Cigarette smoking has been shown to cause a variety of life-threatening diseases such as lung cancer, colon cancer, emphysema, and heart disease. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), there are more than 400,000 Americans who die from cigarette smoking. And one in every five deaths are related to smoking. Smoking affects all parts of the body, directly or indirectly, including the digestive system.
Smoking and the digestive system
Smoking can harm the digestive system. It can contribute to common disorders of the digestive system such as heartburn and peptic ulcers. Smoking also increases the risk of having Crohn’s disease and possibly the formation of gallstones. Smoking may also damage the liver, causing liver disease.
Smoking causes heartburn.
Heartburn is a painful, burning feeling in the chest. This is caused by stomach acid that flows back into the esophagus—a tube that connects the mouth to the stomach. Heartburn is a common symptom of Gastroesophageal Reflux Disease (GERD).
Normally, stomach acid is prevented from flowing back into the esophagus by the lower esophageal sphincter (LES)—a muscular valve at the lower end of the esophagus. Smoking, however, causes weakening of the LES. Stomach acid may flow back to the esophagus. The inner lining of the esophagus does not have the same protection as the stomach against stomach acid. When stomach acid flows back to the esophagus, it causes irritation of the esophageal lining, thus, causing heartburn.
Smoking and Peptic Ulcer
Peptic ulcer is one of the most common disorders of the digestive system. A peptic ulcer is a sore in the lining of the stomach or the duodenum—the first part of the small intestine.
Peptic ulcers may be caused by the bacterium Helicobacter Pylori (H. Pylori); long-term use of pain relievers such as aspirin and ibuprofen; and, in some cases, cancerous tumors of the stomach or the pancreas.
Smoking has been shown to increase the development of peptic ulcers. It also increases people’s risk of infection from a bacterium called Helicobacter pylori and increases the risk of the formation of an ulcer from alcohol and over-the-counter pain relievers.
Stomach acid may also play a role in the development of ulcers. The stomach acid is normally absorbed by the food that we eat. The acid that is not absorbed by the food enters the duodenum and is neutralized by sodium bicarbonate—a substance made by the pancreas. Some studies show that smoking reduces the amount of sodium bicarbonate produced by the pancreas. This causes problems in the neutralization of acid in the duodenum. Other studies also suggest that, over time, cigarette smoking may increase the amount of acid produced in the stomach.
Smoking and Liver Disease
The liver is a large organ located in the upper right abdomen. One of its major functions is to process drugs, alcohol, and other toxic substances and removes it from the body. Research shows that smoking affects the ability of the liver to process these substances. If the liver has been damaged, it may affect the dose of medication used to treat a disease. Research also suggests that smoking may worsen liver disease caused by too much alcohol drinking.
Smoking and Crohn’s Disease
Crohn’s disease is a chronic form of inflammatory bowel disease. It causes swelling deep in the lining of the intestine, which causes pain. Crohn’s disease patients may also experience diarrhea. Although the disease usually affects the small intestine, it may also affect other parts of the digestive tract.
Research shows that smoking increases the risk of having Crohn’s disease than nonsmokers. Smokers who stopped smoking may still be at risk of having this disease. Smokers with Crohn’s disease have been linked to have a higher rate of relapse, repeat surgery, and the need for drug therapy.
The exact reason why smoking increases the risk of having Crohn’s disease is unclear, but some researchers believe that smoking might cause a decline in the intestine’s defenses, decrease in blood flow to the intestine, or cause changes in the immune system that result in inflammation.
Smoking and the formation of gallstones
Although several studies suggest that smoking may increase the risk of having gallstones and that the risk may be higher for women, this has yet to be established. Research results on this topic are not consistent and more study is needed.
Can the damage be reversed?
Some of the effects of smoking on the digestive system appear to be of short duration. For example, the effect of smoking on the pancreas’s bicarbonate production does not appear to last. Within a half-hour after smoking, the production of bicarbonate returns to normal. The effects of smoking on how the liver handles drugs also disappear when a person stops smoking. However, people who no longer smoke still remain at risk for Crohn's disease.
