Drink to Your Health?
Over the last five years, the health
benefits of moderate drinking have been widely celebrated in the
headlines. To those who think everything enjoyable must be bad
for you, this news might seem like a dream come true.
Studies show, for example, that health benefits only come with
moderate drinking and are greatest for older men. And even moderate
drinking is not recommended for women who are pregnant or thinking
of becoming pregnant, or for people who are under 21.
The strongest medical evidence exists for the link between moderate
drinking and a reduced risk of heart disease.
Dr. Kenneth Mukamal, an internist at Beth Israel Deaconess Medical
Center and assistant professor at Harvard Medical School in Boston,
was the lead author of a New England Journal of Medicine
study examining the roles of drinking patterns and heart disease
that found, after 12 year of follow-up, that men who consumed
alcohol between three and seven days a week had fewer heart attacks
than men who drank once a week.
Below, Mukamal discusses the risk and benefits of moderate drinking.
Do we know why moderate drinking lowers
heart disease risk?
We think that a lot of the benefits of alcohol are on the blood
vessels and on blockages in the arteries to the heart and to the
brain. This might be related to alcohol's effect on the good cholesterol,
the HDL cholesterol. In fact, alcohol affects HDL levels just
about as strongly as any other lifestyle factor. People also think
that alcohol may lower heart attack risk by acting as a blood
What are some of the other health benefits
associated with moderate drinking?
A wide variety of health effects have been attributed to moderate
drinking. A lower risk of diabetes has been seen in women and
men. There actually have been experiments done in which alcohol
was administered over a couple of months to people without diabetes.
In those studies, most of which have been conducted in women interestingly,
it looks like moderate drinking improves the body's sensitivity
to insulin. It may actually lower insulin levels altogether and
may prevent diabetes through that mechanism.
More recently we've done some work on moderate drinking and
dementia. We looked at a group of older adults in the United States
average age was in the mid-70s and found a reduced
risk. There has been some more work in slightly younger populations
from Europe, and those studies have fairly consistently suggested
that older adults who were drinking moderately may have a lower
risk of dementia. We're not exactly sure what the mechanisms may
be behind that. Some of it may very well be because drinking tends
to occur in social settings and just the process of getting out
and socializing may be an important way to prevent dementia.
There is also evidence that moderate drinking may prevent silent
strokes or other subtle types of brain injury that we know over
time can predispose to dementia. I think it's still an area where
we need some more investigation.
Is the pattern of alcohol consumption
In most of the studies that look at this issue, people have been
asked "How much alcohol do you usually drink?" When that question
is asked, people take an average. For example, I drink 10 drinks
a month. But 10 drinks a month is very different for someone who
has them all on one night vs. someone who has them on 10 different
nights of the month.
That kind of detail surprisingly hasn't been available in most
of the studies that have been devoted to this topic. In our study
we tried to figure out the drinking pattern that's most closely
tied to lower heart attack risk. What we found in a study of about
38,000 men was that the key factor wasn't what men were drinking,
or frankly even so much how much they were drinking at a time,
but how frequently they were drinking alcohol.
We found that men who were drinking at least three to four days
a week or more had lower heart attack risks than people who had
one drink a week. We also have some very strong studies showing
that heart disease risk, while lower amongst moderate drinkers,
can be substantially higher among people who drink to excess even
occasionally. They don't have to be drinking excessively every
single night to potentially have a greater heart attack risk.
Many of the effects of moderate drinking, such as acting as
a blood thinner, are only true at moderate levels of drinking.
Those effects actually go away and reverse if people drink too
What constitutes one drink?
What doctors usually consider a drink is basically a medium glass
of wine, a 1.5 oz shot of spirits, or a can or bottle of beer.
All of those have roughly similar amounts of pure alcohol in them.
We usually define moderate drinking as up to one drink per day
for adult women who aren't pregnant and up to two drinks per day
for adult men. Some guidelines recommend that moderate drinking
among adults over 65 be limited to one drink per day.
Are the heart benefits of alcohol consumption
the same for men and women?
In general, when we're thinking about the putative health benefits
of moderate drinking, they mostly apply to older people and to
men. Issues for women and for younger individuals are much more
difficult to sort out.
The role of alcohol consumption in heart disease varies strongly
by gender. The reason for that is twofold. On the one hand, women
at any given age tend to have lower risks of heart disease than
men do. As a result, the benefits of moderate drinking accrue
disproportionately to men. At the same time, there are some particular
risks of drinking for women that don't exist for men. There is
some evidence that women may be particularly prone, for example,
to liver disease related to drinking. Even moderate drinking may
increase breast cancer risk. And, while the effects on heart attack
risk are roughly similar in men and women, I think it's even more
difficult to determine what the ideal level of drinking ought
to be for women than it is for men.
I think it is fair to say that if young women in general are
drinking with the expectation that there is some health benefit
to it for them, they're probably mistaken. Young women are a group
of people for which, as of now, we basically have no clear proof
that the overall balance of alcohol's risks and benefits is going
to work in their favor.
What are some of the risks of moderate
There is fairly consistent evidence that breast cancer rates are
higher among women who drink moderately. I think that's important
because obviously breast cancer is very common disease. I certainly
think women at high risk for breast cancer should talk with their
doctors about whether they should be drinking any alcohol.
Another important risk, which is unrecognized for many people
in this country, is that even moderate drinking among people with
hepatitis C may increase their risk of permanent liver damage.
Anybody who is known to have hepatitis C shouldn't be drinking
any alcohol at all. People who have risk factors for hepatitis
C ought to be tested because it will very substantially impact
what the potential risks are related to moderate drinking.
In addition, although we don't think moderate drinking necessarily
clouds our judgment, it turns out that it probably does. In simulated
driving tests that were done as far back as the 1950s, people
have realized that at very low blood alcohol levels, simulated
driving performance is impaired. When I say low blood alcohol,
what I'm talking about is as low as .02 percent.
Some studies, for example, the analysis of the National Alcohol
Survey, showed something similar. You begin to see higher risks
of injury even when people are reporting one drink a day. That's
why we still recommend that even moderate drinking occur in the
home, preferably tied to meals. That is not so much because we
find that that drinking with a meal is more likely to lower heart
disease risk, for example, but because it's the safest way to
prevent high blood alcohol levels that can get people into accidents.
What about people with a history of
Although it has been bantered back and forth, most people think
that people who have a personal history of alcoholism very rarely
can return to social drinking. People who, for personal or family
reasons have never had alcohol before, at least as of now, probably
shouldn't start drinking for any health reason.
What is your advice for an individual
who is weighing the risks or benefits of moderate drinking?
It's hard to give any single piece of advice because of all the
things we've learned about moderate drinking. The potential risks
and benefits are going to vary by a person's health history, their
age, sex and family history. The number of factors that would
have to go into the decision is really very substantial. As a
primary care doctor myself, these are long discussions that people
should have with their doctor. I would not recommend that anybody
go out tomorrow and start drinking alcohol simply on the basis
of results that we and others have presented.
I would say that for people who are drinking moderately and
are able to control it and don't have any of the absolute reasons
why they shouldn't be drinking alcohol, that there is no evidence
now that that's a bad thing to do. Beyond that, I don't think
right now we have enough evidence to say that anybody should take
up drinking just for any particular benefit unless their doctors
recommend that they do so.
Reference Source 104