Alcohol and Health

Alcohol is a central-nervous-system depressant that affects judgment, coordination, and inhibition. Mild alcohol intoxication causes a relaxed and carefree feeling, as well as the loss of inhibitions. After several drinks a person will exhibit impaired judgment, poor coordination, and slurred speech, while consumption of alcohol in large amounts can lead to coma and even death. Blood alcohol concentration (BAC) is a measurement of the amount of alcohol in a person's blood. Most states consider a person to be legally drunk at a BAC between .08 and .10. At a BAC level of .40 to .50, a person may go into a coma, while a BAC level of .60 to .70 will cause death.

Alcoholic beverages can be divided into three categories: beer, wine, and distilled spirits. Beer includes beer, ale, and malt liquor; wine includes wine,

champagne, wine coolers, and vermouth; and examples of distilled spirits are gin, rum, vodka, and whiskey. Alcohol provides no vitamins or minerals , only calories . Small amounts of alcohol are absorbed from the mouth, approximately 20 percent is absorbed in the stomach, and the remaining 80 percent is absorbed in the small intestine.

About 7 percent of Americans abuse alcohol or suffer from alcoholism. Alcoholism can be identified through four symptoms: (1) a craving or strong urge to drink alcohol, (2) not being able to stop drinking, (3) physical dependence , and (4) tolerance . Physical dependence occurs when an individual depends on the presence of alcohol to function normally. Tolerance occurs when the same amount of alcohol results in a lesser effect; therefore, more alcohol must be consumed in order to feel the same effect. Alcohol abuse differs from alcoholism in that it does not include a strong craving for alcohol, the loss of control over one's drinking, or physical dependence. Individuals may have a problem with alcohol abuse if they exhibit one or more of the following symptoms: work and money problems, drinking while driving, being arrested due to drinking, exhibiting violent or aggressive behaviors, or continuing to drink despite the problems that result from drinking.

Alcoholism

Although there is a debate among experts over whether alcoholism should be considered a disease, the National Institute on Alcohol Abuse and Alcoholism recognizes alcoholism as a disease. The risk for developing alcoholism is influenced by a person's genes and lifestyle behaviors. Alcoholism is a chronic disease that lasts for a lifetime. If diagnosed and treated early, however, alcoholism may be completely cured and severe complications prevented. Chronic alcohol abuse increases a person's risk for developing serious health problems, such as liver disease, high blood pressure , heart disease , stroke , cancer (especially cancer of the esophagus, mouth, and throat), and pancreatitis.

Approximately two million Americans suffer from liver damage caused by alcohol abuse. About 10 to 20 percent of heavy drinkers will develop cirrhosis of the liver, which is characterized by scarring of the liver and causes irreversible damage. If heavy drinkers do not stop drinking, cirrhosis can cause poor health and, ultimately, death. In addition to cirrhosis, heavy drinkers may suffer from chronic liver disease or alcoholic hepatitis .

Damage to the liver can lead to problems with blood sugar levels. When alcohol is present in the body, the liver works to metabolize it. Because the liver is busy metabolizing alcohol, it is often not able to adequately maintain blood sugar levels, which may result in hypoglycemia (low levels of blood sugar). Hypoglycemia is most likely to occur in individuals who have not maintained an adequate diet . When it occurs, the brain is not able to receive the energy it needs to function, and symptoms such as hunger, weakness, headache, tremor, and even coma (in severe cases) may occur.

Chronic alcohol abuse can lead to poor nutritional status. Chronic heavy drinkers do not eat adequate amounts of food because of the high caloric content of alcohol. This prevents them from getting the required vitamins and minerals to maintain health and well-being. Furthermore, when a person consumes large amounts of alcohol, it impedes or halts the digestion of food, as alcohol decreases the secretion of digestive enzymes from the pancreas. Alcohol also inhibits the absorption of nutrients into the blood. This decrease in digestion and absorption over a long period of time can lead to malnutrition .

High-Risk Groups

While alcohol abuse and alcoholism affect virtually every segment of the population, certain groups are at greater risk. Young adults between the ages of eighteen and twenty-nine have the highest prevalence of alcohol abuse, and persons who begin to drink at an early age, especially before the age of fourteen, have a greater risk for developing problems with alcohol. Persons with a family history of alcohol abuse or alcoholism are also more likely to experience alcohol-related problems. In the United States, American Indians and Alaska Natives (AI/ANs) have the highest rates of current and heavy drinking of all racial or ethnic groups. Deaths from chronic liver disease and cirrhosis are nearly four times greater among AI/ANs compared to the general U.S. population. They also have a higher prevalence of drunk driving compared to the general U.S. population.

