How Alcohol Affects Your Immune System

You might know some of the risks associated with drinking too much alcohol, such as liver damage. But one health threat from overdoing it may be more surprising: Alcohol can weaken your body's important line of defense, your immune system.

That can put you at risk for long-term disease, according to the National Institute of Alcohol Abuse and Alcoholism (NIAAA). Even a short bout of binge drinking leaves you at higher risk for infection for about 24 hours.

"It is well documented that drinking more than three drinks in one day on most days of the week or drinking more than five drinks on any day is damaging to the immune system," says Amitava Dasgupta, PhD, a professor in the Department of Pathology and Laboratory Medicine at McGovern Medical School, UTHealth in Houston.

"Alcohol damages the ability of your immune system to fight viral infections. In fact, both the Surgeon General and the World Health Organization advise anyone at high risk for COVID-19 to avoid alcohol because it increases your risk for infection."

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Alcohol has been linked to the following immune system problems, according to the NIAAA:

• Increased risk of infection
• Increased risk of complications from surgery
• Prolonged recovery from injury or illness
• Decreased ability to fight cancer
• Alcoholic liver disease

Here's how alcohol damages the immune system, per the NIAAA:

• Alcohol kills bacteria in your gut. That can upset the balance of helpful and harmful bacteria essential for immune system function. This can increase your risk for irritable bowel disease, food allergy and diabetes.

• Alcohol can damage your gut enough to allow microbes to leak from your gut into your bloodstream. This can allow microbes to reach your liver and interfere with your liver's ability to make proteins that your immune system needs.

• Your immune system relies on a variety of immune system cells, including white blood cells, that are reduced by high levels of alcohol. Loss of these cells increases your risk for viral and bacterial infections and decreases your ability to benefit from vaccinations.

• Drinking alcohol during pregnancy can disrupt the development of your baby's immune system.

"Alcohol also destroys the protective lining inside your respiratory tract that your immune system uses to prevent upper respiratory tract infections like the common cold," Dasgupta says. Lung conditions linked to alcohol include pneumonia, tuberculosis and acute respiratory distress syndrome, according to the NIAAA.

What about moderate alcohol and the immune system? Moderate drinking is defined as up to one drink per day for people assigned female at birthday and up to two drinks per day for people assigned male at birth, per the NIAAA.

"Although there is no evidence that moderate drinking harms the immune system, it is better to stick to wine or beer since these have lower percent alcohol," Dasgupta says. "Higher percent alcohol in hard liquor may kill more bacteria in the gut."

"The only remedy for an immune system damaged from drinking alcohol is to stop drinking. If you are not able to drink in moderation, you should avoid alcohol," Dasgupta says.

"Immune system recovery depends on how long you have been drinking, how much and how much damage you have done to your liver. Although your immune system may recover over time, at some point, liver damage becomes irreversible and your immune system will not recover."

The immune system is very complex and relies on a delicate balance. You may be at higher risk for immune system damage from alcohol if you are over age 65 because your immune system naturally weakens with age. There is no evidence that any immune system supplements are effective, according to Harvard Health Publishing. Instead, these lifestyle changes are the best ways to support your immune system:

• Drink only in moderation or avoid alcohol.
• Don't smoke.
• Exercise regularly.
• Eat a diet with lots of fresh fruits and vegetables. If you do not get enough fresh fruits and vegetables, consider taking a multivitamin.
• Maintain a healthy weight.
• Get enough sleep.
• Reduce stress.

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