Although alcohol is legally produced, sold, and used in our society, it is one of the most toxic substances on our list of addictive drugs. It is toxic to several organ systems in the body, including the liver, bone marrow, brain, heart, stomach lining, and pancreas.

When alcohol is metabolized in the liver, it causes a general inflammation, which leads to the development of fatty deposits in liver cells. Over time, with repeated inflammation due to alcohol, some people develop scarring in the liver, which leads to cirrhosis. The word “cirrhosis” literally means “scarring.” As these scars form between liver cells, the liver contracts and becomes hardened, resulting in a reduced ability of the liver to perform its function of clearing wastes from the system. It also blocks the flow of blood through the liver. Blood in the large veins coming out of the abdomen starts to back up, resembling a clogged drainage system. This results in symptoms such as hemorrhoids or fluid collection in the abdomen. Over the long term, bulging areas occur in large veins in such places as the esophagus, and these can rupture, leading to serious hemorrhage. The liver also produces important clotting factors, and a damaged liver leads to problems with slow blood clotting. A hemorrhage in this situation is very serious. Since the liver is not clearing wastes, a build-up of ammonia can occur in the blood-stream, leading to inflammation of the brain and decreased consciousness.

Alcohol is toxic to the bone marrow as well. The cells that are the forerunners of mature blood cells are damaged, and larger, less mature red blood cells are released into the system. Alcohol also damages the immune system, with the result that alcoholics are more prone to a variety of serious infections.
Alcohol has several specific toxic effects on the brain.

Many alcoholics become deficient in vitamin B-1, or thiamine.

A part of the brain that is important in the processing and storing of memory is particularly sensitive to the combined effect of the vitamin deficiency and the presence of alcohol.

When this part of the brain is destroyed, it causes the person to lose the capacity to retain any new information. Alcohol also is destructive to the cerebellum, the part of the brain that controls balance and muscle movement. In some individuals, the part of the brain that connects the two hemispheres is also damaged, and there seems to be a hereditary disposition to this type of brain damage. Some alcoholics develop auditory hallucinations, which are voices that are usually derisive and unpleasant. This also seems to be due to brain damage caused by the alcohol. And, in addition, alcohol causes generalized damage to all nerve cells, which can lead to dementia, or loss of intellectual functioning. This can be quite severe, rendering the person in need of supervised institutional care.

Alcohol damages muscle tissue, which is most serious when the damage occurs to the heart muscle. Alcoholic cardiomyopathy is a condition in which the heart muscle has been damaged, and is flabby and dilated. When the heart does not pump effectively, heart failure results. Also, the heart beats in an uncoordinated fashion, compounding the problem.

Alcohol is toxic as well to the lining of the stomach and the digestive tract. It is not uncommon for people to have acute gastritis (irritation of the stomach) following a drinking binge. This can cause pinpoint bleeding, which results in vomiting, diarrhea, and anemia. If this happens in a person with cirrhosis, it can result in a disastrous gastrointestinal hemorrhage.

Alcohol irritates the pancreas, an organ lying beneath the stomach across from the liver. Its function is to produce digestive enzymes and insulin. When it is inflamed, it releases its digestive enzymes and begins to destroy itself. This is a very painful condition. Furthermore, repeated episodes of pancreatic inflammation eventually damage the cells that make insulin. Without insulin, the body cannot control blood sugar, and this causes a diabetic condition.

Alcohol, which is socially acceptable and legal in most countries, is one of the most toxic of the addictive drugs to all body systems. Even social drinkers, who do not develop addiction to alcohol, are not immune to its toxicity.

Elizabeth Connell Henderson, M.D.

Glossary

Appendix A: Regulation of Addictive Substances

Appendix B: Sources of Additional Information