Like garlic and leeks, onions too are an allium vegetable that were cultivated 2000 years ago in ancient Egypt. Particularly rich in polyphenol and flavanoids, care should be taken not to over-peel the papery layer of onions for fear of losing much of the essentials. Including onions in your diet is also a great way to prevent colorectal, laryngeal, ovarian, oral, and esophageal cancers. It has been specially effective to keep the heart and blood vessels in an excellent condition and a great defense against heart attacks. There is good news for menopausal women too! Eating onions can help them gain bone density and lower the risk of fractures due to accidental falls. Also rich in sulphur, onions are very beneficial for the formation of connective tissues. The other main nutrients found in onions include Vitamin A, B6, C, E, sodium, potassium, iron, and dietary fibre. Onions also contain the coveted allyl propyl disulphide which helps in maintaining optimum blood sugar levels too.