The following information regarding alcohol and nutrition is from Nutrition Concepts and Controversies, by Francis Sizer and Ellie Whitney (10th Edition, 2006 Thompson Learning, Inc.), pages 91-98.
Alcohol and Nutrition: Do the benefits outweigh the risks?
“On average, people in the United States consume from 6 to 10 percent of their total daily energy intake as alcohol. Drinking habits span a wide spectrum: many adults drink no alcohol whatsoever, some take a glass of wine only with meals, others take in large quantities of alcohol daily because of life-shattering addiction. A third of U.S. college students drink alcohol in a pattern that identifies them as binge drinkers, although, when asked, more than 90 percent say that they are not binge drinkers. Whether or not they recognize the problem, many college students will pay a high price in terms of their health and safety as a result of episodes of heavy drinking. Moderate drinkers usually consume the calories of alcohol in addition to their normal food intake, so the alcohol contributes to their daily calorie totals. Alcohol is not just an energy source, however; it is also a psychoactive drug and a toxin to the body.
Despite its toxicity, people want to know if there is an amount of alcohol they can drink safely or whether they may derive benefits, particularly for the health of the heart, by drinking.
Moderation is not easily defined because tolerance to alcohol differs among individuals. In general, women cannot handle as much alcohol as men and should not try to match drinks with male companions. Health authorities have set limits at not more than two drinks a day for the average-sized healthy man and not more than one drink a day for the average-sized, healthy woman. Note that these are not average amounts, but daily maximums. In other words, a person who drinks no alcohol during the week but then takes seven drinks on a Saturday night is not a moderate drinker–instead, that alcohol intake pattern characterizes binge drinking.
Some people can safely consume ‘moderate’ doses of alcohol; others, especially those prone to alcohol addiction, cannot handle nearly so much without significant risk. If you think your own drinking might not be moderate or normal or if alcohol has caused problems in your life, you may want to seek a professional evaluation.
Who should not drink alcohol?
Children and adolescents. The earlier in life drinking begins, the greater the risk of alcoholism later on.
People of any age who cannot restrict their drinking to moderate levels. Especially, people recovering from alcoholism, problem drinkers, and people whose family members have alcohol problems.
Women who may become pregnant or who are pregnant or breatsfeeding. Alcohol is especially dangerous to the development of the embryo during the first few weeks, before a woman knows she is pregnant.
People who plan to drive, operate machinery, or take part in other activities that require attention, skill, or coordination to remain safe. Alcohol remains in the blood for several hours after taking even a single drink.
People taking medications that can interact with alcohol. Alcohol alters the effectiveness or toxicity of many medications, and some drugs may increase blood alcohol levels.
People with medical conditions worsened by alcohol, such as liver disease.
What is alcohol?
In chemistry, the term alcohol refers to a class of chemical compounds whose names end in “-ol.” Alcohols affect living things profoundly, partly because they act a lipid solvents. Alcohols can easily penetrate a cell’s outer lipid membrane, and once inside, they denature the cell’s protein structures and kill the cell. Because some alcohols kill microbial cells, they make useful disinfectants and antiseptics.
The alcohol of alcoholic beverages, ethanol, is somewhat less toxic than others. Sufficiently diluted and taken in small enough doses, its action in the brain produces euphoria. Used in this way, alcohol is a drug, and like many drugs, alcohol presents both benefits and hazards to the taker. Its effects depend on the quantity of alcohol consumed.
Alcohol Enters the Body
From the moment an alcoholic beverage is swallowed, the body pays special attention to it. Unlike food, which requires digestion before it can be absorbed, the tiny alcohol molecules can diffuse right through the stomach walls and reach the brain within a minute. Ethanol is a toxin, and a too-high dose of alcohol triggers one of the body’s primary defenses against poison–vomiting. Many times, though, alcohol arrives gradually and in a beverage dilute enough that the vomiting reflex is delayed and the alcohol is absorbed.
A person can become intoxicated almost immediately when drinking, especially if the stomach is empty. When the stomach is full of food, molecules of alcohol have less chance of touching the stomach walls and diffusing through, so alcohol reaches the brain more gradually. By the time the stomach contents are emptied into the small intestine, however, alcohol is absorbed rapidly whether food is present or not.
