Onions are a hugely versatile vegetable that is consumed all over the world. They’re a member of the lily family and are scientifically known as Allium cepa. Onions have been a food source for centuries, and have also been used for medicinal purposes for just as long. Native Americans would use onion to treat colds and insect bites, in Chinese culture they were used to warm the body and induce perspiration, and in Europe they were even used as currency.
Onions have been used to help loosen congestion, relieve gas, calm an upset stomach, stimulate the appetite, lower cholesterol, prevent blood clots, reduce blood sugar levels and improve the circulatory system. Onion juice has also been used topically, to treat bacterial and fungal infections, remove warts, stimulate hair growth and relieve earache.
Onions contain high levels of antioxidants like anthocyanins, which give red onions that deep reddish-purple color, and quercetin, which is thought to potentially protect against heart disease and cancer. Onions also contain biotin, manganese, copper, vitamin B6, vitamin C, phosphorus, potassium, folate and more.
Onions are diuretic, and adding them to your diet can help reduce fluid retention. Onions are best eaten raw as cooking them can destroy the beneficial enzymes, but eating them in any form is better than not eating them at all.