Alcohol

Medically reviewed by Drugs.com. Last updated on Aug 23, 2023.

What is alcohol?

The term "alcohol" has been synonymous with "spirituous" liquids for the past 300 years. The history of alcohol consumption, along with codes limiting its consumption go back to 1700 B.C. There are four types of alcohol: methyl alcohol, ethyl alcohol, propyl alcohol and butyl alcohol. Ethyl Alcohol, or ethanol (C₂H₅OH), is the type used in the production of alcoholic beverages. The other three types, methyl, propyl and butyl alcohol, if consumed can result in blindness and death, even in relatively small doses.

Alcohol, or ethanol, is the intoxicating agent found in beer, wine and liquor. Alcohol is produced by fermentation of yeast, sugars, and starches.¹ Fruits such as grapes, and grains like barley and wheat are most commonly used for wine, beer and liquors. Other plants, such as the cactus or sugar cane may be used in liquor production.

Fourteen grams or about 0.6 fluid ounces of pure alcohol equals one “drink”. Examples of this amount may include one twelve ounce beer (5 percent alcohol), eight to nine ounces of malt liquor (7 percent alcohol), 5 ounces of wine (12 percent alcohol) or 1.5 fluid ounce “shot” of 80 proof liquor (40 percent alcohol).

In the U.S., The Federal Uniform Drinking Age Act, signed into law in 1984 raised the minimum drinking age to 21 years. All states now prohibit the purchase of alcohol by youth under the age of 21 years since 1988. It is illegal to sell or buy alcohol for anyone under the age of 21. According to The Office of the Surgeon General, alcohol is used by more young people in the United States than tobacco or illicit drugs, resulting in a serious public health concern.²

Alcohol (Ethanol) Pharmacology

Alcohol is a clear, volatile liquid that is highly soluble in water. The absorption of alcohol (ethanol) is decreased by food, especially fatty food. Absorption occurs primarily from the intestine. Alcohol distributes into body water. Blood-alcohol concentration (BAC) is dependent upon weight and body fat, amount and time frame of alcohol consumption, and food effects. Drinking alcohol over shorter time periods or in larger quantities and on an empty stomach will lead to a higher BAC. BAC is usually expressed in grams per deciliter (g/dL). In all 50 U.S. states, 0.08 g/dL would be equal to 0.08 percent BAC, or the legal limit at which one is no longer allowed to drive. Regulations are more strict in many states for drivers less than 21 years of age.

Alcohol is metabolized primarily (90 percent) in the liver. The enzyme alcohol dehydrogenase converts alcohol to acetaldehyde, a sympathomimetic toxin often blamed for the ‘hangover’ effect. Acetaldehyde is further metabolized by aldehyde dehydrogenase to acetic acid, and eventually to carbon dioxide and water. Excretion of small amounts of alcohol also occur through the urine, lungs/breath, and sweat. Alcohol excretion by the lungs constitutes the basis for the Breathalyzer test given by law enforcement who may suspect drinking and driving.

Alcohol elevates the inhibitory neurotransmitter GABA (gamma amino butyric acid) and reduces nerves signals along that neuronal pathway. Because of this action, alcohol is known as a central nervous system (CNS) depressant, and lowers both cognitive and physical capacities. Combination with other CNS depressants, such as opiates, barbiturates, or benzodiazepines can have additive and dangerous effects.

Health Hazards Due to Alcohol Abuse

Long-term alcohol misuse is associated with liver and cardiovascular disease, cancer, and nervous system damage as well as psychiatric problems such as depression, anxiety, and antisocial personality disorder.⁴

Alcohol, and its consumption can cause a number of marked changes in behavior. Even low doses significantly impair judgment and coordination. In small amounts, it can induce feelings of relaxation and tranquillity, suppress anxiety, and in some, inspire feelings of confidence. However, as the dose is increased, normally beyond six ounces of 100 proof alcohol, the pleasant euphoric feelings begin to give way to feelings of depression. Intoxication occurs because the liver is unable to metabolize more than one ounce of alcohol every hour. Therefore, when a person consumes more alcohol than the body can metabolize, intoxication occurs. Intoxication can generally last anywhere from one to 12 hours, and the after-effects (“hang-over”) of intoxication can last 24 hours or more.

Repeated use of alcohol can lead to increased tolerance that in turn leads to greater amounts required to achieve its desired effects. Once the body develops a dependence to alcohol, a sudden cessation of its intake is likely to produce withdrawal symptoms. Withdrawal symptoms can be life-threatening and include severe anxiety, tremors, hallucinations, and convulsions.

Alcohol can be lethal if the amount of alcohol reaches a concentration above 460 milligrams of alcohol per 100 milliliters of blood (0.46 g/dL). Death from respiratory depression can occur with severe alcohol intoxication, and this can be hastened if alcohol is combined with CNS depressant medications.

Mixing alcohol with caffeine, either in premixed drinks or by adding liquor to energy drinks has become a common way for younger crowds to consumer alcohol. With this dangerous combination, drinkers may feel somewhat less intoxicated than if they had consumed alcohol alone. However, they are just as impaired and more likely to take risks. This drinking practice often takes place in and around college campuses.

