Supporting a Healthy Immune System:

Part 2: Functional Foods

For Part 2 in our series on Supporting a Healthy Immune System, we’ll be discussing functional foods that you can add into your daily routine. The term “functional food” means that the food provides us with additional benefits beyond the nutrients that it provides. Some of these foods might help the liver or improve blood pressure, but we’ll be focusing on the ones that support immune system function.

Note: just like any medication or supplement, herbal products may interact with other medications. Check in with your care provider before starting anything new.

Fire Cider

Fire cider is made with apple cider vinegar and has ingredients like garlic, onion, ginger, and peppers. Not only is it warming to the body (thanks to horseradish, ginger, and peppers), but contains herbs that are also thought to have antiviral or antibacterial effects. You can take a spoonful of it straight, but we like to use it to flavor our veggies anywhere you would use vinegar – it makes for an amazing salad dressing! If you’re ready to make a batch, Health Coach Kelsea walks you through a basic recipe to get you started. 


Elderberry syrup is an herbal tonic that not only has vitamin C, but some health professionals think it might be helpful for flu treatment if taken in the first 72 hours of having symptoms. (There’s real science behind it, too!) Want to give it a try? It is available for purchase here, or you can even make your own with Kelsea! The recipe is simple and will keep in the fridge for 2-3 months, perfect to keep on hand for cold and flu season. 


If you like mushrooms, you can expand beyond the typical white button, portabella, or cremini and add varieties like shiitake, enoki, maitake, or oyster to your meals. These less common mushrooms are considered functional foods as they have been found to enhance the immune system and reduce inflammation. If you can’t find fresh mushrooms, shiitake are often sold dried to reconstitute at home. Bonus – you can use the leftover soaking water as a tasty broth in recipes!



Not only are berries tasty, they also contain a type of plant chemical called anthocyanidins. That blue, red, or purple color in your berry? Those are the anthocyanins, which are a type of flavonoid. These plant chemicals have been found to have a lot of positive effects in the body, and are thought to help support the immune system. If fresh berries aren’t in season, you can usually find frozen blueberries, blackberries, or strawberries. Add frozen to a smoothie, thaw and add to yogurt, or bake them into a tasty dessert.

Chat with a Health Coach and let them know what functional food you’ll be adding to your routine this week!

Reviewed by Heather King, MS, RDN​, CDE

on March 13th, 2020. Heather is a Certified Diabetes Educator, has been a Registered Dietitian for over 12 years, and is Brook's Health Director.