Alcohol consumption also influences T-cell activation both in humans and in mouse models (Cook et al. 1991, 1995). Thus, C57BL/6 or BALB/c mice that consumed 20 percent ethanol in water for up to 6 months showed a greater frequency of activated T cells, increased rapid IFN-γ response, and heightened sensitivity to low levels of TCR stimulation, with no requirement for a second signal (Song et al. 2002; Zhang and Meadows 2005). By incompletely understood mechanisms, alcohol abuse leads to a disruption of the intestinal barrier integrity which in combination with the mucosal injury induced by alcohol, increases the permeability of the mucosa . The intestinal barrier is a semipermeable structure that allows the uptake of essential nutrients and immune sensing while being restrictive against pathogenic molecules and bacteria . Numerous studies have demonstrated that ethanol, its metabolites, and alterations of the gut microbiome suppress intestinal tight junction protein expression [58,59,60,61] producing that the epithelial layer becomes leaky or “permeable”.
- Alcohol feeding suppresses the production and secretion of certain acute-phase proteins (i.e., type II cell surfactant).
- Suppression of inflammatory factors like cytokines is further achieved by the inhibition of histone deacetylases (HDACs) activity.
- Cytokines can also modulate important behavioral functions including learning and memory (Hao, Jing et al. 2014) possibly due to their role in neuroplasticity (Sheridan, Wdowicz et al. 2014).
- Your immune system has several different cell types, each of which has a different but very important job to help keep you healthy.
In contrast to these deleterious effects of heavy alcohol exposure, moderate alcohol consumption may have beneficial effects on the adaptive immune system, including improved responses to vaccination and infection. The molecular mechanisms underlying ethanol’s impact on the adaptive immune system remain poorly understood. Cytokines are affected by alcohol on several levels as they are induced by certain pathways affected by alcohol, which again, in turn, can be modulated by other cytokines.
Moderate alcohol consumption ‘boosts immune system’
This review, briefly summarized in Table 1, covers a broad aspect of innate immunity modulated by alcohol. For instance, dendritic cells and natural killer cells, as important parts in direct cell-mediated resistance to pathogens and other stimuli, have to be addressed in the context of alcohol’s immuno-modulatory properties. A great number of studies have also focused on the induction of apoptosis in PMNs and their longevity in the case of inflammation. Modern research has also proven that innate and adaptive immunity are not two separate compartments of immunity but, rather, interchanging and simultaneous components of host defense.
For now, we have to acknowledge, due to the lack of knowledge, that Homer Simpson may have been right. Alcohol alters the composition of the IMB, resulting in an alteration of the amount and type of neuroactive substances produced by the microbiota, which may lead to behavioral alteration . Alcohol modifies the intestinal microbiota, pH and permeability of the intestine, causing an increased entry of endotoxins into our CNS and brain, leading to neuroinflammatory processes. These may include infections after surgery, traumatic injury, or burns; accelerated progression of HIV disease; adult respiratory distress syndrome and other opportunistic lung infections; and infection with hepatitis C virus, cirrhosis, or liver cancer (hepatocellular carcinoma). The white blood cells, tissues and organs that make up our body’s immune system are designed to fight off infections, disease and toxins. 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.
Drinking impairs immune cells in key organs
The adaptive immune response can be distinguished from innate immunity by the capability of generating immunological memory, or protective immunity against recurring disease caused by the same pathogen (Janeway 2008). 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. This alcohol-mediated dendritic cell dysfunction prevents the organism from generating virus-specific adaptive immune responses involving CD4+ and CD8+ lymphocytes, which may contribute to the acquisition and persistence of hepatitis C infection (Siu et al. 2009).
Alcohol has been proven to affect the microbiome in the gastrointestinal tract, with alcoholics having a different and higher bacterial load in their gut. Once the integrity of the gut mucosa is impaired, LPS enters the portal circulation contributing to enhance the inflammatory changes in other organs such liver and brain. Numerous sources of evidence gathered from experiments carried out in rodents show that modifications in the composition of gut microbiota impact in the brain functions and behavioral aspects , including the predisposition to high alcohol consumption . Leclercq et al.  found a correlation between leaky gut and inflammation with modifications in scores of depression, anxiety and social interactions in alcohol craving.
Surprising Ways Alcohol Affects Your Health — Not Just Your Liver
In the last years, microbiota has been extensively studied regarding its impact on various diseases. There is also evidence that alcohol abuse disrupts those epithelial barriers in gastrointestinal and respiratory tracts. Because this review focuses on does alcohol weaken your immune system the alcohol-mediated innate immune response, we discuss this topic only briefly. Additionally, disregarding the specificity of the innate immunity, the influence of alcohol-induced oxidative stress on cardiovascular system has to be considered as well.
TLR4-deficient mice prevented such neuroinflammation, synaptic and myelin alterations, as well as long-term cognitive alterations . 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. In addition to these changes in cytokine function, investigators also have shown a contribution of barrier dysfunction to the postinjury increase in infections in intoxicated people (Choudhry et al. 2004). Thus, alcohol intoxication can suppress chemokine production and impair the expression of proteins that allow neutrophils to adhere to other cells at the site of infection, which also contributes to increased susceptibility to infection. For example, in a model of lung infection, acute alcohol intoxication suppressed the production of certain chemokines (i.e., CINC and MIP-2) during infection and inflammation, thereby markedly impairing the recruitment of additional neutrophils to the site of infection (Boé et al. 2003).
In addition, oxidation of ethanol by CYP2E1 leads to the formation of reactive oxygen species (ROS). Elevated levels of ROS cause oxidative stress which has been shown to play a role in several harmful processes including cancer development, atherosclerosis, diabetes, and inflammation (Tuma and Casey 2003). In conclusion, alcohol can enable pathogens to enter the systemic blood flow, a process that may lead to an increased susceptibility of patients with infections. Furthermore, the induction of DAMPs in a sterile environment by alcohol should be a focus of further research, because, potentially, this may provide novel understanding of the chronic inflammation after alcohol consumption in case of no visible damage to organs. These foods may help your body make more of the white blood cells you need to fight off infections.
The severity of this alcohol-induced hepatitis directly correlates with cytokine concentration, yet they can normalize after recovery . Studies over the last 30 years have clearly demonstrated that chronic ethanol abuse impairs the functions of both T cells and B cells. Chronic alcohol consumption results in lymphopenia with a loss in circulating T cells and B cells. The decrease in T cells is accompanied by increased homeostatic proliferation, which in turn leads to increased T-cell differentiation, activation, and conversion to the memory phenotype.