Drinking Patterns and Heart Attacks

People
picture science differently. For some, it’s a Gothic
laboratory and Victor Frankenstein shrieking, “It’s alive!”
For others, it’s a quiet and understated, sterile,
well-lighted, modern and nondescript workplace. For still
others, science is epidemiology, the statistical study of
what affects the health of populations.

What science really is
amounts to attitude and discipline: objective collection and
analysis of data, while avoiding confounding factors. It
must be reproducible, correctable, and accepting of
progress. It is ever changing.

So it should be no surprise
that we are often presented, simultaneously or sequentially,
with varying answers to the same question.

A recent illumination
casting shadows was the instantly and widely publicized
long-term study of 38,O77 male health professionals reported
by Kenneth J. Mukamal, et al. in The New England Journal of
Medicine of January 2OO3. Frequency of drinking turned out
to be the key determinant of cardiac health in this study.
Those who consumed alcohol three or four days per week had
32 percent fewer heart attacks than those who drank less
than once weekly. The men drinking five to seven days weekly
sustained 37 percent fewer heart attacks than the non- or
almost non-drinkers.

It didn’t matter whether
the amount consumed on a drinking day was less than one or
more than three drinks. It didn’t matter what kind of
beverage was consumed. Drinking with meals appeared to make
no difference. Ingrained beliefs got no respect.

An accompanying editorial,
“To Drink or Not To Drink?”, predictably advised caution
vis-a-vis alcohol, and wondered helpfully whether it was
time for a direct clinical trial of alcohol in
cardiovascular disease, perhaps starting with those already
afflicted.

Two additional research
projects published this year may shed more light. Tolstrup,
et al. (Addiction, March 2OO4) followed the relation of
drinking pattern to mortality in 56,535 middle-aged men and
women in Denmark during a ten-year period. The risk of death
for both sexes was significantly lower among those who drank
frequently than for those who, while consuming the same
total quantity, concentrated their consumption. The highest
risk occurred in women and men who did all their drinking on
one day a week or more rarely. Like almost all other studies
this one showed a correlation between moderate drinking and
reduced mortality.

The same issue of Addiction
contains a study of Trevisan, et al. from Buffalo and
Berkeley, which addresses the effects of drinking patterns
on the risks of non-fatal heart attacks of 427 white men,
with 9O5 controls. The results agreed with Mukamal’s and
Tolstrup’s that frequent (or regular) drinking is healthy,
in moderate quantity, but determined that food with drink is
favorable. Specifically, Trevisan’s findings can be
summarized that men who scatter their drinking throughout
the week have only 45 percent of the risk of heart attack of
abstainers; men who drink on weekends only have a higher
risk than all-week drinkers and no less risk than
abstainers; only those who drink mostly (at least 75 percent
of the time) with food, even snacks, have significantly
lower risk than abstainers.

During the last twenty
years, a mountain of data, mostly epidemiological, has been
accumulated indicating that alcohol consumption enhances
health and reduces deaths, chiefly by reducing the risk of
our biggest killer: heart attack. Heart attacks kill more
people – male, female, whatever race – in the developed
world than anything else. The “French paradox” dramatically
encapsulated this relationship: French wine drinkers have
fewer heart attacks despite indolence, fatty diets and
smoking. Moderate drinkers live longer than both abstainers
and heavy drinkers.

For a long time the notion
that drinking could be healthy had to disencumber itself
from attacks of critics who could not bring themselves to
accept that alcohol in any form, in any quantity, could be
beneficial to health. Eventually the weight of evidence
muffled their protests, but they still abound, squirming in
discomfort at any admission by a reluctant government or the
medical establishment that drinking might be helpful. They
are certainly not scientists.

A number of respectable
hypotheses, still under study, on the salutary effects of
alcohol continue to contend for attention. I feel confident
that we shall clarify the relationships of cardiovascular
health to drinking eventually, but science is difficult to
hurry. The various views are not necessarily mutually
exclusive.

The simplest position is
that it is not the alcohol or wine at all that helps our
hearts, except figuratively, but that the lifestyle of those
who partake moderately of wine happens to be more
heart-healthy than that of others. This view, however,
ignores direct experimental as well as epidemiologic
evidence that alcohol in moderation and the antioxidant
components of wine possess attributes that preserve the
health of the arterial blood vessels nourishing the heart
and other organs.

Some investigators propose
that it is only the alcohol that counts, that it doesn’t
matter what one drinks, but this supposition ignores the
continually accumulating evidence that compounds of wine in
addition to alcohol play a role. It is the general belief
among physicians familiar with the data that alcohol itself
contributes about half the benefits. Alcohol (ethyl alcohol
or ethanol) stimulates the liver to increase production of
high-density lipoproteins (HDL) – “good cholesterol” – which
leach out damaging low-density lipoprotein (LDL) – “bad
cholesterol” – from blood-vessel walls, then carry it back
to the liver for excretion in the bile. Alcohol also
modulates some pathways of blood clotting, and by this means
may further reduce heart attack risk, for a blood clot on a
diseased artery wall is the coup de grace of a heart
attack.

Most of us believe that a
group of polyphenolic antioxidants, derived from grape skins
– where they act as antifungal agents and in other, unknown,
ways, and extracted into wine during alcoholic fermentation
– are, in concert with alcohol, major health benefactors,
perhaps well beyond heart attack risk reduction. (Inhibition
of oxidation may play roles in protection from cancer,
aging, degenerative diseases, dementia, and various internal
toxins.) Compounds of this sort enhance the color, flavor
and preservation of wine. Among the most familiar are
resveratrol, quercetin and the catechins. As antioxidants,
they would act favorably on LDLs, which become most toxic
only after oxidation. Polyphenols also modulate blood
clotting and perhaps inflammation, and may be of importance
in maintaining the health and vigor of the vital inner
layers of the arterial walls by activating the production of
the key nitric oxide. It is too early to assess the
significance of their inhibition of the bacteria,
Helicobacter pylori and Chlamydia pneumoniae, suspected
provokers of atherosclerosis, or of endothelin-1, a small
protein accused of being a prime factor in the genesis of
coronary disease. Details of the influences of moderate
drinking have been discussed frequently in these
commentaries.

Now we have the new
studies, which suggest that frequent dollops of alcohol in
any form, no matter with or without meals, according to
Mukamal, substantially reduce the risk of heart attack. This
deserves attention. They are large and carefully done
projects by experienced hands over many years. But they are
heir to the uncertainties of epidemiologic observation,
notoriously tricky, and must shoulder the burden of squaring
their own results with those of the multitude alluded to in
the preceding paragraph. They involve a minority of women.
They cannot be taken as definitive.

As for me, I would continue
to drink wine moderately for enjoyment, regularly and mostly
with meals, and take continued comfort in the well-supported
belief that both abstention and excess are distinct risks to
health and longevity.