Food as Medicine: Prickly Pear Cactus (Opuntia ficus-indica, Cactaceae)

History and Traditional Use


Range and Habitat

The cactus genus Opuntia encompasses a large group of species characterized by flat, jointed or segmented pads known in botany as cladodes and in Spanish as nopales (singular: nopal).1 The cladodes are cylindrical or conical in shape, covered with clusters of spines, and are uniquely adapted to a dry desert climate due to thick, waxy stems that store water and minimize water evaporation in much the same way that leaves do.2 Yellow, orange, pink and red flowers grow on the plant. Pear-shaped fruits, called tunas, mature on the cactus pads in early fall. Two types of spines grow on the pads: large, fixed spines, and small, barbed spines that detach from the plant easily.3 The fruit often has clusters of smaller, inconspicuous spines and vary in color from green, yellow, red, orange, and purple. The fruit contains hard seeds surrounded by a fleshy portion. These succulent shrubs are drought-tolerant and grow in arid and semiarid climates. The prickly pear is native to Mexico but now grows across the United States, Australia, and South Africa.4 Prickly pear can be cultivated and propagated easily because the pads can be removed from the plant and replanted, forming a new growth.


Phytochemicals and Constituents

Opuntia species contain a variety of nutrients and bioactive compounds that are beneficial for human health. The pad and fruit compositions differ, but both provide various levels of macronutrient distribution, vitamins, minerals, and phytochemicals.

The fruits of the Opuntia species are rich in antioxidant pigments called betacyanins.5 Betacyanins from cactus pear fruit have been found to reduce low-density lipoprotein (LDL) cholesterol levels after consumption and protect against oxidation.6 Numerous flavonol glycosides, plant-derived secondary metabolites with important antioxidant properties, have been isolated from O. ficus-indica fruit concentrates.7

Pads of the Opuntia species contain manganese, which is essential for glucose metabolism8; magnesium, which helps the body regulate protein synthesis, muscle and nerve function, blood glucose, and blood pressure9; and vitamin C.

Historical and Commercial Uses

The prickly pear has been used traditionally in a variety of ways, including the treatment of digestive problems, edema, and topically for burn and wound care.10 The bitter plant also has been used as a diuretic, a fever reducer, for vitiligo (localized loss of pigmentation in the skin), urinary problems, tumors, abdominal fluid buildup, inflammation, liver problems, anemia, ulcers, bronchitis, hemorrhoids, bladder stones, inflammation of the eyes, lower back pain, spleen enlargement, and management of human immunodeficiency virus (HIV).3,11 Mashed pads historically were used to relieve heat and inflammation. They were also applied to boils for quick removal of pus. The flowers were used for lung problems, including bronchitis and asthma. The fruit of the plant was used to cool the body, treat gonorrhea and whooping cough, expel phlegm from the lungs, control excessive coughing, and increase bile secretion. Indigenous tribes in Mexico and the Pima tribe in central and southern Arizona use the cactus as a treatment for diabetes. Additional historical uses of the species include treatment of hangovers, prostate enlargement, and rabies.12

Opuntia cacti played an important role in the daily life and economy of the Aztec and Maya since they served not only as sources of food for humans and livestock but also as host plants for the cochineal insect (Dactylopius coccus).13 Cochineals are used to make carmine dye, a highly prized red dye for textiles. Carmine-dyed wool and cotton remain important mediums in Mexican folk art.

Currently, Opuntia is cultivated in arid and semiarid climates across the world including Mexico, Argentina, Brazil, Tunisia, Italy, Israel, China, Spain, and California.3,14 Uses of different components of the prickly pear encompass traditional uses as well as use for food and beverages, for livestock fodder, dye, soap, drinking water purification, thickening agent, and as a protective hedge for fencing.10 Mexico, Spain, Italy, northern Africa, and the United States commonly use the plant for food, consuming both the pad and the fruit.3

