Smoking may affect the entire body, increasing the chances of developing several life-threatening ailments such as heart disease, emphysema, and lung cancer.
Smoking leads to numerous diseases and several types of cancers of the digestive system, such as stomach cancer, bowel cancer and colon polyps. The diseases caused as a result of smoking leads to the deaths of about 400,000 Americans annually.
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Effects on the Stomach Due to Smoking
It is known that smoking increases the threat of cancers of the pancreas, stomach, mouth, liver, rectum, colon, and esophagus, and can cause conditions such as gastro esophageal reflux disease (GERD).
GERD and Heartburn
Heartburn is the feeling of pain or irritation in the chest caused by reflux, i.e., when the acidic semidigested food in the stomach flows back into the esophagus. The gastric acid helps to break down the food but does not directly affect the stomach; however, the esophagus is at risk from these acids.
The lower esophageal sphincter is a circular muscle located between the stomach and the esophagus, which gets weakened due to smoking. The lower esophageal sphincter also retains food substances in the stomach without allowing them to flow back into the esophagus. Nicotine weakens the sphincter.
Food contents in the stomach may flow back into the esophagus due to the weakening of the lower esophageal sphincter, leading to possible heartburn and damage to the lining of the esophagus. GERD occurs when backflow or reflux is present at least twice a week. This can cause narrowing of the esophagus which results in obstruction of food passage, and may also cause alterations in the esophageal cells which may contribute to cancer.
The risk of developing colonic polyps is high in people with the smoking habit. Colonic polyps develop on the mucosal lining of the colon or rectum. While a few polyps are benign or noncancerous, others may tend to become malignant. When a smoker develops colonic polyps the polyps tend to be multiple, and larger, and have a higher possibility of recurrence.
Liver diseases such as biliary cirrhosis and nonalcoholic fatty liver disease (NAFLD, a condition in which fat is deposited in the liver) are known to be worsened by smoking.
Research has proved that smoking impairs the ability of the liver to process medications and remove toxic substances and alcohol from the body. The dosage of some drugs may have to be adjusted in smokers, in at least some cases.
The risk of developing Crohn's disease is higher in former and current smokers than in individuals who have never smoked. Crohn's disease is an inflammatory intestinal condition which creates pain and irritation in the GI tract.
This disease can affect any region of the GI tract; the lower part of the small intestine is frequently affected and could lead to diarrhea and pain. Complications such as obstruction of the intestines and involvement of neighboring tissues by intestinal mucosal ulceration may arise from Crohn's disease.
Surgery is required to excise the damaged portion of the intestine. Smoking may also reduce the intestinal defenses, lower the flow of blood to the intestines, or promote inflammation by producing alterations in the immune system.
When men and women with Crohn’s disease are compared, the effects associated with smoking are seen to be more prevalent in women than men. Studies are ongoing to identify the mechanism behind the aggravation of Crohn’s disease in smokers.
The risk of developing peptic ulcers increases with smoking. The duodenum is the initial part of the small intestine and is most frequently affected by peptic ulcers. Long-term use of nonsteroidal anti-inflammatory drugs (aspirin and ibuprofen) and infection with bacteria such as H. pylori are the two most common causes of peptic ulcers.
Smoking itself increases the risk of chronic H. pylori infection and predisposes to the recurrence of peptic ulcers because of delayed healing in smokers. Finally, studies reveal that smoking does not itself increase the production of acid, but rather inhibits the production of pepsin.
Research shows that the risk of developing gallstones increases in smokers. However, more research is required since study outcomes are inconsistent. The gallbladder in which is stored bile produced by the liver may develop tiny solid particles known as gallstones.
Digestive enzymes are carried from the liver, pancreas, and gallbladder to the duodenum by several ducts. Gallstones may move into and be trapped in these ducts and cause abdominal pain, inflammation, and infection.
The risk of developing pancreatitis increases in smokers. The pancreas is located near the duodenum; inflammation of the pancreas is termed as pancreatitis. Digestive enzymes secreted by the pancreas generally remain inactive until they enter the small intestine. However, when pancreatitis occurs, pancreatic tissues are attacked by the digestive enzymes when inflammation occurs in the pancreas.
Reviewed by Liji Thomas, MD.