Alcohol, or ethyl alcohol (ethanol), refers to the intoxicating
ingredient found in wine, beer and hard liquor. Alcohol
arises naturally from carbohydrates when certain micro-organisms
metabolize them in the absence of oxygen, called fermentation.
Beer, wine and other liquor contain different amounts of alcohol. The
amount of alcohol in distilled liquor is known as ?proof?. Proof
refers to the amount of alcohol in the liquor; for example,
100 proof liquor contains 50% alcohol, 40 proof liquor contains
20% alcohol, and so on. Traditional wine has approximately
8-14% alcohol, while regular beer has 4-6% alcohol.
Recent studies show that moderate use of alcohol may have
a beneficial effect on the coronary system. In general,
for healthy people, one drink per day for women and no more
than two drinks per day for men would be considered the maximum
amount of alcohol consumption to be considered moderate use. (By ?healthy? people,
we are referring to non-pregnant women, individuals not addicted
to alcohol, and people without pre-existing medical conditions,
among others). However, the amount of alcohol that a
person can drink safely is highly individual, depending on
genetics, age, sex, weight and family history, etc. A ?drink? is
considered to be:
How Alcohol Travels Through the Body
4-5 ounces of wine
10 ounces of wine cooler
12 ounces of beer
ounces of distilled liquor (80 proof whiskey, vodka, scotch,
Alcohol is metabolized extremely quickly by the body. Unlike
foods, which require time for digestion, alcohol needs no digestion
and is quickly absorbed. Alcohol gets ?VIP? treatment
in the body ? absorbing and metabolizing before most other
nutrients. About 20 percent is absorbed directly across
the walls of an empty stomach and can reach the brain within
Once alcohol reaches the stomach, it begins to break down
with the alcohol dehydrogenase enzyme. This process reduces
the amount of alcohol entering the blood by approximately 20%. (Women
produce less of this enzyme, which may help to partially explain
why women become more intoxicated on less alcohol than men.).
In addition, about 10% of the alcohol is expelled in the breath
Alcohol is rapidly absorbed in the upper portion of the small
intestine. The alcohol-laden blood then travels to the liver
via the veins and capillaries of the digestive tract, which
affects nearly every liver cell. The liver cells are
the only cells in our body that can produce enough of the enzyme
alcohol dehydrogenase to oxidize alcohol at an appreciable
Though alcohol affects every organ of the body, it?s most
dramatic impact is upon the liver. The liver cells normally
prefer fatty acids as fuel, and package excess fatty acids
as triglycerides, which they then route to other tissues of
the body. However, when alcohol is present, the liver
cells are forced to first metabolize the alcohol, letting the
fatty acids accumulate, sometimes in huge amounts. Alcohol
metabolism permanently changes liver cell structure, which
impairs the liver?s ability to metabolize fats. This
explains why heavy drinkers tend to develop fatty livers.
The liver is able to metabolize about ½ ounce of ethanol per
hour (approximately one drink, depending on a person?s body
size, food intake, etc.). If more alcohol arrives in
the liver than the enzymes can handle, the excess alcohol travels
to all parts of the body, circulating until the liver enzymes
are finally able to process it. (Which is another good reason
not to consume more than one drink per hour.).
How the Liver Breaks Down Alcohol
The alcohol dehydrogenase enzyme breaks down alcohol by removing
hydrogen in two steps:
1. Alcohol dehydrogenase oxidizes
alcohol to acetaldehyde
2. Acetaldehyde dehydrogenase
oxidizes the acetaldehyde to acetyl CoA. These reactions produce
hydrogen ions (acid). The B vitamin niacin (in its role as
the coenzyme NAD) picks up these hydrogen ions (becoming NADH). Thus
when alcohol is metabolized, NAD diminishes and NADH increases.
