Garlic and onion have long been used to treat bronchitis and asthma, and they have been shown to inhibit allergen-induced responses. The ingredient that possesses these characteristics is called quercetin. It can be found as a dietary supplement in health food stores. Allicin, the ingredient in garlic, is available in capsule form as well.
Colds or the Flu
Garlic helps boost the immune system and fights bacteria and yeast. You can eat garlic in foods, but during cold season it is helpful to take a garlic supplement. It is readily available in capsule form. Take up to 5,000 micrograms per day.
Hay Fever and Allergies
Garlic contains an anti-inflammatory substance called quercetin, which can help calm an allergic response in the body.
High Blood Pressure
Garlic has been used to cure many ailments for thousands of years, and it is known to help lower blood pressure and cholesterol. You can eat raw or lightly cooked garlic every day. If you prefer, you can take garlic in capsule form, which is readily available.