HerbalEGram: Volume 12, Issue 1, January 2015

Editor’s Note: This article is the continuation of the new HerbalEGram “Food as Medicine” series. Each month, HerbalEGram will highlight a conventional food and briefly explores its history, traditional uses, nutritional profile, and modern medicinal research. We also feature a nutritious recipe for an easy-to-prepare dish with each article to encourage readers to experience the extensive benefits of these whole foods. With this series, we hope our readers will gain a new appreciation for the foods they see at the supermarket and frequently include in their diets.

History and Traditional Use

Range and Habitat

Horseradish (Armoracia rusticana, Brassicaceae) is a hardy perennial native to southeastern Europe and western Asia. Today, it is grown in the temperate regions of Europe, Asia, and North and South America, as well as some parts of Africa and New Zealand.¹ The plant grows in clumps with bright green leaves that radiate out from the main taproot, which is cultivated as a food ingredient.² Small, white, four-petaled flowers grow from a stalk that can reach two to three feet or higher when flowering.² Young leaves two to three inches in length also can be harvested for use in salads.³

Horseradish is easy to cultivate and often will continue to thrive even during periods of neglect.⁴ While technically a perennial, it is best treated as an annual or biennial crop due to the root’s tendency to become woody and unpalatable with age. Once established, horseradish grows well in full sun and slightly moist soil.¹

Phytochemicals and Constituents

Glucosinolates, sulfur-containing secondary metabolites, give horseradish its characteristic spicy flavor.⁵ Horseradish contains eight different glucosinolates, of which sinigrin, gluconasturtiin, glucobrassicin, and neoglucobrassicin are the most common.⁵ Once inside the body, glucosinolates are broken down into powerful derivatives called isothiocyanates and indoles, which are believed to be the main cancer-preventive constituents of horseradish and other cruciferous vegetables (i.e., vegetables of the family Brassicaceae).^1,6

Horseradish also contains minerals such as phosphorous, calcium, magnesium, and potassium.⁷ Freshly grated roots contain minimal fat, are low in calories, and rich in vitamin C. Cooking horseradish can strip it of its nutritional value, so it is best used fresh.¹

Historical Uses

Horseradish root has been ground into a spice, prepared as a condiment, and used medicinally for more than 3,000 years. It was used topically by both the Greeks and Romans as a poultice to ease muscle pain, such as back aches and menstrual cramps.³ Internally, it was used to relieve coughs and as an aphrodisiac.⁴ Starting in the Middle Ages (ca. 1000-1300 CE), horseradish was incorporated into the Jewish Passover Seder as one of the maror, or bitter herbs.³ In the 16th century, Europeans began using horseradish in sauces and condiments as well as for its medicinal applications.

Historically, horseradish was used to treat a wide variety of illnesses including asthma, coughs, colic, toothache, and scurvy (due to its vitamin C content). Grated horseradish poultices were used to ease pain associated with gout and sciatica, and also were infused in milk to clarify the skin and remove freckles.³ Currently, horseradish is consumed regularly in the form of ready-to-use sauces and dips.² In 2005, the Horseradish Information Council reported that in the United States, 24 million pounds of horseradish roots were processed into six million gallons of prepared horseradish sauce.³

Modern Research & Uses

The chemoprotective role of horseradish’s gluconsinolate content against various types of cancers in humans has been widely studied.^8,9 A hydrolyzed form of the glucosinolate sinigrin has been shown to suppress the growth of cancerous tumors in vitro and protect against further DNA damage.^9,10 One hypothesis is that glucosinolates may work by enhancing the liver’s ability to detoxify carcinogens.¹⁰ Using a rat model, researchers found that sinigrin affects many organs involved in carbohydrate and lipid metabolism, including the liver, pancreas, and intestine.¹¹ Sinigrin also reduced lipid levels in the blood, suggesting that it could be beneficial in reducing elevated triglyceride levels after meals, a risk factor for coronary artery disease.¹¹

Horseradish also contains allyl isothiocyanate, which is a well-recognized antimicrobial agent against a variety of organisms including pathogens like Escherichia coli (E. coli), a common food-borne pathogen, and Helicobacter pylori (H. pylori), a bacteria known to cause stomach ulcers and increase the risk for gastric cancer.¹² Due to its antibiotic properties, horseradish can be used to treat urinary tract infections and destroy bacteria in the throat that can cause bronchitis, coughs, and other related problems.¹³ In a recent study, isothiocyanates extracted from horseradish showed antimicrobial activity against ten different oral microorganisms.¹⁴ Although broccoli (Brassica oleracea var. italica), Brussels sprouts (B. oleracea var. gemmifera), and other cruciferous vegetables also contain these compounds, horseradish has up to ten times more glucosinolates than other members of the family Brassicaceae.¹⁰

Horseradish root was approved as a nonprescription medicine ingredient by the German Commission E for treatment of infections of the respiratory tract and as supportive treatment in urinary tract infections.¹³ In the United States, horseradish root is the active ingredient of Rasapen, a urinary antiseptic drug.¹³ Horseradish is considered a strong diuretic and, coupled with its antibacterial properties, acts to flush out harmful bacteria or other inflammatory agents in the bladder sooner than they normally would be eliminated.¹⁰

Isothiocyanates in horseradish root are released when hydrolyzed by other active enzymes, which are activated only when the root is scratched.¹⁵ Fumes released from grating or cutting the root can irritate the membranes of the eyes and nose, and therefore horseradish should be prepared in a well-ventilated room and care should be taken in its use.

