SCIENTIFIC NAME(S): Allium cepa Family: Liliaceae, Alliaceae



Central Asia is believed to be the region of origin of the onion. Onions were used as early as 5000 years ago in Egypt, as seen on ancient monuments. Ancient Greek and Roman recordings also refer to the onion. During the Middle Ages, onions were consumed throughout Europe. They were later thought to guard against evil spirits and the plague, probably because of their strong odor. Onion "skin" dye has been used for egg and cloth coloring for many years in the Middle East and Europe. Columbus was said to have brought the onion to America. Folk healers used the onion to prevent infection. The combination of onions and garlic cooked in milk is a European folk remedy used to clear congestion. Onions are also used in homeopathic medicine.

Botany :- The onion plant is a perennial herb growing to about 1.22 m high, with 4 to 6 hollow cylindrical leaves. On top of the long stalk, greenish-white flowers are present in the form of solitary umbels growing up to 1-inch wide. The seeds of the plant are black and angular. The underground bulb, which is used medicinally, is made up of fleshy leaf sheaths forming a thin-skinned capsule. The onion is one of the leading vegetable crops in the world.

Uses of Onion

Onion is used as an antimicrobial, cardiovascular-supportive, hypoglycemic, antioxidant/anticancer, and asthma-protective agent, although some of these effects have not been clinically proven. In folk medicine, onion has been used for asthma, whooping cough, bronchitis, and similar ailments. Other uses include the treatment of stingray wounds, warts, acne, appetite loss, urinary tract disorders, and indigestion. Onion skin dye has been used as an egg and cloth coloring.

Side Effects of Onion

The toxicity of large doses of onion has been unresolved, but the stomach may be affected. Frequent contact with onion seeds has been reported as an occupational allergen.


Most human studies that have shown an effect from onions used at least 25 grams per day and often two to four times that amount. Though some studies have found cooked onions acceptable, several studies suggest that onion constituents are degraded by cooking and that fresh or raw onions are probably most active. If a tincture, syrup, or oil extract is used, 1 tablespoon three times per day may be necessary for several months before effects are noted.


Certain sulfur compounds (eg, propanethial-s-oxide) escape from the onion in vapor form and hydrolyze to sulfuric acid when it is cut, causing the familiar eye irritation and lacrimation. Corneal swelling from onion exposure has been reported. Using a sharp knife also minimizes the crushing of onion tissue and liberation of volatiles, and cutting an onion under running water avoids lacrimation. Ingestion of onion seems relatively safe, as the German Commission E lists no contraindications, side effects, or interactions from the plant. With large intake, the stomach may be affected, and frequent contact with onion rarely may cause allergic reaction. The onion seeds have been reported as an occupational allergen. Onion toxicity is only accociated with high intake. A review of onion discussing ingestion of large amounts of the bulb finds toxicity unresolved.

© Natural-Medicinal-Herbs.Com. All rights reserved.

Disclaimer :- The information contained in this web site is for educational purposes only and is not intended or implied to be a substitute for professional medical advice. Readers should not use this information for self-diagnosis or self-treatment, but should always consult a medical professional regarding any medical problems and before undertaking any major dietary changes. We will not be liable for any complications or other medical accidents arising from or in connection with the use of or reliance upon any information on this web site.