Horseradish and wasabi: Flavor, Cooking Use and Health Facts
Horseradish and wasabi are sharp, nose-clearing roots eaten fresh or as a paste; the heat fades fast, and the health research is thin, with one small memory trial on a wasabi extract.
Content last updated . This page has not been medically reviewed.
In the kitchen at a glance
Flavor:Hot / pungentSour / tangyEarthy
Aroma: Almost no smell until cut, then a sharp, sinus-clearing sting.
Used in: rice and grains, soups and stews, tea and drinks
Usual amount in food: About 1 teaspoon (5 g) of prepared horseradish is the USDA household measure; we found no source that sets a usual recipe amount.
What it is
Horseradish is the thick white root of Armoracia rusticana, a plant in the mustard family. It probably comes from southeastern Europe and western Asia. [1] Wasabi is the knobby green stem base (rhizome) of Eutrema japonicum, also called Wasabia japonica, which is native to Japan. [2] The two are relatives in the same plant family, and are often confused. [1][2] Real wasabi is hard to grow, since it needs cool, humid, shaded conditions, so it is scarce and costly outside Japan. [2]Flavor and aroma
The whole root has little smell. Cutting or grating releases an enzyme that turns stored plant compounds into allyl isothiocyanate, the source of the heat. [1][4] Wasabi works the same way, and its burn is felt more in the nose than on the tongue. It is not oil-based like chili heat, so it is short-lived and washes away with more food or drink. [2] Air and heat weaken the bite and add bitterness. [1] Freshly grated horseradish is the sharpest, and sauces made from it are milder. [1]How it is used in cooking
- With meat and fish: horseradish is a condiment across Europe, served with roast beef in the UK and with meat and fish in Eastern and Central Europe. [1]
- Sauces and mixes: variations add beetroot (chrain), apple, cream or sour cream. It is also in cocktail sauce and the Bloody Mary. [1]
- Festival use: many Ashkenazi Jews use it as the bitter herb at Passover, and it flavors a Polish Easter soup. [1]
- Sushi: wasabi paste is eaten with sushi, and chefs often place it between the fish and the rice. It also flavors snacks such as coated peas. [2]
- Grating: wasabi is traditionally grated on coarse sharkskin, now often on a fine metal grater, and some restaurants grate it to order. [2]
- Wasabi leaves: fresh leaves can be eaten raw or pickled. [2]
Much of the "wasabi" served outside Japan is horseradish mixed with mustard, starch and green color, and some packs hold no wasabi plant. [2] Real wasabi is naturally green. [2] A German variant uses citric acid or lemon juice in place of vinegar. [1] The sources we read do not say when to add it, whether to toast it, or give general substitutes.
Normal food amounts
| Measure | Grams | Source |
|---|---|---|
| 1 teaspoon, prepared horseradish | 5 g | USDA [7] |
| 1 tablespoon, prepared horseradish | 15 g | USDA [7] |
| Typical recipe amount | Not found | We opened no source that states one |
What one teaspoon (5 g) of prepared horseradish provides, calculated from USDA values per 100 g:
| Nutrient | One teaspoon |
|---|---|
| Energy | about 2.4 kcal |
| Vitamin C | about 1.2 mg |
| Potassium | about 12 mg |
| Calcium | about 2.8 mg |
| Sodium | about 21 mg |
| Fiber | about 0.2 g |
The USDA SR Legacy data are from 2018, describe prepared horseradish (grated root with vinegar and salt), and real products vary. [7] USDA SR Legacy has no entry for wasabi in the file we used, so we give no wasabi numbers. A wasabi source says it is eaten in such small amounts that its nutritional value is negligible. [2] We did not compare any of these numbers with official daily values, so we do not call either root a "good source" of anything.
