Asparagus
Protection spears filled with Folate

Healing advantages:
Prevent birth defects
Protect your heart
Reduce risk to cancer
Feed your eyes
Boost your immune system


Asparagus is a perennial, an almost leafless member of the lily family. The spears we buy in the store are actually the shoots from an underground crown. It takes up to 3 years for crowns to develop enough to begin producing shoots, but once they do, they can produce for up to 20 years.

This chart graphically details the %DV that a serving of Asparagus provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Asparagus can be found in the food rating chart. A link that takes you to the In-Depth Nutritional Profile for Asparagus, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

Heart Health
Folate is essential for a healthy cardiovascular system. Folate is involved in the methylation cycle, a biochemical event in which a methyl group--one atom of carbon and three atoms of hydrogen--is transferred from one molecule to another. Methylation reactions are the body's biochemical "spark plugs" in a wide variety of very important reactions. For example, methylation is crucial for the proper transcription of DNA, and transforms norepinephrine into adrenaline, and serotonin into melatonin. When the methylation cycle flows smoothly, the amino acid methionine is transformed into homocysteine, which is quickly converted into cysteine, and then back into methionine. Folate (along with vitamins B6 and B12) is necessary for the conversion of homocysteine into cysteine. When folate levels are low, blood levels of homocysteine rise, a situation that significantly increases the risk for heart disease. Homocysteine promotes atherosclerosis by reducing the integrity of blood vessel walls and by interfering with the formation of collagen (the main protein in connective tissue). Elevations in homocysteine are found in approximately 20-40% of patients with heart disease, and it is estimated that consumption of 400 mcg of folate daily would reduce the number of heart attacks suffered by Americans each year by 10%. Just one serving of asparagus supplies almost 66% of the daily recommended intake of folate.

A Natural Diuretic
Asparagus is a very good source of potassium (288 mg per cup) and quite low in sodium (19.8 mg per cup. Its mineral profile, combined with an active amino acid in asparagus, asparagine, gives asparagus a diuretic effect. Although some popular articles on asparagine link this amino acid to the distinct urinary odor that can follow along after consumption of asparagus, research studies suggest that this odor stems from a variety of sulfur-containing compounds (discussed in detail under the Individual Concerns section below). Historically, asparagus has been used to treat problems involving swelling, such as arthritis and rheumatism, and may also be useful for PMS-related water retention.

Food for Healthy Gut Flora
Asparagus contains a special kind of carbohydrate called inulin that we don't digest, but the health-promoting friendly bacteria in our large intestine, such as Bifidobacteria and Lactobacilli, do. When our diet contains good amounts of inulin, the growth and activity of these friendly bacteria increase. And when populations of health-promoting bacteria are large, it is much more difficult for unfriendly bacteria to gain a foothold in our intestinal tract.

A Birth Defect Fighter
Especially if you're thinking about becoming pregnant or are in the early stages of pregnancy, make asparagus a frequent addition to your meals. A cup of asparagus supplies approximately 263 mcg of folate, a B-vitamin essential for proper cellular division because it is necessary in DNA synthesis. Without folate, the fetus' nervous system cells do not divide properly. Inadequate folate during pregnancy has been linked to several birth defects, including neural tube defects like spina bifida. Despite folate's wide availability in food (it's name comes from the Latin word folium, meaning "foliage," because it's found in green leafy vegetables), folate deficiency is the most common vitamin deficiency in the world.

Description
Asparagus is a perennial garden plant belonging to the Lily family (Liliaceae). While approximately 300 varieties of asparagus have been noted, only 20 are edible. Asparagus, its fleshy spears topped with bud-like compact heads, is often thought of as a luxury vegetable, prized for its succulent taste and tender texture. It is harvested in the spring when it is 6 to 8 inches tall. While the most common variety of asparagus is green in color, two other edible varieties are available. White asparagus, with its more delicate flavor and tender texture, is grown underground to inhibit its development of chlorophyll content, therefore creating its distinctive white coloring. It is generally found canned, although you may find it fresh in some select gourmet shops, and it is generally more expensive than the green variety since its production is more labor intensive. The other edible variety of asparagus is purple in color. It is much smaller than the green or white variety (usually just 2 to 3 inches tall) and features a fruitier flavor. It also provides benefits from phytonutrients called anthocyanins that give it its purple color. With prolonged cooking, the purple color may disappear.

