Prickly pear cactus

Description

A member of the Cactaceae (or cactus) family, prickly pear cactus, also known as nopal, grows in the United States, Mexico, and South America. It also flourishes in Africa, Australia, and the Mediterranean.

Although prickly pear cactus can tolerate a wide range of temperature and moisture levels, it grows best in sunny, desert-like conditions. Over a dozen species of prickly pear cactus belong to the Opuntia genus, but all of them have flat, fleshy, green-colored pads that look like large leaves and are oval to round in shape. With a tendency to grow quickly and at odd angles, the pads are actually the stems of the plant. It is in the pads that the moisture is stored. In general, the pads range from 4 in (10 cm) to 18 in (46 cm) in length. Larger pads have been known to grow as wide as 9 in (23 cm) or more. The height of a prickly pear cactus can vary and be anywhere from less than a foot to 7 ft (2.1 m) tall.

Like most cactus plants, the prickly pear cactus has long, sharp spines that protrude from the pads. In addition, harder-to-see tiny spines, called glochids, can be found at the base of the more predominant spines. Disguised in fuzzy-looking patches, the glochids appear harmless. However, they come off the pad easily and once they've gotten into a person's skin, they can be difficult to remove and cause irritation for days.

The pads and fruit of the prickly pear cactus are edible. The fruit can be peeled and eaten raw. However, many experts suggest that the fruit is best when it is made into candy, jelly, juice, or wine. It is also available dried or in extract form.

From early spring to summer, the cactus blossoms and sets fruit, which line the edges of the pads. Anytime thereafter, until late fall, the fruit ripens and is ready to be picked. The fruit should be harvested only when ripe and, according to Savio, "Those that are best for eating fresh ripen from September to November." Once picked, the fruit has a brief shelf life—typically under a week.

Most often, the flowers of the prickly pear cactus are red, yellow, or purple with each flower yielding one fruit. On average, the fruit grows to be about 2.5 in (7 cm) long and is cylindrical in shape. Although the fruit's flesh can be found in many different colors, such as white, green, yellow, red, or purple, most people in the United States are familiar with the reddish-purple or dark red variety; whereas in Mexico, the white-skinned varieties are most common.

In a 1998 paper presented in Santiago, Chile, at the International Symposium on Cactus Pear and Nopalitos Processing and Uses, Armida Rodriguez-Felix and Monica A. Villegas-Ochoa reported that the chemical composition of prickly pear cactus pads is not unlike most vegetables. High in amino acids (building blocks of proteins and highly bioactive, generally), prickly pear cactus is said to be high in fiber, B vitamins, magnesium , and iron . Rodriguez-Felix and Villegas-Ochoa listed the following ingredients as well:

• water
• carbohydrates
• protein
• fat
• minerals
• vitamin C
• beta carotene

General use

Prickly pear cactus has been used for healing purposes and as food for centuries. Loaded with protein and vitamins, the cactus, also known as nopal, has been used to treat diabetes, stomach problems, cuts and bruises, sunburn , windburn, constipation , and cold symptoms. Folk remedies abound, such as the one that involves heating the pads and placing them on a cold sufferer's chest to relieve congestion.

In an article published in The Hindu, India's national newspaper, Ms. Margarita Barney de Cruz, president of the Group to Promote Education and Sustainable Development, was quoted as having said that nopal was even used in the sixteenth to eighteenth centuries for painting churches and convents. Apparently, according to Barney de Cruz, this practice originated in rural Mexico when it

was discovered that prickly pear cactus could be used to make a highly effective waterproof paint for homes.

Rural residents, especially farmers, in Mexico and elsewhere have utilized the prickly pear cactus for years as an effective way to mark property lines, as well as a protective barrier against predators, both animal and human. In central Africa, the juice from the pads has long been considered an effective mosquito repellent.

An important part of the Mexican culture for centuries, prickly pear cactus is still being used there for medicinal and nutritional purposes. In Worldwide Gourmet, edited by Michele Serre, prickly pear cactus reportedly is one of the most important food crops collected by the native population and is widely eaten as both a fruit and vegetable. In northern Mexico, the pads are often fed to dairy cows in order to add a unique and sweet flavor to their milk. Not only is this feed inexpensive, but also the resulting dairy product is highly prized among local consumers.

