Asparagus is a dietary prebiotic and contains a dietary fiber called oligosaccharides. Prebiotics improve the immune system by preventing inflammation. Asparagus also contains antioxidants like vitamin C, vitamin E, vitamin K, zinc, and folate (vitamin B9) to fight off illnesses.
17. Shiitake Mushrooms
Shiitake mushrooms, mostly grown in Japan, are known as medicinal mushrooms because of their immune-boosting effects and antioxidants. Within these mushrooms are also polysaccharides, terpenoids, sterols, and healthy lipids, all of which have immune-boosting and anticancer effects.
Broccoli might not be the favorite of most six-year-olds, but it should be on every person’s list of foods that keep you from getting sick. Broccoli contains polyphenols, which are important antioxidants that fortify the immune system. If possible, eat broccoli raw or cooked lightly. Fresh broccoli holds more of its nutrients than cooked broccoli.