Author: James Anderson

Moderate alcohol consumption and the immune system: a review

Alcoholics Anonymous is available almost everywhere and provides a place to openly and nonjudgmentally discuss alcohol issues with others who have alcohol use disorder. And prolonged alcohol use can lead to mental health conditions like anxiety and depression. That’s because your body already has processes in place that allow it to store excess proteins, carbohydrates and fats. So, your system prioritizes getting rid of alcohol before it can turn its attention to its other work.

Alcohol abuse suppresses multiple arms of the immune response, leading to an increased risk of infections. The course and resolution of both bacterial and viral infections is severely impaired in alcohol-abusing patients, resulting in greater patient morbidity and mortality. Multiple mechanisms have been identified underlying the immunosuppressive effects of alcohol. Analyses of alcohol’s diverse effects on various components of the immune system provide insight into the factors that lead to a greater risk of infection in the alcohol-abusing population. Some of these mechanisms are directly related to the pathology found in people with infections such as HIV/AIDS, tuberculosis, hepatitis, and pneumonia who continue to use and abuse alcohol.

Numerous studies have demonstrated alcohol-related impairment of T-cell responses to various challenges. In other studies, chronic alcohol feeding impaired Th1 responses to a hepatitis C virus protein, a defect that was hypothesized to result from impaired secretion of IL-2 and GM–CSF by dendritic and T-cells (Geissler et al. 1997). This alcohol-induced defect in Th1 immunity correlates with suppression of IL-12 secretion by macrophages and dendritic cells (Waltenbaugh et al. 1998). Thus, it appears that alcohol inhibits Th1 immune responses and may predispose the organism to Th2 responses and that this shift is at least partly mediated by suppression of IL-12. Few studies have investigated the effects of alcohol abuse on complement activation and its relationship with the incidence and severity of infection; instead, the focus of studies on alcohol-induced alterations in complement has been on liver injury (Pritchard et al. 2008).

1. The activities of T-cells and B-cells are intricately intertwined through the actions of various cytokines to orchestrate an effective immune response to any pathogen the organism may encounter.
2. Molina and colleagues review research showing that alcohol impairs recovery from three types of physical trauma—burn, hemorrhagic shock, and traumatic brain injury—by affecting immune homeostasis.
3. For those who have a risk factor for COVID-19, like heart disease or diabetes, he recommends drinking even less.
4. Monocytes and macrophages are leukocytes with a single-lobed nucleus that also act as phagocytes and which therefore also are called mononuclear phagocytes.
5. Alcohol use can cause respiratory complications such as pneumonia, empyema, respiratory syncytial virus, tuberculosis, lung abscess, and adult respiratory distress syndrome (ARDS).

Several lines of evidence show that the number and function of B-cells are reduced by chronic alcohol. For example, chronic alcoholics exhibit loss of B-cells in the periphery and a reduced capacity to generate protective antibodies (Cook et al. 1996). In addition, chronic alcohol can decrease the number of B-cells that produce an antibody type called IgA5 in one of the layers of mucous membranes (i.e., the lamina propria), which is indicative of altered mucosal immunity (Lopez et al. 1994). Finally, alcohol inhibits the responsiveness of B-cells at certain developmental stages (i.e., blasts, which are the precursors to the antibody-secreting plasma cells) to various cytokines, particularly to IL-2 and IL-4. However, alcohol may have a dual effect on B-cell function because some studies have reported that B-cells also could be activated in alcohol-consuming people (Drew et al. 1984). The immune system is typically categorized into the innate and adaptive immune response systems, both of which are essential components in the body’s defense against pathogens.

Short-Term Effects of Alcohol on the Immune System

After binding to LPS, monocytes are activated and mature into macrophages that travel to the site of infection to secrete important cytokines for the inflammatory response. Several studies have demonstrated the dose-dependent effect that alcohol has on preventing both monocytes and macrophages from binding to the bacterial cell wall component lipopolysaccharide (LPS). Cellulitis is a bacterial infection of the skin’s deeper layers that causes pain, swelling, and, redness in the skin’s infected area. It’s a common infection, but it can cause serious health complications if left untreated and spread breaks in the skin, such as cuts, bites, ulcers, and puncture wounds, which can allow bacteria into the skin. When alcohol damages the gastrointestinal tract’s barrier, bacteria and toxins can enter the bloodstream easily, potentially leading to septicemia and sepsis. “Alcohol intake can kill normal healthy gut bacteria, which help to promote health and reduce risk of infection,” Mroszczyk-McDonald said.