Today, prickly pear cactus is still being used as a remedy for many of the same problems it was used for in the past. For example, it is still commonly used topically to treat cuts, insect bites, sunburn, and windburn. Over the past three decades, some interesting studies have been conducted on the healing properties of prickly pear cactus, with a primary research focus on its effectiveness in lowering blood sugar levels. Wholehealthmd.com reported that animal studies done in the 1990s indicate that extracts of the prickly pear at doses lower than traditionally used can reduce blood sugar levels. This is promising for the possible development of easy-to-use extracts that may some day be effective for use in treating diabetes in humans. With regard to the cactus pads themselves, not the extract, some interesting studies have indicated that the cooked pads do help reduce sugar levels, thereby validating traditional medicinal usage. According to the experts at wholehealthmd.com, one theory of the mechanism of blood sugar lowering is that the high fiber from the pad's gooey pectin absorbs sugar in the body, and then enables the body to very slowly release sugar through the course of the day.

Two 1988 studies, one published in Diabetes Care and the other in the Archives of Investigative Medicine, conducted by Frat-Munari and colleagues indicated that consuming 100 to 500 grams of cooked pads was beneficial in treating humans with diabetes. Results confirmed a drop of between 8 to 31% of blood glucose readings. The Frati-Munari studies involved three groups on three separate "treatments." One group took nopal, one group took a water placebo, the third took zucchini squash. The water group experienced no change in serum glucose levels, whereas a slight increase of serum glucose concentrations was measured in the zucchini squash group. Those taking nopal displayed improvements in elevated blood sugar.

In a similar study published by the Texas Journal of Rural Health in 1998, Keith Rayburn, M.D., and colleagues had an interestingly different outcome. In the study by Rayburn et al, although blood sugar readings also fell after consumption, the water ingestion group showed a declining glucose concentration, whereas in the studies by Frati-Munari that was not the case. Dr. Rayburn and colleagues compared their study to two studies with similar findings (one by Chen et al conducted in 1988 and another by Gannon et al conducted in 1989) and made three important assessments. One explanation for the different findings might have to do with the water control group. It may have had a declining glucose reading because its members were allowed to drink as much water as they liked, which could have had a blood-sugar-lowering effect. Secondly, although the use of nopal in folk culture is not limited to one species, Rayburn and colleagues did point out that the nopal used in their study differed from the nopal used in the 1988 studies by Frati-Munari and colleagues. In fact, Rayburn and his colleagues specifically stated, "We cannot rule out the possibility that O. streptacantha might have more activity than other species." Finally, and perhaps most importantly, Rayburn and colleagues concluded, "Despite lacking an acute hypoglycemic effect in our subjects, it is possible that nopal has other important metabolic effects, such as lowering lipids or increasing insulin sensitivity, as suggested by Frati-Munari et al [in two studies published in 1991]."

In a literature review published in 2002 by the Journal of American Pharmacists Association, Drs. Shapiro and Gong investigated the uses of several products and conclude that based on the evidence, several natural products in common use can lower blood glucose in patients with diabetes.

Interesting research continues to be conducted to validate or discover new ways in which prickly pear cactus can be used medicinally. For example, in a 1998 study published in Archives of Pharmaceutical Research by Dr. E. H. Park and colleagues, it was suggested that prickly pear cactus pads could be used to reduce inflammation and help relieve stomach problems. Some evidence also exists that prickly pear cactus could be effective in reducing cholesterol levels, but more research needs to be conducted.

Preparations

Gloves should be worn when the pads and fruit are removed from the cactus. Even those varieties regarded as "spineless" have glochids, so beware. To avoid getting punctured by the spines, use a long, sharp knife to cut and tongs to lift the pads and fruit away from the plant. Place the cuttings in a bowl or basket with handles. Novices should continue to wear gloves until all the spines are removed. To remove the spines, simply scrape them off with a blunt knife, while holding the pad at its base. Another way to remove the spines is to burn them off by passing the pad over an open flame, but this should be done with great care and suitable utensils such as tongs with heat resistant handles. Many experts recommend cutting off the edges or peeling them entirely. Most experts agree that the young, bright green pads are the most tender and the best ones for culinary purposes.

