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Best Way to Boost Your Immunity Now, Says Science

Protect yourself against every virus with this advice from a noted cardiologist.

There are protective measures you can take to protect your body against infection from any virus, and they all involve strengthening your immune system. Here are 16 ways to boost your immunity against coronavirus, according to a top cardiologist, health organizations, and the latest research. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You May Have Already Had COVID.


Avoid Processed Foods

hamburger or cheeseburger, deep-fried squid rings, french fries, drink and ketchup on wooden table

One simple way to boost immunity is to maintain a fresh, clean diet, says board certified cardiologist and nutrition expert Luiza Petre, M.D. "Reduce inflammation and build your immune system in your body by eating organic unprocessed, food, avoid sugar and anything that comes in a box," she says. This includes lots of vegetables, herbs and fruits rich in vitamin C. "What we eat can help prevent and keep chronic inflammation in check," she continues. 


Make a Healthy Eating Plan

woman preparing vegetable salad in modern kitchen

An overall healthy eating plan provides nutrients that help keep your immune system working well. "Fruits and vegetables contain natural components called phytonutrients that help protect against inflammation," says Dr. Petre. "Healthy fats, such as monounsaturated fats and omega-3 fatty acids also help inflammation. Foods high in saturated fats and highly processed will increase inflammation and weaken your immunity."


Get in Your Garlic and Onion

Slate plate with fresh garlic and onion on wooden table.

Dr. Petre encourages amping up your garlic and onion intake. "Garlic is rich in allicin, which boosts the immune system and helps fight colds. Additionally, it has antimicrobial and antiviral properties that help fight viral infections and bacteria," she explains, recommending consuming one clove two to three times per day. Onion, on the other hand, is rich in quercetin, "which is a very potent flavonoid and antioxidant that has histamine regulating effects, antiviral properties, and helps immunity," she explains. "Onions are loaded with immune boosting nutrients like sulfur compounds, selenium, zinc, and vitamin C."


Amp Up Your Vitamin C

sweet and ripe mandarines (tangerines) with leaves

Dr. Petre points out that vitamin C rich fruits—oranges, grapefruit, and mandarins included—are called the "muscle of the immune system" for a good reason. "They help increase the white cell production and improve lymphocytes T function—key players in fighting infections. As an antioxidant, vitamin C fights free radicals in the body which may help prevent or delay certain cancers and heart disease, and promote healthy aging."



Eat Omega-3-Rich Foods

Plant-based and animal sources of Omega-3 acids

Omega 3-rich foods—including sardines, salmon, avocado and nuts—are great at fighting viruses. "Each of these enhance the function of immune cells, by improving white blood cell function," says Dr. Petre. 

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Add in Some Beta Glucan-Rich Foods

Shiitake mushroom on wooden table

Shiitake mushrooms, yeasts, seaweed, and algae are all powerhouse beta glucan rich foods that aid in improving T cell function and having antiviral properties, according to Dr. Petre. "They increase host immune response by enhancing natural killer cells and macrophage function, as well as activating the defense immune cascade," she explains. 


Go Green

Broccoli, baby spinach and green beans salad in ceramic bowl

Make sure to keep your diet green, Dr. Petre encourages. "Broccoli and spinach are both gems full of vitamins A, C and D as well as fiber, antioxidants, and antioxidants increase the ability of the immune system to fight infection." The key to keeping its power intact is to cook it as little as possible—or better yet, eat it raw.

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Vitamin D-Rich Foods

Natural sources of vitamin D and Calcium

Vitamin D is a key component of improving immunity. A few vitamin D rich foods include fatty fish, eggs, mushrooms, oysters, and caviar. "They're known to be 'better than vaccines,' and popular in the winter season to fight against viral infections, as vitamin D is a strong modulator and enhances natural immunity," says Dr. Petre. 


Take Probiotics

glass bowls against grunge wood: cucumber pickles, coconut milk yogurt, kimchi, sauerkraut, red beets, apple cider vinegar

Probiotics, aka live bacteria, can help establish a healthy gut, "and that is where immunity starts," says Dr. Petre. "Roughly seventy percent of our immune system resides in our gut. Probiotics are the key to balancing the gut microbiome and strengthening our immune system. They protect our bodies from dangerous pathogens, promote energy, enhance mood, and enrich our health in numerous ways." You can either take probiotics as a supplement or eat fermented foods—such as kimchi or sauerkraut—which feed the healthy bacteria.  

