11 Best Immune-Boosting Foods to Fight COVID-19, Say Doctors
Unfortunately, the coronavirus pandemic is still in full swing—and as a result, the Centers for Disease Control & Prevention (CDC) is maintaining its recommendations to wash your hands frequently, wear a face covering when around others, practice social distancing, and regularly disinfect household surfaces in order to protect yourself. But your body also has its own defense system, too: the immune system. Fortunately, doctors say that there are certain foods that can enhance this complex network's ability to fight off infections like the coronavirus. The best immune-boosting foods to fight COVID-19 range from fruits and veggies to spices and shellfish—but the thing they all have in common is that they provide the key nutrients your body needs.
Antioxidants, vitamins, and minerals play a major role in how effectively your immune system can respond to invaders—like virus particles that enter your system. That's why one of the best ways to ward off illness is to stick to a healthy, diverse diet.
"With both the pandemic and the flu becoming more severe during the colder months, It's especially important to ensure your immune system is in a good position to fight the virus if you do get COVID-19 or any other illness," says Dr. Nate Favini, MD, MS, and Medical Lead of the preventive primary care practice Forward. "There are many factors that play a role in boosting your immune system—but your diet, your exercise, the amount of sleep that you get, and your stress levels are the biggest factors that are under your control. You should eat a well-balanced diet that is rich in vegetables and healthy oils, and low in sugar and processed foods."
Here are some foods and beverages you'll want to stock up on stat in order to ensure your immune system is in tip-top condition amidst the pandemic. And for more healthy tips, be sure to check out our list of The 7 Healthiest Foods to Eat Right Now.
According to Dr. Josh Axe, D.N.M., C.N.S, founder of Ancient Nutrition and author of the upcoming book Ancient Remedies, bone broth boosts the immune system by supporting the health of your gut and reducing inflammation. It contains collagen and amino acids, both of which play a crucial role in gut health—which as it turns out, is linked to immune health. Some of the amino acids that bone broth contains include:
- Glutamine, which helps to rev up your metabolism so your immune system can work more efficiently
- Glycine, which improves your quality of sleep, an essential aspect of immune health
- Arginine, which is crucial for liver and immune system functioning
While you can find commercially prepared packaged bone broths at many health food stores, Dr. Axe highly recommends making your own at home—using a combination of pasture-feed, and hormone- and antibiotic-free animal products as well as vegetables—in order to maximize the potential benefits.
This should come as no surprise, but experts highly recommend adding some citrus fruit to your diet. These fruits are packed with vitamin C—which according to Dr. Axe, can strengthen the immune system.
"Some studies have shown that for people with increased stress on their bodies (athletes like marathoners or skiers and soldiers in subarctic conditions), vitamin C may be helpful in reducing the risk of getting the common cold, perhaps cutting infection rates by as much as 50%," says Dr. Favini. "Other studies in the general population have demonstrated that Vitamin C can shorten the duration of the common cold as well."
It's worth noting that oranges and grapefruit are better sources of vitamin C than lemons and limes.
Dr. Axe says that this powerful plant can help to cleanse the lymphatic system, thus supporting the body's ability to eliminate toxins. Ginger is also known for its anti-oxidative and anti-inflammatory properties, thanks to compounds like shogaol, paradol, and zingerone. This is noteworthy given that chronic inflammation has been shown to potentially increase your chances of getting sick.
Drinking tea with fresh ginger root is a great way to take advantage of these benefits—or you could whip up a shot of ginger juice, adding honey and lemon juice for added antibacterial and antiviral effects.
"Leafy greens are some of the world's most nutritious foods," says Dr. Axe. "They contain several types of flavonoid antioxidants, and they are rich in vitamins A and C."
Specifically, research has found that the nutrients in cruciferous vegetables such as arugula, kale, and mustard greens help to ensure that key immune cells in the gut and skin known as IELs (intra-epithelial lymphocytes) function properly.
Did you know that bell peppers contain more vitamin C than oranges? A 1-cup serving contains 152 milligrams—or 169% of your daily recommended value for this vitamin. That's pretty impressive when you consider that 1 cup of oranges contains 96 milligrams.
Not only that, but Dr. Axe points out that yellow, orange, and red bell peppers are packed with beta-carotene, which helps to promote immune system health by fighting oxidative stress in the body.
