Scientific Name: Yucca
Other Names: Adam's Needle, Bear Grass, Dagger Plant, Joshua Tree, Mohave Yucca, Our-Lord's-Candle, Soapweed, Spanish Bayonet, Yucca species

Who is this for?

Uses

Although no well-controlled human studies have been conducted for verification, a few animal studies and case reports suggest a limited role for oral yucca in treating both cardiovascular conditions and high cholesterol levels. First, yucca contains a proven antioxidant, a chemical known as resveratrol. Antioxidants are thought to protect body cells from damage caused by a chemical process called oxidation. Oxygen free radicals, natural chemicals produced by oxidation, are involved in the development of several conditions including heart diseases. By limiting oxidation, resveratrol and other antioxidants may help prevent damage to blood vessels and other changes that may contribute to the development of heart disease. In addition, yucca contains a high percentage of saponins, chemicals that dissolve in both water and oil. In the stomach and intestines, some saponins may fasten onto cholesterol particles in the blood, thereby preventing cholesterol absorption by the body and promoting its elimination. Although saponins from yucca have not been studied specifically, saponins from other plant sources also attach to bile, effectively removing it from circulation. The body then has to use some dietary or stored cholesterol to make more bile, further reducing the amount of cholesterol that stays in the blood.

Traditionally, yucca has been used orally to treat arthritis and related ailments such as bursitis (inflammation of the pads that separate tendons from bones) and gout (a very painful inflammation—usually of a single joint such as the big toe—caused by excess uric acid). Although little research supports the specific use of yucca for treating arthritis, some researchers believe that saponins generally may interfere with the production of a chemical that keeps the body from making new cartilage for joints. Saponins may also have anti-inflammatory effects. In one small study conducted about 30 years ago, oral yucca seemed to show some mild relief of pain, stiffness, and swelling among some of the participants who took daily doses of various yucca extracts for periods of up to 15 months. However, the lengths of time that the participants took yucca, the yucca products they used, and the dosages they took all varied greatly. Many participants also took conventional arthritis remedies, such as aspirin, in addition to yucca during the study period. Results of this study have not been verified by more recent controlled research, so they cannot be viewed as conclusive. As an antioxidant, yucca may also have potential as an anticancer, antiviral, and immune-stimulating agent. The antioxidant effects of yucca may also protect the liver from some of the damage caused by certain drugs, chemicals, or chronic alcohol abuse. Some case reports may also show that yucca may prevent or lessen the severity of migraine headaches. All these possible effects need further study to prove or disprove them, however.

Topical yucca is thought to help stop minor bleeding from cuts and scrapes. Because the saponins in it may be anti-inflammatory, yucca may also help to relieve itching and swelling from insect bites, sunburn, and other minor skin injuries. Reportedly, yucca and other saponin-containing herbal products have been applied to the scalp for treating dandruff and to the skin for treating eczema and psoriasis. While none of these possible uses has been proved by study results, yucca’s soapy consistency does make it a good soap or shampoo substitute.

Precautions

No cases of human toxicity from yucca have been reported in medical literature.However, the roots of yucca species contain chemicals called saponins, which may be used in pesticides because they are poisonous to insects and other small creatures. Saponins are not absorbed from the gastrointestinal tract in humans; therefore, they do not appear to be toxic to humans when taken by mouth or used topically. If injected into the blood, however, saponins can dissolve red blood cells.

What side effects should I watch for?

Ingesting several times the recommended daily dose of oral yucca could result in severe diarrhea.

Individuals taking yucca orally have also reported:

• Bitter taste in the mouth
• Irritated mouth
• Nausea
• Sore throat
• Upset stomach
• Vomiting

Applied topically, yucca preparations possibly may further irritate open scrapes or cuts.

What interactions should I watch for?

No interactions between yucca and prescription drugs, non-prescription drugs, other herbal products, or foods have been reported. However, because few reliable studies of yucca have been conducted in humans, its possible interactions are not understood completely.

Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals. For specific information on how yucca interacts with drugs, other herbals, and foods and the severity of those interactions, please use our Drug Interactions Checker to check for possible interactions.

Should I take it?

Yucca that is used in medicine generally comes from the leaves and flower stalks of over 30 species of related shrubs or small trees that grow primarily in desert areas of the American southwest and other dry areas of North America. Some yucca species, however, have adapted for cooler, wetter climates such as those in the central plains states. The large, fleshy, sword-shaped leaves of most yuccas stay green all year and their clusters of white or yellow-green flowers bloom on tall central spikes. Some species of yucca have flowers that smell stronger at night so they attract a specific kind of moth that pollinates the plants. Yuccas all contain chemicals called saponins that give them a bitter taste and a soapy feel. Because saponins are toxic to many small animals and insects, yucca plants are not usually attacked by garden pests. In general, the roots contain more saponins than the leaves and stalks do, so yucca roots are not used as much for medicine.

