1).Onion is a term used for many plants in the genus Allium. it usually refers to Allium cepa. Allium cepa is also known as the "garden onion" or "bulb" onion. It is grown underground by the plant as a vertical shoot that is used for food storag. 2).Wide-ranging claims have been made for the effectiveness of onions against conditions ranging from the common cold to heart disease, diabetes, osteoporosis, and other diseases. They contain chemical compounds believed to have anti-inflammatory, anticholesterol, anticancer, and antioxidant properties such as quercetin. For all varieties of onions, the more phenols and flavonoids they contain, the more antioxidant and anti-cancer activity they provide And Some studies have shown that increased consumption of onions reduces the risk of head and neck cancer. The onion bulb contains an essential oil that is rich in sulphur compounds.It is antibacterial,antiseptic,diaphoretic,diuretic,galactogogue,stomachic,vermifuge and vulnerary.It is used in the treatment of colds and abdominal coldness and fullness.Use of the bulb in the diet impedes internal parasities.Externally,the bulb can be made into a poultice to drain pus from sores,boils and abscesses.
1.Anti-cancer effect.Onions are rich in flavonoids and selenium.Flavonoids scavenge free radicals anti-oxidants.Selenium is a powerful anti-oxidant,it can remove the body for a variety of free radicals,with anti-cancer,anti-aging effect.