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Never has the phrase “What a wild time to be alive” felt more true. And never has frantically googling "immune system booster foods" felt more rational. In the face of coronavirus COVID-19, doing everything you possibly can to stay healthy is the right move.
One thing nutritionists and doctors want you to know: You can control how you feel right now by checking in on your mental health and eating immune system booster foods that nourish your body and potentially help your fight infections too.
It’s important to note that there is absolutely no “magic bullet” vitamin, mineral, or food item that will protect you from coronavirus or any other virus that may come our way. (So no, don't buy into the supplements, tinctures, or oils being touted on Facebook.) However, there are foods and steps we can take to help our minds and bodies prepare to fight off illness and feel stronger. “What we have to do is let people know that there is so much they can do to reduce their risk and improve their health overall,” Terry Wahls, M.D., a clinical professor of medicine at the University of Iowa Carver College of Medicine and author of The Wahls Protocol: A Radical New Way to Treat All Chronic Autoimmune Conditions Using Paleo Principles, says. “Just feeling in control can be calming.”
Wahls and others are on a mission to help us all during these uncertain times by providing a blueprint of all the immune system booster foods we should be eating in abundance right now.
1. Nonstarchy vegetables
Just about every doctor and nutritionist on the planet will tell you to eat your veggies to stay healthy. But when it comes to boosting your immune system, starchy vegetables like potatoes don't count. Instead, go hard on the greens like spinach and kale, which help your immune system function properly from your skin to your gut.
And go for “cabbage, greens, onions, mushrooms, and garlic," Wahls says. Now is not the time to worry about having garlic breath. Embrace the stink instead because a 2015 study found that garlic could help boost the human immune system, assisting in the production of virus-fighting white blood cells.
2. Fermented foods
Wahl also encourages people to add plenty of fermented vegetables, like kimchi or sauerkraut, to their diet, which she says will help build a healthier gut microbiome that could protect you from infections. She also suggests everyone buys fermented foods without added sugars (sorry, no sweet pickles here), and if you can, make your own.
3. Plenty of protein
“If you're a meat eater, that's meat, fish, and poultry," says Wahls. "If you’re not, then have gluten-free grains and legumes.” This is because protein is a building block for our body's tissue and organs, making it imperative when trying to rebuild healthy cells.
4. Fatty fish
Fatty fish like salmon and tuna are some of the best protein sources for packing in extra micronutrients like vitamin D. “The key micronutrients consumers should be ensuring they try to get enough of are vitamin A, vitamin D, and zinc,” says Mike Rogowski, Ph.D., senior nutrition scientist at Plexus Worldwide. “These nutrients are particularly important in the activation of our immune cells.” And if you don't eat fish or meat, that's okay as other vitamin-D-rich foods include fortified milk and mushrooms.
5. Cheese
Yes, you still can enjoy the finer things in life right now, which most certainly includes cheese. That's because hard cheeses are particularly high in zinc, which we mentioned above, is particularly powerful in fighting off viruses. Not a fan of cheese? Try navy beans.
6. Berries
Go ahead, eat all the berries you want. Berries are well-known for their antioxidant properties, which are disease-fighting compounds that will assist the immune system in fighting off infections and potentially help you get better quicker if you are ill. Even a cup a day will help.
7. Citrus fruits
You shouldn’t sleep the power of vitamin C—which is found in citrus fruits like oranges, grapefruits, and mandarins. According to a 2017 survey of studies, three controlled trials found that vitamin C prevented pneumonia, two controlled trials found a treatment benefit of vitamin C for pneumonia patients, and 148 animal studies showed vitamin C may alleviate or prevent infections caused by bacteria and viruses.
8. Sweet potatoes and squash
Foods that are high in vitamin A include sweet potatoes, spinach, winter squashes, and carrots. It's an important nutrient as it is "known as an anti-inflammation vitamin because of its critical role in enhancing immune function," a 2018 study suggested. Vitamin A, the authors wrote, "has both promoting and regulatory roles in both the innate immune system and adaptive immunity; therefore, it can enhance the organism’s immune function and provide an enhanced defense against multiple infectious diseases."