Buying, storing and preparing
- Forms: fresh root or rhizome, jarred prepared horseradish, wasabi paste and powder, and wasabi leaves. [1][2]
- Storing prepared horseradish: keep it in the refrigerator. A home-preservation source says the pungency of fresh horseradish fades within 1 to 2 months even when chilled, so make small batches. [3]
- Home recipe: that source grates peeled root and mixes it with 5% white vinegar and a little salt, in sealed jars in the refrigerator. [3]
- Grated wasabi: it loses flavor quickly if left uncovered. Bottled paste is usually made from dried powder. [2]
- Grated horseradish keeps its color and bite best when cold and covered. Air darkens it and adds bitterness. [1]
- Adulteration: see the mix-up with horseradish, mustard and dye above. [2]
Health: what research says
Eating a little of these roots as a condiment is very different from taking concentrated extracts or pure mustard-oil compounds.Food amounts vs supplements
| In normal cooking | In supplements and extracts | |
|---|---|---|
| Typical amount | About 5 g per teaspoon of prepared horseradish (USDA); no usual recipe amount found [7] | A wasabi extract capsule with 100 mg of extract and 0.8 mg of 6-MSITC was used in one trial [5] |
| What studies mostly used | We found no study of horseradish or wasabi eaten as a condiment | A wasabi extract in one trial; a nasturtium plus horseradish combination in others [5][6] |
| What we can say about benefit | Nothing; no trial tested food amounts | Preliminary, from small or single trials [5][6] |
| Main safety limit | Heat on the nose, eyes and mouth; stomach upset in sensitive people | Pure mustard oil caused reactions in a small report [4] |
What the evidence shows
| Use | What the sources found | Strength of evidence | Form and population |
|---|---|---|---|
| Memory in older adults | A 72-person double-blind trial found better working and episodic memory after 12 weeks than placebo, with no gains in other tests; the authors ask for replication. [5] | Promising but limited | Wasabi extract capsule, healthy adults aged 60 and over [5] |
| Acute bronchitis | One trial of a nasturtium and horseradish combination reported faster symptom improvement. [6] | Promising but limited | Combination product, patients with bronchitis [6] |
| Recurrent cystitis | One trial of the same combination reported fewer recurrences in women; the manufacturer funded it. [6] | Promising but limited | Combination product, women [6] |
| Blood vessel lining function | Small pilot studies after 0.5 to 2.4 mg of allyl isothiocyanate in older adults and smokers; the review says most heart-related evidence is from animals. [4] | Insufficient evidence | Pure compound, small groups [4] |
| Cancer prevention | Cell and animal work only; the review says protective effects appear only at levels higher than diet gives. [4] | Lab or animal only | Pure compound [4] |
| Sinus congestion, colds | No trial of horseradish alone found [6] | Insufficient evidence | Not studied |
For supplement forms, trials and interactions in depth, see the full herb guide: Horseradish.
Official statements
- United States: the 2025 review states that allyl isothiocyanate is a "natural flavoring" generally recognized as safe within regulatory levels, with a 0.1% concentration cap. [4]
- European Union: the same review states a limit of 5 mg per kg in food. It does not reconcile the units. [4]
Related pages
Health connections for Horseradish and wasabi
What research links to this spice, and how strong the evidence is. Most studies use concentrated extracts or doses far above what you eat; each card says which.
Memory in healthy older adults (wasabi extract)
Preliminary or mixedA 72-person double-blind trial found better working and episodic memory after 12 weeks of a wasabi extract capsule than placebo, with no gains in other tests.
Supplements: Supplement finding only (100 mg extract with 0.8 mg 6-MSITC); no study of wasabi as food.
Acute bronchitis (nasturtium-horseradish combination)
Preliminary or mixedOne trial of a nasturtium and horseradish combination reported faster symptom improvement in bronchitis.
Supplements: Combination product only; not food amounts.
Recurrent cystitis (nasturtium-horseradish combination)
Preliminary or mixedOne manufacturer-funded trial of the combination reported fewer recurrences in women.
Supplements: Combination product only; not food amounts.
Blood vessel lining function
Not enough evidenceSmall pilot studies after 0.5 to 2.4 mg of allyl isothiocyanate in older adults and smokers; most heart-related evidence is from animals.
Supplements: Pure compound; not shown for condiment amounts.
Cancer cell and animal findings
Lab or animal research onlyAllyl isothiocyanate affected cancer cells in the lab and reduced colon polyps in mice; the review says benefit appears only at levels higher than diet provides, and lung evidence is unclear.
Supplements: Lab or animal only; not shown in people.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (1)
- Memory SupportPreliminary or mixed
One small trial of a wasabi extract capsule found better working and episodic memory in healthy older adults; not tested for food amounts.
Body systems (4)
- Brain & FocusPreliminary or mixed
One small wasabi extract trial reported better memory in older adults.
- Digestive SystemDocumented risk
Stomach upset after pure mustard oil in a small report; fresh wasabi leaves commonly cause diarrhea.
- Nervous SystemPreliminary or mixed
One small wasabi extract trial reported better memory in older adults.
- Reproductive SystemDocumented risk
Oral allyl isothiocyanate harmed pregnant rats and embryos; no human data.
Body parts (3)
Conditions & symptoms (2)
- Acute BronchitisPreliminary or mixed
One trial of a nasturtium-horseradish combination reported faster symptom improvement; not horseradish alone.
- CystitisPreliminary or mixed
One manufacturer-funded trial of the combination reported fewer recurrences in women; not horseradish alone.
