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Many plants in the genus Allium are known by the common name onion but, used without qualifiers, it usually refers to Allium cepa. Allium cepa is also known as the 'garden onion' or 'bulb' onion and 'shallot'. Medicinal properties and health benefits Evidence suggests that onions may be effective against the common cold, heart disease, diabetes, osteoporosis, and other diseases. They contain anti-inflammatory, anticholesterol, anticancer, and antioxidant components such as quercetin. In many parts of the world, onions are used to heal blisters and boils. A traditional Maltese remedy for sea urchin wounds is to tie half a baked onion to the afflicted area overnight. In the morning, the spikes will be in the onion. In the United States, products that contain onion extract (such as Mederma) are used in the treatment of topical scars, though studies have found no evidence that they are effective. Onions, like garlic, are members of the Allium family, and both are rich in powerful sulfur-containing compounds that are responsible for their pungent odors and for many of their health-promoting effects. Onions contain allyl propyl disulphide, while garlic is rich in allicin, diallyl disulphide, diallyl trisulfide and others. In addition, onions are very rich in chromium, a trace mineral that helps cells respond to insulin, plus vitamin C, and numerous flavonoids, most notably, quercetin. The higher the intake of onion, the lower the level of glucose found during oral or intravenous glucose tolerance tests. Experimental and clinical evidence suggests that allyl propyl disulfide is responsible for this effect and lowers blood sugar levels by increasing the amount of free insulin available. Allyl propyl disulfide does this by competing with insulin, which is also a disulphide, to occupy the sites in the liver where insulin is inactivated. This results in an increase in the amount of insulin available to usher glucose into cells causing a lowering of blood sugar. In addition, onions are a very good source of chromium, the mineral component in glucose tolerance factor, a molecule that helps cells respond appropriately to insulin. Clinical studies of diabetics have shown that chromium can decrease fasting blood glucose levels, improve glucose tolerance, lower insulin levels, and decrease total cholesterol and triglyceride levels, while increasing HDL-cholesterol levels. Marginal chromium deficiency is common in the United States, not surprising since chromium levels are depleted by the consumption of refined sugars and white flour products as well as the lack of exercise. One cup of raw onion contains over 20% of the Daily Value for this important trace mineral. The regular consumption of onions has, like garlic, been shown to lower high cholesterol levels and high blood pressure, both of which help prevent atherosclerosis and diabetic heart disease, and reduce the risk of heart attack or stroke. These beneficial effects are likely due to onions' sulfur compounds, its chromium and its vitamin B6, which helps prevent heart disease by lowering high homocysteine levels, another significant risk factor for heart attack and stroke. Onions have been singled out as one of the small number of vegetables and fruits that contributed to the significant reduction in heart disease risk seen in a meta-analysis of seven prospective studies. Of the more than 100,000 individuals who participated in these studies, those whose diets most frequently included onions, tea, apples and broccoli-the richest sources of flavonoids-gained a 20% reduction in their risk of heart disease. Quercetin, an antioxidant in onions, and curcumin, a phytonutrient found in the curry spice turmeric, reduce both the size and number of precancerous lesions in the human intestinal tract, suggests research published in Clinical Gasteroenterology and Hepatology. A compound newly identified in onions called gamma-L-glutamyl-trans-S-1-propenyl-L-cysteine sulfoxide (GPCS) inhibits the activity of osteoclasts (the cells that break down bone). The more GPCS given in this animal study, the more the bone resorptive (breakdown) action of osteoclasts was inhibited. Onions may be especially beneficial for women, who are at increased risk for osteoporosis as they go through menopause, by destroying osteoclasts so that they do not break down bone. Several anti-inflammatory agents in onions render them helpful in reducing the severity of symptoms associated with inflammatory conditions such as the pain and swelling of osteo- and rheumatoid arthritis, the allergic inflammatory response of asthma, and the respiratory congestion associated with the common cold. Both onions and garlic contain compounds that inhibit lipoxygenase and cyclooxygenase (the enzymes that generate inflammatory prostaglandins and thromboxanes), thus markedly reducing inflammation. Onions' anti-inflammatory effects are due not only to their vitamin C and quercetin, but to other active components called isothiocyanates. These compounds work synergistically to provide relief from inflammation. In addition, quercetin and other flavonoids found in onions work with vitamin C to help kill harmful bacteria, making onions an especially good addition to soups and stews during cold and flu season. Origin and distribution Allium cepa is known only in cultivation, but related wild species occur in Central Asia. The most closely-related species include Allium vavilovii Popov & Vved. and Allium asarense R.M. Fritsch & Matin from Iran.