The U.S. Department of Health and Human Services and the U.S. Department of Agriculture recommend that alcohol be consumed in moderation only. Moderation is considered two drinks per day for men and one drink per day for women (one drink is defined as twelve ounces of beer, five ounces of wine, or 1.5 ounces of a distilled spirit). Drinking alcohol is inappropriate for recovering alcoholics, persons under the age of twenty-one, persons taking medication, those who plan to drive, and women who are pregnant or plan to become pregnant.

College Binge Drinking

Alcohol abuse is considered the most significant public health problem facing college students in the United States. It is estimated that more than 500,000 injuries and 70,000 cases of sexual assault a year result from alcohol abuse among students, and more than 1,400 students die each year as a result of their injuries. Two out of every five students report an episode of binge drinking—which is usually defined as five or more drinks in a row—in any given two-week period. During the 1990s, as government and health organizations began to recognize the magnitude of the problem, the U.S. Surgeon General set a goal of reducing binge drinking by 50 percent by the year 2010, and colleges sharply increased alcohol education programs and penalties for excessive or underage drinking. Nevertheless, the rate of binge drinking on college campuses remained virtually unchanged between 1993 and 2001, the year of the last comprehensive study.

—Paula Kepos

There is no known safe level of alcohol consumption during pregnancy, as it could injure the fetus. Alcohol consumption during pregnancy may result in fetal alcohol syndrome (FAS) or fetal alcohol effects (FAE). FAS is characterized by growth retardation, facial abnormalities, and central-nervous-system dysfunction. FAS is irreversible and will affect children their entire life. If a fetus's exposure to alcohol during pregnancy is not severe enough to cause FAS, it may result in fetal alcohol effects (FAE), alcohol-related developmental disabilities (ARDD), or alcohol-related neurodevelopmental disabilities (ARND).

In conclusion, knowing the effects of alcohol on the body and the consequences of alcohol abuse and misuse is very important. When consumed in large amounts or irresponsibly, alcohol can cause extensive damage to health and well-being, including liver damage, poor nutritional status, birth defects, and death. Therefore, if alcohol is consumed, it should be done so responsibly and in moderation only.

see also Fetal Alcohol Syndrome; French Paradox; Malnutrition; Pregnancy.

Laura Nelson

Bibliography

Kinney, Jean (2000). Loosening the Grip: A Handbook of Alcohol Information, 6th edition. Boston: McGraw-Hill Higher Education.

Leone, Bruno, ed. (1998). Alcohol: Opposing Viewpoints. San Diego, CA: Greenhaven Press.

Marshall, Ronald (2001). Alcoholism: Genetic Culpability or Social Irresponsibility? New York: University Press of America.

Internet Resources

Centers for Disease Control and Prevention. "Fetal Alcohol Syndrome." Available from <http://www.cdc.gov/ncbddd>

National Institute on Alcohol Abuse and Alcoholism. "Alcohol and Minorities: An Update." Available from <http://www.niaaa.nih.gov/publications>

National Institute on Alcohol Abuse and Alcoholism. "Alcohol and Nutrition." Available from <http://www.niaaa.nih.gov/publications>

National Institute on Alcohol Abuse and Alcoholism. "Frequently Asked Questions on Alcohol Abuse and Alcoholism." Available from <http://www.niaaa.nih.gov/>

Robert Wood Johnson Foundation. "Substance Abuse: The Nation's Number One Health Problem." Available from <http://www.rwjf.org/resourcecenter>

U.S. Department of Health and Human Services, and U.S. Department of Agriculture. "Dietary Guidelines for Americans, 2000." Available from <http://www.health.gov/dietaryguidelines>

Alcohol and Health

Ethanol, C₂H₅OH, also known as ethyl alcohol or grain alcohol, is the only common alcohol that humans are able to digest. Alcohol is readily absorbed by the body when consumed in an aqueous solution. All common alcoholic drinks are aqueous solutions of ethanol.

Alcohol absorption generally begins in the stomach, although most absorption takes place from the small intestine. Because alcohol is distributed to all body fluids (in proportion to the water content of that fluid), alcohol can be detected and quantitatively measured in the blood, urine, cerebrospinal fluid, and water vapor from the lungs. Drug testing for alcohol level relies on this fact.

