Does Alcohol Harm Your Immune System?

If you've ever indulged in a bit too much wine or one too many cocktails, you know alcohol -- especially in excess -- has some unpleasant gastrointestinal (GI) side effects. Since gut health is important for supporting your immune system, this can lead to weakened immunity and other negative side effects.

Here's what you need to know about how alcohol plays a role.

ALCOHOL METABOLISM AND YOUR GUT

Most alcohol is metabolized by your stomach and liver, however, a small proportion is cleared by the gut. As alcohol consumption increases, the proportion of alcohol metabolized by your gut also increases. In other words, the more you drink, the more pressure you put on your gut to process alcohol.

Gut metabolism of alcohol produces free radicals that can damage the cells of the GI tract and studies suggest alcohol can lead to changes in your microbiome and intestinal inflammation. Having a healthy microbiome has been tied to weight loss and even better sleep. The gut is an important protective layer between the outside world and our bloodstream, and even small changes in permeability and function (caused by free radicals from metabolizing alcohol) appear to negatively impact other systems such as the liver, brain and immune defenses.

Moreover, many people with inflammatory bowel syndrome (IBS) and inflammatory bowel disease (IBD) report alcohol triggers their symptoms.

IMMUNITY AND ALCOHOL

Research suggests even in moderate amounts (usually defined as one drink per day for women and two drinks for men), alcohol impairs immunity through various mechanisms such as promoting inflammation, altering gut function and the microbiome, reducing barrier integrity in the lungs and blocking anti-inflammatory mechanisms. What's more, alcohol can impair sleep and lead to dehydration, two factors that can further weaken the immune system.

THE BOTTOM LINE

We still have a lot to learn about the relationship between alcohol, the GI tract and immunity. That said, if you choose to drink, limit your consumption to one standard drink a day for women or two standard drinks a day for men, or less, to minimize health risks, including GI inflammation. If you have a particularly sensitive gut or a pre-existing condition such as IBD or IBS, you may need to cut your alcohol consumption even further. Make sure to prioritize a well-balanced diet with gut-friendly foods, move your body regularly and get quality sleep to best support your immune system and overall health.

Originally published April 2020, updated March 2023

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