Excessive use of alcohol can lead to alcoholism, or alcohol dependence. There are four cardinal symptoms in alcoholism: craving, loss of control, physical dependence, and tolerance. A clinician is able to diagnose alcoholism based upon a specific set of criteria published by the American Psychiatric Association and the World Health Organization.⁵

Drinking and driving results in numerous car accidents, injuries, and deaths each year. In 2009, there were over 10,800 crash fatalities with a driver BAC of 0.08 or higher, roughly 32 percent of total traffic fatalities for the year. Of these drivers, fifty-six percent had had a BAC of 0.15 or greater. However, since 1982, alcohol-related fatalities have dropped from 60 percent to 38 percent in 2009.⁶

Alcoholism is a treatable disease, but is considered a lifelong, chronic illness that requires counseling, support and often medication to control cravings. Relapses are a common problem for alcoholics. Risks for developing alcoholism include a genetic predisposition and lifestyle practices. Stress, ease of alcohol availability, and peer groups can increase the risk for alcoholism.

Extent of Alcohol Use and Abuse

The prevalence of alcohol use in the U.S. is widespread. According to the US Department of Health and Human Services 2010 Summary Health Statistics for U.S. Adults from the National Health Interview Survey, the percent of adults 18 years of age and older who were current regular drinkers (at least 12 drinks in the past 12 months) was 50.9 percent. The percent of adults who were current infrequent drinkers (1-11 drinks in the past 12 months) was lower, at 13.6 percent.⁷

Alcohol use and binge drinking among teens is a major public health concern. In 1999, alcohol use among high school students was reported in 1 out of every 2 students. In 2009, current alcohol use rates among high school students decreased to 42 percent, with 24 percent reporting episodic heavy or binge drinking.⁸

In 2009, 10 percent of high school students reported driving during the past 30 days when they had been drinking alcohol. Twenty-eight percent of students reported riding in a car or other vehicle during the past 30 days driven by someone else who had been drinking alcohol.⁸

Alcohol Use in Pregnancy

No amount of alcohol consumption can be considered safe in pregnancy. Alcohol is quickly transferred from the mother’s bloodstream to the fetus by the placenta and umbilical cord. Alcohol can be toxic to the developing baby, not only in the first three months of pregnancy when important organs are developing, but at any time, as brain development continues throughout pregnancy. Damage can also occur early in pregnancy before a woman might know she is pregnant. Although there is no known safe amount of alcohol that a woman can drink, the risk for miscarriage, birth defects, growth retardation and mental defects increase the more alcohol a pregnant woman consumes in one setting and the more frequently she drinks overall.

Women who are planning to become pregnant or who have recently learned they are pregnant should not drink alcohol. It is wise to seek the advice of a health care provider if alcohol cannot be stopped prior to conception and throughout pregnancy. Both the Centers for Disease Control and The U.S. Surgeon Generals Office warn women not to drink during pregnancy.

Mothers who drink alcohol excessively during pregnancy may give birth to infants with fetal alcohol spectrum disorders (FASD) or fetal alcohol syndrome (FAS) that can include irreversible physical and mental changes to the baby. FASD may include life-long learning disabilities, poor memory, hyperactivity, poor attention span, speech or language delays and other disorders. FAS may lead to growth retardation, mental disorders, skeletal and facial abnormalities, and heart defects. It is important not to drink at all while pregnant, prior to a planned pregnancy or if effective birth control is not used.^{9, 10, 11}

Beneficial Effects of Alcohol

Consumption of small amounts of alcohol are reported to have beneficial cardiovascular health benefits, particularly the consumption of red wine. Red wine contains substances such as resveratrol and flavonoids that have antioxidant properties and may lend cardioprotective effects to the heart. However, only small amounts of wine or alcohol are suggested to be beneficial.

Antioxidants may help prevent heart disease by increasing levels of high density lipoprotein (HDL), or "good" cholesterol and protecting against artery damage. Antioxidants in red wine are called polyphenols and may be protective for heart vessel linings. Resveratrol is a polyphenol that comes from the skins of red grapes. It is also theorized that the beneficial heart effects of red wine might be possible by simply drinking red or purple 100% grape juice or eating red grapes.

The cardioprotective effect alcohol may not be restricted to red wine.  Some research studies have shown that moderate amounts of all types of alcohol benefit your heart, not just alcohol found in red wine. However, more research is needed. Moderate consumption of alcohol may raise HDL, reduce the formation of blood clots, and help prevent artery damage due to low density lipoprotein (LDL), or “bad” cholesterol.

It is not suggested to start drinking for prevention of heart disease. Neither the American Heart Association nor the National Heart, Lung and Blood Institute recommend starting to drink alcohol simply to prevent heart disease. Alcohol can lead to other health issues and may be addictive.

Only moderate drinking is recommended for those that already drink. Moderate drinking is defined as an average of two drinks a day for men and one drink a day for women. A drink is defined as 12 ounces (355 milliliters, or mL) of beer, 5 ounces (148 mL) of wine or 1.5 ounces (44 mL) of 80-proof liquor.¹²

Treatment Options for Alcohol Abuse and Alcoholism

The treatment of alcoholism requires strong family, social and medical support. Treatment for alcohol dependence usually involves a wide array of interventions, including stepped therapy, group support, individual counseling, and medications.

Some patients may opt to join Alcoholic Anonymous (AA), a group support organization available for men and women since 1935. Over 2 million recovered alcoholics in the United States, Canada, and other countries belong to AA.¹³

Medical treatments for alcohol dependence include three approved oral medications - disulfiram (Antabuse), naltrexone (Depade, Revia) and acamprosate (Campral) - and an injectable long-acting form of naltrexone (Vivitrol). Use of these medical treatments may work to help reduce drinking, relapses, and lead to full recovery and abstinence from alcohol. According to one review, naltrexone and acamprosate have strong evidence and are recommended as treatment options for alcohol dependence in conjunction with behavioral therapy. Disulfiram has not been shown to increase abstinence rates or decrease relapse rates or cravings compared with placebo, and it is not recommended for routine use in primary care.¹⁴

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