Wasabi: the best trial on it did not use wasabi

Seventy-two healthy adults aged 60 and over in Sendai took a capsule of isolated 6-MSITC, the pungent compound of the wasabi root, for 12 weeks. Against placebo their working memory and episodic memory improved, with effect sizes of eta squared 0.11 to 0.19, while processing speed, short-term memory and attention did not move. That is a supplement, not a condiment, and nobody has measured how much 6-MSITC a spoon of paste holds, so the dose does not carry across. It is also the strongest thing on this page, a single randomized trial in one age group in one city. The other wasabi trial gave 9 mg a day of the same compound to 8 young men and moved no marker of muscle damage or inflammation, which in a pilot that small means too little power rather than a demonstrated absence. Everything else here about the pungent chemistry was measured on broccoli, mustard and cabbage, and each line below says which.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• The raw root and the paste sold as wasabi are different foods: 17 mg of sodium and 41.9 mg of vitamin C per 3.5 oz (100 g) in the root against 3390 mg of sodium and none of the vitamin C in the paste. — Three USDA SR Legacy records published 2019-04-01: Wasabi, root, raw (FDC 168583), Wasabi (FDC 171831) and Snacks, peas, roasted, wasabi-flavored (FDC 173157), per 3.5 oz (100 g) (n = 3 records) Evidence E source
  Root 109 calories, sodium 17 mg, vitamin C 41.9 mg, fiber 7.8 g, potassium 568 mg, copper 0.155 mg; paste 292 calories, sodium 3390 mg, vitamin C 0, sugars 13.2 g, fat 10.9 g; wasabi peas 432 calories, sodium 300 mg, vitamin C 0, protein 14.11 g

What a real portion looks like

• The wasabi portion in the US survey database is 2 g per piece of sushi and 16 g per tablespoon, against a 130 g cup of sliced raw root. — USDA FNDDS household measures for Wasabi paste (food code 75534550) and Wasabi peas (food code 41304000), plus the USDA SR Legacy portion for Wasabi, root, raw (n = 5 measures) Evidence E source
  Wasabi paste 1 tablespoon 16 g, guideline amount per piece of sushi 2 g, quantity not specified 5 g; wasabi peas 1 cup 120 g, quantity not specified 30 g; wasabi root raw 1 cup sliced 130 g

What your body absorbs

• Isothiocyanates from 14 days of a high-glucosinolate diet reached the knee joint fluid of patients awaiting knee replacement, while the low-glucosinolate group had none. — 40 patients with knee osteoarthritis randomized to a low or high glucosinolate diet for 14 days before total knee replacement (n = 40) Evidence B source
  Isothiocyanates detected in synovial fluid of the high glucosinolate group only, mirrored by a rise in plasma isothiocyanates and sulforaphane; 125 differentially expressed synovial proteins between groups
• The ready-made isothiocyanate was recovered at 70.6 percent of the dose against 17.8 percent for its glucosinolate precursor, so the form eaten decides how much gets in. — Healthy volunteers in three inpatient cohorts of four, on a crucifer-free diet, given broccoli sprout extract every 8 hours for 7 days, 21 doses (n = 12) Evidence B source
  Dithiocarbamate recovery 17.8 +/- 8.6 percent of dose at 25 micromol glucosinolate, 19.6 +/- 11.7 percent at 100 micromol glucosinolate, 70.6 +/- 2.0 percent at 25 micromol isothiocyanate

What cooking and storage change

• Adding 1 g of powdered brown mustard to 7.1 oz (200 g) of cooked broccoli raised urinary sulforaphane metabolite from 9.8 to 44.7 micromol per gram creatinine in 12 adults, over four times more. — 12 healthy adults in a crossover trial, 7.1 oz (200 g) of cooked broccoli with and without 1 g of powdered brown mustard, all urine collected for 24 hours (n = 12) Evidence B source
  Urinary SF-NAC 9.8 +/- 5.1 micromol per g creatinine without mustard against 44.7 +/- 33.9 with mustard, over fourfold higher bioavailability
• Cooked Brassica leaves without allyl isothiocyanate cut aflatoxin-induced DNA damage by 33 to 35 percent in 22 adults, while the raw leaves that kept the isothiocyanate cut it by a non-significant 21 percent. — 22 healthy subjects eating a raw or cooked Brassica carinata preparation for five days each in a randomized crossover design (n = 22) Evidence B source
  Cooked minus 35 percent DNA damage with S9 mix and minus 33 percent without (p at most 0.01); raw minus 21 percent with S9 mix only (p = 0.08); raw lowered plasma PGE2, neither changed antioxidant capacity