[1] However Zohary and Hopf warn that "there are doubts whether the vavilovii collections tested represent genuine wild material or only feral derivatives of the crop Uses Onions are available in fresh, frozen, canned, pickled, and dehydrated forms. Onions can be used, usually chopped or sliced, in almost every type of food, including cooked foods and fresh salads, and as a spicy garnish; they are rarely eaten on their own but usually act as accompaniment to the main course. Depending on the variety, an onion can be sharp, spicy, tangy and pungent or mild and sweet. Onions pickled in vinegar are eaten as a snack. These are often served as a side serving in fish and chip shops throughout the United Kingdom. Onions are a staple food in India, and are therefore fundamental to Indian cooking. They are commonly used as a base for curries, or made into a paste and eaten as a main course or as a side dish. Tissue from onions is frequently used in science education to demonstrate microscope usage, because they have particularly large cells which are readily observed even at low magnifications Historical uses It is thought that bulbs from the onion family have been used as a food source for millennia. In Caananite Bronze Age settlements, traces of onion remains were found alongside fig and date stones dating back to 5000 BC. However, it is not clear if these were cultivated onions. Archaeological and literary evidence such as the Book of Numbers 11:5 suggests cultivation probably took place around two thousand years later in ancient Egypt, at the same time that leeks and garlic were cultivated. Workers who built the Egyptian pyramids may have been fed radishes and onions. The onion is easily propagated, transported and stored. The Ancient Egyptians worshipped it, believing that its spherical shape and concentric rings symbolized eternal life. Onions were even used in Egyptian burials as evidenced by onion traces being found in the eye sockets of Ramesses IV. They believed that if buried with the dead, the strong scent of onions would bring breath back to the dead. In ancient Greece, athletes ate large quantities of onion because it was believed that it would lighten the balance of blood. Roman gladiators were rubbed down with onion to firm up their muscles. In the Middle Ages onions were such an important food that people would pay for their rent with onions and even give them as gifts.[5] Doctors were known to prescribe onions to relieve headaches, coughs, snakebite and hair loss. The onion was introduced to North America by Christopher Columbus on his 1492 expedition to Haiti. Onions were also prescribed by doctors in the early 1500s to help with infertility in women, and even dogs and cattle and many other household pets. |
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MEDICINAL QUALITIES OF ONION Research shows that onions may help guard against many chronic diseases. That's probably because onions contain generous amounts of the flavonoid quercetin. Studies have shown that quercetin protects against cataracts, cardiovascular disease, and cancer. In addition, onions contain a variety of other naturally occurring chemicals known as organosulfur com-pounds that have been linked to lowering blood pressure and cholesterol levels. Onions contain 25 active compounds that appear to inhibit the growth of cancerous cells alliin being the main constituent. Onion has been found to help combat heart disease, inhibit strokes, lower blood pressure and cholesterol, and stimulate the immune system. The potassium salts and the flavonoides that are present perform an anti-inflammatory action. The essential oil is an expectorant, antiseptic, antifungal, anticoagulant, high-blood pressure, antithelmitic, balsamic, rubefciant, and has analgesic properties In investigating the use of onion in medicinal terms, the onion is found to be a remedy for conditions with symptoms like those which are caused by exposure to onions, such as watering eyes, and a burning and running nose. When looking at the symptoms of cold, it is ironic that we would treat this ailment with an almost like-with-like therapy. Alliums are antibacterial and anti-fungal, so they can help ward off colds and treat colds with sinus congestion that shifts from side to side in the head. Onion will relieve coughs that cause a ripping or tearing pain in the throat or a cough that is merely an irritating dry tickle. The watery and inflamed eyes due to sinus con-gestion and hay fever will be greatly relieved with onion. The onions ability to relieve congestions especially in the lungs and bronchial tract, is hard to believe until you have actually witnessed the results. The drawing of infection, congestion and colds out of the ear is also remarkable. The onion will relieve stomach upset and other gastrointestinal disorders and it will also strengthen the appetite. Onions help prevent thrombosis and reduce hypertension, according to the American Heart Association. The natural constituents of yellow or white onions can “…raise HDL cholesterol. The onion is being used for compresses to be applied to the skin for acne, arthritis, and congestion, and used internally for worms. The onion is also known for its diuretic properties. There have been cases in which the onion has been proven to be so effective as an antiviral that a cut piece of onion placed in a closed off room will prevent the person in the room to be safe from viruses. Onion will relieve headache centered behind the forehead; earache in children and adults; stuffed up nose with discharge that makes nostrils and upper lip sore or stuffed up nose with discharge from the alternate nostril; toothache, especially in the molar area or the shifting from side to side or from one tooth to another; hoarseness and the early stages of laryngitis; abdominal colic in babies. |
