How good oral health may help you keep your immune system strong during coronavirus

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Fighting off infections, germs and diseases like COVID-19 is the job of your immune system. Keeping your immune system strong is one of the main goals of good health and fitness.

As the gateway into the body, the mouth provides a point of entry for bacteria and germs to enter your respiratory system and blood stream.¹ Therefore, maintaining good oral health can help keep your immune system robust and working properly, which is important during a global pandemic.

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How gum disease weakens your immune system

Bacteria in your mouth can cause gum disease. That bacteria feeds and grows on food debris that accumulates in and around the edges of your gums and between the teeth.²

The early form of gum disease is called gingivitis and is easily reversed by removing the bacterial film, called plaque, with a toothbrush, floss, and a professional cleaning by a dentist or dental hygienist. If your gums bleed when you brush or eat hard foods, you probably have gingivitis. The bleeding is caused by inflammation—redness and swelling—of the gums.

More severe gum disease, called periodontitis, can only be treated by a dentist or dental hygienist. In periodontitis, the inflammation caused by the bacteria attacks not only the gums but also the underlying bone that holds the teeth in place.³

The job of your immune system is to attack and kill the bacteria that invades your body. Inflammation caused by the bacteria is the signal for your immune system to go into action. In healthy people, mild infections go unnoticed because the immune system does its job of getting rid of the bad bacteria. But when a person is not healthy, the immune system cannot keep up and diseases take over.⁴

Periodontal disease—severe gum infections—are an example of a disease that causes the immune system to overload, requiring outside help from oral health experts to get the inflammation and disease under control.

How can infection in my mouth hurt the rest of my body? 

Gingivitis and periodontal diseases are inflammatory diseases caused by an overabundance of bacteria in the mouth. When the gums become red and inflamed, the immune system steps in to attack the bacteria causing the inflammation. These bacteria are the enemy of the immune system and work hard to disrupt its germ-killing abilities.⁵

As the immune system focuses its attention on your mouth, it must ignore other parts of the body where infections or inflammation occur. A study by the University of Pennsylvania found that the bacteria that causes gingivitis “…subverts the immune system” and promotes further inflammation by prohibiting the immune system’s ability to “eat” the invading bacteria.⁶

Immune system-related diseases include asthma, eczema, allergic rhinitis, HIV/AIDS, type 1 diabetes, rheumatoid arthritis, lupus, heart disease and inflammatory bowel disease. Other conditions weaken the immune system such as certain cancer treatments, organ transplants, and medications for some conditions. Temporary weakening of the immune system occurs during bouts with head colds, the flu virus, mononucleosis and the measles. Smoking, alcohol use and poor nutrition can also weaken your immune system.⁷

Keeping your mouth healthy and free of infection allows the immune system to concentrate its efforts on the rest of the body. Much like an army that diverts to one battlefront while the enemy attacks elsewhere, the immune system can shift its attention to acute infections in your mouth while leaving others to thrive in other parts of the body.

How can I keep my immune system strong?

When your immune system is strong and functioning correctly, bacteria in your mouth and other parts of your body don’t pose a threat. Your immune system quickly eliminates the danger and prevents infections from happening.

Keeping a strong immune system during the COVID-19 pandemic requires the same strategies as recommended for general healthy living.⁸

  • Minimize stress

  • Exercise regularly

  • Get adequate sleep

  • Brush your teeth daily

  • Wash hands regularly

  • Cook meats thoroughly

  • Maintain a healthy weight

  • Eat a healthy diet heavy with fruits, vegetables, lean meats, and healthy fats

  • Floss to remove bacteria between your teeth that your toothbrush cannot reach

  • Have your teeth professionally cleaned at regular intervals (when the pandemic is over)

In addition to these healthy lifestyle choices, it is equally important to avoid poor choices including those that are detrimental to your teeth:

  • Do not smoke

  • Avoid a diet filled with sugar

  • Avoid acidic drinks like soda

  • Drink alcohol in moderation

Your oral health affects your overall health

Bacteria from your mouth do not normally enter your bloodstream. But if you allow the bacteria to remain in your mouth unchecked, it can lead to gum disease and inflammation, causing your immune system to weaken and ignore other parts of your body.

Nearly half of all adults in the United States over age 30 suffer from some form of gum disease.⁹ Inflammation from gum disease can lead to tooth and bone loss. This inflammation causes your immune system to work overtime. Keeping gum disease at bay by regular brushing, flossing, and having professional teeth cleanings allows your immune system to focus its attention on other body systems where infections might be lurking.

Links to external sites are provided for your convenience in locating related information and services. Guardian, its subsidiaries, agents and employees expressly disclaim any responsibility for and do not maintain, control, recommend, or endorse third-party sites, organizations, products, or services and make no representation as to the completeness, suitability, or quality thereof.

Brought to you by The Guardian Life Insurance Company of America (Guardian), New York, NY. Material discussed is meant for general illustration and/or informational purposes only and it is not to be construed as tax, legal, investment or medical advice. This is not dental care advice and should not be substituted for regular consultation with your dentist. If you have any concerns about your dental health, please contact your dentist's office.


  1., 2019

  2. (Last accessed April 2020)

  3., 2020

  4. (Last accessed April 2020)

  5., 2014

  6., 2014

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  8., 2020

  9., 2018


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