Native Americans used yucca stems for fibers to make baskets, clothing, or mats; its roots for soap; its fruits for juice; and its leaves, flowers, fruits, and seedpods for food. Cooking yucca breaks down the saponins in it, so food sources of yucca may not offer the medicinal advantages thought to be associated with it. The roots of some types of yucca are used to make dyes. Yucca extract is FDA-approved to be used as a foaming agent in foods such as beer and soft drinks. It is also used as an additive in flavorings, foods, pet foods, shampoo, and soap.

Dosage and Administration

Note: Uninterrupted oral use of yucca is not recommended for periods longer than 3 months at a time, due to the chance that fat-soluble vitamins may be depleted because saponins inactivate fats in the gastrointestinal system.

As a dietary supplement, yucca is available as capsules, tablets, or liquid to take by mouth. Doses for commercially available oral forms, which usually come in strengths between 380 mg and 490 mg, are generally taken twice a day and based on body weight. For a tea, 7 mg to 8 mg (about a quarter of an ounce) of dried yucca roots or stalks can be boiled in 16 ounces of water for about 15 minutes. After the resulting liquid is strained to remove solid particles, it may be consumed as a tea—usually divided into three cups or four cups.

Yucca is also available in liquids, gels, or creams to apply topically as needed. Cooled yucca tea may be used as a wash, and fresh yucca roots may be boiled until soft and then mixed with petroleum jelly for an ointment.

Summary

Today, oral yucca is thought to have some mild effectiveness in preventing and treating heart conditions and high cholesterol levels. Some unconfirmed evidence suggests it may help relieve the symptoms of arthritis. It may also provide antioxidant benefits in several different conditions. Topical forms of yucca can help relieve inflammation and minor skin irritation.

Risks

No major risks have been associated with the oral or topical use of yucca. The saponins in it can dissolve red blood cells, however, if it is injected into the blood.

Side Effects

The main side effects reported from oral yucca are stomach upset and irritation of mucous membranes. Applied to broken or severely irritated skin, topical yucca may worsen irritation.

Interactions

No interactions have been reported between yucca and prescription drugs, non-prescription drugs, other herbal products, or foods.

Last Revised August 8, 2006

References

Anon: Yucca. In: DerMarderosian A, Beutler JA, eds. Facts and Comparisons: The Review of Natural Products. St. Louis, MO, Facts and Comparisons. 2002.

Balestrieri C, Felice F, Piacente S, et al. Relative effects of phenolic constituents from Yucca schidigera Roezl. bark on Kaposi's sarcoma cell proliferation, migration, and PAF synthesis. Biochemistry and Pharmacology. 2006;71(10):1479-1487.

Bassarello C, Bifulco G, Montoro P, et al. Yucca gloriosa: A source of phenolic derivatives with strong antioxidant activity. Journal of Agricultural and Food Chemistry. Epublished ahead of print. July 11, 2007.

Bingham R, Bellew BA, Bellew JG. Yucca plant saponin in the management of arthritis. Journal of Applied Nutrition. 1975;27(2-3):45-50.

Bingham RD, Harris H, Laga T. Yucca plant saponin in the treatment of hypertension and hypercholesterolemia. Journal of Applied Nutrition. 1978;30:127-136.

Cheeke PR. Actual and potential applications of Yucca schidigera and Quillaja saponaria saponins in human and animal nutrition. Proceedings of the Phytochemical Society of Europe. 2000;45:241-254.

Cheeke P, Piacente S, Oleszek W. Anti-inflammatory and anti-arthritic effects of yucca schidigera: A review. Journal of Inflammation (London). 2006;3:6.

Duffy CF, Killeen GF, Connolly CD, Power RF. Effects of dietary supplementation with Yucca schidigera Roezl ex Ortgies and its saponin and non-saponin fractions on rat metabolism. Journal of Agricultural and Food Chemistry. 2001;49(7):3408-3413.

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HealthNotes, Inc. Yucca. 2002. Available at: http://www.mycustompak.com/healthNotes/Herb/Yucca.htm Accessed November 18, 2002.

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Last Revised July 18, 2007

Note: The above information is not intended to replace the advice of your physician, pharmacist, or other healthcare professional. It is not meant to indicate that the use of the product is safe, appropriate, or effective for you.

In general, herbal products are not subject to review or approval by the U.S. Food and Drug Administration (FDA). They are not required to be standardized, meaning that the amounts of active ingredients or contaminants they contain may vary between brands or between different batches of the same brand. Not all of the risks, side effects, or interactions associated with the use of herbal products are known because few reliable studies of their use in humans have been done.

This information is provided for your education only. Please share this information with your healthcare provider and be sure that you talk to your doctor and pharmacist about all the prescription and non-prescription medicines you take before you begin to use any herbal product.

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