Spices · Spice
Horseradish and Wasabi
Armoracia rusticana (horseradish); Eutrema japonicum (wasabi) · also called Western wasabi, Japanese horseradish, chrain, rábano picante (Spanish)
Horseradish and wasabi are sharp roots eaten in tiny amounts as condiments. Most wasabi paste sold outside Japan is horseradish, mustard and green colour, not real wasabi. Research on them is thin: one small memory trial and two combination-medicine trials, all using supplements or a two-plant product, not the condiment. The main cautions are the burn in the nose and eyes, concentrated products, and rare reports of harm from very large mouthfuls.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Horseradish and Wasabi
Horseradish and wasabi are sharp roots that add heat to food in very small amounts. They are relatives, but real wasabi is scarce, and much wasabi paste is horseradish with mustard and green colour. They are foods, not proven remedies. The health research is early and mostly uses supplements.
What they are
Horseradish (Armoracia rusticana) is a large white root, probably from southeastern Europe and western Asia. Wasabi (Eutrema japonicum) is the knobby green rhizome of a plant native to Japan, and it is hard to grow. Both are in the mustard family and often confused.
The whole root has little smell. Cutting or grating lets an enzyme turn a stored compound (sinigrin) into allyl isothiocyanate, which makes the sinus-clearing sting. Air and heat weaken it, so freshly grated horseradish is sharpest and jarred sauces are milder. Wasabi's burn is felt in the nose more than the tongue and is short-lived because it is not oil-based.
USDA data for prepared horseradish (grated root with vinegar and salt), per 100 g: 48 kcal, 3.3 g fibre, 24.9 mg vitamin C, 246 mg potassium and 420 mg sodium. One teaspoon (5 g) is only about 2.4 kcal and 1.2 mg vitamin C. Raw wasabi root per 100 g has 109 kcal, 41.9 mg vitamin C and 568 mg potassium, but it is eaten in tiny amounts, so its nutritional value is negligible.
In the kitchen
Horseradish is a condiment across Europe: with roast beef in the UK, with fish and meat in eastern and central Europe, and as chrain, often with beetroot, with gefilte fish. It goes into cocktail sauce and Bloody Marys, and is the bitter herb at Passover.
Wasabi paste goes between the fish and the rice in sushi. Real wasabi is traditionally grated on sharkskin or a fine metal grater and loses flavour quickly if left uncovered. Bottled paste is usually made from dried powder. Fresh leaves can be eaten raw or pickled.
Wasabi's imitators matter: outside Japan the usual substitute is horseradish with mustard, starch and green colour, and some packs list no wasabi plant at all. Real wasabi is naturally green. A home-preservation source says the sharpness of fresh horseradish fades within 1 to 2 months even in the fridge, so make small batches.
What the research shows
No trial tested horseradish or wasabi eaten as a condiment. One 12-week trial of a wasabi extract capsule found better working and episodic memory in 72 healthy older adults, but not in other thinking tests, and a wasabi product company funded it. Open-label studies of wasabi powder in fatigue and ME/CFS had no placebo group. A pilot in eight men found no effect on muscle damage.
Two trials tested a branded combination of nasturtium herb and horseradish root. It sped recovery from acute bronchitis in 384 patients and lowered repeat bladder infections in 217 women. Neither shows that horseradish alone works.
A 2025 review says the cancer-cell and colon findings for the heat compound come from cells and animals at levels higher than food provides. Heart-related effects are mostly from animals.
Condiment, extract or medicine
The memory, fatigue, ME/CFS and exercise studies used a wasabi extract or the isolated compound 6-MSITC. The bronchitis and cystitis trials used a branded two-plant medicine. The vessel and cancer findings come from the pure compound. These are different products from the condiment, and one cannot stand in for another.
Amounts
This page gives no amounts to eat. The USDA household measures (5 g for a teaspoon of prepared horseradish) describe portions, not advice. Ask a doctor, pharmacist or dietitian what is right for you, especially if you are pregnant, have a thyroid condition or take regular medicines.
At a glance
Traditional uses history, not proof
- Horseradish: a condiment with roast meat and fish across Europe, and the bitter herb at Passover
- Wasabi: a pungent paste eaten with sushi in Japan
- Long use as a condiment is not proof that either root treats any condition
Studied for research
- Memory in healthy older adults, low certainty (wasabi extract capsule, one trial)
- Acute bronchitis, low certainty (nasturtium plus horseradish medicine, one trial)
- Preventing repeat bladder infections, low certainty (same combination, one trial)
- Daily fatigue and sleep, very low certainty (wasabi powder, open label)
- ME/CFS symptoms, very low certainty (wasabi extract, 15 people, open label)
- Muscle damage after exercise, no effect seen (wasabi compound, 8 men)
- Blood vessel lining and cancer cells, insufficient evidence (pure compound, review)
Main compounds
- Allyl isothiocyanate (the heat)
- Sinigrin (its mild precursor)
- 6-MSITC (the wasabi compound used in trials)
- Gluconasturtiin
- Vitamin C (small amounts in prepared horseradish)
Common forms
- Fresh grated horseradish root
- Prepared horseradish (grated root with vinegar and salt)
- Fresh grated wasabi rhizome and wasabi leaves
- Wasabi paste and powder, often made with horseradish and mustard
- Capsules, extracts and a nasturtium plus horseradish medicine (the trials used these, not the condiment)
Research links: Memory trial of a wasabi extract (Nutrients, 2023) · Review of allyl isothiocyanate: benefits, safety, rules (Foods, 2025) · Case report: takotsubo after wasabi (BMJ Case Reports, 2019) · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Armoracia rusticana (horseradish) and Eutrema japonicum (wasabi)
- Naming authority
- P.Gaertn., B.Mey. & Scherb. and (Miq.) Koidz. (both GBIF accepted)
- Synonyms
- Cochlearia armoracia L. (horseradish, as named by Linnaeus; per Wikipedia); Wasabia japonica (Miq.) Matsum. (wasabi; GBIF lists it as a synonym of Eutrema japonicum)
- Common names
- Horseradish (English); Western wasabi (seiyo wasabi) (Japanese, for horseradish (per Wikipedia)); Wasabi; Japanese horseradish (English, for Eutrema japonicum); Chrain (khren, kren) (Yiddish and Slavic names for horseradish sauce (per Wikipedia)); Rabano picante (Spanish (general knowledge, not from a source read))
- Family or group
- Brassicaceae, the mustard (cabbage) family, which also holds mustard, broccoli, cabbage and radish (GBIF; Wikipedia).
- Classification
- Plantae > Tracheophyta > Magnoliopsida > Brassicales > Brassicaceae > Armoracia (horseradish); Eutrema (wasabi) > Armoracia rusticana; Eutrema japonicum
- Native range
- Horseradish is likely native to southeastern Europe and western Asia (Wikipedia). Wasabi is native to Japan, the Russian Far East including Sakhalin, and the Korean Peninsula (Wikipedia). Secondary source.
- Habitat
- Wasabi grows naturally along stream beds in mountain river valleys in Japan and needs cool, shaded, humid conditions (Wikipedia). Horseradish is a hardy perennial that can become invasive in gardens (Wikipedia).
- What it looks like
- Roots: Horseradish: a large, white, tapered root (Wikipedia). The intact root has little smell.; Stems: Wasabi: the part sold is the rhizome, or the rhizome plus the base of the stem; the 'root' is a common name for it (Wikipedia).; Leaves: Horseradish leaves are bright green, up to about 1 m long; wasabi leaves are large, on long thin stalks (Wikipedia). Both leaves are edible; wasabi leaves commonly cause diarrhea.; Flowers: Horseradish has scented white four-petalled flowers; wasabi flowers in clusters from late winter to early spring (Wikipedia).; Fruit: Not verified.
