Onion and other Allium vegetables are characterized by their rich content of thiosulfinates, sulfides, sulfoxides, and other odoriferous sulfur compounds. The thiosulfinates exhibit antimicrobial properties. Onion is effective against many bacteria including Bacillus subtilis, Salmonella, and E. coli.
The Value of Onions
Vigour, lustre of the body and mental power increase with the use of onions. From medical point of view, white onions are more useful. White onions are stimulant, vitalizing, pungent, promoters of virility, heavy, refreshing, stimulative of gastric fire and lubricous. They produce cough. They increase strength and induce sleep. They are a remedy for tuberculosis, cardiac troubles, dyspepsia, leprosy, piles, swelling and blood impurities.
The onion loses its vitamin C content when preserved for a long time.
The onion has effective germicidal properties. On account of its content of a volatile oil, the onion is very useful in respiratory disorders.
Onions are widely used in salads. But to get the maximum benefit of the onion, one should take two or three teaspoonfuls of onion-juice mixed with honey. White onions should be preferred for medicinal uses.
In virile disorders, one should take onion-juice with honey daily in the morning for two to three weeks. This will increase one's virility. The onion saves one from sunstroke. If one suffers from sunstroke, the onion relieves it. Eating onion in the morning and at bed-time is beneficial in jaundice.
It has been proved that onion-juice is a very effective vermifuge (substance which kills worms). Unlike many vermifuges, onion-juice is more harmless and free from side-effects.
The onion dislodges mucous and prevents its fresh formation. The onion is beneficial to the aged. The onion is also beneficial in intestinal disorders. The use of onions stimulates the process of peristalsis (contraction and expansion) of the intestines and removes intestinal putrefaction and flatulence. It is also useful in indigestion and biliousness.
The juice of the onion together with sugar is a capital remedy for bleeding piles.
Onions can be used 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.
The World Health Organization (WHO) supports the use of onions for the treatment of poor appetite and to prevent atherosclerosis. An onion extract was found to decrease allergy-induced bronchial constriction in asthma patients.
Onions are a very rich source of fructo-oligosaccharides. These oligomers stimulate the growth of healthy bifidobacteria and suppress the growth of potentially harmful bacteria in the colon. In addition, they can reduce the risk of tumors developing in the colon.
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.
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.
Use and Safety
Onions have a universal appeal. They are safely consumed by most people. However, consuming large quantities of onions can lead to stomach distress and gastrointestinal irritation that may result in nausea and diarrhea.
Onions, and other Allium species, are highly valued herbs possessing culinary and medicinal value. Some of their beneficial properties are seen after long-term usage. Onion may be a useful herb for the prevention of cardiovascular disease, especially since they diminish the risk of blood clots. Onion also protects against stomach and other cancers, as well as protecting against certain infections. Onion can improve lung function, especially in asthmatics. The more pungent varieties of onion appear to possess the greatest concentration of health-promoting phytochemicals.