Alcohol and Autoimmunity: How Drinking Affects the Immune System

Written by Claire, Nutritional Therapist and Functional Medicine Practitioner at The Autoimmune Clinic

For many people, December brings an increase in social events, celebrations, and alcohol consumption. For those living with autoimmune conditions, however, this rise in alcohol intake may sometimes come with unintended effects on immune balance and symptom control.

Alcohol, specifically ethanol, interacts with the immune system in several biologically ways that may place additional strain on an already sensitive immune system. In the context of alcohol and autoimmunity, the most relevant mechanisms include effects on the gut barrier, histamine handling, and systemic inflammation.

Understanding how alcohol influences immune function can help individuals make more informed and strategic choices during the festive season.

Alcohol, the Gut Barrier, and Autoimmunity

The intestinal lining acts as a critical frontline defence for the immune system. Its role is to allow nutrients to enter the bloodstream while preventing bacteria and inflammatory compounds, such as lipopolysaccharides (LPS), from crossing into circulation.

Ethanol has been shown to compromise this barrier through multiple mechanisms. Both human and animal studies suggest that alcohol may disrupt tight junction proteins, damage intestinal epithelial cells, and negatively alter the gut microbiome. Collectively, these changes may increase intestinal permeability, often referred to as ‘leaky gut’.

When bacterial products cross the gut barrier, they can drive immune activation and low-grade systemic inflammation. For individuals with autoimmune disease, this pathway is particularly relevant, as immune signalling is already heightened. During disease flares or periods of more frequent drinking, this gut-immune interaction may contribute to symptom exacerbation.

Tip: In the context of alcohol and autoimmunity, increased gut permeability represents a trigger for symptom flares, particularly with regular or higher intake. Reducing or avoiding alcohol during periods of active symptoms is often a sensible approach for many.

Alcohol, Histamine, and Immune Reactivity

Histamine is another important factor, particularly for individuals with mast cell activation, histamine intolerance, or immune-mediated reactivity.

Alcohol can affect histamine balance in several ways. Many alcoholic beverages, especially wine, champagne, beer, and other fermented drinks, contain histamine. In addition, ethanol and its metabolites may impair histamine breakdown by inhibiting diamine oxidase (DAO), the primary enzyme responsible for degrading histamine in the gut. Alcohol may also directly stimulate mast cell histamine release.

The combined effect can be increased histamine activity, contributing to symptoms such as flushing, headaches, itching, palpitations, gastrointestinal discomfort, and in some individuals, heightened immune activation.

Tip: If histamine-related symptoms form part of your autoimmune picture, both the type and quantity of alcohol matter. Lower-histamine options, smaller amounts, eating before drinking, and adequate hydration may help reduce symptom severity.

Alcohol, Inflammation, and the Immune System

A substantial body of research has examined alcohol’s effects on inflammation and immune function. Systematic reviews and meta-analyses consistently demonstrate that heavy or chronic alcohol intake is associated with elevated inflammatory markers, including interleukin-6 (IL-6), alongside impaired innate immune responses.

Although much of this research focuses on chronic alcohol use, experimental studies suggest that even episodic binge drinking can acutely disrupt immune signalling and gut integrity. From an alcohol and autoimmunity perspective, this supports the concept that alcohol may contribute to a pro-inflammatory environment that can aggravate autoimmune disease activity in susceptible individuals.

Some helfpful tips to navigate the festive period for those living with autoimmune conditions

If you live with an autoimmune or inflammatory condition, particularly one involving gut symptoms, mast cell activation, or histamine sensitivity, the following strategies may help reduce risk over the festive period:

• Reduce frequency and total intake. Fewer drinking occasions and lower overall consumption may lessen the impact on gut integrity and immune activation.

• Choose lower-histamine options. Clear spirits such as vodka or gin are generally lower in histamine than red wine, champagne, beer, or other fermented drinks. Keep mixers simple to avoid additional triggers.

• Avoid drinking on an empty stomach. Protein and fat slow alcohol absorption and may reduce direct irritation of the gut lining.

• Hydrate and pace intake. Alternating alcoholic drinks with water supports metabolic clearance and may help limit total consumption.

• Consider medications and supplements. Alcohol can interact with medications commonly used in autoimmune care. When in doubt, seek professional advice.

If you are unsure how alcohol affects your immune system, tracking your response can be helpful.

A simple diary noting what was consumed, quantities, and symptoms over the following 24 to 72 hours may help identify personal thresholds and inform future choices, ideally in discussion with your healthcare provider or your practitioner.