Helping patients enhance immune system function with food

Photo Cred: Alyson McPhee/Unsplash

By Kellie Blake, RDN, LD, IFNCP

Now, more than ever, my patients are eager to learn which foods help boost the immune system.  As integrative providers, we know lifestyle on the whole is ultimately responsible for creating a healthy body, including a robust immunity. While there is no one magical food or supplement to recommend, there are many nutrients known to enhance immune system function.

As an integrative dietitian, I educate my patients on modifiable lifestyle factors including sleep, stress management, exercise, and nutrition. I also teach them how to incorporate certain foods on a routine basis to complement the other lifestyle factors and create more immune system resilience.

With many patients spending extra time at home, there is greater opportunity to get them in the kitchen to create wholesome meals. With just a few simple recipes, patients can begin to improve nutritional status and immune system function while hopefully creating a lifelong love of cooking.  

There are countless nutrients with immune-boosting properties. Below are some of my favorites along with some simple suggestions for adding them to the daily routine. I prefer one-pot meals to maximize nutrient intake in an easy way to prevent overwhelming patients who are busy or new to cooking. 

Cruciferous vegetables from the genus Brassica, are a powerful group containing plant metabolites such as glucosinolates, anthocyanins, flavonoids, and terpenes, which have been shown to stimulate the immune system, prevent oxidative stress, enhance detoxification, reduce cancer risk, and inhibit cancer cell proliferation and malignancy. Some examples include kale, kohlrabi, cabbage, Brussels sprouts, broccoli, cauliflower, arugula, radishes, and collard greens. Cruciferous vegetables can be eaten cooked in many ways, but I often suggest adding one or more in the raw form to a morning green smoothie. 

Cacao is a functional food due in part to its flavanol content, which has been shown to inhibit lipid peroxidation and regulate the immune response. In addition, cacao can influence the gut microbiota much the way pre and probiotics do. I recommend using a high-quality organic cacao powder that can be added to green smoothies, baked goods, and hot beverages to provide a rich, chocolatey flavor without all the ingredients found in processed chocolate. 

Mushrooms contain beta-glucans, which are powerful polysaccharides found in fungi. Mushrooms have been shown to enhance immune system function by boosting natural killer cells. They are also a source of vitamin D, which is crucial for immune system function. There are many different types of mushrooms, all with different actions and benefits and I educate clients to include a variety of mushrooms from reputable sources each week. Mushrooms can be grilled, sautéed, chopped and added to sauces, meat and bean dishes, served raw on a salad, or powdered and consumed in a hot beverage or smoothie.

Bone Broth, especially from chicken bones, is helpful for maintaining the health of the intestinal tract, which is the largest immune system organ. The gelatin found in bone broth has been shown to have an anti-inflammatory effect in the intestine. When inflammation is reduced and the intestinal barrier is intact, the immune response is appropriate and strong. Bone broth can be enjoyed as a warm beverage, but my favorite way to incorporate this gut healing food is in a hearty soup or stew.

Immune-Supporting Recipes

Green Smoothies

These are the perfect vessel for delivering maximum immune-boosting nutrition, plus they taste like dessert, so my patients are more willing to incorporate them daily. The combinations are literally endless and green smoothies can easily be made in the evening and stored in the refrigerator for a quick, nutritious breakfast or post-workout shake. This cacao nut butter smoothie combines the immune-supporting nutrients found in blueberries, cruciferous vegetables, and cacao with the gut-healing benefits of acacia powder and collagen peptides to create a delicious, wholesome treat.

Cacao Nut Butter Smoothie

Serving: 1

Ingredients

• 10 ounces nut milk (I like coconut, but almond works well too)
• 1 cup fresh or frozen spinach
• ½ cup chopped red cabbage
• 1 tablespoon chia seeds
• ½ teaspoon cinnamon
• 1 tablespoon nut butter
• 1 tablespoon cacao powder
• 1 teaspoon acacia powder
• ½ scoop vanilla collagen peptides
• ½ scoop vanilla vegan protein powder
• ½ cup frozen blueberries
• ¼ frozen banana

Directions

1. Add all but the frozen ingredients to blender pitcher and blend until smooth, about 1 minute
2. Add the frozen ingredients and blend again until smooth

Soup

Soups are another great way to pack in immune-enhancing nutrients in one pot. This hearty lentil soup combines the gut healing properties of bone broth with powerful cruciferous kale. Bonus, it’s a simple recipe that can be enjoyed all year. I often have patients make a batch of this on the weekend for a nutritious, quick lunch option throughout the week.