Fatty Liver and Liver Disease
During alcohol metabolism, NAD becomes unavailable for
the many other vital body processes for which it is needed,
including glycolysis, the TCA cycle and the electron transport
NAD, the energy pathway is blocked, and alternative routes
are taken, with serious physical consequences:
of hydrogen atoms shifts the body?s balance toward acid.
of NADH slows the TCA cycle, resulting in a build up of pyruvate
and acetyl CoA. Excess acetyl CoA results in fatty acid
synthesis and fat begins to clog the liver. (An
accumulation of fat in the liver can be observed after only
a single night of heavy drinking).
With moderate drinking, the liver can process alcohol fairly
safely. However, heavy drinking overtaxes the liver resulting
in serious consequences. A liver clogged with fat causes
liver cells to become less efficient at performing their necessary
tasks, resulting in impairment of a person?s nutritional health. Fatty
liver is the first stage of liver deterioration in heavy drinkers,
and interferes with the distribution of oxygen and nutrients
to the liver?s cells. If the condition persists long
enough, the liver cells will die, forming fibrous scar tissue
(the second stage of liver deterioration, or fibrosis). Some
liver cells can regenerate with good nutrition and abstinence,
however in the last stage of deterioration, or cirrhosis, the
damage to the liver cells is the least reversible.
Alcohol and Malnutrition
For moderate drinkers, alcohol does not suppress food intake,
and may actually increase appetite. Chronic alcohol consumption
appears to have the opposite effect. Alcohol causes euphoria,
which depresses appetite, so that heavy drinkers tend to eat
poorly and become malnourished.
Alcohol is very rich in energy, packing 7 calories per gram. But
like pure sugar or fat, the calories are void of nutrients. The
more calories an individual consumes in alcohol, the less likely
it is that they will eat enough food to obtain adequate nutrients. To
make matters worse, chronic alcohol abuse not only displaces
calories from needed nutrients, but also interferes with the
body?s metabolism of nutrients, leading to damage of the liver,
digestive system, and nearly every bodily organ.
Effects of Alcohol Consumption
Increases risk of gouty arthritis
Increases the risk of cancer in the liver, pancreas,
rectum, breast, mouth, pharynx, larynx and esophagus
Fetal Alcohol Syndrome
Causes physical and behavioral abnormalities in the
Raises blood pressure, blood lipids and the risk of
stroke and heart disease in heavy drinkers. Heart
disease is generally lower in light to moderate drinkers.
Raises blood glucose
Lowers blood glucose, especially for people with diabetes
Enlarges the kidneys, alters hormone functions, and
increases the risk of kidney failure
Causes fatty liver, alcoholic hepatitis and cirrhosis
Increases the risk of protein-energy malnutrition,;
low intakes of protein, calcium, iron, vitamin A, vitamin
C, thiamine, vitamin B6 and riboflavin, and impaired
absorption of calcium, phosphorus, vitamin D and zinc.
Causes neuropathy and dementia; impairs balance and
Increases energy intake, but not a primary cause of
Causes depression, anxiety and insomnia
To Drink or Not to Drink?
Moderate use of alcohol can be an enjoyable, safe experience
if used with caution. If you do choose to drink, sip each drink
slowly, and always consume alcohol with food. Spaces
drinks out to no more than one drink per hour, and consume
plenty of water in between drinks. Never drink while
pregnant and never drive when intoxicated.
- Do you have a problem with Alcohol?
- Have you ever felt you should cut down on your drinking?
- Have people annoyed you by criticizing your drinking?
- Have you ever felt bad or guilty about your drinking?
- Have you ever had a drink the first thing in the morning
to steady your nerves or get rid of a hangover?
If you answered ?yes? to one question, you may have a problem
with alcohol. More than one ?yes? answer makes it highly
likely that a problem exists. If you feel you have a
problem with alcohol, please see your health professional right
away. Effective treatment is available.
For more information:
Council on Alcoholism and Drug Dependence ? Information
on alcoholism and traditional treatment methods
Institute on Alcohol Abuse and Alcoholism - Information
on alcoholism and traditional treatment methods