History
Asparagus has been prized as an epicurean delight and for its medicinal properties for almost 2000 years. Originating in the eastern Mediterrean region, it has become naturalized throughout much of the world. It was thought to be cultivated in ancient Egypt with varieties discovered in northern and southern Africa. Falling into relative obscurity in the Middle Ages, asparagus was "rediscovered" and popularized in the 18th century by Louis XIV. Today, asparagus is cultivated in most subtropical and temperate parts of the world with the majority of commercially available asparagus grown in United States, Mexico, Peru, France, Spain and other Mediterranean countries.

How to Select and Store
Asparagus stalks should be rounded, and neither fat nor twisted. Look for firm, thin stems with deep green or purplish closed tips. The cut ends should not be too woody, although a little woodiness at the base prevents the stalk from drying out. Once trimmed and cooked, asparagus loses about half its total weight. Occasionally, white asparagus that has a milder flavor than green asparagus is available. White asparagus is buried under soil to block chlorophyll production, thus resulting in a white plant. Some markets also offer purple asparagus, which has a fruitier flavor than green or white asparagus.

Use asparagus within a day or two after purchasing for best flavor. Store in the refrigerator with the ends wrapped in a damp paper towel, and be sure to place the asparagus in the back of the refrigerator away from any light, since folate is destroyed by exposure to air, heat or light.

Tips for Preparing Asparagus
Asparagus can be served hot or cold. While it is not necessary to peel asparagus, you should cut off the fibrous base before cooking. Wash it under cold water to remove any sand or soil residues.

You can tie asparagus stalks in a bundle to steam them, as this will make it easier to remove the stalks once cooked. If you find you enjoy this unusual vegetable so much that you become a true aficiando, you might consider purchasing one of the special tall, narrow steamers available that allow asparagus to be cooked to perfection-the tips are steamed while the thick stalks are cooked thoroughly in the boiling water. Avoid cooking asparagus in iron pots as the tannins in the asparagus can react with the iron and cause the stalks to become discolored. If your recipe calls for cold asparagus, plunge the stalks into cold water immediately after cooking, then remove them quickly; letting them soak too long can cause them to become soggy.

A Few Quick Serving Ideas
For a delectable hors d'oeuvre, roast asparagus along with other vegetables such as pattypan squash, Portobello mushrooms, and beets. Steamed asparagus served with light lemon vinaigrette makes a delightfully refreshing salad.
Toss freshly cooked pasta with asparagus, olive oil and your favorite pasta spices. We especially enjoy thyme, tarragon and rosemary. Chopped asparagus make a flavorful and colorful addition to omelets. Healthy sauté asparagus with garlic, shiitake mushrooms and tofu or chicken.

Individual Concerns
Contrary to popular belief, persons who experience a strong odor coming from their urine after eating asparagus are not in any danger from eating this vegetable. A variety of different chemicals-all breakdown products of asparagus-can be found in the urine in connection with the "asparagus smell". These chemicals generally fall within a chemical category called mercaptans (or to use a more modern term, thiols). They include dimethyl sulfide, dimethyl disulfide, dimethyl sulfoxide, bis-(methylthio)methane, S-methyl thioacrylate, S-methyl-3-(metyhylthio)thiopropionate and dimethyl sulphone. Different people form different amounts of these compounds after eating asparagus, and many people cannot smell the odor, even when they produce the compounds.

Asparagus and Purines
Asparagus contains naturally-occurring substances called purines. Purines are commonly found in plants, animals, and humans. In some individuals who are susceptible to purine-related problems, excessive intake of these substances can cause health problems. Since purines can be broken down to form uric acid, excess accumulation of purines in the body can lead to excess accumulation of uric acid. The health condition called "gout" and the formation of kidney stones from uric acid are two examples of uric acid-related problems that can be related to excessive intake of purine-containing foods. For this reason, individuals with kidney problems or gout may want to limit or avoid intake of purine-containing foods such as asparagus

Nutritional Profile
Asparagus is an excellent source of vitamin K, the B vitamin folate, vitamin C, vitamin A. Asparagus is a very good source of numerous B vitamins - including vitamin B1, B2, B3 and B6 - as well as dietary fiber, manganese, copper, phosphorus, potassium and protein.

In-Depth Nutritional Profile
In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for asparagus is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.