- Cultivation
- Horseradish: perennial, root dug after the first autumn frost and one or more offshoots replanted. Wasabi: hard to grow; needs flowing cool water and shade; much of it is grown in Shizuoka and Nagano in Japan (Wikipedia). Secondary source.
- Harvest and processing
- Horseradish root is grated, often with vinegar and salt, to make prepared horseradish. Wasabi rhizome is grated into paste; store-bought paste is usually made from dried wasabi powder (Wikipedia).
- Look-alikes and adulterants
- Name: Imitation wasabi (horseradish, mustard, starch and green colour); Note: A very common product sold as wasabi outside Japan. Real wasabi is naturally green and costs more (Wikipedia). Check the ingredient list.; Name: Horseradish leaves and docks (Rumex); Note: Wikipedia says horseradish leaves may be mistaken for dock leaves. A plant should be identified by an expert before eating.
- Sustainability and conservation
- Not assessed.
Photographs
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| Antiquity to the Middle Ages (horseradish) | Cultivated since antiquity and named by classical writers; roots and leaves were used as traditional medicine in the Middle Ages; the root was a meat condiment in Germany, Scandinavia and Britain. | s-wiki-horseradish (secondary reference (Wikipedia); not independently verified) |
| 1597, England (horseradish) | John Gerard describes horseradish stamped with a little vinegar as a sauce Germans eat with fish and such meats, as mustard is eaten. | s-wiki-horseradish (secondary reference (Wikipedia); not independently verified) |
| Festivals (horseradish) | Many Ashkenazi Jews use grated horseradish as the bitter herb (maror) at Passover; chrain is the horseradish sauce, often with beetroot, served with gefilte fish. | s-wiki-horseradish (secondary reference (Wikipedia); not independently verified) |
| 8th century, Japan (wasabi) | The oldest record of wasabi as a food dates to the 8th century. Its popularity in English-speaking countries has grown with sushi since about 1980. | s-wiki-wasabi (secondary reference (Wikipedia); not independently verified) |
| Today | Because real wasabi is hard to grow, western horseradish is widely used in its place, in Japan as well as elsewhere. | s-wiki-wasabi (secondary reference (Wikipedia); not independently verified) |
Traditional use shows how it was used. It does not show that it works or is safe today.
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Allyl isothiocyanate (AITC) PubChem 5971 | isothiocyanate (mustard oil) | Root or rhizome, released when cut or grated Not stated in the sources read. | The main source of the sharp heat of horseradish, wasabi and mustard. It forms when the enzyme myrosinase acts on sinigrin as cells are broken. It irritates the nose and eyes. It is unstable and fades with air and heat. 15 16 3 | Human data |
| Sinigrin PubChem 6911854 | glucosinolate (the stored, mild precursor of AITC) | Root Not stated in the sources read. | Stored apart from myrosinase in the intact plant; the two meet when the plant is cut. 15 3 | Reference |
| Gluconasturtiin PubChem 656555 | glucosinolate (a second precursor in horseradish) | Root Not stated in the sources read. | Wikipedia names it as a second glucosinolate that horseradish turns into pungent compounds when crushed. 15 | Reference |
| 6-(Methylsulfinyl)hexyl isothiocyanate (6-MSITC) PubChem 9815648 | isothiocyanate | Wasabi rhizome Not stated in the sources read. | A characteristic wasabi compound. Wasabi extracts standardised to it were tested in small human trials for memory, fatigue and muscle damage (see Benefits). 6 5 7 8 | Human data |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| The heat sensor TRPA1 (the 'wasabi receptor') | TRPA1 | Wikipedia says the nerve target of mustard oil is the chemosensory receptor TRPA1, also called the wasabi receptor. This is why the burn is felt in the nose. This explains the sensation; it is not a health benefit. 16 | Reference |
| Release of the heat compound when the root is cut | myrosinase acting on sinigrin | Cutting or grating breaks the cells, and the enzyme turns sinigrin into allyl isothiocyanate. Air and heat then weaken the heat and add bitterness. 15 3 | Reference |
| Antioxidant, anti-inflammatory and cancer-cell effects of AITC | PPAR (colon polyps in mice, per the review) | A 2025 review reports these effects of pure AITC in the lab and in animals; the review says benefit in colon work appears only at levels higher than food gives. Not shown in people. 3 | Lab and animal |
Absorption, metabolism and elimination
- Absorption
- Not found for horseradish or wasabi as food.
- Distribution
- Not found.
- Metabolism
- Not found.
- Elimination
- Not found.
- Bioavailability
- Not established in the sources read.
Isolated compounds versus whole extracts
The memory, fatigue, ME/CFS and exercise studies used a wasabi-extract capsule or the isolated compound 6-MSITC. The bronchitis and cystitis trials used a branded two-plant medicine. The blood-vessel and cancer findings come from pure allyl isothiocyanate in small studies, cells and animals. None of these is wasabi paste or horseradish eaten as a condiment, and each is labelled where it appears.
Nutritional composition
Nutrition from USDA FoodData Central (SR Legacy, records dated 2019-04-01, read 2026-10-26). Prepared horseradish (FDC 173472; grated root with vinegar and salt), per 100 g: 48 kcal, 1.18 g protein, 0.69 g fat, 11.29 g carbohydrate (7.99 g sugars), 3.3 g fibre, about 85 g water, 24.9 mg vitamin C, 57 micrograms folate (DFE), 56 mg calcium, 27 mg magnesium, 246 mg potassium, 420 mg sodium. One teaspoon (5 g) holds about 2.4 kcal, 0.2 g fibre, 1.2 mg vitamin C, 12 mg potassium and 21 mg sodium. One tablespoon (15 g) holds about 7 kcal, 0.5 g fibre, 3.7 mg vitamin C, 37 mg potassium and 63 mg sodium. Wasabi, root, raw (FDC 168583), per 100 g: 109 kcal, 4.8 g protein, 0.63 g fat, 23.54 g carbohydrate, 7.8 g fibre, about 69 g water, 41.9 mg vitamin C, 128 mg calcium, 568 mg potassium, 17 mg sodium. USDA gives no condiment-sized portion for the raw root, and Wikipedia says wasabi is eaten in such small amounts that its nutritional value is negligible. A separate USDA entry named simply Wasabi (FDC 171831, filed under sauces) lists 292 kcal and 3,390 mg sodium per 100 g (about 19 kcal and 220 mg sodium per 6.5 g teaspoon); the record does not say what product it describes. Values are for the USDA samples and vary with product, vinegar and salt. These figures are not compared with daily values, so neither food is called a good source of anything.
3 low certainty2 very low certainty3 not enough evidence
What was looked at
The 8 benefits and uses checked for Horseradish and Wasabi, each with how strong the evidence is. Tap one to open it.
- Memory in healthy older adults (wasabi extract capsule)Low certainty
- Acute bronchitis (nasturtium plus horseradish medicine)Low certainty
- Preventing repeat bladder infections (nasturtium plus horseradish medicine)Low certainty
- Daily fatigue and sleep (wasabi 6-MSITC powder)Very low certainty
- Myalgic encephalomyelitis / chronic fatigue syndrome (wasabi extract)Very low certainty
- Muscle damage after hard exercise (wasabi compound)Not enough evidence
- Blood vessel lining function (pure allyl isothiocyanate, small studies)Not enough evidence
- Cancer cells in the lab and in animals (allyl isothiocyanate)Not enough evidence
Lab markers tracked in the studies
Working memory and episodic memory test scoresBronchitis severity scoreRecurrence of bladder infection (cystitis)Fatigue, sleep and mood scoresPerformance status in ME/CFSMuscle damage and calpain-1 markers after exerciseEndothelial (blood vessel lining) function
What is Horseradish and Wasabi good for?