Modern Research

Treatment of diabetes has been cited as a traditional use for Opuntia, prompting research on its effects on various health parameters associated with diabetes. Rats with induced diabetes fed nopal flour from medium-sized pads followed by glucose were found to have a reduced post-meal glucose peak.15 A 40% reduction in fasting blood sugar was also seen in rats that consumed nopal flour, and a 30% decrease from treatment with nopal flour made with smaller pads. The results suggest that the maturity (as indicated by the size) of the pad modifies the blood sugar-lowering effects of Opuntia. The fiber found in the pad could be the primary component responsible for its blood sugar-lowering effects, delaying the absorption of carbohydrates from foods. Additional benefits have been found in animal studies: concentrated juice from the fruit of O. ficus-indica has been found to protect against ulcer formation in rats.7

Studies in humans have also explored the antidiabetic properties of prickly pear. A recent small study of type 2 diabetics found that consumption of steamed nopales significantly reduced spikes in blood glucose levels and serum insulin levels up to one hour after consumption of a high-carbohydrate breakfast.16 The study also found a significant decrease in the glucose-dependent insulinotropic peptide (a hormone released from the small intestine that stimulates insulin production17) after consumption of nopales and a high-carbohydrate breakfast. In pre-diabetics, a product formulated with both cladode and fruit skin extract of O. ficus-indica, named OpunDia™ (Martin Bauer Group, Vestenbergsgreuth, Germany), has been found to reduce blood glucose spikes 60, 90, and 120 minutes after ingestion followed by 75 g of a glucose solution.18

Studies have found additional uses for the fruit and cladodes of the prickly pear. The cladodes of the prickly pear cactus contain high levels of calcium and have been studied for their effects on bone mineral density. Urine calcium/creatinine levels decreased (increased urinary excretion of calcium can be a symptom of bone-destroying diseases, among other physiological abnormalities), and bone mineral density in the total hip region was increased in women 35 to 55 years old after daily consumption of 55 g of dehydrated nopal.19 Premenopausal women consuming 15 g of dehydrated nopal also had increased bone mineral density of the lumbar spine region. The 15 g of dehydrated nopal contained 500 mg of calcium and used nopales harvested at a high maturity stage. Furthermore, consumption of tortillas filled with cactus fruit jam increased blood antioxidant levels, blood vitamin C levels, and protected lipids from oxidation in human participants.20 The jam-filled tortillas also significantly reduced blood glucose, total cholesterol, and triglyceride levels. Some evidence of antiviral properties, immunomodulation, improvement of platelet function, and neuroprotection have also been noted.3

Interestingly, some research suggests that prickly pear may be a useful and practical tool for water filtration. A study from 2010 found that prickly pear gel filtered out 98% of bacteria in a contaminated water sample. The researchers noted that the cactus could “become a sustainable and affordable water purification method in the rural communities of developing countries.”21


Nutrient Profile22

Macronutrient Profile: (Per 100 g [approx. 1 1/4 cup sliced] raw nopal)

16 calories
1.3 g protein
3.33 g carbohydrate
0.1 g fat

Secondary Metabolites: (Per 100 g [approx. 1 1/4 cup sliced] raw nopal)

Very good source of:

Calcium: 164 mg (16.4% DV)
Vitamin C: 9.3 mg (15.5% DV)
Magnesium: 52 mg (13% DV)

Good source of:

Vitamin A: 457 IU (9.1% DV)
Dietary Fiber: 2.2 g (8.8% DV)
Potassium: 257 mg (7.34% DV)
Vitamin K: 5.3 mcg (6.63% DV)

Also provides:

Vitamin B6: 0.07 mg (3.5% DV)
Iron: 0.6 mg (3.33% DV)
Riboflavin: 0.04 mg (2.35% DV)
Niacin: 0.41 mg (2.05% DV)
Zinc: 0.25 mg (1.67% DV)
Phosphorus: 16 mg (1.6% DV)

DV = Daily Value as established by the US Food and Drug Administration, based on a 2,000 calorie diet.


