Healing Kitchen

The Many Layered Benefits of Onions
Do onions bring tears to your eyes? It is worth getting used to if you want strong healthy bones. Investigators at the University of Bern in Switzerland (Nature, 9/23/99) found that onions increase skeletal mass and inhibit the natural breakdown of bone.

The team fed male rats a small amount of dried onion daily for one month. Compared with rats given a control diet, the bones of the animals fed onion had a 17% increase in bone-strengthening minerals such as calcium. In addition, the researchers studied female rats whose ovaries had been surgically removed--a technique that rapidly induces the bone loss and osteoporosis that can occur after menopause. Feeding these female rats onion protected their bones as well. In fact the more onion the animals ate, the greater the benefits.

Strong Bones and More
Scientists aren't sure which specific ingredients in onions should be credited for these bone-building benefits. And it's a long way from rats to people. But onions contain a variety of antioxidants, sulfur compounds, and other substances thought to promote health. Onions also contain such nutrients as vitamin C, potassium, and folate (folic acid).

Disease-Fighting Quercetin
Chief among onion's health-giving ingredients is a plant pigment called quercetin. Quercetin is a potent antioxidant; foods rich in antioxidants are believed to slow aging, fight cataracts, and possibly lower the risk of many types of cancer. In addition, quercetin may help relieve asthma, bug bites, eczema, and hay fever by blocking allergic and inflammatory responses in the airways and other areas. It may likewise be beneficial against inflammatory joint conditions, such as rheumatoid arthritis and gout.

Quercetin is found in tea and apples as well, but investigators at Wageningen Agricultural University in the Netherlands report that our bodies absorb quercetin much more readily from onions than from those other foods.

A Healthy Heart
Researchers have found that onions keep blood platelets from clumping. Although the effect is not nearly as strong as that of a drug such as Coumadin, onions' mild blood-thinning effect may help prevent the formation of blood clots, a major cause of heart attack and stroke.

Diabetes and Ulcers
A number of studies suggest that onions may be beneficial for a host of other problems as well, although you'd likely have to eat very large amounts of the vegetable to get specific therapeutic effects. For example, onions contain a compound called allyl propyl disulfide (APDS) that may act like certain oral prescription diabetes drugs that lower blood sugar. Onions may also help prevent ulcers by prohibiting growth of the ulcer-causing bacteria H. pylori.

Suggested dose: For general health benefits, nutritionists recommend eating at least two onions a week. To get the anti-inflammatory and allergy-reducing benefits of quercetin, supplements are your best bet, since onions don't contain high enough amounts of the compound. (You'd have to eat about three dozen onions to get the amount in a pill.) Take 500 mg of quercetin two or three times a day, between meals.

Author: the WholeHealthMD Advisor
Date Published: 03/15/2000
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