According to the Cleveland Clinic, once you take a sip of alcohol, your body prioritizes breaking down alcohol over several other bodily functions. The body doesn’t have a way to store alcohol like it does with carbohydrates and fats, so it has to immediately send it to the liver, where it’s metabolized. When someone is exposed to a virus, the body mounts an immune response to attack and kill the foreign pathogen.
According to the 2019 National Survey on Drug Use and Health from the Substance Abuse and Mental Health Services Administration, 69.5% of people in the United States reported drinking within the last year. 25.8% of people classified their recent consumption habits as binge drinking (excessive drinking in a defined amount of time). “The only remedy for an immune system damaged from drinking alcohol is to stop drinking. If you are not able to drink in moderation, you should avoid alcohol,” Dasgupta says. This condition occurs when bacteria enter the chest cavity’s pleural space, typically due to pneumonia or a post-surgery infection. A weakened immune system increases an individual’s chances of developing empyema.
You probably already know that excessive drinking can affect you in more ways than one. Those who have any of the known risk factors for COVID-19, like heart disease or diabetes, should drink even less. That said, evidence also shows that even smaller amounts of alcohol can affect the immune system. Drinking also makes it harder for your body to properly tend to its other critical functions, like fighting off a disease. Alcohol has been flying off the shelves as people try to combat boredom during lockdown, with some reports estimating that alcoholic beverage sales surged by 55 percent toward the end of March. The goal is to treat the underlying cause of what’s compromising your immune system.
Alcohol modulates gene expression—that is, the generation of mRNAs and, ultimately, functional proteins from the DNA template—through changes in noncoding microRNA (miRNA) levels and epigenetic modifications. Such epigenetic changes can promote (red arrow) or inhibit (black arrow) the expression of mRNAs as well as promote the expression of certain miRNAs (including the processing of precursor molecules called pri-micro RNA into mature miRNA). Conversely, miRNAs can inhibit the actions of the methylation machinery and expression of proteins involved in histone modifications as well as can interfere with the transcription of mRNAs. But drinking can weaken this system, leaving us vulnerable to infections and diseases. To this end, heavy drinkers have been shown to exhibit an increase in both IgA and IgM levels when compared to both moderate and light male drinkers. Within the GI tract, alcohol exposure can also alter the number and abundance of microorganisms present within the microbiome, all of which play an important role in normal GI function.
The respiratory tract contains cilia, which are microscopic projections that move the mucus toward the throat. Alcohol impedes ciliary function in the respiratory system’s upper airways, allowing mucus to enter the lungs, which can lead to pneumonia. Alcohol also impairs immune cell function and weakens epithelial barrier function in the lower airways, which can cause bacterial respiratory infections. As described earlier for adult humans, alcohol can lead to increases in Ig levels during development, even if the numbers of mature B cells decrease. Thus, maternal alcohol consumption during pregnancy (12 mg/week for most of the pregnancy) increased IgE levels in the umbilical cord blood of the infants (Bjerke et al. 1994).
“Although there is no evidence that moderate drinking harms the immune system, it is better to stick to wine or beer since these have lower percent alcohol,” Dasgupta says. The frequency at which a person drinks also determines how much it affects the immune system. A person who drinks every day is more likely to have a weakened immune system and experience health complications than someone who rarely drinks or only drinks on occasion.
In vivo studies in humans confirmed these observations, demonstrating that binge drinking (i.e., consuming 5 to 7 drinks within 90 to 120 minutes) promoted T-cell apoptosis and decreased Bcl-2 expression (Kapasi et al. 2003). Much progress has been made in elucidating the relationship between alcohol consumption and immune function and how this interaction affects human health. Normal immune function hinges on bidirectional communication of immune cells with nonimmune cells at the local level, as well as crosstalk between the brain and the periphery. These different layers of interaction make validation of the mechanisms by which alcohol affects immune function challenging. Significant differences between the immune system of the mouse—the primary model organism used in immune studies—and that of humans also complicate the translation of experimental results from these animals to humans.
Recent studies suggest that the increase in IgA levels may be mediated by an ethanol-induced elevation of the enzyme neuronal nitric oxide synthase (nNOS) in the animals’ intestine, because inhibition of nNOS before ethanol injection suppressed the IgA increase (Budec et al. 2013). However, additional studies are needed to fully uncover the mechanisms that underlie increased Ig production while B-cell numbers are reduced. Alcohol consumption also influences T-cell activation both in humans and in mouse models (Cook et al. 1991, 1995). Frequent and heavy alcohol consumption can suppress the immune system, making the body vulnerable to viruses and infections. Alcohol misuse can cause short-term effects such as the common cold or gastrointestinal complications, but it can also lead to more serious conditions such benzo belly as cancer, septicemia, or, liver disease.
Alcohol can have a range of harmful effects on the body, which can diminish a person’s immune response and put them more at risk for COVID-19. “Alcohol intake can kill normal healthy gut bacteria, which help to promote health and reduce risk of infection,” Mroszczyk-McDonald said. In the lungs, for example, alcohol damages the immune cells and fine hairs that have the important job of clearing pathogens out of our airway. Sometimes, they can develop abnormal infections people wouldn’t develop with a functioning immune system. “People who have well-controlled HIV might have a bit of a dampened immune system, but overall, their immune system can function very well because of how excellent and easily treatable our medications are these days for HIV,” states Dr. Krajcik.
