GENERAL DESCRIPTION A perennial or biennial herb up to 1,2 metres high with hollow leaves and flowering stem, and a globelike fleshy bulb.
DISTRIBUTION Native of western Asia and the Middle East, it has a long history of cultivation all over the world, mainly for culinary use.
HERBAL / FOLK TRADITION Onion has an ancient reputation as a curative agent, highly extolled by the schools of Galen ans Hippocrates. It is high in vitamins A, B and C and shares many of the properties of garlic, to which it is closely related. Raw onion helps to keep colds and infections at bay, promotes strong bones and a good blood supply to all the tissues. It acts as an effective blood cleanser which along with the sulphur it contains, helps to keep the skin clear and in good condition. It has a sound reputation for correcting glandular imbalance and weight problems; it also improves lymphatic drainage, which is often responsible for oedema and puffiness.
Onion has long been used as a home ‘simple’ for a wide range of conditions: ‘As a poultice they are invaluable for the removal of hard tumours. In this form they afford relief in cases of suppressed gout or obstructed circulation… Onions tend to soothe the nerves and induce sleep. They stimulate the action of the skin and remove obstructions of the viscera… raw onions, bruised are good for burns and scalds in the absence of other remedies … applied to the sting or bite of any poisonous insect often proves all that is desired.’
ACTIONS Anthelmintic, antimicrobial, antirheumatic, antiseptic, antisclerotic, antispasmodic, antiviral, bactericidal, carminative, depurative, digestive, diuretic, expectorant, fungicidal, hypocholesterolaemic, hypoglycaemic, hypotensive, stomachic, tonic, vermifuge.
CHARACTERISTICS A pale yellow or brownish-yellow mobile liquid with strong, unpleasant, sulphuraceous odour with a lachrymatory (tear-producing) effect.
PRINCIPAL CONSTITUENTS Mainly dipropyl disulphide, also methylpropyl disulphide, dipropyl trisulphide, methylpropyl trisulphide and allylpropyl disulphide, among others.
AROMATHERAPY / HOME USE None, due to its offensive smell.
OTHER USES Used in some pharmaceutical preparations for colds, coughs, etc. The oil is extensively used in most major food categories, especially meats, savouries, salad dressings, as well as alcoholic and soft drinks. It is not used in perfumery work.