Japanese Horseradish

BotanicalBest with a meal

What is it

Japanese horseradish (wasabi, Wasabia japonica or Eutrema japonicum) is a green rhizome traditionally used as a pungent condiment. It also appears in supplements for its isothiocyanate compounds.

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Cognitive function

Limited Evidence

A small Japanese trial in older adults found that 6-MSITC supplementation improved memory and learning scores. Replication is needed.

Antimicrobial / antioxidant

Limited Evidence

Wasabi ITCs show antibacterial and antioxidant activity in vitro. Clinical relevance at supplement doses is uncertain.

How it works

Wasabi contains glucosinolates that, when the tissue is damaged, are converted by the enzyme myrosinase into isothiocyanates (ITCs) such as 6-methylsulfinylhexyl isothiocyanate (6-MSITC). These compounds have antibacterial, antioxidant, and Nrf2-activating activity in laboratory studies, supporting detoxification enzyme expression. Clinical research is limited but growing, with small studies on cognitive function and metabolic markers.

Dosage

Wasabi rhizome extract doses in supplements typically range from 100-600 mg/day. ITC content varies widely by product.

When and how to take it

Often taken with meals to support digestion and reduce stomach irritation.

2 commercial forms

Compare the main delivery options and what they’re best suited for.

Wasabi rhizome extract (standardized)

The form most studied.

Standardized to 6-MSITC or total ITCs.

Wasabi leaf extract

Less studied.

Different compound profile than rhizome.

Safety

Safe in culinary amounts. Concentrated extracts may cause GI upset, heartburn, or irritation. Most commercial 'wasabi' paste contains horseradish and food coloring rather than real wasabi.

Who should be cautious

People with peptic ulcers, GERD, or inflammatory GI conditions should be cautious. Avoid high doses in pregnancy due to insufficient safety data.

Interactions

No significant clinical interactions reported. Theoretical interactions with anticoagulants given mild antiplatelet activity at concentrated doses.

Food sources

Real Japanese wasabi (rhizome)

Amount
5-10 g
%DV
—

Frequently asked questions

Is most 'wasabi' actually wasabi?⌄

No. Most paste sold outside Japan is horseradish, mustard, and green coloring. True wasabi is rare and expensive.

Does wasabi improve memory?⌄

One small trial suggests possible benefit in older adults; the evidence is preliminary.

References

Japanese Horseradish on Wikidata — Wikidata link

Japanese Horseradish on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Japanese Horseradish (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.