The World's Healthiest Foods
Asparagus

The fleshy green spears of asparagus are both succulent and tender and have been considered a delicacy since ancient times. This highly prized vegetable arrives with the coming of spring. In California the first crops are picked as early as February, however, their season generally is considered to run from April through May. The growing season in the Midwest and East extends through July.

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.

 


Health Benefits

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.

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 60% 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 strong diuretic effect. Asparagine is also responsible for the strong odor often produced in the urine after asparagus is eaten--a harmless and temporary effect. 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.

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.

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

How to Enjoy

For some of our favorite recipes, click Recipes.

Tips for Preparing Asparagus:

Asparagus

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 boil 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 omelettes.

Healthy sauté asparagus with garlic, shiitake mushrooms and tofu or chicken.

Safety

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

Introduction to Food Rating System Chart

The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents (similar to other information presented in the website, this DV is calculated for 25-50 year old healthy woman); the nutrient density rating; and, the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. For more detailed information on our Food and Recipe Rating System, please click here.

 

Asparagus, Boiled
1.00 cup
43.20 calories
Nutrient Amount DV
(%)
Nutrient
Density
World's Healthiest
Foods Rating
vitamin K 91.80 mcg 114.8 47.8 excellent
folate 262.80 mcg 65.7 27.4 excellent
vitamin C 19.44 mg 32.4 13.5 excellent
vitamin A 970.20 IU 19.4 8.1 excellent
tryptophan 0.05 g 15.6 6.5 very good
vitamin B1 (thiamin) 0.22 mg 14.7 6.1 very good
vitamin B2 (riboflavin) 0.23 mg 13.5 5.6 very good
manganese 0.27 mg 13.5 5.6 very good
dietary fiber 2.88 g 11.5 4.8 very good
vitamin B6 (pyridoxine) 0.22 mg 11.0 4.6 very good
copper 0.20 mg 10.0 4.2 very good
vitamin B3 (niacin) 1.95 mg 9.8 4.1 very good
phosphorus 97.20 mg 9.7 4.1 very good
protein 4.66 g 9.3 3.9 very good
potassium 288.00 mg 8.2 3.4 very good
iron 1.31 mg 7.3 3.0 good
zinc 0.76 mg 5.1 2.1 good
magnesium 18.00 mg 4.5 1.9 good
selenium 3.06 mcg 4.4 1.8 good
calcium 36.00 mg 3.6 1.5 good
World's Healthiest
Foods Rating
Rule
excellent DV>=75% OR Density>=7.6 AND DV>=10%
very good DV>=50% OR Density>=3.4 AND DV>=5%
good DV>=25% OR Density>=1.5 AND DV>=2.5%

References

  • Berg MJ. The importance of folic acid. J Gend Specif Med 1999 May-Jun;2(3):24-8.
  • Bornet FR, Brouns F, Tashiro Y et al. Nutritional aspects of short-chain fructooligosaccharides: natural occurrence, chemistry, physiology and health implications. Dig Liver Dis 2002 Sep;34 Suppl 2:S111-20.
  • Clarke R, et al. Hyperhomocystenemia: an independent risk factor for. New Eng J Med 324 (1991):1149-55.
  • Ensminger AH, Esminger M. K. J. e. al. Food for Health: A Nutrition Encyclopedia. Clovis, California: Pegus Press; 1986.
  • FDA News. Folic acid to fortify US food products to prevent birth defects. FDA News. Feb 29 1996.
  • Glueck, CJ, et al. Evidence that homocysteine is an independent risk factor. Am J Cardiology(1995):132-6.
  • Margen S and the Editor, Univ of California at Berkley Wellness Letter. The Wellness Encyclopedia of food and nutrition. New York: Health Letter Associates 1992.
  • McGee H. On food and cooking: The science and lore or the kitchen. New York: Collier Books 1984.
  • National Food Safety Database. National Food Safety Database. http://www.foodsafety.ufl.edu.
  • Rieder M. Prevention of neural tube defects with periconceptional folic acid. Clin Perinatol, 21: 483-502 1994.
  • Suitor CW. Food folate vs. synthetic folic acid: a comparison. J Am Diet Assoc 1999;99:285.
  • Wood, Rebecca. The Whole Foods Encyclopedia. New York, NY: Prentice-Hall Press; 1988.
  • Yaeger S and the Editors of Prevention Health Books. The Doctor's Book of Food Remedies. St. Martin's Press 1998.

This page was updated on: 2005-05-06 18:30:11
© 2002 The George Mateljan Foundation