The most pungent of the plant kingdom inhabitants, garlic contains the immune-stimulating compound allicin, which promotes the activity of white blood cells to destroy cold and flu viruses. It also stimulates other immune cells, which fight viral, fungal, and bacterial infections. Garlic kills with near 100 percent effectiveness the human rhinovirus, which causes colds, common flu, and respiratory viruses.
Onions, like garlic, contain allicin. They also contain quercetin, a nutrient that breaks up mucus in your head and chest while boosting your immune system. Additionally, the pungency of onions increases your blood circulation and makes you sweat, which is helpful during cold weather to help prevent infections. Consuming raw onion within a few hours of the first symptoms of a cold or flu produces a strong immune effect.
Spicy, pungent, and delicious, ginger reduces fevers, soothes sore throats, and encourages coughing to remove mucus from the chest. Anti-inflammatory chemicals like shagaol and gingerol give ginger that spicy kick that stimulates blood circulation and opens your sinuses. Improved circulation means more oxygen is getting to your tissues to help remove toxins and viruses.
The cayenne family of hot peppers (cayenne, habanero, Scotch bonnet, and bird peppers, to name a few) contains capsicum — a rich source of vitamin C and bioflavonoids, which aid your immune system in fighting colds and flus. It does this by increasing the production of white blood cells, which cleanse your cells and tissues of toxins.
Squash is a good source of vitamin C and carotene. The six carotenoids (out of the 600 found in nature) found most commonly in human tissue — and supplied by squash and other gourds — decrease the risk of various cancers, protect the eyes and skin from the effects of ultraviolet light, and defend against heart disease.
Like other leafy greens, kale offers up a good dose of vitamin E. This immunity-boosting antioxidant is known for increasing the production of B cells, those white blood cells that kill unwanted bacteria. Whether you eat kale raw in a salad, steam it, or lightly sauté it, you’ll reap all of its wonderful benefits.
Adding a bit of citrus to your diet goes a long way toward fending off your next cold or flu. Packed with vitamin C, oranges and grapefruits help increase your body’s resistance to nasty invaders.
Green tea is a potent source of antioxidants called polyphenols — especially catechins. Some studies have found that catechins can destroy influenza and common cold viruses.
Miso soup is the plant-based version of chicken-noodle soup. It has wonderful healing properties that are amazing at boosting immunity. As a living food, miso is loaded with enzymes and healthy bacteria that help fight infection and keep your cells thriving.
For centuries, people around the world have turned to mushrooms for a healthy immune system. Contemporary researchers now know why. Studies show that mushrooms increase the production and activity of white blood cells, making them more aggressive. This is a good thing when you have an infection.