What it does to your health

• Observational data link the highest cruciferous vegetable intake with 19 percent lower lung cancer risk across 31 studies. — Participants of 31 observational studies comparing the highest with the lowest category of cruciferous vegetable intake (n = 31 studies) Evidence C source
  Summary odds ratio or relative risk 0.81 (95% CI 0.74 to 0.89)

Safety, limits and interactions

• Seven days of 21 doses of broccoli sprout glucosinolates or isothiocyanates produced no toxicity across 32 blood tests, with liver and thyroid markers examined in detail. — Healthy inpatient volunteers in a phase I safety, tolerance and pharmacokinetics study, monitored during 7 days of dosing and for 3 days after (n = 12) Evidence B source
  No significant or consistent abnormal events; transaminases, TSH, total T3 and free T4 examined specifically
• Laboratory, animal and human data reviewed together cast doubt on the idea that Brassica plants suppress thyroid function when iodine intake is adequate. — 123 in vitro, animal and human studies of brassica plants and extracts on thyroid mass, histology, TSH, T3, T4 and iodine uptake (n = 123 studies) Evidence D source
  No adverse effect on thyroid function reported when brassica vegetables are eaten with adequate iodine intake; goitrogenic mechanisms of glucosinolates and isothiocyanates described but not confirmed in humans

What people believe that the data does not support

• The EU register holds no authorized health claim for glucosinolates, and the claim that foods containing them strengthen the body's defenses is listed as non-authorized. — EU Register on nutrition and health claims, snapshot 2026-09-21, 2330 claims of which 262 authorized (n = 2 claims found for glucosinolates, 0 authorized) Evidence E source
  POL-HC-7196 Non-authorized; POL-HC-7997 on sulforaphane glucosinolate also non-authorized; no register entry at all for wasabi, isothiocyanate or allyl isothiocyanate

Who this works differently for

• Twelve weeks of a wasabi 6-MSITC supplement improved working memory and episodic memory against placebo in 72 healthy adults aged 60 and over, with effect sizes of eta squared 0.11 to 0.19. — 72 healthy adults aged 60 and over in Sendai, average age 65.43 years, 19 men and 53 women, 12 weeks of supplement or placebo (n = 72) Evidence B source
  Working memory DS-B F(1,66) = 8.20, eta squared 0.11; episodic memory LM immediate F(1,66) = 15.80, eta squared 0.19; LM delayed F(1,66) = 10.39, eta squared 0.14; no change in processing speed, short-term memory or attention

What is still unknown

• Nine mg a day of the wasabi compound 6-MSITC left every muscle damage and inflammation marker unchanged after eccentric exercise in 8 healthy young men. — 8 healthy young males in a crossover trial, 9 mg per day of 6-MSITC or placebo from 1 day before to 4 days after 30 maximal eccentric elbow flexor contractions (n = 8) Evidence B source
  Plasma calpain-1 similar between conditions; creatine kinase, urinary titin, muscle strength, range of motion, soreness and transverse relaxation time all unaffected