The main studied uses and how strong the human evidence is for each. Every result is for a supplement, a pure compound or a two-plant medicine, not for horseradish or wasabi eaten as a condiment.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Memory in healthy older adults (wasabi extract capsule)
Low certaintyOne 12-week trial in healthy adults aged 60 and over found better working memory and episodic memory with a wasabi extract capsule than with placebo. Other thinking skills did not improve. The capsule is a supplement, not wasabi as a condiment, and a wasabi product company paid for the trial.
1 studiesA wasabi extract capsule standardised to 6-MSITC. Not tested with was…
Studies, doses and limits
What the trials found
72 healthy adults aged 60 and over were randomly given 6-MSITC (from wasabi) or placebo for 12 weeks in a double-blind trial (Nouchi 2023). Tests covered executive function, episodic memory, processing speed, working memory and attention.
Results
The 6-MSITC group improved more than placebo on working memory and episodic memory. No other thinking test improved significantly.
Effect sizes as reported
The abstract reports no effect sizes; none are repeated here.
Why this rating
Low, not higher. One trial of 72 people, 12 weeks, healthy volunteers, funded by a wasabi product company, and no independent repeat was found.
Form and dose studied
A wasabi extract capsule standardised to 6-MSITC. Not tested with wasabi paste or fresh wasabi.
Who was studied
Healthy adults aged 60 and over.
Limits
No study of eating wasabi or horseradish as a condiment was found. Capsules and the condiment are not the same thing. Results may not carry over to people with memory problems.
Why researchers looked
6-MSITC is a heat compound found in wasabi. Lab work suggests it has antioxidant and anti-inflammatory actions, so researchers asked whether it helps thinking in older age.
Traditional use
Eaten as a condiment: horseradish with roast meat and fish in Europe, wasabi with sushi in Japan. Long use as a condiment is not proof that either root treats any condition.
Proposed mechanism Lab or hypothesis
The authors say 6-MSITC has antioxidant and anti-inflammatory actions and discuss how this could help memory. This is the paper's reasoning, not something the trial measured.
A proposed mechanism does not show that the effect happens in people.
No side-effect details were in the abstract.
Acute bronchitis (nasturtium plus horseradish medicine)
Low certaintyA large trial of a branded medicine made from nasturtium herb and horseradish root found symptoms improved faster than with placebo. It is a two-plant combination, so it does not show that horseradish alone helps, and it says nothing about horseradish as a condiment.
1 studiesA fixed branded combination of nasturtium herb and horseradish root. …
Studies, doses and limits
What the trials found
A randomised, double-blind, placebo-controlled phase IV trial in 384 patients with acute bronchitis (195 treated, 189 placebo). The main measure was a bronchitis severity score that adds ratings of five symptoms (Albrecht 2023).
Results
Symptoms improved significantly faster than with placebo from day 3, with less coughing, mucus and chest pain, and the difference lasted to day 10.
Effect sizes as reported
The abstract gives no numbers for the score difference.
Why this rating
Low. One trial of one branded combination. The authors ran or analysed the trial and the abstract does not name the sponsor.
Form and dose studied
A fixed branded combination of nasturtium herb and horseradish root. Not tested as food.
Who was studied
Patients with acute bronchitis (ages not given in the abstract).
Limits
Two plants in one product, so no credit can go to horseradish alone. A cough that lasts, brings up blood or comes with breathlessness needs a doctor.
Why researchers looked
Both plants make isothiocyanates, compounds with antibacterial and anti-inflammatory actions in the lab, so the combination was tested for chest infections.
Traditional use
Eaten as a condiment: horseradish with roast meat and fish in Europe, wasabi with sushi in Japan. Long use as a condiment is not proof that either root treats any condition.
Proposed mechanism Lab or hypothesis
The authors say the combination produces three different isothiocyanates with antibacterial, anti-inflammatory and immune-modulating actions. This is the trial's rationale, not a measurement.
A proposed mechanism does not show that the effect happens in people.
A trial of 384 patients reported no safety details in its abstract.
Preventing repeat bladder infections (nasturtium plus horseradish medicine)
Low certaintyA 2026 trial in women with repeat bladder infections (cystitis) found fewer recurrences over six months with a nasturtium and horseradish medicine than with placebo. Again it is a combination, so it does not show that horseradish alone works, and the effect faded after treatment stopped.
1 studiesA herbal combination of nasturtium herb and horseradish root, taken a…
Studies, doses and limits
What the trials found
A phase III double-blind trial in Germany of 224 enrolled adults; 217 women were analysed (110 herbal, 107 placebo). The main measure was the first recurrence of a urinary infection over 180 days of prevention (Albrecht 2026, EudraCT 2013-004653-25).
Results
Recurrence was about 40% (day 90) and 48% (day 180) with placebo, against 26% and 36% with the herbal combination. The overall risk of a recurrence was 36% lower (HR 0.64, 95% CI 0.42 to 0.97, p=0.0327). In follow-up to 360 days the effect pointed the same way but was no longer statistically significant. No significant difference in side effects.
Effect sizes as reported
HR 0.64 (95% CI 0.42-0.97) for the first recurrence over 180 days.
Why this rating
Low. One trial of one combination; the benefit was modest and not significant in follow-up; the authors work with the product's research organisation and the abstract does not name the sponsor.
Form and dose studied
A herbal combination of nasturtium herb and horseradish root, taken as prevention. Not tested as food.
Who was studied
Mostly women with recurring uncomplicated cystitis.
Limits
A combination, so no credit can go to horseradish alone. A bladder infection with fever, back pain or blood in the urine needs a doctor.
Why researchers looked
The same isothiocyanate content that made the combination a candidate for chest infections was tested for keeping urinary infections from coming back.
Traditional use
Eaten as a condiment: horseradish with roast meat and fish in Europe, wasabi with sushi in Japan. Long use as a condiment is not proof that either root treats any condition.
Proposed mechanism Not stated
The trial names the herbal combination as a prevention drug; the abstract gives no mechanism.
A proposed mechanism does not show that the effect happens in people.
No significant differences between groups for any reported side effect.
Daily fatigue and sleep (wasabi 6-MSITC powder)
Very low certaintyA small open-label study with no placebo group found that healthy volunteers with daily tiredness reported less fatigue, better sleep and better mood after four weeks of a wasabi-extract powder. Without a placebo group, this cannot be told apart from expectation or chance. A separate safety check found no side effects at higher amounts.
1 studiesPowder with 6-MSITC extracted from wasabi rhizome. A supplement, not …
Studies, doses and limits
What the trials found
20 healthy volunteers with daily fatigue took a powder with 6-MSITC extracted from wasabi for 4 weeks in a single-arm, open-label study. A separate double-blind, placebo-controlled safety study used 30 healthy volunteers (Nakajima 2023).
Results
Fatigue before a mental task, sleep and mood improved. Fatigue after the mental task did not improve, and autonomic nerve function, stress and immune markers did not change. In the safety study there were no changes in the measured parameters and no side effects.
Effect sizes as reported
The abstract gives p-values only in general terms; no numbers are repeated.
Why this rating
Very low. The efficacy part had no placebo group and only 20 people, and the study was registered after it was done.
Form and dose studied
Powder with 6-MSITC extracted from wasabi rhizome. A supplement, not the condiment.
Who was studied
Healthy adults with daily fatigue.
Limits
Single-arm design; healthy people only; short; the authors say effectiveness needs further research.
Why researchers looked
A Japanese team asked whether the wasabi compound 6-MSITC eases everyday tiredness and sleep.
Traditional use
Eaten as a condiment: horseradish with roast meat and fish in Europe, wasabi with sushi in Japan. Long use as a condiment is not proof that either root treats any condition.
Proposed mechanism Not stated
No mechanism was tested; the authors only say further research is needed.
A proposed mechanism does not show that the effect happens in people.
In the safety part no side effects were seen, in 30 healthy volunteers over 4 weeks.
