5/9

5. Decrease symptoms of seasonal allergies

Rosmarinic acid is a compound found in peppermint, as well as rosemary and other plants in the mint family. In one three-week study involving 29 people with seasonal allergies, those given a supplement containing rosmarinic acid ad fewer instances of itchy nose, itchy eyes and other allergy-related symptoms than those given a placebo. In an animal study, rats that suffered from allergic rhinitis—an irritation and inflammation of the mucous membrane inside the nose—experienced fewer allergic symptoms such as sneezing and itchy nose after being given peppermint extract.