As we live through the COVID-19 pandemic, the interest in understanding the workings of the immune system and how we can support our immune health has grown dramatically.
It is important to note that, clinically, there is no single food or nutrient shown to prevent infection by COVID-19 or to treat the infection once it occurs. Similarly, there isn’t a single supplement or botanical that will protect us from becoming infected or experiencing severe symptoms. Please follow the CDC and WHO recommendations to minimize exposure to the virus.
That being said, there is a lot we can do to support our immune function with healthy lifestyle choices and a well-rounded whole foods diet rich in plant foods, vitamins, minerals, and antioxidants.
Did you know 70% of our immune cells live in our gut? These cells constitute a critical barrier of defense against pathogens. Taking care of our digestive system and the microbial life in us is paramount for immune health. We can support our microbiome with our diet!
Some of the vitamins and minerals that have evidence for supporting immune health are vitamin A, vitamin C, vitamin D, vitamin E, zinc, selenium, and iron (among others).
Foods rich in vitamin A include carrots, sweet potato, spinach, and beef liver. Vitamin C is abundantly found in bell peppers, broccoli, kiwi fruit, brussels sprouts and citrus fruits like orange and grapefruits. Dietary sources of Vitamin D are salmon, tuna, eggs, and dairy. We can find Vitamin E in almonds, hazelnuts, peanuts, and sunflower seeds.
It is also important to consume an adequate amount of calories, protein (since antibodies are made of protein components), complex carbohydrates high in fiber (since fiber feeds our gut bacteria, which is also an important piece to our immune health), and omega-3 fatty acids ( which are anti-inflammatory). Salmon and small fish such as anchovies, herring, and sardines are high in the omega-3 fatty acids EPA and DHA. Algae omega-3 fats are comparable to those found in fish (fish actually get their fats by eating these algae!). An algae supplement is an option for those who follow vegetarian or vegan diets. Flaxseeds, walnuts, and chia seeds provide plant sources of ALA omega-3 (a precursor to EPA and DHA).
On the other hand, alcohol, excess sodium, saturated fats, and sugar suppress immune function. Sugar suppresses the immune system response for several hours after being ingested. Do your best to minimize or completely avoid alcoholic beverages, fast food, refined carbohydrates (crackers, cookies, white bread), soda and other sweetened beverages, and ultra-processed foods.
You may have noticed I am not talking about “boosting” the immune system. We want to “support” optimal function, so the immune system is neither suppressed nor overreactive. An overreactive immune system can cause an exaggerated inflammatory response and damage the infected tissues. If unchecked an overreactive immune system may progress into an auto-immune disorder in certain individuals (depending on lifestyle and genetic factors).
ROUNDUP OF IMMUNE SUPPORTING FOODS
Let’s expand upon the examples given above and discuss more foods that support the immune system. This should be an easy one to remember. The famous G-BOMBS! The acronym, coined by Dr. Joel Fuhrman, refers to Greens, Beans, Onions, Mushrooms, Berries and Seeds.
GREENS: here come our dark leafy greens! Spinach, kale, mustard greens, broccoli, bok choy. They are full of antioxidants, phytonutrients, calcium, and folate. Folate is important in producing antibodies. Eat in smoothies, salads, soups, or sautéed with onions and garlic.
BEANS: beans, peas, and lentils contribute to immune function thanks to their high content of fiber and resistant starch which feed the gut microbiome. Beans are great in soups, as salad toppers, and as spreads like hummus.
ONIONS: as well as shallots, scallions, leeks, garlic, and chives. They all belong to the Allium family and contain organosulfur compounds. For maximum activity, crush or chop these foods 15 minutes before cooking (which allows enough time for the compounds to form) and do not overcook. Enjoy in soups, stir fries, dressings, and salads.
MUSHROOMS: maitake, shiitake, oyster, cremini, portobello… have been studied for their immune modulating activity. Mushrooms are wonderful when sautéed, in soups, pasta, as a topping for toast, or in salads.
BERRIES: they are high in phytochemicals, antioxidants, and vitamins that may help the immune system. Pterostilbene is an antioxidant compound found in blueberries and it has been studied for its anti-inflammatory activity. Berries are fantastic eaten raw when in season or added to smoothies when frozen. At home we warm up frozen berries and use as topping for yogurt, muesli, and oatmeal.
SEEDS (AND NUTS): walnuts, hazelnuts, almonds, chia seeds, flaxseeds, hemp seeds, pumpkin seeds, and Brazilian nuts are rich in fiber, omega-3 fats, iron, zinc, vitamin E, and calcium. Zinc is an important mineral needed for the growth and development of immune cells and for the synthesis of antibodies. Nuts and seeds are a great snack or grab and go breakfast option. They can be blended into seed and nut butters and added to toast, smoothies, oatmeal, or fruit like apple slices.
If you are interested in learning more about nutrition and immunity, visit this “Immunity in Brief” article, published by the Linus Pauling Institute at Oregon State University. It is a very comprehensive, evidence-based review on the subject.
Now the fun part. Let’s put this information into practice in the kitchen!
RECIPES FOR IMMUNE SUPPORT
- Sardine and avocado salad
- Vegetarian ramen
- Creamy roasted garlic and kale soup with cauliflower
NUTRITION FUN FOR THE KIDDOS
- Talk to you child about the importance of fruits and vegetables for our health and complete this crossword puzzle together.
- Get the kids involved in chopping radishes for the ramen dish. This may be a fun “new food” for them. They can color and write about their favorite thing about radishes afterwards in this coloring sheet.
- Joking around: “What is the coolest vegetable? A rad-ish!”