9. Foods you enjoy
“We have to choose foods we enjoy,” says Willow Jarosh, a registered dietitian. “Within enjoyment, aiming to balance meals with a combination of fruit and veggies, protein-rich foods, and carbohydrate-rich foods can help us meet nutrient needs to keep the immune system working well and also help us keep our energy and blood sugar levels stable.”
It's also important to remember—especially in times when money might be tight—that staying healthy doesn't have to mean placing an expensive Whole Foods order. "Eating consistently is important, no matter what that food is. Think about trying to get through something stressful when you're fed versus hungry," says Jarosh. "We need to be fed and that is priority number one."
Foods You Should Avoid
This one is going to hurt a little. According to the experts, it’s time we stay away from alcohol. At least in excess. “Excessive alcohol intake can affect our sleep—it reduces REM sleep—and it can also alter our gut bacteria,” Jarosh says. “Exploring how you can reduce your alcohol intake if it is excessive is important to gut health and immune health.”
Rogowski agrees, adding, “Alcohol is probably the first thing that should go. It can make you more stuffed up and contributes to dehydration.”
Wahls also says you should probably put the cookies away too. “There are things that we do that make things dramatically worse for our immune cells. So, things that elevate your blood sugar, you gotta get off that,” Wahls says. “Sugar-sweetened beverages and any added sugar in your diet, desserts, sweets, high-glycemic-index foods, things like white bread, pasta, cereal—try to replace all of that.”
And in case you needed a little science to back up the claims to stay away from sugar, alcohol, and other healthy foods, we’ve got you: According to a 2018 study by researchers at the University of Bonn, the body’s immune system reacts similarly to high-fat and high-calorie foods as it does to a bacterial infection, causing “acute inflammation,” which worsens the body’s ability to fight true disease.
What to Eat If You Do Get Sick
For Jarosh, the answer is simple: Eat foods that feel soothing. “For many people, this is smoothies, soups, liquids,” she says. “Hydration is really important, so ‘watery’ foods like smoothies and soups can be helpful if drinking plain water seems difficult.” (If you're not feeling plain water, Jarosh also suggests adding a splash of Health-Ade kombucha to add flavor.)
If you’re sick, Wahls wants you to add a few more key vitamins to the mix: vitamin C and the all-important vitamin D. “Bone broth can be really good and apple cider vinegar and water, or lemon juice and water," she says. "Having lemon juice in water especially helps because it gives you additional vitamin C.” She says to aim for one gram of vitamin C a day if you’re fighting off infection.
It’s not only key to keep up vitamin intake if you’re sick, but to push protein too, Rogowski adds. “In order to mount an immune response to an infection, the body needs to rapidly ramp up its numbers of white blood cells, including macrophages and T cells, as well as producing antibodies from B cells,” he says. “If the body doesn’t have enough protein available, it will cannibalize muscle to meet its needs to fight infection.”
Lastly, but perhaps most important, Wahls says, sick or not, now is the time to feed both your body and your mind to keep stress levels at bay. “It’s really time for self-care,” she says. “So prayer, meditation, anything. These are stressful times, but there still things I am grateful for.”
She says writing down one or two sentences a day on some aspect of your life that you still have gratitude for can be important. This can help reduce cortisol levels, your body’s stress hormone, which can help reduce inflammation in the body as well. According to a 2012 study conducted by researchers at the University of Wisconsin-Madison, meditation or exercising can help cut the number of days people feel sick due to respiratory illnesses, such as a cold or flu. Additionally, participants who did suffer from an illness during the study reported less severe symptoms. “Go to bed at the same time every night and turn off the phone,” Wahls says. “Take an Epsom salt bath, do self-massage, smell lavender oil, drink chamomile tea.”