Anyone who has had an alcoholic drink has experienced one of alcohol’s physical effects: alcohol increases urine output (because alcohol depresses the brain’s production of anti-diuretic hormone). Loss of body water leads to thirst. The only fluid that relieves dehydration is water, so alternating alcoholic beverages with nonalcoholic ones will quench thirst. Otherwise, each drink may worsen the thirst.
The water that is lost due to hormone depression takes with it important minerals, such as magnesium, potassium, calcium, and zinc, depleting the body’s reserves. These minerals are vital to fluid balance and to nerve and muscle coordination. When drinking incurs mineral losses, the losses must be made up in subsequent meals to avoid deficiencies.
If a person drinks slowly enough, the alcohol, after absorption, will be collected by the liver and processed without much effect on other parts of the body. If a person drinks more rapidly, however, some of the alcohol bypasses the liver and flows for a while through the rest of the body and the brain.
Alcohol Arrives in the Brain
When alcohol flows to the brain, it first sedates the frontal lobe of the cortex, the reasoning part. As the alcohol molecules diffuse into the cells of this lobe, they interfere with reasoning and judgment.
With continued drinking, the speech and vision centers of the brain become sedated, and the area that governs reasoning becomes more incapacitated.
Still more drinking affects the cells of the brain responsible for large-muscle control; at this point people under the influence stagger or weave when they try to walk.
Finally the conscious brain becomes completely subdued, and the person passes out. Now the person can drink no more. This is fortunate because a higher dose would anesthetize the deepest brain centers that control breathing and heartbeat, causing death.
If a person drinks fast enough, though, the alcohol continues to be absorbed,and its effects continue to accelerate after the person has gone to sleep. Every year, deaths attributed to this effect take place during drinking contests. Before passing out, the drinker drinks fast enough to receive a lethal dose.
Brain cells are particularly sensitive to excessive exposure to alcohol. The brain shrinks, even in people who drink only moderately. The extent of the shrinkage is proportional to the amount drunk. Abstinence, together with good nutrition, reverses some of the brain damage, and possible all of it, if heavy drinking has not continued for more than a few years. Prolonged drinking beyond an individual’s capacity to recover, however, can do severe and irreversible harm to vision, memory, learning ability, and other brain functions.
Alcohol Arrives in the Liver
The capillaries that surround the digestive tract merge into veins that carry the alcohol-laden blood to the liver. Here the veins branch and rebranch into capillaries that touch every liver cell. The liver cells make the largest share of the body’s alcohol-processing machinery. The routing of blood through the liver allows the cells to go right to work detoxifying substances before they reach other body organs such as the heart and brain.
The liver metabolizes alcohol
The liver makes and maintains two sets of equipment for metabolizing alcohol. One is an enzyme that removes hydrogens from alcohol to break it down; the name alcohol dehydrogenase (ADH), almost says what it does. This enzyme handles about 80 percent or more of the alcohol in the body. the other set of alcohol-metabolizing equipment is a chain of enzymes, named MEOS, which is thought to handle about 10 percent of alcohol. the remaining 10 percent is excreted through the breath and in the urine. Because the alcohol in the breath is directly proportional to the alcohol in the blood, the breathalyzer test that law enforcement officers administer when someone may be driving under the influence of alcohol accurately reveals the person’s degree of intoxication
The amount of alcohol a person’s body can process in a given time is limited by the amount of ADH enzymes residing in the liver. If more molecules of alcohol arrive at the liver cells than the enzymes can handle, the extra alcohol must wait. It circulates again and again through the brain, liver, and other organs until enzymes are available to degrade it.
Women absorb about one-third more alcohol than men do, even when the women are the same size as the men and drink the same amount of alcohol.
The body takes about an hour and half to metabolize one drink, depending on the person’s size, previous drinking experience, how recently the person has eaten, and the person’s current state of health. The liver is the only organ that can dispose of significant quantities of alcohol, and its maximum rate of alcohol clearance cannot be speeded up. this explains why only time restores sobriety. Walking will not because muscles cannot metabolize alcohol. Nor will drinking a cup of coffee help. Caffeine is a stimulant, but it won’t speed up the metabolism of alcohol. The police say that a cup of coffee only makes a sleepy drunk into a wide-awake drunk.
