The findings of a new study suggest healthy lifestyle factors adopted by people who habitually drink moderate amounts of alcohol keep their hearts strong—not the alcohol itself (JAMA Netw Open. 2022;5:e223849). These findings challenge past observational studies that repeatedly show a lower risk of cardiovascular disease (CVD) with light to moderate alcohol intake, compared with people who drink heavily or not at all.
The cohort study evaluated the effects of all levels of alcohol consumption on CVD risk in 371,463 individuals of European genetic ancestry. Specifically, researchers focused on the impact of alcohol consumption on hypertension, coronary artery disease, myocardial infarction, stroke, heart failure and atrial fibrillation. Variables such as blood pressure, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and C-reactive protein level were also examined.
For the study, participants were grouped into one of five categories: abstainers (0 drinks/week), light (>0 to 8.4 drinks/week), moderate (>8.4 to 15.4 drinks/week), heavy (>15.4-24.5 drinks/week) and abusive (>24.5 drinks/week).
Researchers assessed the prevalence of CVDs within each drinking group and evaluated potential differences in lifestyle factors, including smoking frequency, body mass index (BMI), self-reported physical activity, cooked vegetable intake, red meat consumption and self-reported health by drinking category. After adjusting for the measured lifestyle factors, researchers re-estimated CVD hazards.
Researchers also studied human genetic data, tapping traditional mendelian randomization and nonlinear mendelian randomization to assess for potential causality and association.
Similar to findings of prior studies, researchers found lower risk of hypertension, coronary artery disease, myocardial infarction, stroke, heart failure and atrial fibrillation among light and moderate alcohol drinkers, with increased risk among people who abstain or drink heavily. However, individuals in the light and moderate consumption groups reported healthier lifestyle behaviors than abstainers, including lower rates of smoking, lower BMI, higher physical activity and higher vegetable intake.
When researchers adjusted for healthy lifestyle factors, cardioprotective associations with modest alcohol intake were null.
“For each condition, all amounts of alcohol consumption were associated with an increased risk of disease,” researchers wrote. “Furthermore, increased alcohol consumption was associated with increases in disease risk that were exponential and unequal in magnitude, even when comparing light and moderate levels of consumption (i.e., between one and two drinks per day).”
The study also showed substantial differences in heart health risk across levels of alcohol consumption, marking potentially important implications for public health recommendations. Current guidance from the 2020-2025 Dietary Guidelines for Americans advises limiting alcohol intake to two drinks a day for men and one drink a day for women.
“Specifically, our results suggest that consuming as many as seven drinks per week is associated with relatively modest increases in cardiovascular risk,” researchers wrote. “However, nonlinear modeling uncovered unequal increases in cardiovascular risk when progressing from 0 to 7 vs 7 to 14 drinks per week in both men and women. Although risk thresholds are inherently somewhat subjective, these findings again bring into question whether an average consumption of 2 drinks per day (14 drinks per week) should be designated a low-risk behavior.”
Rachel Adams joined Informa’s Health & Nutrition Network in 2013. Her career in the natural products industry started with a food and beverage focus before transitioning into her role as managing editor of Natural Products INSIDER, where she covered the dietary supplement industry. Adams left Informa Markets in 2019.