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HERBAL FORMULAS OF ONION The bulb of the onion is the part of the onion that is mostly used in cooking and medicinal applications. The greens may also be used in cooking and for flavoring. The onion may be tinctured with a menstruum of apple cider vinegar. This will last for a relatively long period of time. The onion may also be chopped and dried either on a screen or in a low-heated dehydrator and stored in an airtight, dark colored container away from light and heat, especially if planning to store the onion for a longer period of time. Once the onion is dried it may also be ground and powered and stored in an airtight, dark colored container away from light and heat. For conditions in which there is a cough whether it is due to a dry tickle in the throat to the extreme of a wracking, throat-ripping cough, we’ve found that the formula in which Dr. Christopher recommends in his Herbal Home Health Care is the best cough syrup we’ve ever used. This onion cough syrup is prepared by chopping several large onions into a double boiler. Cover the onions with honey. Boil the water beneath the double boiler. Once the honey has begun to liquefy add an ounce of horehound herb, liquorice root or cherry bark or any combination of these herbs. These herbs will magnify the expectorant properties of the cough syrup. Cover and let this concoction simmer in the double boiler for 4 to 5 hours. Strain the liquid syrup from the herb; bottle, label and refrigerate. The cough syrup will last several weeks in the refrigerator. Be sure that the honey has been harvested from the area from which you live and that it is a good pure honey in which no sugar has been used or that has not been pasteurized or changed from its natural state. Another excellent formula is to be used for earaches and ear infections. And it is simple to prepare and apply. Take a medium sized onion, remove the peal and slice the onion in half. Bake the onion halves in the oven until it is between starting to become translucent and translucent. Cool the onion until the warmth of it can be tolerated on the sensitive area of the ear. It is advisable to rub some olive oil on the ear and around the ear to prevent any skin reactions. Place the warm onions on both ears, (when treating ears, always treat both at the same time) and wrap them onto the ear with a layer of plastic wrap, a bandage and secure this on the head with a nightcap. Garlic oil may also be placed in the ears before the onions are applied to fight infection. The use of onions that have been sliced and lightly sautéed in olive oil until just translucent and laid on the chest, covered with a plastic wrapped with a bandage or covered with a towel and kept warm with a hot water bottle will allow the expectoration action to relieve congestion of the lungs and bronchial tract |
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Onions and eye irritation As onions are sliced, cells are broken, allowing enzymes called alliinases to break down amino acid sulfoxides and generate sulfenic acids. Sulfenic acids are unstable and spontaneously rearrange into a volatile gas called syn-propanethial-S-oxide. The gas diffuses through the air and eventually reaches the eye, where it reacts with the water to form a diluted solution of sulfuric acid. This acid irritates the nerve endings in the eye, making them sting. Tear glands produce tears to dilute and flush out the irritant. Supplying ample water to the reaction prevents the gas from reaching the eyes. Eye irritation can, therefore, be avoided by cutting onions under running water or submerged in a basin of water. Rinsing the onion and leaving it wet while chopping may also be effective. Another way to avoid irritation is by not cutting off the root of the onion, or by doing it last, as the root of the onion has a higher concentration of enzymes. Chilling or freezing onions prevents the enzymes from activating, limiting the amount of gas generated. Using a sharp blade to chop onions will limit the cell damage and the release of enzymes that drive the irritation response. Having a fire, such as a candle or a burner, will help as the heat and flames will draw in the onion gas, burn it, and then send it up with the rest of the flame exhaust. In the heat, the chemical changes such that it no longer irritates the eyes. Contact lenses prevent the irritation from occurring. The volume of sulphenic acids released, and the irritation effect, differs among Allium species. |
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Propagation Onions may be grown from seed or, most commonly, from sets. Onion sets are produced by sowing seed very thickly one year, resulting in stunted plants which produce very small bulbs. These bulbs are very easy to set out and grow into mature bulbs the following year, but they have the reputation of producing a less durable bulb than onions grown directly from seed and thinned. Either planting method may be used to produce spring onions or green onions, which are onions harvested while immature. Green onion is a name also used to refer to Allium fistulosum, the Welsh onion, which is said not to produce dry bulbs. - Shallots and ten other onion (Allium cepa L.) varieties commonly available in the United States were evaluated: Western Yellow, Northern Red, New York Bold, Western White, Peruvian Sweet, Empire Sweet, Mexico, Texas 1015, Imperial Valley Sweet, and Vidalia. In general, the most pungent onions delivered many times the benefits of their milder cousins.
Shallots have the most phenols, six times the amount found in Vidalia onion, the variety with the lowest phenolic content. Shallots also have the most antioxidant activity, followed by Western Yellow, New York Bold, Northern Red, Mexico, Empire Sweet, Western White, Peruvian Sweet, Texas 1015, Imperial Valley Sweet, and Vidalia. Western Yellow onions have the most flavonoids, eleven times the amount found in Western White, the variety with the lowest flavonoid content. For all varieties of onions, the more phenols and flavonoids they contain, the more antioxidant and anti-cancer activity they provide. When tested against liver and colon cancer cells, Western Yellow, New York Bold and shallots were most effective in inhibiting their growth. The milder-tasting varieties—Western White, Peruvian Sweet, Empire Sweet, Mexico, Texas 1015, Imperial Valley Sweet, and Vidalia—showed little cancer-fighting ability. |
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