Nutrient Profile

Macronutrient Profile: (Per 1 tablespoon [15 g] raw horseradish)

Calories: 7

Protein: 0.18 g

Carbohydrates: 1.69 g

Fat: 0.1 g

Secondary Metabolites: (Per 1 tablespoon [15 g] raw horseradish)

Good source of:

Vitamin K: 0.2 mcg (2.5% DV)

Folate: 9 mcg (2.25% DV)

Dietary fiber: 0.5 g (2% DV)

Potassium: 37 mg (1.1% DV)

Magnesium: 4 mg (1% DV)

Calcium: 8 mg (0.8% DV)

Zinc: 0.12 mg (0.8% DV)

Vitamin B6: 0.01 mg (0.5%DV)

Phosphorus: 5 mg (0.5% DV)

Niacin: 0.06 mg (0.3% DV)

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

Recipe: Kale and Potato Hash

Recipe courtesy of EatingWell magazine¹⁶

Ingredients:

·       8 cups torn kale leaves

·       2 tablespoons freshly grated horseradish

·       1 medium shallot, minced

·       1/2 teaspoon freshly ground pepper

·       1/4 teaspoon kosher salt

·       2 cups shredded cooked potatoes

·       3 tablespoons extra virgin olive oil

Directions:

1.    Place kale in a large microwave-safe bowl, cover, and microwave until wilted, about 3 minutes. Drain, cool slightly, and finely chop.

2.    Meanwhile, mix horseradish, shallot, pepper, and salt in a large bowl. Add the chopped kale and potatoes; stir to combine.

3.    Heat oil in a large nonstick skillet over medium heat. Add the kale mixture, spread into an even layer, and cook, stirring every 3 to 4 minutes and returning the mixture to an even layer, until the potatoes begin to turn golden brown and crisp, 12 to 15 minutes total.

—Hannah Bauman

References

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2. Van Wyk B-E. Food Plants of the World: An Illustrated Guide. Portland, OR: Timber Press; 2005.
   
   
3. The Essential Guide to Horseradish. The Herbal Society of America website.  Available here. Accessed January 5, 2015.
   
   
4. National Geographic Society. Edible: An Illustrated Guide to the World's Food Plants. Washington, DC: National Geographic Society; 2008.
   
   
5. Alnsour M, Kleinwächter M, Böhme J, Selmar D. Sulfate determines the glucosinolate concentration of horseradish in vitro plants (Armoracia rusticana Gaertn., Mey. & Scherb.). J Sci Food Agric. 2013;93(4):918-923.
   
   
6. Rinzler CA. The New Complete Book of Herbs, Spices, and Condiments: A Nutritional, Medical, and Culinary Guide. New York, NY: Checkmark Books; 2001.
   
   
7. US Department of Agriculture. USDA National Nutrient Database for Standard Reference, Release 27. Available here. Accessed January 5, 2015.
   
   
8. Hayes JD, Kelleher MO, Eggleston IM. The cancer chemopreventive actions of phytochemicals derived from glucosinolates. Eur J Nutr. 2008;47(2):73-88.
   
   
9. Bonnesen C, Eggleston IM, Hayes JD. Dietary indoles and isothiocyanates that are generated from cruciferous vegetables can both stimulate apoptosis and confer protection against DNA damage in human colon cell lines. Cancer Res. 2001;61(16):6120-6130. Available here. Accessed January 5, 2015.
   
   
10. Patel DK, Patel K, Gadewar M, Tahilyani V. A concise report on pharmacological and bioanalytical aspect of sinigrin. Asian Pac J Trop Biomed. 2012;2(1):S446-S448.
    
    
11. Okulicz M. Multidirectional time-dependent effect of sinigrin and allyl isothiocyanate on metabolic parameters in rats. Plant Foods Hum Nutr. 2010;65(3):217-224.
    
    
12. Luciano FB, Holley RA. Enzymatic inhibition by allyl isothiocyanate and factors affecting its antimicrobial action against escherichia coli O157:H7. Int J Food Microbiol. 2009;131(2): 240-245.
    
    
13. Blumenthal M, Goldberg A, Brinkmann J, eds. Herbal Medicine: Expanded Commission E Monographs. Austin, TX: American Botanical Council and Newton, MA: Integrative Medicine Communications; 2000.
    
    
14. Park HW, Choi KD, Shin IS. Antimicrobial activity of isothiocyanates (ITCs) extracted from horseradish (Armoracia rusticana) root against oral microorganisms. Biocontrol Sci. 2013;18(3):163-168. Available here. Accessed January 5, 2015.
    
    
15. Duke JA, ed. CRC Handbook of Medicinal Spices. Boca Raton, FL: CRC Press; 2002.
    
    
16. Kale and Potato Hash. EatingWell. October/November 2005. Available here. Accessed January 13, 2005.