Myalgic encephalomyelitis / chronic fatigue syndrome (wasabi extract)
Very low certaintyA 15-person open-label study found that people with ME/CFS rated some symptoms better after 12 weeks of a wasabi extract. The two main fatigue scales did not change significantly. With no control group and so few people, this is only a first signal.
1 studiesA wasabi extract with 6-MSITC. A supplement, not the condiment.
Studies, doses and limits
What the trials found
15 patients (3 men, 12 women, aged 20 to 58) took wasabi extract containing 6-MSITC for 12 weeks in an open-label trial with before-and-after comparisons (Oka 2022).
Results
Performance status improved (p=0.001), as did headache frequency, muscle pain, brain fog, word-finding trouble, light sensitivity, mood vigour, a pain-pressure threshold and a thinking-speed test. The Chalder Fatigue scale and a numerical fatigue rating did not change significantly. No serious adverse reactions.
Effect sizes as reported
Examples from the abstract: headache 4.1 to 3.0 times a week; muscle pain 4.1 to 2.4 times a week; Trail Making Test 53.0 to 38.1 seconds.
Why this rating
Very low. Fifteen people, no control group, support from a company named in the paper, and the main fatigue scales showed no significant change.
Form and dose studied
A wasabi extract with 6-MSITC. A supplement, not the condiment.
Who was studied
Patients with ME/CFS aged 20 to 58.
Limits
Open label, so expectation could explain the gains. Not a test of wasabi as food.
Why researchers looked
The same compound was tested in a long-term fatigue illness because it was thought to calm inflammation in the brain.
Traditional use
Eaten as a condiment: horseradish with roast meat and fish in Europe, wasabi with sushi in Japan. Long use as a condiment is not proof that either root treats any condition.
Proposed mechanism Not stated
The authors say 6-MSITC has anti-inflammatory and antioxidant effects and has been reported to help neuroinflammation and memory. They did not measure this in the trial.
A proposed mechanism does not show that the effect happens in people.
No serious adverse reactions were reported in the 15 patients.
Muscle damage after hard exercise (wasabi compound)
Not enough evidenceA very small crossover trial found that the wasabi compound 6-MSITC did not reduce muscle damage or soreness after hard arm exercise in young men.
1 studiesThe isolated wasabi compound as a supplement.
Studies, doses and limits
What the trials found
Eight healthy young men took 6-MSITC or placebo from 1 day before to 4 days after 30 hard eccentric arm contractions, in a randomised, double-blind crossover pilot (Tanabe 2022).
Results
Plasma calpain-1 and all muscle-damage and inflammation markers were the same as with placebo.
Effect sizes as reported
No difference to report.
Why this rating
Insufficient. A null result, but only eight men, so a real small effect could be missed.
Form and dose studied
The isolated wasabi compound as a supplement.
Who was studied
Healthy young men.
Limits
Very small pilot. Not a test of wasabi as food.
Why researchers looked
Animal work suggested 6-MSITC blocks a muscle-damaging enzyme called calpain-1, so the idea was tried in people.
Traditional use
Eaten as a condiment: horseradish with roast meat and fish in Europe, wasabi with sushi in Japan. Long use as a condiment is not proof that either root treats any condition.
Proposed mechanism Animal research
An animal study showed 6-MSITC inhibits calpain-1 activation. In this human trial plasma calpain-1 did not differ from placebo.
A proposed mechanism does not show that the effect happens in people.
Not reported in the abstract.
Blood vessel lining function (pure allyl isothiocyanate, small studies)
Not enough evidenceA 2025 review says small, early studies found better blood-vessel lining function after small amounts of pure allyl isothiocyanate, the heat compound of mustard, horseradish and wasabi. The review's heart evidence is mostly from animals. Nothing here shows that eating horseradish or wasabi protects the heart.
1 studiesPure allyl isothiocyanate, not a food.
Studies, doses and limits
What the trials found
The 2025 review says preliminary studies saw increased endothelial function after AITC in several groups, including healthy older adults and smokers. The underlying studies were not opened for this page.
Results
Small human studies of pure AITC reported better vessel lining function; the review calls them preliminary.
Effect sizes as reported
Amounts and size of effect were not repeated from the review.
Why this rating
Insufficient. The human work is small and early, second-hand through a review, and uses a pure compound.
Form and dose studied
Pure allyl isothiocyanate, not a food.
Who was studied
Older adults and smokers, per the review.
Limits
Second-hand; underlying studies not read. Pure compound, not horseradish or wasabi.
Why researchers looked
Healthy blood vessel lining (endothelium) matters for circulation, so researchers asked whether the compound helps it.
Traditional use
Eaten as a condiment: horseradish with roast meat and fish in Europe, wasabi with sushi in Japan. Long use as a condiment is not proof that either root treats any condition.
Proposed mechanism Animal research
The review says AITC protected the vessel lining in rats given it ahead of time. This is animal evidence.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab: pure concentrated forms can irritate.
Cancer cells in the lab and in animals (allyl isothiocyanate)
Not enough evidenceIn the lab and in animals, the heat compound affected cancer cells and reduced colon polyps in mice. The review says these effects appear at levels higher than food gives, and the lung evidence is unclear. No human trial shows that eating horseradish or wasabi prevents cancer.
1 studiesPure compound and cell or animal models.
Studies, doses and limits
What the trials found
No human trial of horseradish or wasabi for cancer prevention or treatment was found. The review says colon work suggests potential only at concentrations higher than diet gives (Alibrahem 2025).
Results
Lab and animal effects only.
Why this rating
Insufficient for people. The evidence is lab and animal only.
Form and dose studied
Pure compound and cell or animal models.
Limits
Lab and animal results often do not carry over to people.
Why researchers looked
Isothiocyanates from mustard-family plants have been studied for effects on cancer cells.
Traditional use
Eaten as a condiment: horseradish with roast meat and fish in Europe, wasabi with sushi in Japan. Long use as a condiment is not proof that either root treats any condition.
Proposed mechanism Lab or animal
The review says AITC affects cancer cells in the lab and prevented colon polyp growth in mice by acting on cell-signalling receptors (PPAR). It also says it is unclear from population studies whether allyl compounds protect against lung cancer or might harm the lungs.
A proposed mechanism does not show that the effect happens in people.
Do not use food or concentrated products as a cancer treatment.
