Everything you never knew about the humble onion

March 7, 2006

(This information is a condensed version from whfoods.org)

: : : O N I O N S : : :

Recent research shows that the variety of onions you choose and the way

you prepare them can make a huge difference in the amount of beneficial

compounds, and the antioxidant and anti-cancer effects, they deliver.

In general, the most pungent onions deliver many times the benefits of

their milder cousins. Among varieties of onions commonly available in

the U.S., shallots were found to have the most phenols, and Western

Yellow onions the most flavonoids. When tested against liver and colon

cancer cells, Western Yellow, New York Bold and shallots were most

effective in inhibiting their growth. Summer onions such as Walla

Walla, Vidalia and Maui Sweet Onions are high in sugar content, are not

as high in nutritional value and do not provide the same

health-promoting properties.

The word onion comes from the Latin word unio for " single, " or " one, "

because the onion plant produces a single bulb, unlike its cousin, the

garlic, that produces many small bulbs. The name also describes the

union (also from unio) of the many separate, concentrically arranged

layers of the onion.

Onions are very rich in chromium, a trace mineral that helps cells

respond to insulin, plus vitamin C, and numerous flavonoids, most

notably, quercitin.

Blood-Sugar-Lowering Effects

The higher the intake of onion, the lower the level of glucose found

during glucose tolerance tests. 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 good HDL-cholesterol levels.

Cardiovascular Benefits

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 recent 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.

Colon Cancer Prevention

The regular use of onions, as little as two or more times per week, is

associated with a significantly reduced risk of developing colon

cancer. Onions contain a number of flavonoids, the most studied of

which, quercitin, has been shown to halt the growth of tumors in

animals and to protect colon cells from the damaging effects of certain

cancer-causing substances.

Boost Bone Health

Onions also help maintain healthy bones, suggests a study published in

the March 2005 issue of the Journal of Agricultural and Food Chemistry.

Anti-Inflammatory and Anti-Bacterial Activity

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. Onions'

anti-inflammatory effects are due not only to their vitamin C and

quercitin, but to other active components as well. These compounds work

synergistically to spell relief from inflammation. In addition,

quercitin 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.

Description

Onions may bring a tear to your eye, and a pungency to your breath, but

they will most certainly bring delight to your tastebuds.

History

Onions are native to Asia and the Middle East and have been cultivated

for over five thousand years. Onions were highly regarded by the

Egyptians. Not only did they use them as currency to pay the workers

who built the pyramids, but they placed them in the tombs of kings,

such as Tutankhamen, so that they could carry these gifts bestowed with

spiritual significance with them to the afterlife.

Onions have been revered throughout time not only for their culinary

use, but also for their therapeutic properties. As early as the 6th

century, onions were used as a medicine in India.

Onions should be stored at room temperature, away from bright light,

and in a manner where they are well ventilated. To do this, either

place them in a wire hanging basket or a perforated bowl with a raised

base so that air can circulate underneath. The length of storage varies

with the type of onion. Those that are more pungent in flavor, such as

yellow onions, can stay longer than those with a sweeter taste, such as

white onions, since the compounds that confer their sharp taste help to

preserve them. Scallions should be stored in a plastic bag in the

refrigerator where they will keep for about one week. All onions should

be stored away from potatoes, as they will absorb their moisture and

ethylene gas, causing them to spoil more readily.

Tips for Preparing Onions:

While many people love to eat onions, most dread cutting them since

this process usually brings a tear or two to the eyes. The compound

that causes the eyes to burn is a phytochemical that is produced when

sulfur-compounds released by the onion’s ruptured cells are exposed to

air.

If cutting onions irritates your eyes, there are a few tricks that you

can employ. Chill the onions for an hour or so before cutting. Use a

very sharp knife and always cut the onions while standing; that way

your eyes will be as far away as possible. If cutting onions really

makes you cry, consider wearing glasses or goggles.

So, grab those breath mints and munch away on the humble but healthful

onion!!!!

March 7, 2006

Thank you Taylor for that very informative post.

-

" taylor " <whimsytaylor

Monday, March 06, 2006 6:34 PM

Everything you never knew about the humble

onion