May 11, 2020

Understanding alcohol and the immune system during COVID-19

Researcher with petri-dish
With COVID-19 in the community – and the winter cold and flu season approaching – we examine the impact of alcohol on the immune system.

While limited data is available on the clinical outcomes of coronavirus (COVID-19), what is becoming clear is that people with chronic health conditions seem to be at a higher risk of more severe symptoms. 

This is especially the case for people with chronic lung weakness or existing lung conditions, as severe presentations of COVID-19 are associated with the rapid development of serious pneumonia.1

High levels of alcohol consumption can have an adverse effect on the body’s immune system, particularly the lungs.

How the immune system works

The immune system is divided into two distinct, but interrelated, aspects: 

  • the innate immune system, which provides general immunity, responding to viruses, bacteria and other microorganisms that can cause disease
  • the adaptive immune system, which is responsible for your immune memory; i.e. remembering what a previous infection looked like, such as chickenpox, and stopping it from occurring a second time.  

Excessive alcohol consumption has a negative impact on both aspects of the immune system.2

The body repairs injury and fights infection through a process of inflammation, which is its first response. 

The inflammation response signals to the immune system that something is wrong and needs to be addressed.  

Excessive alcohol can interrupt this inflammation signal and the body may not react to the injury or disease, resulting in increased harm and lowered immunity.3, 4

Excessive alcohol intake can lead to an increased rate and severity of both bacterial and viral infection as the immune system is less able to respond. 

Consequently, heavy drinking can result in a 3-7 times higher vulnerability to serious conditions, such as pneumonia developing as a result of common respiratory tract infections.2, 5

Respiratory system impacts 

The lungs are particularly vulnerable to the effects of alcohol and, combined with the impacts on the general immune response, excessive alcohol intake can directly impact immune cells that protect the lungs. 

Alcohol also impacts the cells within the airways, reducing their ability to remove mucous from the lung, damaging lung tissue, and leading to a chronic weakening of lung function over time. 

This weakening often goes unnoticed until severe infection occurs.5

Gut immune system impacts

Research has pointed to the importance of both the abundance and variety of ‘good’ bacteria in our gastrointestinal tract for healthy immune function. 

Alcohol can significantly impact both the number and the variety of these bacteria in the gut, in turn weakening our immune system.5

The cells that make up the lining of the gastrointestinal tract regulate what is absorbed into the body. Alcohol impacts these cells and allows for larger than normal molecules to be absorbed from the gastrointestinal tract into the body.  This appears to be one of the factors that increases the development and progression of alcohol liver disease.5

While there are still debates within the research as to the immune impacts of low to moderate alcohol consumption, there is a general agreement that excessive alcohol consumption patterns, including chronic and heavy drinking, have a negative impact on immune function.5

If you’re curious or concerned about how much alcohol you’re consuming, you can use the online drinking calculator or call Drug Info at 1300 85 85 84 for information. Looking to cut down on alcohol? There are strategies you can start using to consume less.

  1. Guan W-j, Liang W-h, Zhao Y, Liang H-r, Chen Z-s, Li Y-m, et al. Comorbidity and its impact on 1590 patients with Covid-19 in China: A Nationwide Analysis. European Respiratory Journal. 2020.
  2. Barr T, Helms C, Grant K, Messaoudi I. Opposing effects of alcohol on the immune system. Progress in Neuro-Psychopharmacology and Biological Psychiatry. 2016;65:242-51.
  3. Romeo J, Wärnberg J, Nova E, Díaz LE, Gómez-Martinez S, Marcos A. Moderate alcohol consumption and the immune system: a review. British Journal of Nutrition. 2007;98(S1):S111-S5.
  4. Stadlbauer V, Shah N, De Oca Arjona MM, Mookerjee RP, Jalan R. Alcohol takes the toll on immune function. Liver International. 2010;30(7):934-6.
  5. Sarkar D, Jung MK, Wang HJ. Alcohol and the immune system. Alcohol research: current reviews. 2015;37(2):153.

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