Recipe:
Cactus Casserole with Rice, Ancho Chili, and Cheese

Ingredients:

  • 2 dried ancho chilies, stems and seeds removed
  • 3/4 pound cactus pads (or 1 15-ounce jar/can of nopales, drained and rinsed)
  • 1 tablespoon canola or vegetable oil
  • 1/2 medium yellow onion, diced
  • 3 cloves of garlic, minced
  • 2 cups sour cream
  • 2 teaspoons ground cumin
  • 1 teaspoon dried oregano
  • 1/2 teaspoon ground allspice
  • 1/4 teaspoon cayenne pepper
  • 3 cups of cooked rice (white or brown)
  • 8 ounces Monterrey Jack cheese, shredded
  • Salt and pepper to taste

Directions:

  1. In a dry skillet over high heat, toast the chilies for about 10 seconds on each side, or until they begin to puff. Remove the chilies and soak in hot water until soft, about 20 minutes. Once hydrated, discard the soaking water and place the chilies in a blender or food processor with 1/4 cup of fresh water and blend until paste forms. Set aside.

  2. Heat the oven to 350° F.

  3. If using fresh cactus paddles: remove the thorns by trimming the thick base and edges of the paddle, then scrape the thorns with a paring knife without taking off too much of the green skin. Take care with this step; gloves are recommended. Thinly slice. Place the fresh cactus slices in a pot of water and bring to a boil. Reduce heat and simmer for 15 minutes. Drain and rinse well. Set aside.

  4. In a large skillet, heat the canola oil over medium heat. Add the onions and cook until translucent, about 5-7 minutes. Add garlic and cook for an additional minute, then remove the skillet from the heat. Set aside.

  5. In a bowl, mix together sour cream, prepared ancho chili paste, cumin, oregano, allspice, cayenne, and half of the shredded cheese. Add cooked rice, cactus, and onion-garlic mixture and stir to combine, tasting and adjusting seasoning as necessary. Pour the casserole into a greased baking dish and top with the remaining cheese.

