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Alcohol and Health:
Distilling the Risks and Benefits
Alcohol-related
problems -- from alcoholism to drunk driving -- kill roughly thousands
each year. And they cost billions annually in treatment, lost
productivity and other direct and indirect expenditures.
Some 14 million Americans, or about
7.4 percent of the population, are alcoholics. Millions more binge
drink and otherwise abuse alcohol.
Those grim statistics suggest drinking
is a scourge. But wait, you say. Isn't some alcohol good for me?
What about those reports that a little alcohol each day is a boon
to the heart?
If you're confused about the point
where healthful, moderate drinking becomes unhealthy, heavy consumption,
you're forgiven. With all the research on the effects of alcohol,
it's hard to know when to keep sipping and when to stop.
And with April designated as Alcohol
Awareness Month, now's a good time to set the record straight.
"There is a lot of gradation" in
drinking, says Lorraine Gunzerath, chief of the strategic research
planning branch at the National Institute on Alcohol Abuse and
Alcoholism (NIAAA).
Complicating matters, a person's
genetic makeup likely has much to do with not only how well he
or she tolerates the harmful effects of alcohol, but also how
much they're body responds to the beneficial impact of drinking.
For all the vagaries of tippling,
scientists do know a great deal about what happens to those who
overdo it.
First, some rules of thumb: Scientists
define risky drinking, which can impair judgment and coordination,
as consuming enough alcohol to drive the blood alcohol content
(BAC) to between 0.05 and 0.08, the legal limit recommended by
the National Highway Traffic Safety Administration. In general,
a 160-pound man would have a BAC of 0.05 after consuming two drinks
in a short period of time. For a 140-pound woman, the same two
drinks would result in a BAC of 0.07.
Binge-drinking bouts are concentrated
sprees that drive the BAC above 0.08; they're defined as five
drinks in two hours for men and 4 to 4.5 drinks over that span
for women. And heavy drinking is alcohol consumption that consistently
sends BAC to 0.08 or higher.
U.S. health officials define moderate
drinking as up to two drinks a day for men and one drink a day
for women (pregnant women should abstain completely.) A standard
drink can come in the form of a 12-ounce beer, a 5-ounce glass
of wine, or a 1.5-ounce cocktail of 80-proof liquor.
Chronic, heavy drinking's most
obvious victim is the liver. Cirrhosis of the liver is the buildup
of scar tissue that results from long-term poisoning with alcohol.
A healthy liver can break alcohol down into harmless starches
and sugars within a matter of hours, Gunzerath says. But one of
the initial breakdown products of alcohol is a toxic substance
called acetaldehyde. [Some people are missing a gene that helps
them neutralize acetaldehyde, and as a result they become quite
ill immediately after drinking.]
Gradually, scars in the liver block
blood flow throughout the organ and hinder its performance as
a waste treatment center. Cirrhosis is the country's 12th-leading
cause of disease-related death, claiming 26,000 lives each year,
according to the National Institutes of Health.
Drinking also has been clearly
linked to several forms of cancer that affect the digestive tract
and airways, starting in the mouth and moving down into the esophagus.
Even people who use mouthwashes that contain high concentrations
of alcohol are vulnerable to some of these tumors, scientists
have found.
Alcohol may increase the risk of
stomach and pancreatic cancers, as well as colorectal tumors,
although probably in conjunction with smoking. Heavy drinking
may also raise a woman's risk of breast cancer, although the evidence
here isn't strong.
That's the bad news. The glass-half-full
side of alcohol consumption is this: People who consume alcohol
moderately appear to gain some protection against heart disease,
the nation's leading killer.
Alcohol might protect the heart
and blood vessels in at least two ways. It increases blood levels
of high-density lipoprotein cholesterol (HDL), the so-called good
form of blood fat. And, alcohol thins blood, thus making it less
likely to clot.
That should, in theory, shield
drinkers from strokes, a leading cause of death and disability.
Some studies have found such a protective effect from light-to-moderate
drinking.
One recent study, for example,
found older drinkers cut their risk of strokes, but at an intriguing
-- and still undefined -- cost: A shrinking brain. "There may
very well be a trade-off between improvements in blood vessel
problems and direct injury to brain cells and brain shrinkage,"
says Dr. Kenneth Mukamal, a Harvard University internist who researched
the issue.
However, a study in younger people
turned up no reduction in stroke risk from light-to-moderate drinking.
"We're at an interesting point
where the information that we have is hard to put together because
it seems to be conflicting," Mukamal says. "On the one hand, we
see some negative effects even at light to moderate amounts [of
alcohol]. But on the other hand, studies show that [these drinkers]
have a lower risk of stroke than non-drinkers or heavy drinkers.
Finding the balance of these risks and benefits on the brain is
still a challenge for us."
As Gunzerath points out, even if
alcohol does ward off heart attacks and strokes, drinking may
simply trade liver trouble and cancers for fewer cardiovascular
problems.
The American Heart Association
doesn't recommend that non-drinkers take up alcohol. But the group
does advise people who consume alcohol to do so moderately. The
NIAAA, a division of the National Institutes of Health, recommends
people 65 and older consume no more than one drink a day.
But at least one researcher says
U.S. drinking guidelines are rooted as much in relative morality
as they are in science.
Ruth Engs, an Indiana University
researcher who studies "clean living" movements, says America
is far more conservative about alcohol than other countries. In
Britain, for example, moderate drinking is considered to be up
to 21 drinks per week for men and 14 per week for women -- in
other words, about twice as much as in this country.
"Alcohol is a forbidden fruit,
it's something you can't touch," Engs says.
One result of this ambivalence
toward alcohol is that health officials are reluctant to promote
its benefits, Engs says. "I think unless you're an alcoholic and
have a compulsive behavior, a drink a day is probably a good idea
based on all the medical evidence," she says. "At least 200 to
300 studies [show] a small amount of alcohol is very beneficial."
Gunzerath says the federal government
is funding several key areas of research into the effects of alcohol
on health. They include:
- Looking for factors behind underage
drinking, including what makes adolescents interested in alcohol
and what health effects, if any, are unique to teens and children.
- Developing medications to combat
alcoholism and to blunt the tissue damage from alcohol.
- Looking for chemicals called
biomarkers that may show which people are more sensitive to
the harm or benefits of alcohol. Such markers could predict,
for example, who is likely to become an alcoholic or to suffer
liver damage from excess consumption.
More information
For more on alcohol and health,
visit the National
Institute on Alcohol Abuse and Alcoholism.
Reference
Source 101
For more information on how to prevent other diseases, use
PreventDisease.com's "Quick
Prevention Resources".
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