The bottom line

Start with what is in the jar. USDA analyzed the raw root at 109 calories, 17 mg of sodium, 41.9 mg of vitamin C and 7.8 g of fiber per 3.5 oz (100 g), and the product labeled simply Wasabi at 292 calories, 3390 mg of sodium, no vitamin C and 13.2 g of sugars. Most paste on the market is horseradish with coloring, and the USDA records do not separate the two, so that row describes a category rather than the plant. Portion size rescues the sodium figure. The US survey database gives 2 g of paste per piece of sushi and 16 g per tablespoon, and multiplying those two dataset fields leaves about 68 mg of sodium in the dab, which is arithmetic on the table and not a separate measurement. Wasabi peas are a third food again, 432 calories and 300 mg of sodium per 3.5 oz (100 g), eaten by the 30 g handful. Heat decides whether any of the chemistry survives at all. Grating breaks the root so that myrosinase can turn glucosinolates into isothiocyanates, and heating destroys that enzyme. In 12 adults, adding 1 g of powdered brown mustard to 7.1 oz (200 g) of cooked broccoli lifted the urinary sulforaphane metabolite from 9.8 to 44.7 micromol per gram creatinine, a fourfold gap around a standard deviation of 33.9 that shows how much people differ. Form matters as much as heat. In a phase I study of 12 volunteers the ready-made isothiocyanate was recovered at 70.6 percent of the dose, against 17.8 percent for its glucosinolate precursor. Cooking shifts the profile rather than only shrinking it. Among 22 adults the cooked Brassica preparation, which had lost its allyl isothiocyanate, cut aflatoxin-induced DNA damage by 33 to 35 percent, while the raw version reached a non-significant 21 percent and lowered plasma PGE2 instead. Those three studies used broccoli, mustard and Brassica carinata. Isothiocyanates do travel: after 14 days on a high-glucosinolate diet, 40 patients waiting for knee replacement had them in their joint fluid, and the low-glucosinolate group had none. What that does for a joint the authors left to the next trial. On safety, 12 inpatient volunteers took 21 doses of broccoli sprout glucosinolates or isothiocyanates over 7 days with no toxicity across 32 blood tests, transaminases, TSH, total T3 and free T4 examined specifically, which speaks to acute intake in 12 people and says nothing about years of it. The old thyroid worry looks weak. A review of 123 laboratory, animal and human studies casts doubt on an antithyroid effect in humans when iodine intake is adequate, and that condition is carrying weight, so low iodine intake is where the question stays open. No card in this set covers pregnancy, children, allergy or drug interactions for wasabi, and none sets an upper limit for isolated 6-MSITC, so the two supplement trials above record what was tested and not what is established as safe. We did not find that evidence rather than finding it reassuring. Europe has authorized no health claim for glucosinolates and lists the claim that they strengthen the body defenses as non-authorized. The 19 percent lower lung cancer risk seen with the highest cruciferous intake across 31 observational studies (0.81, 95% CI 0.74 to 0.89) belongs to cabbage-sized helpings of the family, and the authors themselves say other compounds may carry it.

