Health effects of alcohol

Alcohol (also known as ethanol) has a number of effects on health. Short-term effects of alcohol consumption include intoxication and dehydration. Long-term effects of alcohol include changes in the metabolism of the liver and brain, with increased risk of several types of cancer and alcohol use disorder. Alcohol intoxication affects the brain, causing slurred speech, clumsiness, and delayed reflexes. There is an increased risk of developing an alcohol use disorder for teenagers while their brain is still developing. Adolescents who drink have a higher probability of injury including death.

Observational studies suggest a correlation between low to moderate alcohol consumption and cardiovascular protective effects. Several studies and meta-analyses have shown a reduction in overall mortality among light to moderate alcohol drinkers compared to lifetime abstainers. A statement from The Lancet in 2022, based on the 2020 Global Burden of Disease Study, noted that for adults over 40 consuming small amounts of alcohol may reduce risks for cardiovascular disease, stroke, and diabetes.

Even light to moderate alcohol consumption can have negative effects on health, such as by increasing a person's risk of developing several cancers. A 2014 World Health Organization (WHO) report found that harmful alcohol consumption caused about 3.3 million deaths annually worldwide. Negative effects are related to the amount consumed with no safe lower limit seen. Some nations have introduced alcohol packaging warning messages that inform consumers about alcohol and cancer, as well as fetal alcohol syndrome. There are several potential ways for light alcohol drinkers to reduce their cancer risk. Research suggests that dietary intake of folate, in amounts commonly found in daily multivitamins, may help protect women from the increased risk of breast cancer associated with light alcohol consumption. Additionally, two large U.S.-based studies on health professionals found no increased cancer risk from light to moderate alcohol consumption in men who do not smoke. Some observational studies suggest a potential association between alcohol consumption and a decreased risk of certain cancers, such as kidney cancer, thyroid cancer, and non-Hodgkin lymphoma. Multiple prospective studies suggest a protective effect of light to moderate alcohol consumption on cardiovascular health for both men and women. Several mechanisms have been proposed to explain this association. Additionally, alcohol may reduce the risk of clot formation, which can contribute to heart attacks and strokes, and lower the risk of developing diabetes. A 2022 statement from The Lancet, based on its 2020 Global Burden of Disease Study, said that the health risks associated with alcohol consumption vary by age and region, and that for those over age 40, "consuming a small amount of alcohol ... can provide some health benefits, such as reducing the risk of cardiovascular disease, stroke, and diabetes."