Onions have been used for their health benefits for well over 5000 years. They are an excellent source of vitamin B6 and C as well as calcium, biotin, chromium and dietary fiber. Besides these, onions possess beneficial supplies of vitamin B1, K and folic acid. They are also rich in the antioxidants alliinase, flavanoids and quercitin. Quercitin is the most potent of these which works to thin the blood, raise good (HDL) cholesterol, lower bad (LDL) cholesterol and prevent stomach cancer. It also helps to fight diabetes, infections, asthma, hay fever and chronic bronchitis.

Onions provide amino acids which contain sulphur (methionine and cystine). These detoxify your body of damaging heavy metals such as mercury, lead and cadmium. High levels of vitamin C also provide a detoxifying effect as well as a boost to the immune system.

Studies continue to reveal that the antioxidants in onions (as well as their cousins of garlic, chives, leeks and scallions) protect DNA from free radical damage. Therefore, a nutritious diet containing a regular source of onions is good for cancer prevention.