Sources

1. wsbi-daily-r1-11 · reference dataset
   Wasabi, root, raw (FDC 168583): energy 109 kcal, sodium 17 mg, vitamin C 41.9 mg, fiber 7.8 g, potassium 568 mg, copper 0.155 mg, protein 4.8 g per 100 g | Wasabi (FDC 171831): energy 292 kcal, sodium 3390 mg, vitamin C 0.0 mg, sugars 13.2 g, fat 10.9 g, fiber 6.1 g per 100 g | Snacks, peas, roasted, wasabi-flavored (FDC 173157): energy 432 kcal, sodium 300 mg, vitamin C 0.0 mg, protein 14.11 g, fiber 3.8 g per 100 g
   USDA FoodData Central, SR Legacy, published 2019-04-01, FDC 168583, 171831 and 173157 · checked 2026-09-25
2. wsbi-daily-r1-12 · reference dataset
   Wasabi paste, FNDDS 75534550: 1 tablespoon 16 g | Guideline amount per piece of sushi 2 g | Quantity not specified 5 g || Wasabi peas, FNDDS 41304000: 1 cup 120 g | Quantity not specified 30 g || Wasabi, root, raw, FDC 168583: 1 cup, sliced 130 g
   USDA FNDDS, Wasabi paste code 75534550 and Wasabi peas code 41304000 · checked 2026-09-25
3. wsbi-daily-r1-03 · randomized controlled trial
   We detected ITCs in the synovial fluid of the high glucosinolate group, but not the low glucosinolate group. This was mirrored by an increase in ITCs and specifically sulforaphane in the plasma.
   Sci Rep, 2017 · checked 2026-09-25
4. wsbi-daily-r1-04 · phase I clinical trial
   The mean cumulative excretion of dithiocarbamates as a fraction of dose was very similar in cohorts A and B (17.8 +/- 8.6% and 19.6 +/- 11.7% of dose, respectively) and very much higher and more consistent in cohort C (70.6 +/- 2.0% of dose).
   Nutr Cancer, 2006 · checked 2026-09-25
5. wsbi-daily-r1-06 · randomized crossover trial
   When study subjects ingested cooked broccoli alone, mean urinary SF-NAC excreted was 9.8 ± 5.1 μmol per g creatinine, and when cooked broccoli was consumed with mustard powder, this increased significantly to 44.7 ± 33.9 μmol SF-NAC per gram creatinine.
   Mol Nutr Food Res, 2018 · checked 2026-09-25
6. wsbi-daily-r1-07 · randomized crossover trial
   Cooked B. carinata significantly reduced DNA damage induced by AFB1 as compared to baseline levels (+S9 mix: 35%, -S9 mix: 33%, p ≤ 0.01, respectively). Raw B. carinata only reduced DNA damage by S9-activated AFB1 by 21% (p = 0.08).
   Nutrients, 2018 · checked 2026-09-25
7. wsbi-daily-r1-09 · meta-analysis of observational studies
   In the meta-analysis of 31 observational studies, cruciferous vegetable intake is inversely associated with lung cancer risk (summary odds ratio/relative risk = 0.81 and 95% confidence interval = 0.74-0.89 for comparing the highest with lowest intake categories).
   Mol Nutr Food Res, 2018 · checked 2026-09-25
8. wsbi-daily-r1-05 · phase I clinical trial
   Thirty-two types of hematology or chemistry tests were done before, during, and after the treatment period. Indicators of liver (transaminases) and thyroid [thyroid-stimulating hormone, total triiodothyronine (T3), and free thyroxine (T4)] function were examined in detail. No significant or consistent subjective or objective abnormal events (toxicities) associated with any of the sprout extract ingestions were observed.
   Nutr Cancer, 2006 · checked 2026-09-25
9. wsbi-daily-r1-08 · systematic review of mixed evidence
   The vast majority of the results cast doubt on previous assumptions claiming that brassica plants have antithyroid effects in humans. Instead, they indicate that including brassica vegetables in the daily diet, particularly when accompanied by adequate iodine intake, poses no adverse effects on thyroid function.
   Int J Mol Sci, 2024 · checked 2026-09-25
10. wsbi-daily-r1-10 · EU claims register entry
    POL-HC-7196 Glucosinolates Foods containing glucosinolates help strengthen our body's defences. Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-7196, snapshot 2026-09-21 · checked 2026-09-25
11. wsbi-daily-r1-01 · randomized controlled trial
    The 6-MSITC group showed a significant improvement in working memory, measured by DS-B (F (1, 66) = 8.20, η2 = 0.11, adjusted p = 0.000), and in episodic memory performance, measured by LM immediately (F (1, 66) = 15.80, η2 = 0.19, adjusted p = 0.00), LM delay (F (1, 66) = 10.39, η2 = 0.14, adjusted p = 0.03), and FSN (F (1, 66) = 12.65, η2 = 0.16, adjusted p = 0.00).
    Nutrients, 2023 · checked 2026-09-25
12. wsbi-daily-r1-02 · randomized crossover pilot trial
    We performed a randomized, double-blind, crossover design study wherein eight healthy young males were randomly assigned to ingest 9 mg/day of 6-MSITC or placebo from 1 day before exercise to 4 days after exercise (30 maximal isokinetic eccentric contractions of the elbow flexors using an isokinetic dynamometer). ... All muscle damage and inflammatory markers were not affected by 6-MSITC relative to those in the placebo-treated condition.
    J Diet Suppl, 2022 · checked 2026-09-25