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Move That Body!!

woman in sports clothing at home, doing domestic fitness and training abdominals on swiss ball in living room

Dr. Petre points out that exercise is well known to strengthen the immune system. "It is well established that regular physical activity reduces the risks and severity of cardiovascular disease, diabetes, pulmonary disease, various chronic diseases and the effects of aging," she says. Physical activity helps get rid of bacteria in the lungs and airways, which may lower your chance of getting a flu, cold, or other illness and, "Exercise causes change in antibodies and white blood cells which are the body's immune system cells that fight disease." 

One recent study found that exercising at least 5 days a week compared with being sedentary lowered the risk of getting an upper respiratory infection. For those who did get sick, following this routine made their symptoms less severe by 32% to 41%. 



Calm couple in pajamas meditating, listening spiritual practices lessons on laptop, sitting on lotus pose at home

Dr. Petre encourages meditation as an immune-boosting practice. "Meditation lowers the stress level and cortisol level, boosting the body's response to fight viruses," she points out. "It has been confirmed through research that what we feel and think impacts our immune system through chemical messages from the brain. Therefore, negative thinking, stress and emotional states can have a negative impact upon our immune system, creating an environment increasingly susceptible to disease."

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Restore Yourself With Sleep

woman sleeping on bed in bedroom

Make sure to get your Zs if you want to stay healthy. "Sleep helps support the cells and proteins of your immune system to destroy and detect germs. It also helps to remember them, so in the future they can fight them off quicker," Dr. Petre maintains. It also greatly increases your body's immune response, "so make sure you are getting at least seven hours per night."

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Avoid Heavy Alcohol Use

Woman's relaxing at home on the sofa with a bottle of wine and glass by her side.

While it may be tempting to hit the bottle during the pandemic, the World Health Organization recently released a statement warning against it. "Alcohol use, especially heavy use, weakens the immune system and thus reduces the ability to cope with infectious diseases," they explained, adding that it can also cause certain types of cancer, increases the risk of acute respiratory distress syndrome (ARDS), one of the most severe complications of COVID-19, and alter your thoughts, judgment, decision-making and behavior.

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Keep Obesity at Bay

weight loss

If there was ever a time to strive toward a healthy weight, it is now. According to the CDC, severe obesity, defined as a body mass index (BMI) of 40 or above, puts people at higher risk for complications from COVID-19. Just like malnutrition, obesity is known to impair immunity function, according to research. If you believe you are obese, you should speak to your healthcare provider who can help you come up with a healthy weight loss plan. 

The Rx: Registered dietician Ilana Muhlstein lost 100 pounds and shows you how with these 8 Best Weight Loss Tips.


Get Vaccinated

Woman in medical face mask getting Covid-19 vaccine at the hospital

While a COVID-19 vaccine likely won't be available for quite some time, you can ensure your overall immunity is in the best shape possible by making sure you are up to date on all your other vaccines—and also getting the flu shot when it is time. The CDC explains that, "There are many benefits from flu vaccination and preventing flu is always important, but in the context of the COVID-19 pandemic, it's even more important to do everything possible to reduce illnesses and preserve scarce health care resources."

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Beware of Over-Supplementing

Colorful pills and medicine in the hand

Yes, "too much of a good thing" even applies to essential vitamins and nutrients. Because of this, you should avoid popping "immune boosting" supplements, warns D. Barry Boyd, MD, RDN, a Yale Medicine hematologist, oncologist and nutritionist. "Because of the complexity of the immune response—both in potentially controlling viral infections such as Covid as well as contributing the inflammatory response associated with severe and even fatal infections—the 'law of unintended consequences' applies here," he explains. 

Most of this has to do with the uncertainty surrounding the virus, as well as our "limited knowledge of potential adverse and unexpected risks" with "immune boosting" supplement use. He suggests sticking to a simple multivitamin "assuring adequate but not excess nutrient levels," and avoiding anything that promises "super high potency" with excess and unnecessary vitamin levels, based on your diet. And to get through this pandemic at your healthiest, don't miss these 35 Places You're Most Likely to Catch COVID.

Leah Groth
Leah Groth has decades of experience covering all things health, wellness and fitness related. Read more about Leah