Foods that act like an antihistamine include onions and apples, which contain the antioxidant quercetin; pineapples, which contain the compound bromelain; and the herb stinging nettle, which might be a natural antihistamine, explains Healthline. In addition, many fruits and vegetables contain vitamin C, another widespread source of natural antihistamines.
An antihistamine counteracts histamines, which are proteins that cause allergic symptoms such as sneezing, itchy eyes and congestion, according to Healthline. Allergies are the immune system’s reaction to substances such as pollen or dust, which contact the body’s mucous membranes, triggering a release of histamines. While many allergy medicines act like antihistamines, some foods and plants can also work against the body’s production of histamines.