Eat onions, see why.

Whether white, yellow, or red, onions are one of the world’s most popular and versatile vegetables, delivering an unmistakable, pungent heat – some more than others. They’re in demand for cold salads and hot soups, sliced in rings or solid disks on burgers, and chopped in relish. The delicious caramelization that takes place when onions are sautéed is due to their high sugar content. (Try them sautéed with bell peppers for a tasty fajita ingredient.) Spanish red onions are generally milder than white or yellow. The Vidalia variety is one of the sweetest.

The sharp fragrance and flavor emitted by onions is due to the sulfur compound allyl propyl disulphide; it’s allyl sulphide that brings you to tears when peeling one, serving the good purpose of washing the thin epithelial layer of the eyes. Holding peeled onions under cold water for several seconds before slicing minimizes this effect.

Health Benefits of Eating Onions

Onions are loaded with numerous health benefits, and scientists are still discovering how beneficial this vegetable really is. They’re a very good source of vitamin C and B6, iron, folate, and potassium. The manganese content in onions provides cold and flu relief with its anti-inflammatory abilities.

Two phytochemical (plant-derived nutrient) compounds in onions – allium and allyl disulphide – convert to allicin when the bulb is cut or crushed due to enzyme activation. Studies show these compounds to have cancer- and diabetes-fighting properties, while decreasing blood vessel stiffness by releasing nitric oxide. This can reduce blood pressure, inhibit platelet clot formation, and help decrease the risk of coronary artery disease, peripheral vascular diseases, and stroke.

Significant amounts of polyphenols (another phytochemical in onions) and an antioxidant flavonoid called quercetin (which has proven anti-cancer, anti-inflammatory, and anti-diabetic functions) account for the reputation onions have for disease prevention. 

Luckily, cooking onions in soup doesn’t diminish their quercetin value – it simply transfers to the broth. The flavonoids in onions are more concentrated in the outer layers, so discard as little as possible.