Hearty Lentil Soup

Serves: 6

Ingredients

• ¼ cup extra virgin olive oil
• 1 yellow onion, chopped
• 2 medium carrots, diced
• 2 celery ribs, diced
• 2 cloves garlic, minced
• 1 teaspoon dried oregano
• 1 teaspoon dried basil
• 1 cup dry lentils
• 32 ounces organic chicken bone broth
• 1 ½ cups kale, torn into small pieces
• Sea salt and fresh black pepper, to taste

Directions

1. Add olive oil to a large stock pot
2. Over medium heat, add the onions, carrots, celery and cook until onion is tender
3. Add the garlic, oregano, and basil and cook for two minutes
4. Add the lentils and chicken broth and bring to a boil
5. Reduce heat to medium and cook for 20 minutes, or until lentils are softened
6. Just prior to serving, stir in the kale until wilted
7. Season with sea salt and fresh black pepper, if desired

Casseroles

Aside from being the ultimate comfort food, casseroles provide the opportunity to supply powerful immune-supporting nutrients in one dish. This mushroom casserole is a great option for patients desiring the nutritional benefits of mushrooms without the mushroom flavor.

Vegan Mushroom Bake

Serves: 6

Ingredients

• 1 cup uncooked quinoa
• 2 cups water
• 2 tablespoons extra-virgin olive oil
• 1 medium yellow onion, diced
• 1 large red bell pepper, diced
• 1-pound baby portobello mushrooms, chopped
• 1 teaspoon dried thyme
• 1 teaspoon dried oregano
• 1 teaspoon dried basil
• 1 ½ cups unsweetened coconut milk
• 3 tablespoons cassava flour (can also substitute arrowroot)
• 1 teaspoon sea salt
• 1 teaspoon fresh black pepper

Directions

1. Preheat oven to 350˚F
2. In a fine mesh strainer, rinse the quinoa with cold water
3. Add quinoa and 2 cups of water to a medium saucepan over high heat, bring to a boil, cover, reduce heat to low and simmer for 15 minutes
4. In the meantime, to a large skillet, add the olive oil, onion and pepper. Sauté over medium heat for 5 minutes
5. Add the chopped mushrooms and sauté over medium heat for 10 minutes
6. When the quinoa has cooked for 15 minutes, remove from heat, fluff with a fork and set aside
7. Heat the coconut milk for 1 minute in the microwave, then stir in the cassava flour
8. Reduce heat to low and add the cassava flour mixture to the skillet, mix well
9. Remove from heat and stir in the quinoa
10. Add the mixture to a casserole or other oven-safe dish
11. Bake for 35 minutes

While there are many ways to support a healthy immune system with food, it is as important to remain mindful of foods that damage or dampen the immune system.  For optimal immune system function, I encourage patients to avoid inflammatory oils, sugar, and processed and sensitive foods. 

References

Akramiene, D., Kondrotas, A., Didziapetriene, J., and Kevelaitis, E. (2007). Effects of Beta-Glucans on the Immune System. Medicina. Retrieved from: https://pubmed.ncbi.nlm.nih.gov/17895634/?from_term=Mushrooms+and+immune+system&from_filter=simsearch2.ffrft&from_pos=8

Franco, R., Onatibia-Astibia, A., Martinez-Pinilla, E (2013). Health Benefits of Methylxanthines in Cacao and Chocolate. Nutrients. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3820066/

Frasca, G., Cardile, V., Puglia, C., Bonina, C., & Bonina, F. (2012). Gelatin tannate reduces the proinflammatory effects of lipopolysaccharide in human intestinal epithelial cells. Clinical and Experimental Gastroenterology.  Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3358810/

Kapusta-Duch, J., Kopec, A., Piatkowska, E., Borczak, B., & Leszczynksa, T. (2012).  The Beneficial Effects of Brassica Vegetables on Human Health.  Rocz Panstw Zakl Hig Retrieved from: https://pubmed.ncbi.nlm.nih.gov/23631258/?from_term=Cruciferous+vegetables+and+immune+system&from_filter=simsearch2.ffrft&from_pos=6

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