Metabolism

Only about 2 percent of consumed alcohol is excreted unchanged by the lungs or kidneys. The rest is metabolized by the body through biological oxidation with the aid of the enzymes alcohol dehydrogenase and acetaldehyde dehydrogenase. These are induced enzymes (produced in response to need), and are found in larger quantities in heavy drinkers than in nondrinkers.

Alcohol dehydrogenase catalyzes the oxidation of ethyl alcohol to acetaldehyde. Acetaldehyde is moderately toxic and is believed to be a major cause of headaches and hangovers.

The second enzyme, acetaldehyde dehydrogenase, catalyzes the oxidation of acetaldehyde to acetate. A small amount of acetate enters the Krebs (cellular digestion) cycle, while other acetate molecules enter other energy-conversion pathways of the body. The remainder of the acetate is stored as long-chain fatty acids and is ultimately oxidized to form carbon dioxide and water.

Although some human variation exists, the body can metabolize only about one drink (1¼ fluid ounces [0.036 liters]) per hour. Because the oxidation reactions are enzyme-catalyzed, little can be done to speed up the reactions.

Alcohol is processed by the liver. However, excessive quantities of alcohol cannot be processed during a single pass through the liver. Thus, alcohol can have a direct effect on other parts of the body. Most tissue effects are a part of an intricate, interrelated series of events.

Physiological Effects

Alcohol is a vasodilator (the blood vessels dilate or enlarge). Chronically dilated veins are often associated with liver disease, and the "enlarged red nose" of the chronic alcoholic is usually the result of permanently dilated blood vessels. Dilation of the veins of the esophagus can lead to hematemesis (vomiting blood). Late-stage alcoholics have been known to drown in their own blood because of ruptured esophageal blood vessels.

Edema, the accumulation of tissue fluid, occurs with alcohol consumption because when the blood vessels expand, the proteins as well as the fluids within the capillaries leak into the interstitial space . This accumulation between the cells leads to tissue swelling. Because the fluid is not within the blood vessels, apparent dehydration exists. Jaundice (yellowing of the body tissues) is generally caused by excessive bilirubin (a normal body pigment) in the extracellular fluids, and may indicate liver disease.

Alcohol is a central nervous system (CNS) depressant, meaning that with alcohol the central nervous system is operating at decreased efficiency. Alcohol is also a depressant of all major systems of the body. High quantities of alcohol function as an anesthetic. Alcohol also depresses the psychological inhibition and thus may appear to be a stimulant. Because of this apparent stimulation of certain behaviors, psychologists call alcohol a biphasic drug. The combination of CNS depression and inhibition release leads to the symptoms of drunkenness. Drunkenness, a term for which there is no precise definition, varies with body size, metabolic rate, individual absorption, and individual tolerance.

Chronic Alcoholism

Prolonged use of alcohol can lead to compensatory mechanisms for the depressed normal nervous system activity. The nervous system tends to "work harder" to maintain equilibrium and therefore, upon withdrawal of alcohol, the nervous system may experience excessive excitement which may lead to convulsions, seizures, and ultimately delirium tremens (the DT's), a state of restlessness, disorientation, and hallucinations .

Mental impairment in chronic alcohol use is difficult to quantify because some impairment is reparable either by itself or by the construction of alternate nervous routes in the brain. Perhaps the most noticeable of the reparable impairments is personality loss.

Other physiological involvements include sleep apnea , decreased REM (restful) sleep, headaches, inhibition of testosterone synthesis, pancreatic inflammation, and electrolyte imbalance in the blood.

The major nutritional problem with alcohol is poor diet. Also, excessive alcohol ingestion often leads to gastrointestinal irritation, and this can lead to ulcers, colitis (inflamed colon), and other chronic ailments.

It is estimated that about 10 percent of the human population is addicted to alcohol. Probably no single cause of alcohol addiction exists. Certain genetic markers have been discovered, and the genetic component of alcoholism is well documented. Nevertheless, genetics alone does not explain all alcohol addiction. Psychological components to alcohol addiction have also been identified. For most alcohol addicts, the only treatment is total abstinence from alcohol and participation in a program such as Alcoholics Anonymous. The alcoholic's body does not "forget" alcohol, and the induced enzymes mentioned earlier remain ready to continue their metabolic actions if alcohol use resumes.

see also Digestive System; Drug Testing; Krebs Cycle; Liver

Roberta M. Meehan

Bibliography

Alcoholics Anonymous. <www.alcoholics.anonymous.org>.

Blum, K. and J. E. Payne. Alcohol and the Addictive Brain. New York: The Free Press, 1991.

National Institute of Alcohol Abuse and Alcoholism. <www.niaaa.gov/>.