Onion

Onion, Herbaceous biennial plant (Allium cepa) of the family Alliaceae, probably native to southwestern Asia but now grown worldwide, and its edible bulb. Among the hardiest and oldest garden vegetable plants, onions bear a cluster of small, greenish white flowers on one or more leafless stalks.

Onions are an excellent source of antioxidants and contain at least 17 types of flavonoids. Red onions, in particular, contain anthocyanins, plant pigments in the flavonoid family that give red onions their deep color. These may protect against diabetes and certain types of cancer .

When added to the hair and scalp, onion juice can provide extra sulfur to support strong and thick hair, thus preventing hair loss and promoting hair growth. The sulfur from onions may also help promote collagen production. Collagen in turn helps the production of healthy skin cells and hair growth.