Myths and Truths About Alcohol
Myth: A shot of alcohol warms you up. TRUTH: Alcohol diverts blood flow to the skin making you feel warmer, but it actually cools the body.
Myth: Wine and beer are mild; they do not lead to addiction. TRUTH: Wine and beer drinkers worldwide have high rates of death from alcohol-related illnesses. It’s not what you drink, but how much, that makes the difference.
Myth: Mixing drinks is what gives you a hangover. TRUTH: Too much alcohol in any form produces a hangover.
Myth: Alcohol is legal; therefore, it is not a drug. TRUTH: Alcohol is legal, but it alters body functions and is medically defined as a depressant drug.
Alcohol Affects Body Functions
Upon exposure to alcohol, the liver speeds up its synthesis of fatty acids. Fat is known to accumulate in the livers of young men after a single night of heavy drinking and to remain there for more than a day. The first stage of liver deterioration seen in heavy drinkers is therefore known as fatty liver; it interferes with the distribution of nutrients and oxygen to the liver cells. If the condition lasts long enough, fibrous scar tissue invades the liver. This is the second stage of liver deterioration, called fibrosis. Fibrosis is reversible with good nutrition and abstinence from alcohol, but the next (last) stage, cirrhosis, is not. In cirrhosis, the liver cells harden, turn orange, and die, losing function forever.
The presence of alcohol alters amino acid metabolism in the liver cells. Synthesis of some immune system proteins slows down, weakening the body’s defenses against infection. Synthesis of blood lipids speeds up, increasing the concentration of triglycerides and high-density lipoproteins. In addition, excess alcohol adds to the body’s burden and interferes with normal uric acid metabolism, causing symptoms like those of gout.
The reproductive system is also vulnerable to alcohol’s effects. Heavy drinking in women may lead to infertility and spontaneous abortion. Alcohol may also suppress the male reproductive hormone testosterone, leading to decreases in muscle and bone tissue, altered immunity, abnormal prostate gland, and decreased reproductive ability. All of these effects demonstrate the importance of moderation in the use of alcohol.
Alcohol’s Long Term Effects
By far, the longest-term effects of alcohol are those felt by the child of a woman who drinks during pregnancy. When a pregnant woman takes a drink, her fetus takes the same drink within minutes, and its body is defenseless against the effects. Pregnant women should not drink alcohol.
A couple of drinks set in motion many destructive processes in the body. The next day’s abstinence can reverse them only if the doses taken are moderate, the time between them is ample, and nutrition is adequate.
If the doses of alcohol are heavy, however, and the time between them is short, complete recovery cannot take place, and repeated onslaughts of alcohol take a toll on the body. For example, alcohol is directly toxic to skeletal and cardiac muscle, causing weakness and deterioration that is greater, the larger the dose. At autopsy, the heart of a person with alcoholism appears bloated and weighs twice as much as a normal heart.
Alcohol attacks brain cells directly and heavy drinking can result in dementia. Cirrhosis also develops after 10 to 20 years from the cumulative effects of frequent episodes of heavy drinking.
Alcohol abuse also leads to cancers of the breast, mouth, throat, esophagus, rectum and lungs. Daily human exposure to ethanol ranks high among carcinogenic hazards. Once cancer has started, alcohol also seems to promote its development.
Other long-term effects of alcohol abuse include the following: Bladder, kidney pancreas and prostate damage; Bone deterioration and osteoporosis; Brain disease, central nervous system damage, and strokes; Deterioration of the testicles and adrenal glands; Diabetes (type 2 or noninsulin-dependent); Disease of the muscles of the heart; Feminization and sexual impotence in men; Impaired immune response; Impaired memory and balance; Increased risks of death from all causes; Malnutrition; Nonviral hepatitis; Severe psychological depression; Skin rashes and sores; Ulcers and inflammation of the stomach and intestines.
THE FINAL WORD
Alcohol is guilty of contributing not only to deaths from health problems but also to most of the other needless deaths of young people each year, including car crashes, falls, suicides, homicides, drownings, and other accidents. The surest way to escape the harmful effects of alcohol is, of course, to refuse alcohol altogether.
Breast cancer, cirrhosis of the liver, and brain shrinkage–associated with alcohol consumption
Obesity and Food Addictions 