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Nutrition to Keep Immune Function Strong

Good food is the cornerstone of good health. The nutrients we eat play a big role in our wellbeing. Certain fruits and vegetables rich in micronutrients can give our cells a steady stream of foods associated with a healthy immune response. 

Additionally, when we crowd our plate with veggies, we also naturally get higher doses of fiber.  More fiber = more diverse gut bacteria. This has important links to our immune function. 

image of soup with noodles, broccoli, snow peas and chilis

Dig in to these fantastic fruits, veggies and spices to give yourself a wide array of micronutrients and fiber:

  • Brassicas: Mom was right about eating your broccoli. Brassicas (or cruciferous vegetables) include cauliflower, cabbage, bok choy, kale, mustard greens, and arugula; they have wide ranging benefits for human health1.  Some contain a compound called kaempferol, which is being investigated for its antiviral properties2. Kaempferol showed activity against the SARS 1-coronavirus3. (Effects on the novel coronavirus are unknown.)  Please cook these vegetables, especially if you have a thyroid condition.
  • Mushrooms: Mushrooms are known to be immunomodulating (helping our immune system decide how to react to invaders). Research suggests that shiitake mushrooms may improve the human immune response4.  They offer an extra-savory umami flavor, making dishes taste richer.
  • Garlic: People have been capitalizing on garlic’s medicinal qualities for centuries. Research today shows that in addition to its antitumor properties, it may help immune ‘surveillance’ and protect against age-related decline in immune response5.  It’s also a source of kaempferol and an amazing flavor bump–bonus!  Other foods in the allium family (onions, chives, leeks) have similar properties.

NUTRIENT TIP FOR GARLIC AND ONIONS: let them rest 10 minutes after chopping and before cooking. In this time, the medicinal compounds meld and become more bioavailable.

  • Ginger: Like garlic, ginger enjoys a wide spectrum of medicinal benefits. Ginger may promote our antibody production and immune response6. A personal favorite, fresh ginger tea can be a lifesaver when a cold starts with that chilled feeling and scratchy throat. 
  • Grapefruit and citrus fruits: We all know these juicy fruits to be a rich source of vitamin C.  Especially if we’ve been exposed to an upper respiratory virus, a steady supply of vitamin C has been associated with a reduced duration of colds7
  • Capers: Here’s a curve ball! Did you know that capers offer the highest concentrations of quercetin of any food source?   This super cool compound gives our bodies many tools to quell inflammation and replenish antioxidants. Get this: animal experiments have shown that quercetin helps restore antioxidants in the lung after viral exposure.

OTHER FOODS SOURCES OF QUERCETIN include apples (with skins), onions, berries, cherries, grapes and citrus.  Surprise, surprise—some of these excellent foods get marks in two or more categories (onions = kaempferol and quercetin, citrus = vitamin C + polyphenols and quercetin). Read more about this superstar in Herb and Supplement Strategies for Maintaining Strong Host Immunity.

Wondering how to unite these wonder foods into a tasty meal?  How about soup with bok choy, mushrooms and onions simmered with ginger and garlic?  Cap it with some juicy citrus for dessert.  As for the capers–you’ll have to plan on Italian-style salmon simmered with lemon juice, onions, garlic and capers for tomorrow night. 

Buon appetito and stay healthy!


  1. Sanlier N, Guler Saban M.  The Benefits of Brassica Vegetables on Human Health. Scholerna. 2018. 
  2. Calderon-Montano, JM, Borgos-Moron E, Perez-Guerrero C, Lopez-Lazaro M.  A Review on the Dietary Flavonoid Kaempferol. Mini-Review Med Chem. 2011 Apr;11(4):298-344. 
  3. Schwartz S, Sauter D, Wang K. et al. Kaempferol Derivatives as Antiviral Drugs Against the 3a Channel Protein of Coronavirus. Planta Med. 2014 Feb;80(2-3):177-82. Epub 2014 Jan 23.
  4. Adaka S, Adaka R, Shah K. et al.  Garlic: Review of LiteratureIndian Journal of Cancer. 2014; (51)4: 577-581 
  5. Mahasni S, Bukari O. Beneficial effects of an aqueous ginger extract on the immune system cells and antibodies, hematology, and thyroid hormones in male smokers and non-smokers. Journal of Nutrition and Intermediary Metabolism. 2019 March; 15: 10-17
  6. https://www.sciencedirect.com/science/article/pii/S2352385918300598Codoner-Franch, Pilar, Citrus as Functional Food, Current Topics in Nutraceutical Research. 8(4):173-184 · November 2010