The first point of contact for alcohol after consumption is the gastrointestinal (GI) system before it is absorbed into the bloodstream. Here, alcohol can damage the epithelial cells, T-cells, and neutrophils in the GI tract, all of which can alter the gut barrier function and allow intestinal microorganisms to leak into circulation. Although the innate immune response is immediate, it is not specific to any given pathogen. Some of the most notable contributors to the innate immune response include natural killer (NK) cells, neutrophils, monocytes, macrophages, and dendritic cells (DCs). Alcohol also causes the body to metabolize toxic chemicals and increase hormone levels. When a person drinks alcohol, their body metabolizes it into acetaldehyde, a chemical that can damage DNA and prevent the body from repairing it.

Alcohol and the Immune System

Virtually all of these components are affected by alcohol; however, the discussion in the following sections will focus on the first and fourth of these elements. Cirrhosis, on the other hand, is irreversible and can lead to liver failure and liver cancer, even if you abstain from alcohol. But when you ingest too much alcohol for your liver to process in a timely manner, a buildup of toxic substances begins to take a toll on your liver. Your liver detoxifies and removes alcohol from your blood through a process known as oxidation.

Lowered inhibitions can lead to poor choices with lasting repercussions — like the end of a relationship, an accident or legal woes. Each of those consequences can cause turmoil that can negatively affect your long-term emotional health. The morning after a night of over-imbibing can cause some temporary effects on your brain. Things like trouble concentration, slow reflexes and sensitivity to bright lights and loud sounds are standard signs of a hangover, and evidence of alcohol’s effects on your brain.

But there’s plenty of research to back up the notion that alcohol does lead to weight gain in general. If alcohol continues to accumulate in your system, it can destroy cells and, eventually, damage your organs. Those who have any of the known risk factors for COVID-19, like heart disease or diabetes, should drink even less. The World Health Organization (WHO) and U.S. surgeon general have warned people to avoid drinking too much alcohol during the COVID-19 pandemic. One study found that people who got less than 7 hours of sleep were nearly three times more likely to develop a cold compared with those who got 8 or more hours of sleep. “With COVID-19, alcohol is likely to interfere with an individual’s ability to clear SARS-CoV-2 and cause people to suffer worse outcomes, including ARDS, which commonly results in death,” Edelman said.

If you find it challenging to limit or stop your alcohol intake, it may be time to seek help for alcohol addiction. 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. When ALD reaches its final stage, known as alcoholic liver cirrhosis, the damage is irreversible and leads to complications. The damage is irreversible because scar tissues build up and replace the liver’s regenerative cells, preventing the organ from healing. Alcohol also reduces sleep quality, which increases a person’s chances of getting sick and recovering from illnesses.

How alcohol impacts the gut

This exposure increases a newborn’s risk of infection and disease; additional evidence suggests that alcohol’s deleterious effects on immune development last into adulthood. Heavy drinking and chronic alcohol use can significantly impact the immune system and decrease immune function. The first line of host defense involves both structural (i.e., epithelial) cells and immune cells (i.e., macrophages and dendritic cells) at mucosal surfaces. The epithelial cells function as a physical barrier as well as regulators of the innate and adaptive immunity. Particularly important are the epithelial immune barriers of the reproductive, GI, and respiratory tracts.

Prenatal Alcohol Exposure and the Developing Immune System

While binge drinking is typically more harmful than occasional drinking, any amount of alcohol can have adverse effects on the body and its ability to fight infections and diseases. Drinking every day or drinking too much alcohol at a time may affect the immune system more than drinking every other day or every few days, but the healthiest thing to do is abstain from drinking completely. Acute and chronic alcohol exposure can interfere with various aspects of the adaptive immune response, including the antigen presentation required to activate T- and B-cells, the activity of CD4+ and CD8+ T-cells, and the activity of B-cells. Both the innate and the adaptive immune response are critical for effective host defense to infectious challenges. Multiple aspects of both arms of the immunity response are significantly affected by alcohol abuse, as described in the following sections.