An alcoholic beverage a day is claimed to keep coronary heart disease at bay, but only for 15% of the population, confirms a new study at Sahlgrenska Academy, University of Gothenburg in Sweden.
Alcoholic consumption (ethanol intake) at “moderate” level, up to 1 drink a day for women (corresponding to 14 g or 0.6 ounces of ethanol) and 2 drinks a day for men is associated with a decreased risk of coronary heart disease.
However, your favorite nightly tipple may only have cardio-protective benefits for people of a particular genotype of the cholesteryl ester transfer protein (CETP) polymorphism. For the other 85% of the population, this is not the case.
A previous study of men found an association between alcohol consumption and coronary heart disease, but the evidence had not been confirmed in further studies, until now.
The new study, published in Alcohol, specifically re-examines the potential association between alcohol consumption and coronary heart disease with the presence of the CETP TaqIB (rs708272) polymorphism.
There were 618 patients included in the study, including both men and women, below the age of 75. They were from three regional hospitals admitted for acute coronary syndrome and diagnosed with myocardial infarction, with a typical history, ECG, and enzyme changes or unstable angina.
Of the 618 participants, 453 were men and 165 women. First-time acute myocardial infarction or unstable angina was present in 209 men and 86 women, while the remaining 323 had an exacerbation of previously diagnosed coronary heart disease.
Study contributors and 2,921 healthy control subjects answered self-administered questionnaires on environmental and lifestyle-related exposure variables, and anthropometric measures and venous blood samples were collected.
All participants were asked about their intake of different types of alcoholic beverage (low-alcohol beer, medium-strong beer, strong beer, wine, dessert wine and spirits) and the serving size and frequency of consumption.
Participants were tested in order to identify if the CETP TaqIB genotype was present – the genotype found to play a role in the health benefits of alcohol consumption in a previous study. The researchers also tested whether the participants carried the B1 or B2 alleles of this genotype.
Results show that the distribution of CETP TaqIB genotype was similar in both female and male cases and controls. The researchers found:
- The B2 genotype was associated with a lower coronary heart disease risk, with a similar magnitude in men and women
- 19% of participants were homozygous for the CETP TaqIB B2 allele
- The group with intermediate alcohol intake had the lowest risk compared with low intake, but this was markedly more pronounced in B2 homozygotes than in B1 carriers.
The protective effect of B2 genotype in the categories of intermediate or high ethanol intake was more pronounced when the cases were restricted to the first-time coronary cases.
The results echo that of the previous study and confirm that moderate alcohol helps protect against coronary heart disease for the percentage of people who have the genotype.
Prof. Dag Thelle, Professor Emeritus at Sahlgrenska Academy, University of Gothenburg, says:
“In other words, moderate drinking has a protective effect among only 15% of the general population.”
The researchers point out that a common attitude toward alcohol focuses on the breadcrumb that “moderate drinking has health benefits for everyone.” However, evidence suggests that this advice may be too sweeping and needs reassessing.
“Moderate drinking alone does not have a strong protective effect,” comments Prof. Lauren Lissner, who also participated in the study. “Nor does this particular genotype. But the combination of the two appears to reduce the risk of coronary heart disease significantly.”
Study authors devised two hypotheses for how the CETP affects the “good” cardio-protective high-density lipoprotein (HDL) cholesterol that assists in the removal of excess lipids from the blood vessels:
- Alcohol by some means affects the CETP in a way that benefits HDL cholesterol
- Alcohol contains healthy, protective antioxidants.
One or both of these hypotheses may prove correct, but the mechanisms by which HDL cholesterol or antioxidants might act remain unknown.
Prof. Thelle notes:
“Our study represents a step in the right direction, but a lot more research is needed. Assuming that we are able to describe these mechanisms, it may be a simple matter one day to perform genetic testing and determine whether someone belongs to the lucky 15%.”
“That would be useful to know when offering advice on healthy alcohol consumption. But the most important thing is to identify new means of using the body’s resources to prevent coronary heart disease,” he concludes.
Medical News Today recently reported that individuals over the age of 60 who partake in a little drinking may experience better episodic memory in later life.