Connections to the rest of health
How Horseradish and Wasabi connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Nervous System | Biological association | Low certainty | Studied for: Memory in healthy older adults (wasabi extract capsule) Studied for: Daily fatigue and sleep (wasabi 6-MSITC powder) | 6 5 7 |
| Brain Focus | Biological association | Low certainty | Studied for: Memory in healthy older adults (wasabi extract capsule) | 6 |
| Respiratory System | Biological association | Low certainty | Studied for: Acute bronchitis (nasturtium plus horseradish medicine) | 1 |
| Immune System | Biological association | Low certainty | Studied for: Acute bronchitis (nasturtium plus horseradish medicine) Studied for: Preventing repeat bladder infections (nasturtium plus horseradish medicine) | 1 2 |
| Urinary System | Biological association | Low certainty | Studied for: Preventing repeat bladder infections (nasturtium plus horseradish medicine) | 2 |
| Sleep Recovery | Biological association | Very low certainty | Studied for: Daily fatigue and sleep (wasabi 6-MSITC powder) | 5 |
| Musculoskeletal System | Biological association | Very low certainty | Studied for: Myalgic encephalomyelitis / chronic fatigue syndrome (wasabi extract) Studied for: Muscle damage after hard exercise (wasabi compound) | 7 8 |
| Cardiovascular System | Biological association | Not enough evidence | Studied for: Blood vessel lining function (pure allyl isothiocyanate, small studies) | 3 |
| Cellular | Biological association | Not enough evidence | Studied for: Cancer cells in the lab and in animals (allyl isothiocyanate) | 3 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Takotsubo cardiomyopathy | Adverse effect or risk | Single case report | One reported case after a large mouthful of wasabi eaten by mistake. One reported case after a large amount of wasabi. Preparation or compound: A large amount of wasabi |
4 |
| Thyroid disease | General cruciferous statement | A review says these can reduce iodine uptake; nothing specific to horseradish or wasabi. Preparation or compound: Thiocyanates from mustard-family vegetables |
3 | |
| Cystitis | Low certainty, combination product | A trial of nasturtium plus horseradish medicine reported fewer repeat infections in women. Preparation or compound: Nasturtium herb plus horseradish root (medicine) |
2 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Working memory and episodic memory test scores | Biological association | Low certainty | Measured in trials: raised. A lab change is not the same as a health benefit. | 6 |
| Bronchitis severity score | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 1 |
| Recurrence of bladder infection (cystitis) | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 2 |
| Fatigue, sleep and mood scores | Biological association | Very low certainty | Measured in trials: improved. A lab change is not the same as a health benefit. | 5 |
| Performance status in ME/CFS | Biological association | Very low certainty | Measured in trials: improved. A lab change is not the same as a health benefit. | 7 |
| Muscle damage and calpain-1 markers after exercise | Biological association | Not enough evidence | Measured in trials: no-change. A lab change is not the same as a health benefit. | 8 |
| Endothelial (blood vessel lining) function | Biological association | Not enough evidence | Measured in trials: improved. A lab change is not the same as a health benefit. | 3 |
J. Genes, receptors and enzymes
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| TRPA1 | Preliminary mechanism | Reference | The nerve receptor that senses the heat compound; explains the burn in the nose. | 16 |
K. Biological pathways
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Vitamin C | Preliminary mechanism | Reference | Prepared horseradish contains vitamin C (24.9 mg per 100 g, USDA); a teaspoon holds very little. | 14 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Allyl isothiocyanate (AITC) | Biological association | Human | The main source of the sharp heat of horseradish, wasabi and mustard. It forms when the enzyme myrosinase acts on sinigrin as cells are broken. It irritates the nose and eyes. It is unstable and fades with air and heat. Preparation or compound: Root or rhizome, released when cut or grated |
15 16 3 |
| Sinigrin | Biological association | Reference | Stored apart from myrosinase in the intact plant; the two meet when the plant is cut. Preparation or compound: Root |
15 3 |
| Gluconasturtiin | Biological association | Reference | Wikipedia names it as a second glucosinolate that horseradish turns into pungent compounds when crushed. Preparation or compound: Root |
15 |
| 6-(Methylsulfinyl)hexyl isothiocyanate (6-MSITC) | Biological association | Human | A characteristic wasabi compound. Wasabi extracts standardised to it were tested in small human trials for memory, fatigue and muscle damage (see Benefits). Preparation or compound: Wasabi rhizome |
6 5 7 8 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).
Evidence at a glance: what changed in 4 lab markers
Tap a number to show only those markers. Counts are markers, not people.
The evidence
The research centre for Horseradish and Wasabi. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our existing summary for this spice, re-read nutrition in the USDA FoodData Central SR Legacy download, checked species names in GBIF, and searched PubMed for trials, reviews and case reports. Only abstracts were read for the studies, except the 2025 review, read in full. Kitchen and history facts come from Wikipedia and a home-preservation page and are secondary. Items we could not verify are flagged in the research gaps.
Study library: every study we checked 16
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Albrecht 2023 A combination of Tropaeolum majus herb and Armoracia rusticana root for the treatment of acute bronchitis. Phytomedicine · PMID 37167822 · DOI |
Randomised, double blind, placebo controlled phase IV trial |
384 patients with acute bronchitis (195 treatment, 189 placebo) |
Branded fixed combination of nasturtium herb and horseradish root (a medicine, not the food) herb and root not repeated here treatment up to day 10 · vs placebo |
Compared with placebo, the combination group had significantly faster improvement of bronchitis symptoms from day 3, with less coughing, mucus and chest pain. The benefit lasted to day 10. Methods, limits and fundingOutcomes: Bronchitis severity score (sum of five symptom ratings) Limitations: Combination of two plants, so the result cannot be credited to horseradish alone. A branded product; the abstract does not name the sponsor. The authors ran or analysed the trial (project manager of the research organisation, principal investigator, statistician). Bronchitis often clears by itself. Funding and conflicts: Not stated in the abstract. The authors say they do not benefit from a relationship with the sponsor. Read: abstract |
| Albrecht 2026 Clinical evaluation of the efficacy and safety of nasturtium herb and horseradish root versus placebo in the continuous prophylaxis of recurrent uncomplicated cystitis: a double-blind randomised clinical trial. BMC Complement Med Ther · PMID 41782129 · DOI |
Double blind randomised placebo controlled phase III multicentre trial |
217 adults with recurrent uncomplicated cystitis; 217 women in the analysis (110 herbal, 107 placebo) |
Herbal combination of nasturtium herb and horseradish root (a medicine, not the food) herb and root not repeated here 6 months of prevention, then follow-up · vs placebo |
Cumulative recurrence about 40% (day 90) and 48% (day 180) with placebo, against 26% and 36% with the herbal combination. Overall risk of a recurrence 36% lower (HR 0.64, 95% CI 0.42 to 0.97, p=0.0327). The effect stayed in the same direction up to 360 days but was no longer statistically significant. No significant differences in side effects. HR 0.64 for recurrence (0.42-0.97) Methods, limits and fundingOutcomes: Rate of first recurrent urinary tract infection over 180 days Limitations: Combination of two plants. Only women in the analysis. Effect not significant in follow-up. The authors work with the product's research organisation; sponsor not stated in the abstract. Funding and conflicts: Not stated in the abstract. Registration: EudraCT 2013-004653-25 Read: abstract |
| Alibrahem 2025 Health Benefits, Applications, and Analytical Methods of Freshly Produced Allyl Isothiocyanate. Foods · PMID 40002023 · DOI |
Narrative review (open access full text read 2026 10 26) mixed |
n/a (review of mostly lab, animal and small human studies) | Allyl isothiocyanate (AITC), the heat compound of mustard, horseradish and wasabi |
Says endothelial function improved in preliminary studies of small AITC amounts; AITC affected cancer cells in the lab and colon polyps in mice, at levels higher than food gives; lung evidence unclear. Reports transient stomach, breathing, skin and liver effects in four people after pure mustard oil (1.2% AITC); reproductive and developmental toxicity in pregnant rats; thiocyanates from cruciferous vegetables can inhibit iodine transport; no IgE-mediated allergy evidence found even in mustard seed workers with asthma; states a US 0.1% concentration limit and an EU 5 mg/kg limit. Methods, limits and fundingOutcomes: Health effects, safety and regulation of AITC Limitations: A narrative review about the pure compound, not the foods. Its regulatory statements are second-hand and the US and EU units are not reconciled. Source studies for several claims were not opened. Funding and conflicts: Review states it received no external funding. Read: full-text |