Related Readings:
Scientific information provided by the National Digestive Diseases Information Clearinghouse. NIDDK, NIH, DHHS. Publication No. 06–949. February 2006
Page Last Revised: August 2, 2012
Smoking and the digestive system
Smoking can harm the digestive system. It can contribute to common disorders of the digestive system such as heartburn and peptic ulcers. Smoking also increases the risk of having Crohn’s disease and possibly the formation of gallstones. Smoking may also damage the liver, causing liver disease.
Smoking causes heartburn.
Heartburn is a painful, burning feeling in the chest. This is caused by stomach acid that flows back into the esophagus—a tube that connects the mouth to the stomach. Heartburn is a common symptom of Gastroesophageal Reflux Disease (GERD).
Normally, stomach acid is prevented from flowing back into the esophagus by the lower esophageal sphincter (LES)—a muscular valve at the lower end of the esophagus. Smoking, however, causes weakening of the LES. Stomach acid may flow back to the esophagus. The inner lining of the esophagus does not have the same protection as the stomach against stomach acid. When stomach acid flows back to the esophagus, it causes irritation of the esophageal lining, thus, causing heartburn.
Smoking and Peptic Ulcer
Peptic ulcer is one of the most common disorders of the digestive system. A peptic ulcer is a sore in the lining of the stomach or the duodenum—the first part of the small intestine.
Peptic ulcers may be caused by the bacterium Helicobacter Pylori (H. Pylori); long-term use of pain relievers such as aspirin and ibuprofen; and, in some cases, cancerous tumors of the stomach or the pancreas.
Smoking has been shown to increase the development of peptic ulcers. It also increases people’s risk of infection from a bacterium called Helicobacter pylori and increases the risk of the formation of an ulcer from alcohol and over-the-counter pain relievers.
Stomach acid may also play a role in the development of ulcers. The stomach acid is normally absorbed by the food that we eat. The acid that is not absorbed by the food enters the duodenum and is neutralized by sodium bicarbonate—a substance made by the pancreas. Some studies show that smoking reduces the amount of sodium bicarbonate produced by the pancreas. This causes problems in the neutralization of acid in the duodenum. Other studies also suggest that, over time, cigarette smoking may increase the amount of acid produced in the stomach.
Smoking and Liver Disease
The liver is a large organ located in the upper right abdomen. One of its major functions is to process drugs, alcohol, and other toxic substances and removes it from the body. Research shows that smoking affects the ability of the liver to process these substances. If the liver has been damaged, it may affect the dose of medication used to treat a disease. Research also suggests that smoking may worsen liver disease caused by too much alcohol drinking.
Smoking and Crohn’s Disease
Crohn’s disease is a chronic form of inflammatory bowel disease. It causes swelling deep in the lining of the intestine, which causes pain. Crohn’s disease patients may also experience diarrhea. Although the disease usually affects the small intestine, it may also affect other parts of the digestive tract.
Research shows that smoking increases the risk of having Crohn’s disease than nonsmokers. Smokers who stopped smoking may still be at risk of having this disease. Smokers with Crohn’s disease have been linked to have a higher rate of relapse, repeat surgery, and the need for drug therapy.
The exact reason why smoking increases the risk of having Crohn’s disease is unclear, but some researchers believe that smoking might cause a decline in the intestine’s defenses, decrease in blood flow to the intestine, or cause changes in the immune system that result in inflammation.
Smoking and the formation of gallstones
Although several studies suggest that smoking may increase the risk of having gallstones and that the risk may be higher for women, this has yet to be established. Research results on this topic are not consistent and more study is needed.
Can the damage be reversed?
Some of the effects of smoking on the digestive system appear to be of short duration. For example, the effect of smoking on the pancreas’s bicarbonate production does not appear to last. Within a half-hour after smoking, the production of bicarbonate returns to normal. The effects of smoking on how the liver handles drugs also disappear when a person stops smoking. However, people who no longer smoke still remain at risk for Crohn's disease.
Related Readings:
Heartburn
Peptic ulcer
Crohn’s disease
Gallstones
Scientific information provided by the National Digestive Diseases Information Clearinghouse. NIDDK, NIH, DHHS. Publication No. 06–949. February 2006
Page Last Revised: August 2, 2012
