.

Because these effects are related directly to the act of smoking and cessation of smoking is associated with the prompt recovery of the respective functions, smokers will benefit immediately by stopping or reducing cigarette consumption.

Smoking and Liver Disease

Smoking affects the liver via 3 separate mechanisms: toxic (both direct and indirect), immunologic, and oncogenic. The liver normally filters alcohol and other toxins out of the blood. But smoking limits your liver’s ability to remove these toxins from your body. If the liver isn’t working as it should, it may not be able to process medications well. When smoking is combined with drinking too much alcohol, it makes liver disease worse.

There is an association between cigarette smoking and progression of fibrosis in chronic liver diseases. Smoking is associated with accelerated development of hepatocellular carcinoma in patients with chronic hepatitis B or C virus infection.

Tobacco smoking adversely affects lung function, which increases physical limitations and may preclude liver transplantation. Following liver transplantation, smoking is associated with several adverse outcomes, including increased risk of de novo malignancy, vascular complications, and nongraft-associated mortality.

The respiratory illness caused by the novel coronavirus disease COVID-19 serves as a good example of the complex interplay between the lungs and the liver. It is evident that cigarette smoking has important negative effects on a multitude of liver diseases and that patients’ smoking cessation must be prioritized.

Smoking and Crohn’s Disease

Crohn’s disease is a chronic inflammatory bowel disease. It causes inflammation of the digestive tract, which can lead to abdominal pain, severe diarrhea, fatigue, weight loss and malnutrition. This inflammation often spreads into the deeper layers of the bowel. Crohn's disease can be both painful and debilitating, and sometimes may lead to life-threatening complications.

This disease is an autoimmune disorder of the digestive tract. People who smoke are more likely to get Crohn’s than those who do not smoke. Smoking can make Crohn’s Disease worse. People with Crohn’s who smoke may find that they have more severe symptoms and complications such as strictures and fistulas, have more flare-ups, require more steroids and stronger drugs such as immunosuppressants and biologics. Sometimes these drugs are not as effective in people who smoke, are more likely to need surgery and are more likely to have to return for further surgery.

Women who smoke are more likely to develop Crohn’s Disease and to require surgery than men who smoke. Smoking has also been shown to have an association with disease location. Smokers tend to have Crohn’s Disease in the small intestine (small bowel) rather than the colon (large bowel).

Tobacco smoke contains over a thousand different chemicals including nicotine, carbon monoxide, and free radicals. There are several possible ways in which smoking may affect the gut – it may lower the intestines’ defenses, decrease the blood flow in the intestines, or cause changes to the immune system which result in inflammation.

Children and unborn babies exposed to passive smoking may be more likely to develop Crohn’s Disease. Smoking during pregnancy is not advised.

In the non-smoker, Crohn’s seems milder.Giving up smoking is beneficial for people with Crohn’s Disease. The guidelines for people with Crohn’s Disease strongly recommend that people with Crohn’s do not smoke.

Smokers also appear to have a greater need for some of the stronger forms of medical treatment such as immunosuppressant drugs. People who stop smoking are less likely to need repeated surgery compared with people who continue smoking after surgery. Reducing the amount you smoke may have a positive effect on the symptoms.

Smoking and Gallstones

Tobacco smoking is believed to affect the hepatobiliary system and has been associated with increased risk of liver and gallbladder cancer. Some research suggests that smoking increases the risk of developing gallstones. Gallstones form when liquid stored in the gallbladder turns into material that resembles stones. These can range in size from a grain of sand to a pebble.