| Finkel-Oron 2019 Takotsubo cardiomyopathy triggered by wasabi consumption: can sushi break your heart? BMJ Case Rep · PMID 31540920 · DOI |
Case report |
1 60-year-old woman with chest pain after a wedding |
A large amount of wasabi, eaten by mistake (she thought it was avocado) paste or rhizome as eaten not repeated here single occasion |
The authors report the first case of takotsubo cardiomyopathy triggered by eating wasabi. Methods, limits and fundingOutcomes: Chest pain and takotsubo cardiomyopathy (a temporary heart muscle weakness that can look like a heart attack) Limitations: A single case. It shows a rare possibility, not how often it happens. The abstract gives no outcome details. Funding and conflicts: not stated in the abstract Read: abstract |
| Nakajima 2023 Oral administration of 6-methylsulfinylhexyl isothiocyanate extracted from wasabi is safe and improves the fatigue and sleep of healthy volunteers. Biopsychosoc Med · PMID 37612759 · DOI |
Single arm open label study plus a double blind placebo controlled overdose safety study |
50 20 healthy volunteers with daily fatigue (efficacy part); 30 healthy volunteers (safety part) |
Powder containing 6-MSITC extracted from wasabi (a supplement, not the food) rhizome extract not repeated here 4 weeks |
Fatigue before a mental task, sleep and mood improved after 4 weeks. Fatigue after the mental task did not improve; nervous-system, stress and immune markers did not change. In the safety part, no changes in the measured parameters and no side effects were seen. Methods, limits and fundingOutcomes: Fatigue, sleep, mood, autonomic nervous function, stress, immune markers; adverse events Limitations: The effect part had no placebo group, so improvement may be expectation or chance. Small, short, healthy people only. Retrospectively registered. Funding and conflicts: The authors declare no competing interests. Registration: UMIN000049913 Read: abstract |
| Nouchi 2023 Benefits of Wasabi Supplements with 6-MSITC (6-Methylsulfinyl Hexyl Isothiocyanate) on Memory Functioning in Healthy Adults Aged 60 Years and Older: Evidence from a Double-Blinded Randomized Controlled Trial. Nutrients · PMID 37960261 · DOI |
Double blind randomised placebo controlled trial |
72 healthy adults aged 60 and over |
Wasabi extract capsule standardised to 6-MSITC (a supplement, not the food) wasabi supplement (plant part not stated in the abstract) not repeated here 12 weeks · vs placebo capsule |
The 6-MSITC group improved significantly more than placebo on working memory and episodic memory. No significant improvement in the other thinking tests. Methods, limits and fundingOutcomes: Executive function, episodic memory, processing speed, working memory, attention (before and after) Limitations: One small trial, 12 weeks, healthy people only. The abstract gives no effect sizes. Funded by a wasabi product company. Needs repeating by independent teams. Funding and conflicts: Supported by KINJIRUSHI Co. Ltd (wasabi product company), which the paper says had no role in design, analysis or the decision to publish; also Japan Society for the Promotion of Science grants. Read: abstract |
| Oka 2022 Clinical effects of wasabi extract containing 6-MSITC on myalgic encephalomyelitis/chronic fatigue syndrome: an open-label trial. Biopsychosoc Med · PMID 36510244 · DOI |
Single arm open label trial |
15 patients with ME/CFS aged 20 to 58 |
Wasabi extract containing 6-MSITC (a supplement, not the food) rhizome extract not repeated here 12 weeks |
Performance status improved significantly (p=0.001), as did some symptoms (headache, muscle pain, brain fog), a pain threshold and a thinking test. The two main fatigue scales did not change significantly. No serious adverse reactions. Methods, limits and fundingOutcomes: Performance status, fatigue scales, symptoms, pain threshold, Trail Making Test, standing test Limitations: Only 15 people, no control group, so placebo effects and chance cannot be ruled out. The authors call it a possible option, not a proven one. Funding and conflicts: The study was supported by PAL (a company named in the paper's support statement). Read: abstract |
| Tanabe 2022 Effects of 6-(Methylsulfinyl)hexyl Isothiocyanate Ingestion on Muscle Damage after Eccentric Exercise in Healthy Males: A Pilot Placebo-Controlled Double-Blind Crossover Study. J Diet Suppl · PMID 33938371 · DOI |
Pilot randomised double blind placebo controlled crossover study |
8 healthy young men |
6-MSITC (the wasabi compound, as a supplement) isolated compound not repeated here from 1 day before to 4 days after exercise · vs placebo |
Plasma calpain-1 after exercise was the same with 6-MSITC and placebo. None of the muscle damage or inflammation markers differed from placebo. Methods, limits and fundingOutcomes: Plasma calpain-1, creatine kinase, urinary titin, strength, range of motion, soreness Limitations: Eight young men only. A null result from a very small pilot. Funding and conflicts: No funding or conflict statement in the abstract record. Read: abstract |
| s-gbif-armoracia GBIF Backbone: Armoracia rusticana P.Gaertn., B.Mey. & Scherb. (usageKey 3041022) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-gbif-eutrema GBIF Backbone: Eutrema japonicum (Miq.) Koidz. (usageKey 5375216) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-nchfp-horseradish National Center for Home Food Preservation: Pickled Horseradish Sauce · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-168583 USDA FoodData Central: Wasabi, root, raw (FDC 168583) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-171831 USDA FoodData Central: Wasabi (FDC 171831, filed under soups, sauces and gravies) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-173472 USDA FoodData Central: Horseradish, prepared (FDC 173472) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-wiki-horseradish Wikipedia: Horseradish · Source |
Secondary reference n/a |
Methods, limits and fundingRead: full-text | ||
| s-wiki-wasabi Wikipedia: Wasabi · Source |
Secondary reference n/a |
Methods, limits and fundingRead: full-text |
What we do not know yet
- No trial of horseradish or wasabi eaten as a condiment was found for any outcome.
- No trial of horseradish alone was found for bronchitis or cystitis; both used a combination with nasturtium.
- No independent repeat of the wasabi memory trial was found, and several wasabi studies are open label with no control group.
- No drug-interaction, allergy or pregnancy study of the condiments was found.
- The blood-vessel findings are known only through a review, and the regulatory limits for allyl isothiocyanate were not checked against the original rules.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue before the page changes.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Other 7
Working memory and episodic memory test scores
Raised in trials
Scores on computer or paper tests of holding information in mind (working memory) and recalling recent events or lists (episodic memory).
Low certaintyResults and what it means
Why it was measured
These tests show how well memory is working in daily life.
Statistical vs. clinical meaning
A small, industry-funded trial that has not been repeated; the tests are a stand-in for real-life memory.
Safety implication
None reported in the abstract.
| Study | Result | People | Product |
|---|---|---|---|
| 6 | The 6-MSITC group improved significantly more than placebo on working and episodic memory; no significant gain in executive function, processing speed or attention. | 72 healthy adults aged 60 and over | Wasabi extract capsule with 6-MSITC for 12 weeks |
Bronchitis severity score
Lowered in trials
A score that adds up ratings of five bronchitis symptoms, including cough, mucus and chest pain.
Low certaintyResults and what it means
Why it was measured
It is how the trial tracked how fast people felt better.
Statistical vs. clinical meaning
Symptom relief in one trial of a combination product, not proof about horseradish alone.
Safety implication
None reported in the abstract.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | Significantly faster improvement than placebo from day 3, with less cough, mucus and chest pain, lasting to day 10. | 384 patients with acute bronchitis | Nasturtium herb plus horseradish root medicine (combination), up to day 10 |
Recurrence of bladder infection (cystitis)
Lowered in trials
How many people get a new urinary infection during the study.
Low certaintyResults and what it means
Why it was measured
Repeat infections are the problem people want to prevent.
Statistical vs. clinical meaning
A modest reduction in one trial of a combination; the effect did not hold up after treatment.
Safety implication
No significant difference in side effects.
| Study | Result | People | Product |
|---|---|---|---|
| 2 | Cumulative recurrence 48% with placebo and 36% with the herbal combination by day 180; HR 0.64 (95% CI 0.42-0.97, p=0.0327). Not significant in follow-up to 360 days. | 217 women with recurrent uncomplicated cystitis | Nasturtium herb plus horseradish root (combination), 6 months of prevention |
Fatigue, sleep and mood scores
Improved in trials
Questionnaire scores for tiredness, sleep quality and mood.
Very low certaintyResults and what it means
Why it was measured
They show how people feel day to day.
Statistical vs. clinical meaning
Open-label self-report; may be expectation.
