Alcohol and the Immune System: Why You May Want to Stay Dry This Winter


Winter is officially upon us – meaning that it’s now cold and flu season, on top of a global pandemic. As much as you may want to reach for a hot toddy or Irish coffee to help you stay warm, you may want to consider cutting back for your immune system’s sake.

Drinking during the COVID-19 pandemic poses physical and psychological risks. Not only are people drinking more (and drinking alone), but consuming too much alcohol can also weaken your immunity to viruses like the cold, flu, and SARS-CoV-2.

Here’s how alcohol affects your immune system – and why you may want to consider staying dry this winter to prevent getting sick.

Does Alcohol Weaken the Immune System?

You may have noticed that after a long period of excessive drinking, you catch colds more frequently. Alcohol can weaken your immunity to bacteria and viruses in several ways.

Evidence suggests that excessive use of alcohol destroys important components of the immune system that prevent you from getting sick. For example, it may damage the cells lining your airway, making you more susceptible to respiratory infections, or kill the healthy bacteria in your gut, which play an important role in keeping you healthy.
Alcohol also takes away from other bodily functions, like the immune response. When you drink alcohol, the body prioritizes breaking it down over several other normal functions. Because alcohol cannot be stored the same way as macronutrients like carbohydrates, it must be sent directly to the liver, where it is metabolized immediately. As a result, your body may neglect its immune response in favor of metabolizing large amounts of alcohol.

A cartoon graphic of two people with shields to block germs is a metaphor for how alcohol and the immune system effect each other.

How Does Heavy Drinking Lower Your Immune System?

Heavy drinking lowers immunity by impairing your body’s normal defenses. One of the most significant effects of alcohol on the immune system is its effect on white blood cells. Excessive drinking can damage the bone marrow, where white blood cells are produced. This can lead to a low white blood cell count, making it more difficult for your body to fight off foreign invaders. 

Alcohol has also been found to damage the white blood cells themselves. Specifically, excessive drinking can change the structure of macrophages (white blood cells that destroy foreign particles by ingesting them) and T-cells (white blood cells that stimulate the production of other white blood cells, called B-cells, that destroy foreign invaders). 

Another way in which alcohol lowers your immunity is by promoting widespread inflammation throughout the body. Normally, the gut microbiome – a collection of “good bacteria” that live in your intestines – keeps inflammation at bay. When you drink too much alcohol, however, those bacteria are destroyed, allowing molecules called inflammatory cytokines to spread.

Cytokines are a group of chemical messengers that affect the behavior of cells. In particular, the cytokine interleukin-21 promotes the inflammation of cells. Not only does it play an important role in autoimmune diseases, but it also results in autoimmune-like effects in the presence of chronic low-grade inflammation — such as that caused by excessive drinking.

What Counts As Excessive Drinking?

When it comes to immunity, drinking any alcohol puts you at higher risk of getting sick. Drinking on even one occasion can have negative effects on your immunity – for example, by interfering with healthy sleep, which is known to protect against infection.

That being said, there is a big difference between moderate drinking and excessive drinking in terms of its effects on your body and its immune system. Moderate or infrequent drinking does not appear to pose the same risks to your overall health as excessive drinking, which is defined as 14 or more drinks per week.

The Centers for Disease Control and Prevention (CDC) considers “moderate drinking” to consist of one standard drink per day for women or two standard drinks per day for men. A “standard drink” is defined as 12 ounces of beer, five ounces of wine, or a 1.5 ounce shot of liquor.

Binge drinking, in particular, appears to have a negative effect on your immunity. Binge drinking is defined as a pattern of alcohol consumption that rapidly raises blood alcohol concentration (BAC) levels to 0.08% or higher. This amounts to approximately four drinks in a two-hour period for women or five drinks in a two-hour period for men.
According to some experts, research shows that both excessive and binge drinking directly lower your immune system’s defenses. Thus, if you are going to drink alcohol, it is best to limit your drinking to no more than a “moderate” level and to drink no more than a couple of days per week.

A man lying in bed hungover with a bottle of alcohol next to his head.

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 Bacterial and Viral Infections Linked to Drinking Alcohol

Drinking alcohol has been directly linked to a number of bacterial and viral infections. Some of the illnesses with a clear connection to alcohol consumption include:

  • COVID-19. Drinking alcohol has been rumored to kill the virus, but this myth poses a serious risk to your immunity from COVID-19: excessive alcohol consumption damages the epithelial cells that line the lungs, putting you at risk for a complication called acute respiratory distress syndrome (ARDS).
  • Pneumonia. Patients who abuse alcohol may be anywhere from two to nine times more likely to develop pneumonia. In men, regular heavy drinking has been found to raise the risk of pneumonia, as has binge drinking in both sexes. Alcohol consumption is also linked to poorer outcomes from pneumonia, including hospitalization.
  • Hepatitis B and C. The hepatitis B and C viruses are responsible for most cases of chronic hepatitis, or liver inflammation, in the United States. Because alcohol also causes inflammation of the liver, it may worsen the prognosis of hepatitis B and C, leading to cirrhosis (scarring of the liver). Drinking too much alcohol may also weaken your body’s response to certain antiviral drugs used to treat hepatitis B and C.
  • HIV. Research on HIV shows that alcohol misuse may contribute to the spread of the disease. Because alcohol impairs judgment, individuals who drink heavily may be more likely to engage in risky sexual behavior or drug-use that could spread HIV. Once infected with HIV, alcohol use also has an effect on a patient’s prognosis: alcohol abuse may lead to complications, such as cirrhosis, that can impact the progression of HIV. It may also make patients less likely to comply with complicated treatment regimens for HIV.

What to Do if Alcohol Weakens Your Immune Response

The next time you get sick, it may be a good idea to take a break from drinking (that is, even moderate drinking) until you are feeling better. Because your body prioritizes the metabolization of alcohol over its immune response, drinking alcohol when sick may make your illness last longer. Thus, the less you drink while sick, the sooner you can get back to having that nightly glass of wine while healthy and well! 

If you are someone who drinks heavily or regularly binge drinks, getting sick may offer you an opportunity to reflect on your alcohol consumption. You may want to ask yourself if it is worth it to keep drinking this much if it will leave you bedridden for days. Still, quitting alcohol is challenging for many people, especially if they find they are physically dependent on it. In that case, you may want to reach out to a treatment center or mental health professional for support.

Besides avoiding alcohol, there are other things you can do to boost immunity, such as taking supplements. Because vitamin C plays an important role in immunity, you may be able to prevent illness by taking an over-the-counter vitamin C supplement such as Emergen-C. When you are sick, taking elderberry supplements may reduce the duration of your illness. It has also been proven that taking a zinc supplement in the first few days of noticing cold symptoms can reduce the length of the common cold. 

It’s also important for your immune health that you lead a generally healthy lifestyle. Try to eat a wide variety of fresh fruits and vegetables, and get at least 30-60 minutes of moderate exercise a day. If you currently smoke cigarettes or use other tobacco products, it may be worth trying to quit for the sake of your immunity. You should also try to minimize psychological stress; relaxation exercises like meditation or yoga may help.

If you or a loved one is struggling with ceasing or cutting back on drinking alcohol, reach out to Hotel California by the Sea today. We are ready and able to assist you in figuring out your best options for quitting drinking and the use of other mind-altering substances.

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