Thursday, February 11, 2010
Health Benefits of Onions
Onions (Allium cepa) belong to the lily family, the same family as garlic, leeks, chives, scallions and shallots.There are over 600 species of Allium, distributed all over Europe, North America, Northern Africa and Asia. The plants can be used as ornamentals, vegetables, spices, or as medicine. There are over 120 different documented uses of the Alliums.
The onion has been used as an ingredient in various dishes for thousands of years by many cultures around the world. World onion production is steadily increasing so that onion is now the second most important horticultural crop after tomatoes.
Onion and other Allium vegetables are characterized by their rich content of thiosulfinates, sulfides, sulfoxides, and other odoriferous sulfur compounds. The cysteine sulfoxides are primarily responsible for the onion flavor and produce the eye-irritating compounds that induce lacrimation. The thiosulfinates exhibit antimicrobial properties. Onion is effective against many bacteria including Bacillus subtilis, Salmonella, and E. coli. Onion is not as potent as garlic since the sulfur compounds in onion are only about one-quarter the level found in garlic.
Onions have a variety of medicinal effects. Early American settlers used wild onions to treat colds, coughs, and asthma, and to repel insects. In Chinese medicine, onions have been used to treat angina, coughs, bacterial infections, and breathing problems.
Dry onions are a surprising source of fiber and a rich source of healthy sulfur compounds, similar to those found in garlic. Research on onions has lagged behind garlic research, but onions appear to have similar cardiovascular benefits, such as reducing blood pressure and blood cholesterol levels, at least in the short term.
Onions also contain phytochemicals called flavonoids, which help vitamin C in its function, improving the integrity of blood vessels and decreasing inflammation. All this spells help for your cardiovascular system. One particular flavonoid, quercetin, may inhibit tumor growth and help keep colon cancer at bay.
In addition, a newly identified compound appears to rival the prescription drug Fosamax in inhibiting bone loss in menopausal women.
Onions also contain vitamin C and chromium. Chromium is a mineral that helps cells respond to insulin, ultimately assisting with blood glucose control. Green onions, because of their bright green tops, provide a wealth of vitamin A.
Onions contain a number of sulfides similar to those found in garlic which may lower blood lipids and blood pressure. In India, communities that never consumed onions or garlic had blood cholesterol and triglyceride levels substantially higher, and blood clotting times shorter, than the communities that ate liberal amounts of garlic and onions. Onions are a rich source of flavonoids, substances known to provide protection against cardiovascular disease. Onions are also natural anticlotting agents since they possess substances with fibrinolytic activity and can suppress platelet-clumping. The anticlotting effect of onions closely correlates with their sulfur content.
Onion extracts, rich in a variety of sulfides, provide some protection against tumor growth. In central Georgia where Vidalia onions are grown, mortality rates from stomach cancer are about one-half the average level for the United States. Studies in Greece have shown a high consumption of onions, garlic and other allium herbs to be protective against stomach cancer.
Chinese with the highest intake of onions, garlic, and other Allium vegetables have a risk of stomach cancer 40 percent less than those with the lowest intake. Elderly Dutch men and women with the highest onion consumption (at least one-half onion/day) had one-half the level of stomach cancer compared with those consuming no onions at all.
Western Yellow, New York Bold, and Northern Red onions have the richest concentration of flavonoids and phenolics, providing them with the greatest antioxidant and anti-proliferative activity of 10 onions tested. The mild-tasting Western White and Vidalia onions had the lowest antioxidant content and lowest anti-proliferative activity. The consumer trend to increasingly purchase the less pungent, milder onion varieties may not be the best, since the onions with a stronger flavor and higher astringency appear to have superior health-promoting properties.
Nutritive Values of Onions : Per 100 gm.
• Vitamin A : 50 I.U.
• Vitamin B :
• Vitamin C : 9 mg.
• Calcium : 32 mg.
• Phosphorus : 44 mg.
• Potassium : 300 mg.
• Carbohydrates : 10.3 gm.
• Protein : 1.4 mg.
• Calories : 45
Onion is Benenificial in the following conditions:
• Reduce inflammation
• Slightly laxative
• High Blood Pressure
• Lowers cholesterol
• Prolong longevity
• Helps destroy worms and other parasites.
• Bronchitis (inflammation of the bronchial tube)
• Neuritis (inflammation of the nerves)
• Vertigo (inflammation of nerves)
• Diuretic (increases the secretion of urine)
• Diabetes mellitus - lowers blood sugar.
• Valuable for the hair, nails of the fingers and toes, and for the eyes.
• Sinus conditions - helps to drain mucus from the cavities and loosen phlegm.
• Whether fresh or cooked onions have antiplatelet, adhesiveness, thus preventing thrombosis.