Genetic Study Ties Higher Alcohol Consumption To Increased PAD & Stroke Risk

Several observational studies have consistently shown the association between heavy alcohol consumption with an increased risk for certain cardiovascular diseases, but they often use self-reported data making them unable to determine cause. This study used the Mendekian randomization technique to identify genetic variants with known associations to potential risk factors to determine the potential degree of disease risk. 

"Since genetic variants are determined at conception and cannot be affected by subsequent environmental factors, this technique allows us to better determine whether a risk factor—in this case, heavy alcohol consumption—is the cause of a disease, or if it is simply associated," said Susanna Larsson, Ph.D., senior researcher and associate professor of cardiovascular and nutritional epidemiology at Karolinska Institutet in Stockholm, Sweden. "To our knowledge, this is the first Mendelian randomization study on alcohol consumption and several cardiovascular diseases."

Genetic data was analyzed from several large scale consortia as well as the UK Biobank following the health and well being of 500,000 UK residents. Results indicated that higher alcohol consumption has a 3 fold increased risk of PAD, a 27% increase in stroke incidence, and some evidence for a positive association with coronary artery disease; it was noted that the study suggests the mechanism by which higher consumption was associated with the risk of PAD and stroke may be blood pressure.

"Higher alcohol consumption is a known cause of death and disability, yet it was previously unclear if alcohol consumption is also a cause of cardiovascular disease. Considering that many people consume alcohol regularly, it is important to disentangle any risks or benefits," Larsson said.

The American Heart Association believes that alcohol intake can be a part of an adult healthy diet if limited to be consumed in moderation of no more than one drink per day for woman and no more than two drinks per day for men, pregnant women should not drink alcohol at all and neither should anyone when there is a risk to existing health conditions, medication alcohol interaction, or risks to personal safety as well as work safety conditions. One drink is the equivalent to 12 ounces of 5% beer, 5 ounces of 12% wine, or 1.5 ounces of 80 proof distilled spirits. 

This study was not without limitations such as the prevalence of heavy drinking being low in the Biobank, and it being unlikely that the burden of increased risk of CVD is restricted to heavy drinkers alone, as well as the exact amount and frequency of the alcohol consumed could not be quantified for this study. The authors note that the causal role of alcohol consumption on CVD other than PAD and stroke requires additional research.