Challenging the Theory That Light Alcohol Consumption Benefits Heart Health

Challenging the Theory That Light Alcohol Consumption Benefits Heart Health

A recent study conducted by researchers at Massachusetts General Hospital and the Broad Institute of MIT and Harvard is challenging the theory that light alcohol consumption benefits heart health.

The study, which included 371,463 adults from the large-scale UK Biobank database containing in-depth genetic health information, found that alcohol intake at all levels is linked to higher risks of cardiovascular disease (CVD). There was also no significant difference in the rates of heart attack, stroke, or death between participants who consumed alcohol moderately and those who abstained from alcohol altogether.

Let’s explore how researchers came to those findings.

The Study Design

To challenge the theory that light alcohol consumption benefits heart health, researchers at Mass General and the Broad Institute used a technique called mendelian randomization or MR, which is an analytical method that uses genetic variants of known function to examine the causal effect of a modifiable exposure on disease in observational studies.

Among the 371,463 adults studied, the average age was 57 years old and an average alcohol intake of 9.2 drinks per week. The drinking groups were defined in five groups: abstainers (0 drinks/week), light (0-8 drinks/week), moderate (8.4-15.4 drinks/week), heavy (15.4 – 24.5 drinks/week), and abusive (24.5 or more drinks/week).

The study also focused on six CVD phenotypes: hypertension, coronary artery disease, myocardial infarction, stroke, heart failure, atrial fibrillation, and 10 continuous variables. Those 10 continuous variables included systolic blood pressure, diastolic blood pressure, low-density lipoprotein, cholesterol level, high-density lipoprotein cholesterol level, triglyceride level, apolipoproteins A and B levels, y-glutamyl transferase level, and C- reactive protein level.

Lastly, researchers accounted for several lifestyle factors including smoking rates, BMI, physical activity, vegetable intake, red meat consumption, and self-reported health by drinking category.

The Findings

After conducting genetic analyses from participant samples, researchers found that individuals with variants predicting higher alcohol consumption were indeed more likely to drink greater amounts. These individuals also demonstrated substantial differences in cardiovascular risk, such as hypertension and coronary artery disease, across genders when it came to the number of drinks per week.

Additionally, there was minimal increase overall going from 0-7 drinks, whereas there were steeper increases at 14 or more drinks per week and even higher for 21 or more drinks per week. These findings suggest that there is cardiovascular risk for drinkers even at low-level, which is defined by two drinks per day for men and 1 drink per day for women.

Based on the above findings, researchers concluded that no amount of alcohol is protective against CVD and that improvements to cardiovascular health may be more significant for those who consume more modestly.

References
Biddinger, Kiran J., Connor A. Emdin, Mary E. Haas, Minxian Wang, George Hindy, Patrick T. Ellinor, Sekar Kathiresan, Amit V. Khera, and Krishna G. Aragam. “Association of Habitual Alcohol Intake with Risk of Cardiovascular Disease.” JAMA Network Open 5, no. 3 (March 25, 2022). https://doi.org/10.1001/jamanetworkopen.2022.3849.

Massachusetts General Hospital. "Large study challenges the theory that light alcohol consumption benefits heart health: Any observed benefit likely results from other lifestyle factors common among light to moderate drinkers, say researchers." ScienceDaily. www.sciencedaily.com/releases/2022/03/220325122708.htm (accessed March 30, 2022).