CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-04). The draft was written by AI, the existence of all 4 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 2159 · Search date 2026-08-04 · Methodology v0.6

Raw cucumber plus radish,
does it really help with Worsened vitamin C status or clinical deficiency?

30-Second Summary
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Evidence Grade ? · Safety acceptable
Cucumber enzyme exists, but vitamin C deficiency from eating cucumber with radish has not been studied in humans
No serious harm signal was identified for ordinary amounts of cucumber and radish together. People with a specific food allergy should avoid the relevant food.
What the
research shows
The verdict is pending. Cucumber genuinely contains ascorbate oxidase and purified-enzyme activity has been measured. The enzyme oxidizes ascorbate to dehydroascorbate, however, and human erythrocytes rapidly reduce that oxidized form back to ascorbate. No human trial measuring absorption, vitamin status, or deficiency after the cucumber-radish combination was identified, so no score was assigned.
What the
ads claim
Active cucumber enzyme is a real fact. Claiming that it destroys all radish vitamin C and causes deficiency, without measuring total loss in a dish or human status, expands chemistry into an untested clinical outcome.
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Useful facts when choosing a product

  • Purified cucumber ascorbate oxidase had molecular weight about 132,000, eight copper atoms, and specific activity of 3,500 Dawson units/mg.
  • In cucumber juice, reported optimum conditions were pH 6.5 and 40°C; the enzyme was inactive at pH 3.9, and pH 3.4 orange juice stopped measured ascorbate oxidation.
  • A 1990 cutting study found total vitamin C in cut cucumber and radish sprouts equal to fresh samples. It was not a human feeding study of cucumber plus radish root.
  • Human erythrocytes rapidly take up dehydroascorbate and reduce it to ascorbate, so initial oxidation does not equal total loss of biological vitamin C.
  • Heating can denature enzyme protein, but the accessible evidence did not establish residual activity for a specific cooked cucumber-radish recipe across time and temperature.
Gap Measurement · Verdict 2159 · ?
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Nakamura 1968 purified cucumber enzyme and measured molecular weight about 132,000, eight copper atoms, and specific activity 3,500 Dawson units/mg. A 1985 cucumber-juice study reported optimum pH 6.5 and 40°C, inactivation at pH 3.9, and cessation of measured ascorbate oxidation after adding pH 3.4 orange juice. These were food-enzyme experiments, not human trials. Oba 1990 found total vitamin C unchanged in cut cucumber and radish sprouts versus fresh samples. May 1995 showed human erythrocyte reduction of oxidized vitamin C. Funding for the pivotal chemistry work was not confirmed.

02

Why this is classified as ?

Enzyme activity was directly measured, but no human study measured vitamin C absorption, status, or deficiency after cucumber plus radish; the verdict is pending without a score.

Counterpoint. Vitamin C loss can vary with cut size, storage time, oxygen, temperature, and acidity. This does not mean the enzyme is absent.

Rejudgment record. Cross-check applied — Cucumber enzyme and food chemistry were verified, but no human absorption, nutritional-status, or deficiency study tested the cucumber-radish combination

Scoring profile behind this grade
EndpointHHard endpoint - actual events such as death

The scoring table and the verdict agree (?).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Eating cucumber with radish causes human vitamin C deficiency?No eligible human combination study was identified. Enzyme existence is recorded as a measured fact in product_facts.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Purified cucumber-enzyme biochemical analysisOriginal funding not confirmedMolecular weight, copper content, and specific activityMolecular weight about 132,000, eight copper atoms, and 3,500 Dawson units/mgDirect evidence that the enzyme exists
Study 2Food-enzyme study in cucumber juiceOriginal funding not confirmedEnzyme activity by pH and temperatureOptimum pH 6.5 and 40°C; inactive at pH 3.9; oxidation stopped with pH 3.4 orange juiceSupporting acidity and preparation evidence
Study 3Ex vivo transport and reduction study in human erythrocytesUS Public Health Service research supportDehydroascorbate uptake and ascorbate regenerationRapid uptake of oxidized vitamin and intracellular reduction to ascorbateSupporting evidence that oxidation is not complete loss
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Receipt — 4 References

All 4 cited sources were verified for existence at the original page (as of 2026-08-04).

Nakamura T, Makino N, Ogura Y. Purification and Properties of Ascorbate Oxidase from Cucumber. J Biochem. 1968;64(2):189-195.
checked
Kim JW, Park ES, Yoon S. Characteristics of Ascorbic acid Oxidase in Cucumbers. Korean J Nutr. 1985;18(4):312-317.
checked
Oba K. Changes in Vitamin C Contents and Ascorbate Oxidase Activity of Vegetables after Cutting and Washing. J Home Econ Jpn. 1990;41(8):715-721. DOI: 10.11428/jhej1987.41.715.
checked
May JM, Qu ZC, Whitesell RR. Ascorbic acid recycling enhances the antioxidant reserve of human erythrocytes. Biochemistry. 1995;34(39):12721-12728. PMID: 7548025. DOI: 10.1021/bi00039a031.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-04 · Corrections: none

Cite this verdict

Raw cucumber plus radish x vitamin C deficiency Evidence Grade ? card
[Chamgap] Raw cucumber plus radish x vitamin C deficiency — Evidence Grade ?. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/general/cucumber-radish-vitamin-c-deficiency/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.