CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-02). The draft was written by AI, the existence of all 2 cited sources was verified (1 access-limited, verified via index/summary and marked), and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1971 · Search date 2026-08-02 · Methodology v0.6

Cooked tomato products,
does it really help with PSA reduction in men with prostate cancer?

30-Second Summary
D
Evidence Grade D · 28 · Safety caution
The food delivered 30 mg of lycopene, but PSA did not fall in the full randomized comparison
Tomato foods are generally safe, but patients awaiting surgery should discuss products containing added supplements with their clinicians. Tomato allergy and reflux symptoms are possible.
What the
research shows
The grade is D with 28 points. Seventy-nine preoperative prostate-cancer patients were randomized to three groups, but only 75 entered the PSA analysis. The overall three-week comparison was null at P=0.416; the favorable result came only from a post hoc subgroup of 41 intermediate-risk patients.
What the
ads claim
Lycopene content and improved availability after cooking are food properties. They do not establish PSA reduction, and the direct full-group comparison was null.
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Useful facts when choosing a product

  • HPLC analysis showed that the study foods supplied 30 mg of lycopene per day. This measurement is separate from whether PSA changed.
  • Tomato originated in the Americas, reached Europe in the sixteenth century and East Asia later, and is absent from the Donguibogam and Bencao Gangmu.
  • Verdict 384 is C with 50 points for a tomato nutrient complex and ultraviolet skin response, while verdict 763 is C with 44 points for Fruitflow and platelet aggregation. Both use different interventions and indications.
Gap Measurement · Verdict 1971 · D 28
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Randomization assigned 27 participants to control, 27 to tomato, and 25 to tomato plus selenium and omega-3, for 79 total. PSA analyses included 24, 26, and 25 participants, respectively, for 75 total. The current NCT00433797 record lists serum PSA as the sole primary outcome and molecular, oxidative, and inflammatory measures as secondary outcomes. The record was updated after the trial ended, however, so the primary outcome in the original 2007 registration could not be verified. Funding came from the University of Oslo, Oslo University Hospital, the Norwegian Cancer Society, and the Research Council of Norway, with no identified tomato-industry or food-company funding.

02

Why this is classified as D (28)

The full randomized PSA comparison was null in one small, short trial, while the positive result was confined to a post hoc subgroup and confidence intervals were absent. This yields D with 28 points.

Counterpoint. Absent confidence intervals leave some room for meaningful PSA reduction, but the most direct evidence is a null full-group result.

Rejudgment record. Cross-check applied — Null full randomized PSA comparison, post hoc subgroup positivity, and a small short trial

Scoring profile behind this grade
EndpointSSurrogate marker - laboratory or imaging measures
ReplicationR1Single confirmatory trial
IndependenceI2Decisive evidence is publicly or non-profit funded
Effect sizeE0Null
PrecisionCXNo pooled confidence interval could be confirmed

The scoring table and the verdict agree (D).

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
PSA reduction with cooked tomato productsDThe full randomized comparison had P=0.416.

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 1Three-arm randomized three-week preoperative trial75University of Oslo, Oslo University Hospital, Norwegian Cancer Society, and Research Council of NorwayThree-week change in PSAMedian +0.41 vs 0.00 vs +0.14 micrograms/L; overall P=0.416; between-group CI not reportedNull overall comparison with positivity only in a post hoc subgroup
§

Receipt — 2 References

Of 2 cited sources, 1 had limited original-page access (blocked or summary-only) and were verified via index/summary, marked partial; the rest were verified at the original page. As of 2026-08-02.

Paur I, Lilleby W, et al. Tomato-based randomized controlled trial in prostate cancer patients: Effect on PSA. Clinical Nutrition. 2017;36:672-679. DOI: 10.1016/j.clnu.2016.06.014.
checked
ClinicalTrials.gov. NCT00433797.
partial
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-02 · Corrections: none

Cite this verdict

Cooked tomato products x PSA reduction in prostate cancer Evidence Grade D card
[Chamgap] Cooked tomato products x PSA reduction in prostate cancer — Evidence Grade D·28. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/mens/cooked-tomato-products-prostate-cancer-psa/ · 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.