  6. Bake uncovered for 30 minutes, until brown and bubbling.

References

  1. Loflin B, Loflin S. Texas Cacti: A Field Guide. College Station, TX: Texas A&M University Press; 2009.
  2. Nobel, PS. Ecophysiology of Opuntia ficus-indica. In: Mondragón-Jacobo C and Pérez-González S, eds. Cactus (Opuntia spp.) as Forage. Rome, Italy: Food and Agriculture Organization of the United Nations; 2001:13-20.
  3. Chauhan SP, Sheth NR, Jivani NP, Rathod IS, Shah PI. Biological actions of Opuntia species. System Rev Pharm. 2010;1(2):146-151.
  4. Van Wyck BE. Food Plants of the World: An Illustrated Guide. Portland, OR: Timber Press; 2006.
  5. Castellar R, Obón J, Alacid M, Fernández-López JA. Color properties and stability of betacyanins from Opuntia fruits. J Agric Food Chem. 2003;51(9):2772-2776.
  6. Tesoriere L, Allegra M, Butera D, Livrea MA. Absorption, excretion, and distribution of dietary antioxidant betalains in LDLs: potential health effects of betalains in humans. Am J Clin Nutr. 2004;80(4):941-945.
  7. Galati EM, Mondello MR, Giuffrida D, et al. Chemical characterization and biological effects of Sicilian Opuntia ficus indica (L.) Mill. fruit juice: antioxidant and antiulcerogenic activity. J Agric Food Chem. 2003;51(17):4903-4908.
  8. Emsley J. Nature’s Building Blocks: An A-Z Guide to the Elements, 2nd ed. Oxford, UK: Oxford University Press; 2011.
  9. Magnesium: Fact Sheet for Health Professionals. National Institutes of Health Office of Dietary Supplements website. November 4, 2013. Available here. Accessed August 17, 2015.
  10. Shetty AA, Rana MK, Preetham SP. Cactus: a medicinal food. J Food Sci Technol. 2012;49(5):530-536.
  11. Kaur M, Kaur A, Sharma R. Pharmalogical actions of Opuntia ficus-indica: A review. J App Pharm Sci. 2012;2(7):15-18.
  12. Dvorkin-Camiel L, Whelan JS. Tropical American plants in the treatment of infectious disease. J Diet Suppl. 2008;5(4):349-372.
  13. Gibson AC. Red Scales in the Sunset. UCLA College of Life Sciences – Mildred E. Mathias Botanical Garden website. Available here. Accessed August 17, 2015.
  14. Stintzing F, Carle R. Cactus stems (Opuntia spp.): A review on their chemistry, technology, and uses. Mol Nutr Food Res. 2005;49(2):175-194.
  15. Nuñez-López MA, Paredes-López O, Reynoso-Camacho R. Functional and hypoglycemic properties of nopal cladodes (O. ficus-indica) at different maturity stages using in vitro and in vivo tests. J Agr Food Chem. 2013;61(46):10981-10986.
  16. López-Romero P, Pichardo-Ontiveros E, Avila-Nava A, et al. The effect of nopal (Opuntia ficus indica) on postprandial blood glucose, incretins, and antioxidant activity in Mexican patients with type 2 diabetes after consumption of two different composition breakfasts. J Acad Nutr Diet. 2014;114(11):1811-1818.
  17. Glucose-dependent insulinotropic peptide. The Free Dictionary website. Available here. Accessed September 10, 2015.
  18. Godard MP, Ewing BA, Pischel I, Ziegler A, Benedek B, Feistel B. Acute blood glucose lowering effects and long-term safety of OpunDia™ supplementation in pre-diabetic males and females. J Ethnopharmacol. 2010;130(3):631-634.
  19. Aguilera-Barreiro M, Rivera-Márquez JA, Trujillo-Arriaga HM, Tamayo y Orozco JA, Barreira-Mercado E, Rodríguez-García ME. Intake of dehydrated nopal (Opuntia ficus indica) improves bone mineral density and calciuria in adult Mexican women. Food Nutr Res. 2013;57:19106-19115.
  20. Guevara-Arauza J, Paz J, Mendoza S, Guerra R, Maldonado L, González D. Biofunctional activity of tortillas and bars enhanced with nopal. Preliminary assessment of functional effect after intake on the oxidative status in healthy volunteers. Chem Cent J. 2011;5:10-20.
  21. Cactus purifies water on the cheap, finds study. SciDevNet website. Available here. Accessed September 10, 2015.
  22. Basic Report: 11963, Nopales, raw. Agricultural Research Service, United States Department of Agriculture website. Available here. Accessed August 17, 2015.
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Mediterranean Diet: Facts and Health Benefits

Traditionally, Western Europe has two broad nutritional approaches – the Northern European and Southern European. The Mediterranean Diet is Southern European, and more specifically focuses on the eating habits of the people of Crete, much of Greece, and southern Italy.

Today, Spain, southern France, and Portugal are also included; even though Portugal does not have a Mediterranean coast.

The Mediterranean diet includes

  • Lots of plant foods
  • Fresh fruit as dessert
  • High consumption of beans, nuts, cereals (in the form of wheat, oats, barley, corn or brown rice) and seeds
  • Olive oil as the main source of dietary fat
  • Cheese and yogurt as the main dairy foods
  • Moderate amounts of fish and poultry
  • No more than about four eggs each week
  • Small amounts of red meat each week (compared to northern Europe)
  • Low to moderate amounts of wine
  • 25% to 35% of calorie intake consists of fat
  • Saturated fat makes up no more than 8% of calorie intake
Olive oil
Olive oil is one of the main sources of dietary fat.

Fats – the Mediterranean diet is known to be low in saturated fat, high in monounsaturated fat, and high in dietary fiber.

Legumes – the Mediterranean diet includes plenty of legumes. Legumes are plants in the pea family that produce pods which slit open naturally along a seam, revealing a row of seeds.

Examples of legumes include peas, chick peas, lentils, alfalfa, and beans.

Scientists from the University of Toronto reported in Archives of Internal Medicine, October 2012 issue, that eating more legumes helps improve glycemic control in people with diabetes type 2, as well as lessening the risk of developing coronary heart disease.

