Garlic and onions have long been touted as immune boosters

Yes, this is true.

Explanation:

Because garlic is a plant in the onion family that is known for its many health benefits. Most of its health benefits are caused by sulfur compounds formed when a garlic clove is chopped, crushed or chewed. Just one clove of raw garlic contains manganese, Vitamin B6, Vitamin C, selenium, fiber and other trace elements. Garlic has been touted as reducing blood pressure, improving cholesterol levels as well as helping to detoxify heavy metals in the body. Garlic is also considered an antioxidant.