One reason why Dr. Favini recommends eating shellfish is for the wide array of minerals they contain, including iron, magnesium, potassium, and phosphorus. Specifically, zinc plays a super important part in your immune function, and whether you know it or not, oysters contain more zinc per serving than any other food. Selenium, meanwhile—which shellfish is chock-full of—can reduce inflammation and enhance immunity by lowering oxidative stress levels in the body
Shellfish also offer a variety of B vitamins, which help to both regulate inflammation and promote the development of red and white blood cells to keep oxygen flowing throughout your body while it fights off disease. while fighting against disease. Not only that, but the immune system relies on a well-functioning metabolism to work properly, and iodine fuels basically all metabolic activity—and shrimp, lobster, and scallops are all chock-full of this essential mineral.
Dr. Axe says that pineapple is an excellent choice for helping your body to boost its defenses against illness because it has a high concentration of vitamin C. In fact, 1 cup of fresh pineapple chunks contains nearly 79 milligrams of vitamin C, according to The United States Department of Agriculture—which exceeds the RDA for adult women and nearly meets the RDA for adult men.
While this fruit contains a number of beneficial vitamins and minerals, it seems that the enzyme bromelain may be most advantageous for boosting immunity while reducing inflammation.
There's research to back this up, too: one 2019 study of 98 healthy children found that participants who ate canned pineapple over the course of nine weeks had a significantly lower risk of both viral and bacterial infections than those who didn't eat it. Moreover, the children who ate the most pineapple (280 grams daily) had close to four times more white blood cells, which protect the body from infection, than those who only ate 140 grams daily or none at all.
Research has suggested that beta-carotene, an antioxidant that converts to vitamin A, may enhance immune cell function— and carrots are loaded with it. Beta-carotene is actually what gives this vegetable its distinct orange hue. Dr. Axe recommends drinking carrot juice to reap these disease-fighting rewards — while may lose out on some of the dietary fiber by sipping the juice as opposed to munching on the veggie whole, it may be worth it since you'll get more beta-carotene this way. Although 1 cup of cooked carrots contains 12,998 micrograms of beta-carotene (which is 120% of your RDA), 6 oz. of 100% carrot juice contains a whopping 16,740 micrograms.
Plus, carrot juice is also high in vitamin C and vitamin B6—which is crucial for optimal immune response. In fact, studies have found that there's a link between vitamin B6 deficiency and weakened immunity.
Get started with our 41+ Best Carrot Recipes.
"Fermented foods supply the body with beneficial probiotic bacteria that improve gut health, thereby strengthening the immune system," says Dr. Axe, adding that some of the best-fermented foods include kefir, kombucha, sauerkraut, and kimchi.
Kefir—a sour drink made by adding kefir grains to milk—offers a wide range of powerful acids, peptides, and compounds that may boost your body's defenses. And while yogurt is one of the better-known probiotic foods, kefir can actually be a superior source of these friendly health-promoting bacteria—containing up to 61 different strains.
In addition, the probiotic Lactobacillus kefiri—which is unique to kefir—has been shown to inhibit the growth of certain harmful bacteria. Kefir also has a specific type of carbohydrate, kefiran, that's known for its antibacterial properties.
You can either buy kefir at your local market or make it yourself at home by combining kefir grains with the milk of your choosing—either way, it's a fantastic addition to smoothies, overnight oats, protein shakes, and dressings and marinades.
Here are 6 Reasons to Start Drinking Kefir.
According to Dr. Favini, there's a growing body of preliminary research that suggests vitamin D may play a critical role in modulating the way the immune system responds to COVID-19. Salmon is a rich source of this vitamin, which is why he advises adding oily fish like salmon to your grocery list. Research has demonstrated that vitamin D deficiency is associated with increased susceptibility to infection (especially respiratory infections).
Keep in mind that whether the fish was farmed or caught wild can make a significant difference: one 2007 study found that farmed salmon only had approximately 25% of the vitamin D content as wild salmon had.
And in case you were still looking for reasons to up your intake of this nutrient, it's been hypothesized that vitamin D could be extremely important in preventing the "cytokine storm" and acute respiratory distress syndrome that's commonly the cause of death in COVID-19 patients.
One reason why garlic is among Dr. Favini's top food choices for boosting your immune system is that it boasts antiseptic, antibacterial, and antifungal properties—which can help the body resist or destroy viruses. More specifically, this vegetable contains allicin, a potent compound that not only gives garlic its uniquely pungent odor and taste but is also believed to enhance immune resistance.
FYI, a 2007 study that analyzed the effects of lemon, ginger, garlic, and honey extracts on a specific bacteria (Streptococcus mutans) determined that garlic showed the greatest antimicrobial activity.
Now that you know what foods to eat, you should also check out These Foods That May Weaken COVID-19, New Study Says.