The Mediterranean diet – worldwide recognition

The Mediterranean diet became popular in the 1990s – even though the American Scientist Dr. Ancel Keys (1904-2004) publicized the Mediterranean diet while he was stationed in Italy, it was not until about the 1990s that it was widely recognized and followed elsewhere by nutritionally conscious people.

An enigma

Compared to other Western diets, the Mediterranean diet was seen by others as a bit of an enigma. Although fat consumption is high, the prevalence of hypertension, cardiovascular disease, obesity, cancer, and diabetes has always been significantly lower in Mediterranean countries than northern European countries and the USA. The American diet is more similar to the northern European diet – with high red meat consumption, greater consumption of butter and animal fats, and a lower intake of fruit and vegetables, compared to the eating habits of Italy, Greece, southern France, and Spain.

Mediterranean diet more popular in non-English speaking nations

The non-English speaking countries of northern Europe, such as Scandinavia, the Netherlands, Belgium, Germany, Switzerland, and Austria have adopted the Mediterranean diet to a much greater degree than English-speaking nations, such as the UK, Ireland, the USA, Australia and New Zealand.

Dietary habits in Canada vary; with the French-speaking Quebec areas tending more towards a Mediterranean diet, compared to the rest of the country. Many experts believe that is why developed English-speaking nations have a lower life expectancy than the other developed nations.

Mediterranean countries consume higher quantities of red wine, while northern European countries and the USA consume more beer. Red wine contains flavonoids, which are powerful antioxidants, according to a study in the Journal of Natural Products.

The Mediterranean diet, compared to the Anglo-Saxon diet, contains much higher quantities of unprocessed foods.

Health benefits of the Mediterranean diet

Studies have been carried out which compare the health risks of developing certain diseases, depending on people’s diets. People who adopted the Mediterranean diet have been compared with those who have an American or Northern European diet.

An article published in Food Technology in October 2012 explained that plant-based diets either considerably reduce or totally eliminate people’s genetic propensity to developing chronic diseases, such as diabetes type 2, cardiovascular disease, and cancer.

Mediterranean diet helps prevent a genetic risk of stroke – a variant (mutation) in the Transcription Factor 7-like 2 (TCF7L2) gene, which is associated with the development of type 2 diabetes, is also linked to higher stroke risk, especially if a person carries two copies (homozygous carriers).

Scientists from Tufts University, USA, and the CIBER Fisiopatología de la Obesidad y Nutriciόn, Spain, found that the Mediterranean diet may protect homozygous carriers of the mutated gene.

The researchers wrote in the journal Diabetes Care “Being on the Mediterranean diet reduced the number of strokes in people with two copies of the variant. The food they ate appeared to eliminate any increased stroke susceptibility, putting them on an even playing field with people with one or no copies of the variant.”

An Italian study published in BMJ Open reported that people who stick to a Mediterranean diet tend to have better HRQL (health-related quality of life). They added that the link is stronger with mental than physical health. “Dietary total antioxidant and fiber content independently explain this relationship,” they added.

Heart benefits

Researchers at McMaster University found an association between good heart health and certain food groups or dietary patterns including vegetables, nuts, monounsaturated fatty acids, and overall ‘healthy’ dietary patterns, such as the Mediterranean diet. The study was published in the Archives of Internal Medicine.

A later study, published in the American Journal of Medicine, suggested that people who adopt a whole diet approach – such as a Mediterranean diet – have a lower risk of heart attack and cardiovascular-related death than those who follow a strictly low-fat diet

Diabetes

A study published in the BMJ in 2008 revealed that the traditional Mediterranean diet can help protect people from type 2 diabetes.

Mediterranean Diet Enriched with Virgin Olive Oil May Protect the Heart

Forget chocolates and roses this Valentine’s day. Instead, cook up a Mediterranean-inspired meal with lashings of virgin olive oil to win and protect your lover’s, heart. New research reports that a Mediterranean diet rich in virgin olive oil may boost the cardioprotective effects of “good” cholesterol.
[Sandwich with mozzarella, sun-dried tomatoes and arugula]
Consuming a Mediterranean diet rich in virgin olive oil may protect the heart.

