Encyclopedia of Health and Medicine

alcohol 317
sense of relaxation and calmness. At the same
time alcohol increases the presence of dopamine,
resulting in feelings of pleasure or even euphoria.
With continued, excessive alcohol consumption
the brain becomes accustomed to these altered
balances and develops reliance on the alcohol to
maintain them. At the same time the brain develops
TOLERANCE to the presence of alcohol in the
blood circulation; it requires higher doses of alcohol
to elicit the same neurotransmitter responses.
The physical and mental impairments typically
associated with intoxication begins with the most
complex skills and progresses to the least complex
skills. Because judgment is among the complex
skills, by the time a person loses motor function
skills (such as balance and coordination) he or she
is unable to perceive their deficiencies. Memory
storage and retrieval are also high-level skills
impaired early in intoxication, accounting for the
inability to remember events that happen during
intoxication. Long-term, chronic alcohol abuse
(frequent, repeated intoxication) alters GENE
expression within cells that may result in permanent
changes in cell activity.
The uniform standard for legal intoxication in
the United States is a blood alcohol concentration
(BAC) of 0.08 percent, which represents a measure
80 milligrams of alcohol per deciliter (100 milliliters)
of blood. This is the level of alcohol concentration
in the blood circulation at which predictable
impairments typically occur. However, individuals
may appear more or less intoxicated than their
BACs suggest because response to alcohol varies.
Health Benefits of Alcohol Consumption
A number of research studies suggest that for most
people regular, moderate alcohol consumption—
no more than one alcoholic drink daily for women
and two alcoholic drinks daily for men—can
reduce the risk for CARDIOVASCULAR DISEASE (CVD)
such as HYPERTENSION (high BLOOD PRESSURE) and
ATHEROSCLEROSIS (fatty deposits in the walls of the
arteries). Alcohol affects lipid metabolism, raising
levels of high-density lipoprotein (HDL) cholesterol—the
“good” cholesterol. It also influences
COAGULATION processes, altering the activation of
certain coagulation factors in ways that slightly
slow blood clotting. Alcohol appears to help relax
the smooth MUSCLE of the walls of the arteries,
reducing blood pressure. However, health experts
caution that people who do not currently drink
should not start; the potential health benefits do
not sufficiently outweigh the risks. People who
should not drink alcohol under any circumstances
include those who are in recovery from ALCO-
HOLISM and pregnant women. People who take
prescription drugs should be cautious because
alcohol interferes with numerous medications.
Health Risks of Alcohol Consumption
Alcohol toxicity is a serious risk with bouts of
heavy or binge drinking in which a person consumes
large quantities of alcohol in a short time.
A blood alcohol concentration twice the legally
defined level of intoxication, 0.16 percent, results
in the state of euphoria commonly associated with
being intoxicated. At this concentration in the
blood circulation alcohol significantly impairs
judgment, physical coordination, and reaction
time. A blood alcohol level three times the typical
legal limit—0.24 percent—causes extreme confusion
and possibly stupor. With a blood alcohol
level of 0.35 percent the average person is unconscious;
0.50 percent is often a point of no return
leading to RESPIRATORY FAILURE and death.
Short Term
HEALTH RISKS OF ALCOHOL ABUSE
ACCIDENTAL INJURIES
alcohol toxicity
impaired judgment
interaction with medications
reduced inhibition
sleep disturbances
slowed reaction times
Long Term
BERIBERI
CIRRHOSIS
GASTRITIS
HYPERTENSION
LIVER DISEASE OF ALCOHOLISM
PANCREATIC CANCER
STEATOHEPATITIS
acts of VIOLENCE
impaired cognitive function
impaired physical
coordination
short-term memory
difficulties
slurred speech
CARDIOMYOPATHY
FETAL ALCOHOL SYNDROME
GASTROINTESTINAL BLEEDING
LIVER CANCER
NUTRITIONAL DEFICIENCY
PANCREATITIS
STOMACH CANCER
The primary health consequence of chronic,
excessive alcohol consumption is alcoholism.
Alcoholism is an addiction to alcohol (physiologic
and psychologic dependence on alcohol) and is a