Safety implication
No side effects in a 30-person double-blind safety study.
| Study | Result | People | Product |
|---|---|---|---|
| 5 | Fatigue before a mental task, sleep and mood improved after 4 weeks; fatigue after the task, autonomic function, stress and immune markers did not change. No placebo group in this part. | 20 healthy volunteers with daily fatigue | Wasabi-derived 6-MSITC powder, 4 weeks |
Performance status in ME/CFS
Improved in trials
A doctor-rated score of how much daily activity a person can manage.
Very low certaintyResults and what it means
Why it was measured
It captures how much the illness limits everyday life.
Statistical vs. clinical meaning
Open-label with no control group, so only a first signal.
Safety implication
No serious adverse reactions.
| Study | Result | People | Product |
|---|---|---|---|
| 7 | Performance status improved (p=0.001), but the Chalder Fatigue scale and the numerical fatigue rating did not change significantly. | 15 patients with ME/CFS | Wasabi extract with 6-MSITC, 12 weeks |
Muscle damage and calpain-1 markers after exercise
No clear change in trials
Blood and urine markers (such as creatine kinase and titin) plus strength and soreness after hard exercise.
Not enough evidenceResults and what it means
Why it was measured
They show how much the muscle was damaged and how fast it recovers.
Statistical vs. clinical meaning
No effect seen in a tiny pilot.
Safety implication
None reported in the abstract.
| Study | Result | People | Product |
|---|---|---|---|
| 8 | Plasma calpain-1 and all muscle-damage and inflammation markers were not affected by 6-MSITC compared with placebo. | 8 healthy young men | 6-MSITC around hard eccentric exercise |
Endothelial (blood vessel lining) function
Improved in trials
How well the inner lining of blood vessels relaxes and responds.
Not enough evidenceResults and what it means
Why it was measured
Poor function is linked to heart and circulation problems.
Statistical vs. clinical meaning
Second-hand, small and early.
Safety implication
Concentrated AITC can irritate; see the Safety tab.
| Study | Result | People | Product |
|---|---|---|---|
| 3 | The review says preliminary studies saw better endothelial function after pure AITC in older adults and smokers; underlying studies not opened. | Older adults and smokers (per the review) | Pure allyl isothiocyanate (not food) |
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 5
- Heat and irritation: nose, eyes, sinuses and mouth. The heat compound, allyl isothiocyanate, irritates the mucous membranes of the sinuses and eyes when the root is cut or grated. Wasabi's burn is felt mostly in the nose and can be painful depending on how much is eaten. Back off, drink or eat something else, and keep the grated root away from your eyes. Fresh wasabi leaves commonly cause diarrhea. Reference article 15 16
- A large mouthful of wasabi was linked to a heart-muscle problem in one case. A 60-year-old woman went to the emergency department with chest pain after eating a large amount of wasabi at a wedding, thinking it was avocado. Doctors reported takotsubo cardiomyopathy, a temporary heart-muscle weakness that can look like a heart attack. This is one case report, so it shows a rare possibility, not how often it happens. Treat chest pain as an emergency whatever the cause. Case report 4
- Pure mustard oil or concentrated compound is not a condiment. A review reports that four people had stomach, breathing and skin reactions and liver dysfunction about an hour after consuming pure mustard oil containing 1.2% allyl isothiocyanate. The symptoms were temporary. The review cites this second-hand. It is a concentrated product, not the amount in a spoonful of horseradish or wasabi. Case series second hand 3
- Pregnancy: animal warning, no human data found. In pregnant rats and their embryos, oral allyl isothiocyanate caused reproductive and developmental toxicity. No human pregnancy data and no official statement on horseradish or wasabi as a condiment were found. The animal doses and the pure compound are not the same as food. If you are pregnant and want to know about heavy or regular use, ask your midwife or doctor. Animal and review 3
- Thyroid conditions: a general cruciferous-vegetable point. The review says thiocyanates made from mustard-family vegetables can interfere with the thyroid's iodine uptake. It gives no data specific to horseradish or wasabi. If you have a thyroid condition, ask your clinician how much of these foods suits you. Review general 3
Side effects 6
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Burning in the nose, eyes and sinuses; watering eyes Wikipedia is a secondary source; the irritant action is also stated in the 2025 review. | Not established | mild and short-lived in ordinary use Passes quickly; wasabi heat is not oil-based and washes away with food or drink | Reference article 16 15 |
| Diarrhea after fresh wasabi leaves About the leaves, not the rhizome paste. | described as a common side effect; no figure given | not stated Not stated | Reference article 16 |
| Takotsubo cardiomyopathy after a large amount of wasabi Very rare as far as the reports go; one case cannot show a rate. | one case report | serious (needed emergency care) Outcome not given in the abstract | Case report 4 |
| Stomach, breathing and skin reactions and liver dysfunction after pure mustard oil (1.2% AITC) Concentrated oil, not a condiment. | four people, as cited by the review | not stated Symptoms were transient | Case series second hand 3 |
| No side effects of wasabi-extract powder at higher amounts in a safety check A supplement trial, small and short. It does not describe the food. | 0 of 30 healthy volunteers reported side effects, over 4 weeks | none seen n/a | Controlled trial 5 |
| Side effects of nasturtium plus horseradish medicine in a cystitis trial A two-plant medicine, not the food. | No significant differences from placebo for any reported side effect | not stated not stated | Controlled trial 2 |
Liver
No liver injury from eating horseradish or wasabi as a condiment was found. A review cites liver dysfunction in four people after pure mustard oil, and liver effects in rats given the pure compound. LiverTox was not checked. 3
How often. No frequency was found.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Horseradish and Wasabi supports liver health.
Medicines and supplements 2
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Prescription medicines in general prescription | No interaction study of horseradish or wasabi (food or extract) with any medicine was found in this search. | Unknown. Absence of reports is not proof that there is no interaction. | None found Not enough evidence | If you take regular medicines and plan to use concentrated products, ask a pharmacist. A condiment-sized amount of food is not expected to matter, but no source read says so. |
| Thyroid medicines or thyroid disease (iodine uptake) condition | Thiocyanates from mustard-family vegetables can reduce iodine uptake (general statement in a review, not specific to these roots). | Not shown for horseradish or wasabi in any study read. | Review general Very low certainty 3 | Ask your clinician if you have thyroid disease and eat a lot of mustard-family foods. |
Who should check first 6
| Situation | Advice | Evidence |
|---|---|---|
| Known allergy or strong sensitivity to horseradish, wasabi or mustard | Avoid them. No allergy case series was found in this search. The 2025 review found no evidence of an IgE-mediated allergic reaction to allyl isothiocyanate, even in mustard-seed workers with asthma, but says people differ in how irritated they get. | Review 3 |
| Chest pain, shortness of breath or fainting after eating | Get urgent medical help. Do not wait to see if it passes. | Case report 4 |
| Pregnancy or breastfeeding | No official statement was found for these roots as a condiment. Animal studies of the pure compound raised a warning. Ask your midwife or doctor about heavy or regular use. Breastfeeding data were not found. | Animal and review 3 |
| Thyroid disease | Ask your clinician; the iodine-uptake point is general to mustard-family vegetables. | Review general 3 |
| Children | No source read gives guidance for children. The heat can irritate; introduce small tastes only if you choose to and watch their reaction. Ask a paediatrician if unsure. | None found |
| Concentrated mustard oil, pure allyl isothiocyanate or wasabi/horseradish extracts | Do not swallow concentrated products. Ask a doctor or pharmacist before any supplement. | Case series second hand 3 |
Overdose, product quality and regulators
Summary. No toxicity from horseradish or wasabi as a condiment was found in the sources read. The concerns come from concentrated allyl isothiocyanate and from very large mouthfuls.
Animal. The review says oral allyl isothiocyanate caused reproductive and developmental toxicity in pregnant rats and embryos, and specific liver effects in rats that depended on dose and exposure time. Animal doses and the pure compound are not food.
