Alcohol Cuts Risk for Heart Disease by One Third CME/CE

News Author: Fran Lowry
CME Author: Charles P. Vega, MD

Authors and Disclosures

CME/CE Released: 11/30/2009; Valid for credit through 11/30/2010

November 30, 2009 — Spanish men who drink alcohol have a reduced incidence of
coronary heart disease (CHD), according to results in the Spanish cohort of the
European Prospective Investigation into Cancer and Nutrition (EPIC) trial, published
in the November 19 Online First issue of Heart.

"Spain is the world's third largest wine producer and ninth largest beer producer. In
2003, Spain was also in sixth position in the world ranking of alcohol consumption,"
write Larraitz Arriola, MD, from the Public Health Department of Gipuzkoa, Basque
Government, San Sebastian, Spain, and colleagues.

Spain also has one of the lowest CHD mortality rates in the world, along with China,
Switzerland, and France.

Although the association between alcohol consumption and CHD has been widely
studied, with most studies showing a reduced risk for CHD with moderate alcohol
intake, "there are numerous discussions regarding whether this association is causal
or biased," the study authors write.

Inverse Association Between Alcohol Intake and CHD

The aim of this study was to describe the association between alcohol intake and CHD
risk in the EPIC cohort.

The investigators assessed the alcohol intake of 15,630 men and 25,808 women for a
median of 10 years from their responses to a validated dietary history questionnaire.

Participants reported how many glasses of beer, cider, wine, sweet liquor, distilled
spirits, or fortified wines they consumed per day or week during the 12 months
before they were recruited into EPIC. Total alcohol intake was calculated by
multiplying the average ethanol content of a standard glass of whatever type of
alcohol was consumed. In Spain, a "standard drink or glass" is estimated to contain
approximately 10 g of alcohol.

Participants also provided information on lifestyle, including exercise and tobacco use,
and other potential risk factors for heart disease, such as obesity and high cholesterol
levels. All were free of CHD at baseline.

During the 10 years of follow-up, there were 609 coronary events (481 in men and
128 in women), for an incidence rate of 300.56/100,000 person-years for men and
47.93/100,000 person-years for women.

The investigators found an inverse association between alcohol consumption and
CHD.

In a multivariate analysis that adjusted for smoking status, height, educational level,
age, physical activity, waist-to-hip ratio, vitamin E, antithrombotic and
antihemorrhagic drugs, and energy intake, the researchers found that in men,
moderate, high, and very high alcohol consumption was associated with a reduced
risk for CHD.

The adjusted hazard ratio (HR) was 0.90 (95% confidence interval [CI], 0.56 - 1.44)
for former drinkers, 0.65 (95% CI, 0.41 - 1.04) for low consumers, 0.49 (95% CI,
0.32 - 0.75) for moderate consumers, 0.46 (95% CI, 0.30 - 0.71) for high consumers,
and 0.50 (95% CI, 0.29 - 0.85) for very high consumers.

"The HR decreases in the first two categories and then remains stable for the
moderate, high and very high categories," the study authors point out.

Women also benefited from alcohol intake, but the effects were not statistically
significant, perhaps because of the small number of coronary events they
experienced, the study authors write.

A limitation of the study could be residual or unmeasured confounding, they suggest.
"Although we adjusted for several potential confounders in our different models, we
could never be sure about the remaining confounders," they write. In addition, some
of the participants may have changed their alcohol consumption when they became
aware of their heart disease symptoms.

The study authors conclude: "Alcohol intake in men aged 29-69 years was associated
with a more than 30% lower CHD incidence. This study is based on a large
prospective cohort study and is free of the abstainer error."

Not an Interventional Study

William S. Harris, PhD, director of cardiovascular health research at the University of
South Dakota, Sioux Falls, disagrees with this conclusion.

The assertion that alcohol lowers heart disease risk by almost a third, at least in men,
misstates the findings, he told Medscape Cardiology.

"This is an epidemiological study, not an interventional study. Just because people
who report drinking more have less heart disease does not mean that drinking lowers
risk for heart disease. This is an extremely common logical fallacy," he said.

The study supports the idea that alcohol may have some cardioprotective effects.
However, "until you take a group of people and randomly assign them to drinking
alcohol or not, which is never going to happen, and then follow them for...[a certain
amount of] years to see who has heart attacks, you can never say that 'alcohol lowers
heart disease risk,' all you can say is that people who report drinking...[times]
alcoholic beverages per day have less heart disease than people who drink...[a
certain amount of] drinks per day. This is the kind of study that generates
hypotheses, not conclusions."

In response to the comments by Dr. Harris, Dr. Arriola told Medscape Cardiology
that, of course, she agrees her study is an epidemiologic study.

Dr. Arriola also told Medscape Cardiology: "As Dr. Harris says, there is no possible
interventional study to investigate the association between alcohol consumption and
CHD. So cohort studies are probably the best and the only ethical approach to study
the relationship."

She added: "Of course, cohort studies have their limitations. But what we found in
our study was that those men who drank alcohol had less CHD than those who did
not drink. And that is what we tried to explain in the paper."

Dr. Arriola and Dr. Harris have disclosed no relevant financial relationships.