Quercetin-rich whole-onion powder,
does it really help with Reduction of visceral fat?
research showsThe grade is D with 28 points. The 12-week visceral-fat primary endpoint matched registry UMIN000033410 but failed in the full population. Seventy people were randomized, while only 54 entered this analysis; the between-group change was -3.6 cm2, and an unadjusted 95% CI calculated from the table is about -8.8 to +1.6 cm2, leaving room for benefit.
ads claimA borderline P value confined to a low-HDL subgroup should not be advertised as fat loss for the full overweight population when the prespecified full-sample result was null.
Useful facts when choosing a product
- The intervention was 9 g/day powder made from whole onions bred for high quercetin content, not an extract capsule.
- Onions arrived in Korea around the port-opening period, so their absence from Joseon classical texts is expected. Greco-Roman, Indian, and medieval European records mainly concern appetite, digestion, diuresis, and eyes, not body fat; Dioscorides also warned that heavy intake caused headache.
- Verdict 1963 is C with 54 points for raw onion juice and sleep in older adults. This verdict addresses a different outcome, visceral fat.
Chamgap Semantic Classification Code
Candidate index · review held
S.quercetin-rich-whole-onion-powder.UNK.visceral-fat.reduce.UNKSupplements and nutraceuticals > Quercetin-rich whole-onion powder > Unknown > visceral fat > Reduction claim > Unknown
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
Nishimura and colleagues randomized 70 adults with BMI at least 25, 35 per group, to 9 g/day quercetin-rich whole-onion powder or control onion powder for 12 weeks under double blinding. Only 27 per group, 54 total, entered the registered 12-week visceral-fat primary analysis. Changes were -2.4 plus or minus 10.0 cm2 and -6.0 plus or minus 9.0 cm2, giving -3.6 cm2 and P=0.16. The table-derived unadjusted 95% CI is approximately -8.8 to +1.6 cm2. NARO provided matching research funds, and Okamoto Plant Breeding supplied the test foods.
Why this is classified as D (28)
The prespecified surrogate primary endpoint was null, and only 54 of 70 randomized participants entered a small completer analysis. The interval does not exclude benefit, so this is not repeated disproof and earns D with 28 points.
Counterpoint. The low-HDL subgroup signal remains hypothesis-generating but needs independent prespecified confirmation.
Rejudgment record. Cross-check applied — The prespecified visceral-fat primary endpoint was null and only 54 of 70 randomized participants entered the completer analysis
| Endpoint | S | Surrogate marker - laboratory or imaging measures |
| Replication | R1 | Single confirmatory trial |
| Independence | I1 | Mixed funding sources |
| Effect size | E0 | Null |
| Precision | C0 | The confidence interval leaves room for benefit |
Stored derived and displayed grades match; this is not a current recalculation or validity check (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) | Grade | Basis |
|---|---|---|
| Whole-onion powder and visceral-fat reduction in the full population | D | The prespecified primary endpoint was null at P=0.16. |
| Visceral-fat signal in the low-HDL subgroup | C | This post hoc subgroup result needs independent confirmation. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Nishimura et al. 2020 | Double-blind randomized 12-week parallel trial | 70 randomized; 54 analyzed for visceral fat | NARO matching funds and test foods from Okamoto Plant Breeding | Change in visceral-fat area at 12 weeks | Difference -3.6 cm2, P=0.16; calculated 95% CI about -8.8 to +1.6 | Null prespecified surrogate primary endpoint |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-08-02).
Final verification and publication gate: Codex · Evidence date: 2026-08-02 · Corrections: none
Cite this verdict
[Chamgap] Quercetin-rich whole-onion powder x visceral-fat reduction — Evidence Grade D·28. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/weight/quercetin-rich-whole-onion-powder-visceral-fat/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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.