Section 15.3 

Alcohol Abuse

Nearly half of all college students are binge drinkers

If you are a student at an American college, the chances are that you or someone you know spent last weekend on an alcoholic drinking binge. According to the Higher Education Center for Alcohol and Other Drug Prevention, 44% of all college students consume 4-5 alcoholic beverages in a row—enough to classify them as binge drinkers. While this intoxicating behavior might lead to a spicy social life, a failure to drink responsibly can also lead to severe health problems.

Physical Effects

Quite simply, alcohol is a toxin. It breaks down existing tissue and drastically interferes with metabolic processes that build and repair the body. Alcohol abuse can cause cardiovascular difficulties in the form of hemorrhages, heart disease, and high blood pressure. The respiratory system and digestive systems are also exposed to tissue damage. For men, alcohol abuse can upset the hormonal balance causing impotency, sterility, increased breast size, and shrinkage of the testes. For women, infertility, the growth of external genitalia, and reduced breast size can result. Alcohol can even be absorbed into the placenta, causing its most tragic and certain result: fetal alcohol syndrome.

The nervous system can be harmed in several ways by alcohol abuse. Tissue damage is the most obvious baneful effect, which can result in dementia and a host of other syndromes. Other damage occurs as a result of synaptic changes. Alcohol increases the release of the depressant dopamine in the spaces between neurons. Dopamine is a neurotransmitter that passes a nerve impulse from one neuron to another. An excess of a neurotransmitter will produce an exaggerated effect or, in this case, a heightened relaxed state. To compensate for the overabundance of dopamine, the body removes the receptors to reduce the neuron’s sensitivity to the neurotransmitter. After such changes have occurred, the removal of alcohol creates a very dangerous deficit of dopamine. The neurons now lack the receptors to detect the body’s normal amount of dopamine. The lack of the depressant’s detection can produce seizures severe enough to kill the individual. Additionally, the sluggish effects of the added dopamine to the nervous system significantly slow the body’s response capabilities, thereby putting a person in great danger should he or she operate a moving vehicle while intoxicated.

The most severe damage caused by alcohol intake occurs in the liver, which breaks down the drug by means of the alcohol dehydrogenase (ADH). This enzyme utilizes nicotinamide adenine dinucleotide (NAD) to oxidize ethyl alcohol into acetaldehyde:

Acetaldehyde is then further broken down to acetate by aldehyde dehydrogenase (ALDH), which requires NAD’s interaction as well:

The acetate is eventually broken down into carbon dioxide and water. The alcohol not broken down in the liver remains circulating in the body and is released in small amounts through respiration.

Kicking the Habit

Freeing a person from alcohol’s mental and physical dependence involves several steps. First, the individual must by closely supervised until the withdrawal period has passed and must have trained assistance in case he or she seizes or experiences other difficulties. Next, measures must be taken to diminish the addict’s intense craving of the alcohol because alcohol increases the reaction of the pleasure pathway in the brain, making everything seem more pleasurable, and reinforcing the learning process that drinking alcohol is good. A new drug, Naltrexone, breaks this reinforcement by blocking the receptors to this pleasure pathway. The result is a lack of any sense of reward for drinking. Unfortunately, adverse effects accompany the use of Naltrexone. The effects of other drugs and medications are drastically altered. Overdoses of illegal drugs are more common, as the pleasurable effects cannot be felt except at near lethal doses. Lethargy is another common side effect of the drug.

Another drug, Disulfiram, attacks the reward pathway by producing unpleasant side effects to negatively reinforce the drinking of alcohol. Disulfiram competes with NAD on the enzyme ALDH. Acetaldehyde cannot be broken down as quickly and builds up in the body. Acetaldehyde is believed to be responsible for hangovers in producing nausea, vomiting and headaches. Disulfiram therefore produces a severe hangover almost instantly after alcohol consumption. Patients associate the pain with drinking and are dissuaded from doing so. The problem in administering the drug is patient compliance. Patients must be steadily monitored to insure they are taking the medication.

Genetic Links to Alcohol Tolerance

Current research is investigating the variance of alcohol dehydrogenase genes between individuals, which could imply a varied resistance to alcoholism. Studies have found that about half of Asian American males have a mutation in the gene encoding the ALDH enzyme. These men showed much higher concentrations of acetaldehyde in their bloodstream after consuming moderate amounts of alcohol. Males possessing mutations in the chromosomes from both parents had an even greater concentration of acetaldehyde. The inability to break up acetaldehyde would increase the sickness felt when drinking as if taking Disulfiram. One would thus expect those of Asian descent to be more sensitive to alcohol and be therefore less likely to imbibe.

Women need to be extremely conscious of the effect alcohol has on their bodies. Women generally have less water in their bodies relative to men. Since alcohol is water soluble, a woman’s body will not be able to absorb as much alcohol as a male of the same weight. Caution should be taken at all times when there is a risk of pregnancy. The toxicity of alcohol on fetal tissues can prevent them from ever developing normally. Most alcohol related damage causing spontaneous abortion and birth defects occurs before a woman could possibly know she was pregnant.

Responsible Drinking and Health Benefits

While heavy alcohol consumption can have quite detrimental effects on the body, alcohol can be enjoyed responsibly, often with positive results. Studies have shown that drinking one or two servings of alcohol a day can reduce the chances of heart disease. At these low levels, alcohol helps promote healthy levels of HDL cholesterol. This type of cholesterol stores or excretes other types of cholesterol, which may otherwise buildup in the circulatory system. In women, low alcohol consumption increases the amount of estradiol produced. Estradiol is a form of estrogen, which strengthens bones and decreases the risk of coronary artery disease.

Copyright 2002, John Wiley & Sons Publishers, Inc.