Alcohol and the Body | Alcohol

Alcohol affects the brain, body and mental health, with repeated use changing reward, stress and inhibitory systems.

Alcohol does not remain confined to the brain.

After absorption into the bloodstream, it is distributed throughout the body. The liver metabolises most of it, but alcohol and its breakdown products can affect many tissues and organ systems.

The pattern of harm depends on how much and how often a person drinks, the duration of exposure, genetics, nutrition, other health conditions, medicines and numerous other factors. Not everyone develops the same problems.

Liver

The liver carries much of the burden of metabolising alcohol.

Repeated heavy exposure can contribute to fatty liver, inflammation and progressive scarring. Some alcohol-related liver changes can improve when alcohol exposure stops, particularly earlier in the disease process, while advanced cirrhosis may involve permanent structural damage.

Heart and circulation

Heavy or repeated alcohol use can contribute to high blood pressure, abnormal heart rhythms, weakened heart muscle and increased risk of cardiovascular disease.

Acute heavy drinking can also precipitate rhythm disturbances in some people.

Digestive system and pancreas

Alcohol can irritate the gastrointestinal tract and contribute to inflammation, reflux, bleeding and impaired nutrient absorption.

The pancreas can also be affected. Alcohol is an important cause of pancreatitis, a painful and potentially serious inflammatory condition.

Nutrition and the nervous system

Heavy drinking may displace food, interfere with nutrient absorption and metabolism, and contribute to vitamin deficiencies.

Thiamine, or vitamin B1, is particularly important. Severe thiamine deficiency can cause Wernicke encephalopathy, a neurological emergency, and may contribute to Korsakoff syndrome, which can involve profound and persistent memory impairment.

Immune and hormonal effects

Repeated heavy drinking can alter immune function and increase vulnerability to some infections.

Alcohol can also influence hormonal and metabolic systems, with effects varying according to biological sex, age, health and pattern of use.

Cancer

Alcohol is a recognised cause of cancer.

Risk rises with greater exposure, and alcohol is associated with cancers including those of the mouth, throat, oesophagus, liver, bowel and breast.

This is important because cancer risk is not confined to people with alcohol dependence. The relationship concerns alcohol exposure itself.

Injury and acute harm

Many of alcohol's most immediate physical harms come not from chronic disease but from impairment.

Reduced judgement, balance, coordination and reaction time increase the risk of falls, drowning, violence, burns, road crashes and other injuries.

Alcohol can therefore harm the body through several pathways at once: direct biological effects, long-term disease, nutritional consequences and decisions or accidents occurring during intoxication.