Alcohol consumption today involves two contradictory facets. While the advantages of drinking alcohol are seen in terms of its consumption in moderation, its abuse and excessive consumption is currently a major public health problem, resulting in one of the leading causes of death and disability worldwide.
Several studies have shown that moderate alcohol consumption may offer potential health benefits, although at no time is its intake without risk. Moderate consumption is considered to be a maximum intake of 1 drink (35cl 5% beer or 15cl 12% alcoholic strength glass of wine) for women and 2 for men. The intake of these amounts of alcohol has been related to a lower risk of disease and mortality from cardiovascular accidents and with other possible benefits such as reducing the risk of type II diabetes or cognitive deterioration, or raising HDL cholesterol levels. However, it is worth remembering that maintaining a healthy diet and being physically active have many more health benefits and are measures that have been widely studied and recognized as beneficial in this regard.
The most relevant aspect of alcohol consumption, however, is related to its negative impact. It is currently a major public health problem that is responsible for 2.2% and 6.8% of age-standardized deaths in women and men, respectively, in addition to a significant contribution to disability and limitation of quality of life.
It is defined as more than 3 drinks per day or more than 7 drinks per week for women and men over 65 years of age, and more than 4 drinks per day or 14 drinks per week for men under 65 years of age. In addition, binge drinking is referred to as 4 or more drinks in two hours for women and 5 or more for men. It also includes any consumption by pregnant women or persons under 21 years of age. Most people who binge drink will not necessarily be alcoholics or alcohol dependent.
Heavy drinking can increase the risk of serious health problems. In the short term it is associated with injuries, traffic accidents, falls, drowning and burns, violent behavior or alcohol intoxication among others. Among pregnant women it can trigger miscarriages or fetal alcohol spectrum disorders (FASD).
Additionally, over time, long-term excessive alcohol consumption can promote:
- Chronic diseases such as high blood pressure, heart disease, stroke, liver disease and digestive problems, as well as deficiencies of essential vitamins (Wernicke-Korsakoff Syndrome due to Vitamin B1 deficiency).
- Increase the risk of cancer of the breast, mouth, throat, esophagus, larynx, liver, colon and rectum.
- Promotes the weakening of the immune system.
- Learning and memory problems, including dementia and poor school performance.
- Mental health problems, such as depression and anxiety.
- Social problems, such as family problems, work problems and unemployment.
- Alcohol use disorders, or alcohol dependence.
The heritability of alcohol consumption and alcohol use disorders is estimated to be between 5% and 10%. One of the largest GWAS studies to date, involving more than 450,000 participants of European ancestry, has identified 83 markers associated with weekly alcohol consumption. Among the most strongly associated markers, we can find some belonging to genes such as ADH1A, which produces the enzyme alcohol dehydrogenase 1A, involved in alcohol metabolism and catabolism; the KLB gene, commonly involved in fibroblast function, and the SLC39A8 gene, which produces the zinc transporter ZIP8, responsible for the transmembrane transport of zinc, manganese, iron and cadmium.
13.5 million variants
Zhou H et al. Genome-wide meta-analysis of problematic alcohol use in 435,563 individuals yields insights into biology and relationships with other traits. Nature Neuroscience, 25; 2020, 23(7):809-818.