There are important substances in the fruits and vegetables that we consume that influence the immune system. In an article entitled "Effect of Flavonoids on Upper Respiratory Tract Infections and Immune Function: A Systematic Review," investigators found that those taking flavonoid supplements (dosage ranging from 0.2 to 1.2 grams a day) had a third fewer incidence of upper respiratory infections. They conclude, "These findings suggest that flavonoids are a viable supplement to decrease URTI incidence in an otherwise healthy population." Flavonoids are easily found in the foods we eat. For more information on which foods contain flavonoids, see

Disclaimer: People should be taking the least amount of prescription drugs that provide adequate treatment, and to regularly monitor and review what is being taken and how much. This applies to most supplements, too. Please do not make any changes in your treatment without first discussing it with your health care provider. Statements made, or products sold through this website, have not been evaluated by the United States Food and Drug Administration. They are not intended to diagnose, treat, cure or prevent any disease.

Some articles contain affiliate links.