Montserrat Fitó, Ph.D., was the senior author of the new research and coordinator of the Cardiovascular Risk and Nutrition Research Group at the Hospital del Mar Medical Research Institute in Barcelona, Spain, as well as the Ciber of Physiopathology of Obesity and Nutrition, also in Spain. Fitó and team’s findings were published in the American Heart Association’s journal Circulation.

There are two types of molecules called lipoproteins that carry cholesterol in the blood: low-density lipoprotein (LDL) and high-density lipoprotein (HDL).

LDL is known as “bad” cholesterol, since having high levels of LDL can bring about plaque buildup in the arteries, which can result in heart disease and stroke. HDL is known as “good” cholesterol; HDL absorbs cholesterol and carries it to the liver where it is flushed from the body. Having high levels of HDL reduces heart disease and stroke.

Mediterranean diets compared with healthy control diet

A growing body of evidence supports the theory that the Mediterranean diet protects against the development of heart disease. Studies have also shown that the Mediterranean diet improves the lipid profile of HDLs.

“However, studies have shown that HDL doesn’t work as well in people at high risk for heart attacks, strokes, and other cardiovascular diseases and that the functional ability of HDL matters as much as its quantity,” explains Fitó. “At the same time, small-scale trials have shown that consuming antioxidant-rich foods like virgin olive oil, tomatoes, and berries improved HDL function in humans. We wanted to test those findings in a larger, controlled study,” she adds.

The research team aimed to determine whether eating a Mediterranean diet enriched with virgin olive oil or nuts over a long period of time would improve the beneficial properties of HDL in humans.

Fitó and collaborators randomly selected a total of 296 individuals who had a high risk of heart disease and were participating in the Prevención con Dieta Mediterránea study. The participants had an average age of 66 and were assigned to one of three diets for a year.

The first diet was a traditional Mediterranean diet enriched with around 4 tablespoons of virgin olive oil per day. The second, a traditional Mediterranean diet supplemented with a fistful of nuts each day. The third diet was a healthful “control” diet that contained a reduced amount of red meat, high-fat dairy products, processed foods, and sweets.

Both Mediterranean diets emphasized the inclusion of fruit, vegetables, legumes (such as beans, chickpeas, lentils, and whole grains), and moderate amounts of fish and poultry.

Blood tests were conducted at the start and end of the study to measure LDL and HDL levels.

Virgin olive oil-enriched Mediterranean diet enhanced HDL function

The researchers found that total and LDL cholesterol levels were only reduced in the healthful control diet. While none of the three diets significantly increased HDL levels, the two Mediterranean diets improved HDL function, and the improvement was more pronounced in the group enriched with virgin olive oil.

The Mediterranean diet enriched with virgin olive oil improved HDL functions, such as reversing cholesterol transport, providing antioxidant protection, and enabling vasodilation.

Reverse cholesterol transport is the process in which HDL removes cholesterol from plaque in the arteries and takes it to the liver. Antioxidant protection is the ability of HDL to counteract the oxidation of LDL. Oxidation of LDL triggers the development of plaque in the arteries.

Lastly, vasodilator capacity – which relaxes the blood vessels, keeps them open, and keeps the blood flowing – is improved by the Mediterranean diet with virgin olive oil.

Although the control diet was rich in fruits and vegetables like the two Mediterranean diets, the diet was shown to have an adverse impact on HDL’s anti-inflammatory properties. This negative impact was not observed in the Mediterranean diets. A reduction in HDL’s anti-inflammatory capacity is linked with a greater risk of heart disease.

As expected, the researchers only found slight differences in results between the diets, because the variation between the two Mediterranean diets was modest, and the control diet was healthful.

“Following a Mediterranean diet rich in virgin olive oil could protect our cardiovascular health in several ways, including making our ‘good cholesterol’ work in a more complete way.”

Montserrat Fitó

This research could contribute to the development of novel therapeutic targets, such as new antioxidant-rich foods, nutraceuticals, or new drug families that may improve HDL function, conclude the study authors.