Beat back COVID-19 with foods that boost immune health – Osage County Online | Osage County News

Beat back COVID-19 with foods that boost immune health

As Coronovirus (COVID-19) continues to crisscross the globe, each of us should do our part to help stop the spread of this potentially deadly virus. Aside from vigilant hand washing, covering your cough or sneeze with a tissue, avoiding touching your mouth, nose, and eyes, and staying home when sick, a strong immune system is an important ally in keeping you healthy and well.

Strong immune functioning begins by eating a healthy diet. Fortunately, there are plenty of nutrient-dense foods to choose from such as crunchy vegetables, succulent fruit, hearty whole grains, and energy-rich beans, nuts, and seeds. However, there are certain top-notch foods ready and willing to duke it out with the germs, viruses or microbes wanting to cause you harm. Thanks to their antioxidant-rich powers, these foods kick it into high gear helping your immune system work as efficiently and diligently as always.  Not only are they health-promoting but are also available any time of year, providing peak performance for protecting your body from microbial harm.

Consuming these foods several times a week increases your odds of enjoying more healthy and disease-free days than someone who rarely consumes them.  Of course, other factors that help strengthen immune functioning are regular exercise, adequate sleep, minimizing stress, and avoiding smoking. Basically, practicing good health habits is more likely to enhance immune health, increasing your chances of fighting off COVID-19 along with other illnesses.

Best foods for boosting immune health

Citrus fruits

No matter what time of year, citrus fruits are always a winner for promoting immune function. Whether you choose to eat oranges and grapefruit, or lemons and limes, these citrus fruits grown in warmer climates will bring that ray of sunshine into your home on the bleakest of day.

Citrus fruits will also bring to your immune system a healthy dose of the water-soluble vitamin, vitamin C.  Oranges and grapefruit are particularly abundant in vitamin C as they can contain as much as 70 milligrams in one piece of fruit.

Vitamin C is a well-known friend to your immune system.  This vitamin, also known as ascorbic acid, has antibacterial and anti-inflammatory properties that help maintain the integrity of your skin acting as a protective barrier against infection.1

Vitamin C also helps protect immune cells against harmful compounds coming from viral or bacterial infections. In other words, once those disease-causing germs make their way inside you, vitamin C’s role as an anti-oxidant is to take action by putting up a barrier preventing the harmful germs attacking the immune cells.

Many people will take large doses of vitamin C pills with the belief it will protect them from getting sick with a cold or the flu.  It is really more advantageous to get vitamin C from plant foods like citrus fruits since plants contain other beneficial compound that supplements may not.


A longtime kitchen staple, garlic has been used as an elixir of health for thousands of years. Besides warding off vampires – according to folklore – the cloves of garlic may also scare away viruses and bacteria by reducing your risk of infection as it strengthens your immune functioning.2

Thanks to the compound allicin – this organosulfur compound gives garlic its nutritional muscle. However, to activate allicin, garlic must be either finely chopped or crushed, which releases the enzyme allinase causing the formation of allicin. The finer the chopping and the greater the intensity of crushing, the more allicin is activated, leading to a stronger medicinal effect. All that chopping and crushing breaks down cell walls, beginning a flow of chemical reactions including its characteristic smell, which leads to desired sulfides.

Once garlic has been chopped or crushed, don’t be tempted to toss it in hot oil or a cooking dish just yet.  Let it rest for about 10 to 15 minutes, allowing the compounds time to form.  If you toss in garlic right after chopping, it will still give the desired taste but not have quite the medicinal power.


Classified as fungi, rather than a plant or vegetable, mushrooms really do have some medicinal offerings. For example, mushrooms are particularly rich in selenium, an antioxidant protecting body cells from damage, supporting a strong immune system. Better yet, mushrooms also contain beta-glucans, a type of polysaccharide and bioactive compound that stimulates the immune system.3 Mushrooms are also one of the only dietary sources of ergothioneine, an antioxidant protecting red blood cells that transport nutrients and oxygen to body cells.4

It’s easy to add mushrooms to your plate by tossing them into soups, salads, and stir frys, or sautéed with veggies such as zucchini, spinach, or asparagus.

Sweet potatoes

No matter what time of year, sweet potatoes always shine a ray of healthy goodness when served on your dinner plate.  Not only are they a delicious addition to any meal, but they are also rich in vitamin A, a top antioxidant nutrient for maintaining healthy immunity.5 A one-half cup serving of a baked sweet potato contains 960 micrograms (mcg) of vitamin A – the RDA of vitamin A for men is 900 mcg and for women, 700 mcg.

Antioxidants work by helping to neutralize harmful free radicals.  Free radicals are rogue molecules that cause damage to healthy cells. When there is an imbalance between the number of free radicals and antioxidants, this can lead to an interference of the health and functioning of the immune system. Choosing foods rich in vitamin A is important to help fight off any damaging effects from free radicals keeping the immune system strong.

Get your dose of Vitamin D

Let’s start with the best way to obtain the fat-soluble vitamin – the sun. Step outdoors for a dose of the sunshine vitamin better known as vitamin D. Made from natural sunlight, vitamin D is essential for healthy functioning of the immune system, helping to produce antibodies.6 A brisk 10 to 15 minute walk outdoors aids in helping you obtain enough vitamin D to protect your immunity against illnesses.

The best foods sources of vitamin D include fatty fish such as salmon and tuna, egg yolks, mushrooms that state they are vitamin D rich, milk or orange juice fortified with vitamin D, and beef liver. Vitamin D supplements are also commonly used – check with your doctor for recommendation to take especially if your vitamin D level is below 30.

Bottom line

A healthy immune system starts by feeding your body healthy foods. When you feed it wisely with antioxidant rich foods, you’ll be equipping your immune system with the fighting power it will need to defend itself against COVID-19 along with other viruses that can make you sick.


  1. Carr AC, Maggini, S. Vitamin C and immune function. Nutrients. 2017:9(11)
  2. Arreola R, Quintero-Fabian S, Lopez-Roa RI, Immunomodulation and anti-inflammatory effects of garlic compounds. Journal of Immunology Research. 2015;401630.
  3. Batbayar S, Lee DH, Kim HW. Immunomodulation of fungal β-glucan in host defense signaling by dectin-1. Biomol Ther (Seoul). 2012;20(5):433-445.
  4. Beelman RB, Kalaras MD, Richie JP. Micronutrients and bioactive compounds in mushrooms: a recipe for healthy aging? Nutr Today. 2019;54(1):16-22.
  5. Huang Z, Liu Y, Qi G, Brand D, Zheng SG. Role of vitamin A in the immune system. Journal of Clinical Medicine. 2018;7(9): 258.
  6. Battault S, Whiting SJ, Peltier SL, Sadrin S, Gerber G, Maixent JM. Vitamin D metabolism, functions and needs: from science to health claims. Eur J Nutr. 2013;52(2):429-441.

For updated information on Coronavirus, see

Cheryl Mussatto MS, RD, LD is a registered dietitian with a master’s degree in dietetics and nutrition from the University of Kansas, and a bachelor’s degree in dietetics and institutional management from Kansas State University. She is a clinical dietitian for local clinics, an adjunct professor at an area community college where she teaches basic nutrition, and a freelance health and nutrition writer. She is the author of The Nourished Brain: The Latest Science On Food’s Power For Protecting The Brain From Alzheimers and Dementia and The Prediabetes Action Plan and Cookbook. Visit her website at

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