Documented risks and interactions (5)
- Stomach, breathing and skin reactions to pure mustard oil. Four people had stomach, breathing and skin reactions, and liver dysfunction, one hour after pure mustard oil containing 1.2% allyl isothiocyanate; symptoms were transient.
- Irritation of nose, eyes and sinuses. The heat compound irritates the mucous membranes of the sinuses and eyes.
- Pregnancy: animal developmental toxicity. Oral allyl isothiocyanate caused reproductive and developmental toxicity in pregnant rats and their embryos; no human pregnancy data were found.
- Thyroid: iodine uptake and cruciferous thiocyanates. The review says thiocyanates from cruciferous vegetables can reduce iodine uptake; it gives no data specific to horseradish or wasabi.
- Fake wasabi and wasabi leaf diarrhea. Much wasabi sold outside Japan is horseradish with mustard and green dye; fresh wasabi leaves commonly cause diarrhea.
Frequently asked questions
Is horseradish the same as wasabi?
No. They are relatives with the same kind of heat, but horseradish is a white root and wasabi is a green rhizome. [1][2] Much "wasabi" outside Japan is horseradish with mustard and green color. [2]
Why does the heat fade so fast?
The heat compound is released only when the root is cut and it breaks down over time. [1] Wasabi heat is not oil-based, so it passes quickly. [2]
How much is normal?
USDA lists 5 g per teaspoon of prepared horseradish. [7] We found no source for a usual recipe amount.
Is it safe in pregnancy?
We found no human data. Animal work showed harm only with oral doses of the pure compound. [4] Ask your midwife or doctor.
Can I take it with medicines?
The sources we read name no interactions. Ask a pharmacist about extracts or capsules.
Does wasabi help memory?
One small trial of a wasabi extract capsule in older adults found better memory scores. [5] It needs repeating, and it did not test wasabi as food.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety note at a glance
Safety in more detail
- Medicines: the sources we read do not describe medicine interactions for horseradish or wasabi.
- Pregnancy: oral allyl isothiocyanate caused reproductive and developmental harm in pregnant rats at the doses tested. [4] No human pregnancy data were found. Food amounts are not addressed.
- Breastfeeding: the sources we read do not describe it.
- Children: the sources we read do not describe it.
- Allergy: the 2025 review says no IgE-type allergic reaction has been shown for allyl isothiocyanate, and that people differ in sensitivity. [4] Because horseradish, wasabi and mustard are in the same plant family, ask an allergist if you react to mustard. [1][2]
- Liver and kidney: a small report of four people who swallowed pure mustard oil mentions liver dysfunction among the reactions. Very high doses caused liver and kidney lesions in animals. [4]
- Surgery: the sources we read do not describe it.
- Thyroid: the review says thiocyanates from cruciferous vegetables can reduce iodine uptake. It gives no data for these roots specifically. [4] Ask a clinician if you have thyroid disease.
- Quality and contamination: fake wasabi is common. [2] Fresh wasabi leaves commonly cause diarrhea. [2]
- Amounts that cause trouble: the allyl isothiocyanate vapor irritates the nose, eyes and sinuses. [1] Four people had stomach, breathing and skin reactions one hour after pure mustard oil with 1.2% of the compound. [4] That is not a condiment.
References
- Wikipedia — Horseradish. https://en.wikipedia.org/wiki/Horseradish (accessed 2026-10-24; first 100,000 characters read)
- Wikipedia — Wasabi. https://en.wikipedia.org/wiki/Wasabi (accessed 2026-10-24; first 100,000 characters read)
- National Center for Home Food Preservation (US) — Pickled Horseradish Sauce. https://nchfp.uga.edu/how/pickle/vegetable-pickles/pickled-horseradish-sauce/ (accessed 2026-10-24)
- Foods 2025;14(4):579 — Health Benefits, Applications, and Analytical Methods of Freshly Produced Allyl Isothiocyanate (review). https://pmc.ncbi.nlm.nih.gov/articles/PMC11853810 (accessed 2026-10-24; first part read)
- Nouchi R et al. — Benefits of Wasabi Supplements with 6-MSITC on Memory in Healthy Adults Aged 60 and Older: a double-blinded randomized controlled trial. Nutrients 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC10648564/ (accessed 2026-10-24)
- alternativemed.com — Horseradish herb guide, which reports nasturtium and horseradish trials (Albrecht et al., Phytomedicine 2023; BMC Complement Med Ther 2026). /herbs-botanicals/horseradish (site page; the trial papers themselves were not opened here)
- USDA FoodData Central, SR Legacy (April 2018) — Horseradish, prepared (fdc_id 173472), per-100 g values and household portions from the site's USDA data file.