If the pads are small, they can be sautéed in a covered pan with some olive oil and vegetables, such as mushrooms, peppers, onions, or tomatoes. The ingredients should be simmered over low heat until the pad is very tender. Some people also prefer to add ground pepper and herbs such as cilantro, basil, or rosemary . The nopales can also be sautéed until cooked. The pads can also be sliced thin to resemble green beans. As Savio states, "They can be eaten raw in salads, boiled and fried like eggplant, pickled with spices, or cooked with shellfish, pork, chilies, tomatoes, eggs, coriander, garlic , and onions." In an article published by Wilderness Way, Christopher Nyerges suggests that the cut slices be boiled in water, drained, and then boiled again to reduce the sliminess. The slices can then be seasoned with butter and garlic powder prior to serving them. Once dried, the peeled and sliced pads are known as leather britches, according to Nyerges. Much like string beans, the leather britches add texture and fiber to stews and soups.

Omelets containing prickly pear cactus are common in the southwestern United States. When a young cactus pad is cooked in a skillet for use in an omelet, its bright green color will change to "a dull green-almost tan-as it cooks," Nyerges explained.

An interesting suggestion regarding "the importance of a penny" can be found in the Worldwide Gourmet. In an article on prickly pear cactus, the reader is encouraged "to rub a copper penny with baking soda and lemon, heat it on the grill until it turns red, and then put it in the water used to cook the nopal. This allows the water to reach its boiling point more quickly and also neutralizes the viscous substance found in the cactus."

Often tasting similar to watermelon, the fruit can be eaten raw and is delicious chilled. It is filled with little seeds, which account for its grainy texture. The seeds are edible, too, but some people prefer to remove them. In the Native American culture, it is customary to dry and grind the seeds for later use in flour.

According to Nyerges, making juice is simple. Just "press the peeled fruit through a colander to remove the seeds and add an equal amount of water to the sweet, pulpy mass." When chilled, it's a refreshing summer beverage.

For soft, shiny hair, cut a peeled cactus pad into 10 small pieces. Put them in a blender with two cups of water. Turn the blender on low for a few seconds, just enough to get the cactus juices into the water but not so long that the mixture turns to mush. Then strain the pieces out, leaving only the juicy water. The juicy water can then be used as a hair massage, which should be thoroughly rinsed out after one minute. If the mixture is allowed to thicken, it can still be used, although it will take more time to rinse out.

For minor cuts, the juice from the pads has been used traditionally much like aloe vera. Savio suggests to "simply cut off a portion of a [peeled] pad, crush it, and squeeze the juice into the cut; the sap will soothe the wound." When an equal measure of prickly pear cactus and water are mixed, the juice can be somewhat jelly-like, making it an ideal salve for windburn.

Recommended dosages vary, but most experts agree that eating 100 to 500 grams of the prickly pear cactus daily is reasonable, provided that there are no contraindications for doing so. For those that prefer juice, 2 to 4 ounces a day are suggested. If in doubt, consult with a physician or registered dietician for an individual assessment.

Precautions

Even Opuntia cacti, regarded as spineless, have glochids, so beware.

Consuming prickly pear cactus is not recommended while pregnant or breast-feeding. In addition, it has not been established whether it is safe for young children or anyone with severe liver or kidney disease to consume nopal.

In general, prickly pear cactus is considered safe in food form, which has been consumed for centuries by native peoples. However, less is known about the extract form, which should be taken only after consulting a physician.

People taking drugs for diabetes should not consume nopal without first consulting with a physician, since insulin or diabetes medication dosage may be affected.

Because water causes dried nopal to swell, oral doses of dried nopal should be taken with at least 8 ounces of water to avoid potentially dangerous blockages of the esophagus or intestines.

Side effects

Adverse side effects such as mild bloating, diarrhea, headache , and nausea have been reported after consuming nopal.

The experts at wholehealthmd.com caution that it is possible to be allergic to prickly pear cactus, although it isn't common. Signs of an allergic reaction are those typically associated with other food allergies . They include skin rash, hives , swelling, chest pain , breathing problems such as tightness in the chest or throat, and digestive symptoms such as diarrhea or constipation. If any of these reactions occur, one should contact a physician immediately.

Although rare, contact dermatitis has been reported from touching the nopal plant or applying it to broken skin. People with sensitive skin should consult a physician before using nopal as a topical ointment. More common is skin irritation caused by coming in contact with the plant's spines during the collection and cleaning process, which is why gloves should be worn, especially during the collection process.

Interactions

Because some studies have shown that consuming nopal may cause lower blood sugar by increasing the body's ability to absorb insulin, people taking drugs for diabetes, such as Actos, Avandia, Glyset, and Prandin, to name a few, should consult with their physician before adding nopal to their diets .

