Horseradish

Christopher Hobbs:

“Horseradish is a stimulating herb used for lack of appetite as well as for colds and flu and urinary tract infections. It is a good expectorant and is used in respiratory infections. Holding a small quantity of grated horseradish in the mouth is said to alleviate sinus congestion and infections. Externally, it is used to heal infected wounds and relieve inflamed joints, rheumatism and sciatica. It is also used externally to break up mucus in the respiratory tract. Traditionally it was applied to infected wounds and taken internally for urinary disorders. Horseradish is one of the active ingredients in wasabi, a condiment popular in Japanese cuisine.

Horseradish has a taste of ACRID and a temperature of HOT.”

Historical Uses

• Traditional Medicine: Horseradish has long been used in folk medicine as a remedy for respiratory conditions, urinary tract infections, rheumatism, and digestive issues. The root was commonly used to stimulate digestion and clear sinus congestion.
• Antimicrobial Agent: Known for its antimicrobial properties, it was often used to preserve food and as a poultice for wounds.

Modern Clinical Uses by Herbalists & Naturopaths

• Respiratory Health: Used for sinus infections, bronchitis, and colds due to its mucolytic (mucus-breaking) properties.
• Digestive Aid: Often recommended to improve appetite and aid digestion by stimulating gastric secretions.
• Antimicrobial Support: Applied for urinary tract infections and mild bacterial conditions, sometimes paired with cranberry or bearberry.
• Topical Use: In some naturopathic practices, it is used as a rubefacient (skin stimulant) for muscle aches and joint pain.

Chemistry

• Active Compounds:
  • Glucosinolates: These sulfur-containing compounds, such as sinigrin, are hydrolyzed to produce isothiocyanates (e.g., allyl isothiocyanate), which give horseradish its pungency and biological effects.
  • Enzymes: The enzyme myrosinase activates the breakdown of glucosinolates into bioactive compounds when the root is crushed or grated.
  • Volatile Oils: Allyl isothiocyanate is the primary compound responsible for antimicrobial and irritant effects.
• Nutrients: Rich in vitamin C, potassium, calcium, magnesium, and dietary fiber.

Pharmacology

• Antimicrobial Activity: Allyl isothiocyanate has shown inhibitory effects on bacteria, fungi, and some viruses.
• Anti-inflammatory Effects: Studies suggest mild anti-inflammatory properties, possibly through modulation of cytokines.
• Cancer Research: Glucosinolates and their derivatives have been studied for their potential role in chemoprevention, particularly in detoxification of carcinogens.

Safety

• General Safety: Horseradish is generally recognized as safe (GRAS) when consumed in food amounts but may irritate the stomach, throat, or urinary tract in large doses.
• Topical Use: Can cause skin irritation or burns if applied undiluted or left on for too long.
• Contraindications: Avoid in individuals with gastrointestinal ulcers, kidney disorders, thyroid dysfunction (due to goitrogens), or during pregnancy and breastfeeding.
• Drug Interactions: May interfere with thyroid medications or irritate those taking anti-inflammatory drugs.

Dosages

• Internal Use:
  • Fresh root: 1-3 grams per day, often consumed with meals.
• Topical Use: Grated root or poultice applied to the affected area, typically diluted with a carrier or cloth barrier to prevent irritation.
• Essential Oils: Highly concentrated and should only be used in diluted forms under professional guidance.

Clinical Trials

• Sinus Infections and Bronchitis: A few clinical trials support its efficacy as part of herbal combinations for upper respiratory infections, often in conjunction with thyme or primrose root.
• UTI Treatment: Preliminary studies suggest mild antibacterial effects, but larger, controlled trials are lacking.
• Cancer Research: Limited preclinical studies indicate potential chemopreventive effects, but human trials are insufficient to draw conclusions.
• Anti-inflammatory Potential: Early studies explore its role in reducing markers of inflammation, but data remains sparse.

Summary

Horseradish is a pungent medicinal herb with a history of use in respiratory, digestive, and urinary conditions. Modern herbalists and naturopaths utilize its antimicrobial and mucolytic properties, while its glucosinolates are a focus in pharmacological and cancer research. While generally safe in small amounts, care must be taken to avoid irritation or toxicity in large doses. Clinical evidence supports its use in combination therapies, but more rigorous trials are needed to confirm its standalone efficacy.