Alcohol and Your Immune System

This article cites and analyzes the relevant research on alcohol and the immune system while highlighting some illnesses people who become addicted to alcohol are more likely to contract.

Sick man seeing a doctor

For decades, medical experts and addiction researchers have understood the association between excessive alcohol consumption and reduced immune system function, manifested in alcohol users’ greater susceptibility to illnesses like pneumonia. However, more recent findings show a longer list of illnesses people who drink excessively are more likely to contract. Further, recent data suggests alcohol users are more likely to stay sick longer and to suffer more severe consequences than people who succumb to the same illnesses but who do not drink excessively.

Five Ways Alcohol Affects the Body’s Immune System

The journal Alcohol Research published a paper titled “Alcohol and the Immune System,” which summarized how alcohol consumption affects the body’s immune system. Some of the findings included the following data points:1

  1. Alcohol chemicals disrupt immune system pathways, preventing the body’s natural immune defenses from functioning when bacteria, viruses, or foreign pathogens are present. These disruptions can “impair the body’s ability to defend against infection, contribute to organ damage associated with alcohol consumption, and impede recovery from tissue injury.”
  2. Alcohol in the bloodstream hampers both the body’s innate and adaptive immune functions, significantly weakening immune defenses. The effect is one of “predisposing chronic drinkers to a wide range of health problems, including infections and systemic inflammation.”
  3. Fetuses exposed to alcohol are reported to exhibit poorer immune responses later in life than those not exposed to alcohol in utero.
  4. Alcohol significantly affects the structure and integrity of the gastrointestinal (GI) system. According to the above paper, alcohol “alters the numbers and relative abundances of microbes in the gut microbiome.” This altering effect significantly hampers the maturation and function of the immune system, as the extensive community of microorganisms in the intestine both aid normal gut function and promote a better immune response.
  5. Alcohol consumption has also been linked to pulmonary diseases like pneumonia and tuberculosis. Alcohol disrupts function in the upper airways, impairs the function of immune cells in the respiratory system, and weakens the barrier function of the epithelia (a tissue barrier) in the lower airways, putting these systems at greater risk for infection.

People who want to reduce their chances of becoming ill should reduce or eliminate their alcohol consumption. If they cannot do so on their own, they must seek professional help.

Alcohol Consumption Immediately Affects Immune Function

Man reaching for alcohol

The National Institute on Alcohol Abuse and Alcoholism also published findings connecting alcohol consumption and weakened immune response. In that report, the NIAAA highlighted how consuming alcohol immediately reduces immune function, even during the moments that one is drinking.2

According to the findings, people who drink excessively will be more prone to contracting illnesses during their consumption and up to 24 hours after getting drunk. People who frequently drink to excess live with a chronically suppressed immune system, hence their greater likelihood of contracting illnesses like pneumonia and tuberculosis.

Alcohol and Cancer Risk

One of the most critical roles of the human body’s immune system is its ability to ward off cancerous growths and tumors. According to a statement released by the National Cancer Institute, “The evidence indicates that the more alcohol a person drinks–particularly the more alcohol a person drinks regularly over time–the higher his or her risk of developing an alcohol-associated cancer. Even those who have no more than one drink per day and people who binge drink (those who consume 4 or more drinks for women and 5 or more drinks for men in one sitting) have a modestly increased risk of some cancers. Based on data from 2009, an estimated 3.5% of cancer deaths in the United States (about 19,500 deaths were alcohol related.” Those findings show a link between alcohol consumption and cancer risk.3

The above report outlined the types of cancers people who drink alcohol to excess are more likely to contract. These include:

  • Liver cancer
  • Colorectal cancer
  • Head and neck cancer (oral, pharynx, and larynx cancers)
  • Esophageal cancer (particularly esophageal squamous cell carcinoma)
  • Breast cancer (According to the National Cancer Institute, women who consume one drink daily have a 5–9% higher chance of developing breast cancer than women who do not drink)

Findings connecting alcohol misuse with a greater risk for cancer are developing. Further research will likely unveil more cancers that may be more likely to occur in people who drink.

What to Do if Your Loved One Drinks to Excess

Alcohol harms the human body and poses several health risks. Further, alcohol causes a chain reaction within the body, including suppression of immune response. A side effect of drinking too much is that one will be more likely to contract illnesses, which can put individuals who drink alcohol at risk for long-term and potentially permanent health conditions.

If you know someone who drinks excessively and cannot stop doing so on their own, please get them help at a qualified residential alcohol addiction treatment center as soon as possible. Please do not wait until it is too late.


  1. NLM. “Alcohol and the Immune System.” National Library of Medicine, 2015. ↩︎

  2. NIAAA. “Alcohol’s Effects on Health.” National Institute on Alcohol Abuse and Alcoholism, 2023. ↩︎

  3. NCI. “Alcohol and Cancer Risk.” National Cancer Institute, 2023. ↩︎


After working in addiction treatment for several years, Ren now travels the country, studying drug trends and writing about addiction in our society. Ren is focused on using his skill as an author and counselor to promote recovery and effective …
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