In order to avoid hypoglycemia , which is blood sugar that is too low, nopal should not be used in conjunction with other blood sugar medication and herbs such as bitter melon, chromium, kudzu , panax ginseng, or high amounts of ginger without the guidance of a health professional. Symptoms of hypoglycemia include shakiness, confusion, distorted speech, and loss of muscle control. Hypoglycemia is potentially an emergency and even deadly problem, and requires immediate intervention (offering fruit juice or professional health care management).

In theory, because dried nopal becomes gel-like when combined with water, taking it within two hours of other medications (or even after meals) could alter the way food and medications are absorbed in the body. Always consult with a physician or pharmacist before adding dried nopal (or any form of nopal) to your health care regime. Be sure to make a complete list of any other herbal product being taken, as well as any prescribed or over-the-counter medicine, so that an informed decision can be made.

Resources

PERIODICALS

Chen, Y. D., C. Y. Jeng, C. B. Hollenbeck, M. S. Wu, and G. M. Reaven. "Relationship between plasma glucose and insulin concentration, glucose production, and glucose disposal in normal subjects and patients with non-insulin dependent diabetes." Journal of Clinical Investigation. (1988): 21–25.

Frati-Munari, A. C., B. E. Gordillo, P. Altamirano, and C. R. Ariza. "Hypoglycemic effects of Opuntia streptacantha Lemaire in NIDDM." Diabetes Care. (1988): 63–66.

Frati-Munari, A. C., J. L. Q. Lazaro, P. Altamirano Bustamante, M. Banales Ham, S. Islas-Andrade, and C. R. Ariza-Andraca. "The effect of different doses of prickly pear cactus (Opuntia streptacantha Lemaire) on the glucose tolerance test in healthy individuals." Archives of Investigative Medicine. (1988): 143–148.

Frati-Munari, A. C., B. E. Gordillo, P. Altamirano, C. R. Ariza, R. Cortes-Franco, A. Chavez-Negrete, and S. Islas-Andrade. "Influence of nopal intake upon fasting glycemia in type 2 diabetics and healthy subjects." Archives of Investigative Medicine. (1991): 51–56.

Frati-Munari, A. C., N. X. Diaz, P. Altamirano, C.R. Ariza, and R. Lopez-Ledesma. "The effect of two sequential doses of Opuntia streptacantha upon glycemia." Archives of Investigative Medicine (1991): 431–436.

Gannon, M. C., F. Q. Nuttall, S. A. Neil, and E. R. Seaquest. "Effects of dose ingested glucose on serum metabolite and hormone responses in type 2 diabetic subjects." Diabetes Care (1989): 544–552.

Park, E. H., J. H. Kahng, E. A. Paek. "Studies on the pharmacological action of cactus: identification of its anti-inflammatory effect." Archives of Pharmaceutical Research. (1998): 30–34.

Rayburn, K., R. Martinez, M. Escobedo, F. Wright, and M. Farias. "Glycemic effects of various species of nopal (Opuntia sp. ) in type 2 diabetes mellitus." Texas Journal of Rural Health. (1998): 68–74.

Shapiro, K., and W. C. Gong. "Natural products used for diabetes." Journal of American Pharmacists Association. (2002): 217–226.

OTHER

Nyerges, "C. Prickly pear cactus." Wilderness Way [cited June 14, 2004]. <http://www.wwmag.net/pricklycactus.htm>.

"Prickly pear." Wholehealthmd.com [cited June 14, 2004]. <http://www.wholehealthmd.com>.

"Prickly pear and barbary fig." The Worldwide Gourmet [cited June 14, 2004]. <http://gourmet.sympatico.ca/vegetables/south/nopal.htm>

"Prickly pear cactus crop with multiple uses." The Hindu [cited June 14, 2004]. <http://www.hindu.com>.

Rodriguez-Felix, A., and M. A. Villegas-Ochoa. "Postharvest handling of cactus leaves (nopalitos)." Paper presented at the International Symposium of Cactus Pear and Nopalitos Processing and Uses. Santiago, Chile (September 24-26, 1998).

Savio, Yvonne. Prickly pear cactus. Brochure. Small Farm Center, University of California. July 1989 [cited June 14, 2004]. <http://www.sfc.ucdavis.edu/pubs/brochures/pricklypear.html>.

Lee Ann Paradise

opuntia See prickly pear.