Alcohol generally means ethanol or ethyl alcohol; the most commonly used and abused substance known to humankind. Alcohol has profound effects on various organs of the body, including central nervous system, liver and many other organs.
Effects of alcohol on liver:
Human liver has tremendous capacity to withstand alcohol exposure. Chronic intake of small to moderate amount of alcohol or brief intake of huge amount of alcohol that usually leads to intoxication and high level of alcohol in blood, usually does not affect liver in harmful way, provided adequate nutritional intake is obtained. However, at low to moderate intake of alcohol in chronic way leads to mobilization of peripheral fats and increase synthesis of fats in liver in dose dependent manner. Moderate and chronic intake of alcohol also leads to reduced protein secretion by liver (into blood stream) and accumulation of proteins in liver. Chronic exposure of liver to alcohol leads to oxidative stress and liver cell necrosis. Necrosis of liver cells is followed by fibrosis (formation of fibrous tissue).
Metabolism of alcohol in liver leads to formation of acetaldehyde, which can cause damage to liver cells (known as hepatocytes) and inflammation, especially on chronic intake of large amount of alcohol. There is increased peroxidation of lipids and depletion of glutathione, which in combination with vitamin and other nutritional deficiencies results in “alcoholic cirrhosis of liver”, which is the result of chronic exposure of liver to high amount of alcohol for long duration.
Regular alcohol consumption leads to liver microsomal enzyme induction (liver is the organ that synthesize most enzymes) and increased synthesis of various enzymes in liver, which can lead to increased metabolism of various chemicals, including various drugs and make them ineffective.
Effects of alcohol on GIT:
Gastrointestinal tract (GIT) is the first organ to be exposed to alcohol, after consumption. The acid secretion is altered by the presence of alcohol in stomach. Lower concentration (10%) of alcohol in stomach leads to increased gastric secretion, especially gastric HCl (hydrochloric acid), as seen after introduction of 10% alcohol directly into stomach by “Ryle’s tube”.
Higher concentration of alcohol, above 20% leads to reduced gastric secretion, vomiting, nausea, mucosal congestion and gastritis (inflammation of gastric mucosa). Chronic alcoholism is one of the most important causes of chronic gastritis.
Alcohol can reduce tone of LES (lower esophageal sphincter) and lead to increased risk of gastro-esophageal reflux and GERD (gastro-esophageal reflux disease). Alcohol may cause constipation as well as diarrhea. Pancreatitis (inflammation of pancreas) is a serious complication of chronic alcoholism.