Human doses studied. In a double-blind safety study, 30 healthy volunteers took higher amounts of a wasabi-derived 6-MSITC powder for 4 weeks with no changes in measured parameters and no side effects. Amounts are not repeated here.
High dose or long term signals. One case of takotsubo cardiomyopathy after a large amount of wasabi; four people with temporary reactions after pure mustard oil (second-hand).
Overdose response. Not found.
Genotoxicity. Not researched.
The main quality issue is mislabelling: much wasabi sold outside Japan is horseradish mixed with mustard, starch and green colour.
Fake or mixed wasabi. A common substitute is a mixture of horseradish, mustard, starch and green food colouring or spinach powder, and some packs list no wasabi plant at all. Real wasabi is naturally green. In Japan horseradish is called western wasabi. If you avoid mustard or certain colourings, read the ingredient list. 16 15
Salt in prepared products. USDA lists prepared horseradish (grated root with vinegar and salt) at 420 mg sodium per 100 g, and an entry named Wasabi, filed under sauces, at 3,390 mg sodium per 100 g. Raw wasabi root has 17 mg per 100 g. Check the label if you limit salt. 14 13 12
Keeping prepared horseradish. A home-preservation source says the pungency of fresh horseradish fades within 1 to 2 months even when refrigerated. It gives no safety limit for storage beyond that; the sources read give no shelf-life advice for jarred products. 11
| Body | Action | Date |
|---|
When to get medical help
- Chest pain, tightness or shortness of breath after eating a lot of wasabi or horseradish, or fainting
- Swelling of the lips, face or throat, widespread hives or trouble breathing after eating either root
- Severe vomiting, stomach pain, difficulty breathing or yellow skin or eyes after swallowing concentrated mustard oil or an extract
- Eye pain or burning that does not settle after grated root gets in the eye
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
Is horseradish the same as wasabi?
How can I tell real wasabi from fake?
Read the ingredient list. Imitation wasabi is horseradish, mustard, starch and green colouring, and some packs list no wasabi plant. Real wasabi is naturally green and costs more.
Why does the heat fade so fast?
What gives them their sting?
Do horseradish or wasabi improve memory?
One 12-week trial of a wasabi extract capsule in 72 healthy older adults found better working and episodic memory than placebo. A wasabi company funded it and it has not been repeated. Nothing was tested with the condiment.
Do they help with bronchitis or bladder infections?
Do they prevent cancer?
No human evidence shows that. The effects of the heat compound on cancer cells come from cells and animals, at levels the review says are higher than food provides.
Can wasabi be dangerous?
A condiment-sized amount is not expected to be. One case report describes a heart-muscle problem after a large amount of wasabi eaten by mistake. Chest pain after eating it needs urgent care.
Are they safe in pregnancy?
No official statement was found for the condiments. Oral pure allyl isothiocyanate harmed pregnant rats and embryos in animal studies. Ask your midwife or doctor about heavy or regular use.
Can I be allergic to horseradish or wasabi?
No allergy case reports were found in this search. A review found no evidence of an IgE-type allergic reaction to the heat compound, but says people differ in irritation. If you react to mustard, horseradish or wasabi, avoid them and ask a doctor.
Is prepared horseradish a good source of vitamin C?
Per 100 g it has 24.9 mg of vitamin C by USDA data, but a teaspoon (5 g) holds only about 1.2 mg. We do not call it a good source of anything.
Does it affect the thyroid or medicines?
A review says thiocyanates from mustard-family vegetables can reduce iodine uptake, with no data on these roots. No medicine interaction study was found. Ask a clinician or pharmacist if you have thyroid disease.
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Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-26
- Last substantive update
- 2026-10-26
- How we research
- We started from our existing summary for this spice, re-read nutrition in the USDA FoodData Central SR Legacy download, checked species names in GBIF, and searched PubMed for trials, reviews and case reports. Only abstracts were read for the studies, except the 2025 review, read in full. Kitchen and history facts come from Wikipedia and a home-preservation page and are secondary. Items we could not verify are flagged in the research gaps.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown.
Sources 16
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Albrecht U, Stefenelli U, Stange R. A combination of Tropaeolum majus herb and Armoracia rusticana root for the treatment of acute bronchitis.. Phytomedicine. 2023. PMID 37167822. DOI 10.1016/j.phymed.2023.154838. (abstract)
- Albrecht U, Schmitz G, Stefenelli U et al.. Clinical evaluation of the efficacy and safety of nasturtium herb and horseradish root versus placebo in the continuous prophylaxis of recurrent uncomplicated cystitis: a double-blind randomised clinical trial.. BMC Complement Med Ther. 2026. PMID 41782129. DOI 10.1186/s12906-026-05328-z. (abstract)
- Alibrahem W, Nguyen DHH, Kharrat Helu N et al.. Health Benefits, Applications, and Analytical Methods of Freshly Produced Allyl Isothiocyanate.. Foods. 2025. PMID 40002023. DOI 10.3390/foods14040579. (full-text)
- Finkel-Oron A, Olchowski J, Jotkowitz A et al.. Takotsubo cardiomyopathy triggered by wasabi consumption: can sushi break your heart?. BMJ Case Rep. 2019. PMID 31540920. DOI 10.1136/bcr-2019-230065. (abstract)
- Nakajima R, Kanou M, Tokushima M et al.. Oral administration of 6-methylsulfinylhexyl isothiocyanate extracted from wasabi is safe and improves the fatigue and sleep of healthy volunteers.. Biopsychosoc Med. 2023. PMID 37612759. DOI 10.1186/s13030-023-00287-0. (abstract)
- Nouchi R, Kawata NYS, Saito T et al.. Benefits of Wasabi Supplements with 6-MSITC (6-Methylsulfinyl Hexyl Isothiocyanate) on Memory Functioning in Healthy Adults Aged 60 Years and Older: Evidence from a Double-Blinded Randomized Controlled Trial.. Nutrients. 2023. PMID 37960261. DOI 10.3390/nu15214608. (abstract)
- Oka T, Yamada Y, Lkhagvasuren B et al.. Clinical effects of wasabi extract containing 6-MSITC on myalgic encephalomyelitis/chronic fatigue syndrome: an open-label trial.. Biopsychosoc Med. 2022. PMID 36510244. DOI 10.1186/s13030-022-00255-0. (abstract)
- Tanabe Y, Akazawa N, Nishimaki M et al.. Effects of 6-(Methylsulfinyl)hexyl Isothiocyanate Ingestion on Muscle Damage after Eccentric Exercise in Healthy Males: A Pilot Placebo-Controlled Double-Blind Crossover Study.. J Diet Suppl. 2022. PMID 33938371. DOI 10.1080/19390211.2021.1912244. (abstract)
- . GBIF Backbone: Armoracia rusticana P.Gaertn., B.Mey. & Scherb. (usageKey 3041022). . . (full-text)
- . GBIF Backbone: Eutrema japonicum (Miq.) Koidz. (usageKey 5375216). . . (full-text)
- . National Center for Home Food Preservation: Pickled Horseradish Sauce. . . (full-text)
- . USDA FoodData Central: Wasabi, root, raw (FDC 168583). . . (full-text)
- . USDA FoodData Central: Wasabi (FDC 171831, filed under soups, sauces and gravies). . . (full-text)
- . USDA FoodData Central: Horseradish, prepared (FDC 173472). . . (full-text)
- . Wikipedia: Horseradish. . . (full-text)
- . Wikipedia: Wasabi. . . (full-text)
Where to buy
Check the label first. Whatever you buy, look for these:
- Whole or ground: whole spices keep their flavor longer
- The origin and a packed-on or best-by date for freshness
- Organic or non-irradiated labeling if that matters to you
- A resealable, airtight container
Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.
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