CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-04). The draft was written by AI, the existence of all 2 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 2127 · Search date 2026-08-04 · Methodology v0.6

Carbonated mineral water 1.5 L/day,
does it really help with Improved functional dyspepsia and early satiety?

30-Second Summary
C
Evidence Grade C · 40 · Safety caution
The carbonated-water arm improved over time, but the effect versus randomized control was not adequately reported
Carbonation may worsen belching or bloating, and sodium and mineral composition vary by product. Persistent symptoms or weight loss, bleeding, or dysphagia warrant medical assessment.
What the
research shows
The grade is C. In a 21-person double-blind randomized trial, the dyspepsia score in the carbonated-mineral-water arm fell from 7.9±2.8 to 5.4±1.7, but an appropriate between-group treatment effect and confidence interval were not reported. This was a 15-day producer-supported small trial, and actual 1.5-L intake was not verified with urinary measures, so magnitude cannot be judged.
What the
ads claim
The presence of carbonation and bicarbonate is a compositional fact, not proof that dyspepsia improves. Any marketing citation should disclose the 21-person, 15-day design and missing between-group estimate.
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Useful facts when choosing a product

  • The trial prescribed 1.5 L/day in both groups, comparing carbonated mineral water with tap water at equal nominal volume.
  • A later review identified the intervention as Uliveto and classified funding as coming from the mineral-water producer or seller.
  • The 1945 1 mL/kcal recommendation concerned total water from foods and all beverages, not a claim that eight glasses of plain water improve digestion.
Gap Measurement · Verdict 2127 · C 40
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Twenty-one participants were randomized, 10 to carbonated mineral water and 11 to tap water, and apparently all were analyzed. Both arms were prescribed 1.5 L/day, so this tested carbonation and mineral composition rather than extra water volume. The paper did not perform a direct between-group test. Its funding statement reads, "This study was partially supported by Co.Ge.Di S.p.A. (Terme Uliveto, Pisa, Italy)." Terme Uliveto produced and sold the carbonated mineral water used in the trial, supporting the finding that the trial was funded by an interested party. Actual consumption and urinary measures were not reported.

02

Why this is classified as C (40)

The randomized trial measured patient symptoms, but it was a single 21-person, 15-day producer-supported study without a recoverable adjusted between-group magnitude or verified intake contrast, giving C with 40 points.

Counterpoint. The within-arm signal justifies confirmation. Statistical change inside one arm is not the same as efficacy versus the randomized control.

Rejudgment record. Cross-check applied — A 21-person, 15-day producer-supported trial reported within-arm changes without a recoverable adjusted between-group treatment magnitude

Scoring profile behind this grade
EndpointPPatient-reported treatment goal - the symptom is the goal
ReplicationR1Single confirmatory trial
IndependenceI0Evidence comes only from manufacturer studies
Effect sizeEXThe clinical size of the effect could not be judged

The scoring table and the verdict agree (C).

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
Improved functional-dyspepsia scoreCWithin-arm improvement was reported without an adjusted between-group effect.
Improved gastric emptying or colonic transitDDirect testing did not show improvement.
Relief of constipation symptomsCThe positive signal comes from a small, short trial without independent replication.

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 1Double-blind randomized parallel trial11Partially supported by Co.Ge.Di S.p.A. (Terme Uliveto), producer and seller of the tested carbonated mineral waterDyspepsia score and satiety testing over about 15 daysDyspepsia scores changed 7.9±2.8 to 5.4±1.7 versus 9.7±5.3 to 9.9±4.0; no adequate adjusted between-group effect or confidence interval was reported.Exploratory small-trial signal
§

Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-08-04).

Cuomo R, Grasso R, Sarnelli G, et al. Effects of carbonated water on functional dyspepsia and constipation. Eur J Gastroenterol Hepatol. 2002;14(9):991-999. PMID: 12352219. DOI: 10.1097/00042737-200209000-00010.
checked
D'Souza B, Zink A, Langhorst J, et al. How Effective Is Drinking Natural Mineral Water against Heartburn from Functional Dyspepsia, Gastroesophageal Reflux Disease, or Other Causes? Complement Med Res. 2024;31(3):253-265. PMID: 38471489. DOI: 10.1159/000536528.
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

Carbonated mineral water 1.5 L/day x improved functional dyspepsia Evidence Grade C card
[Chamgap] Carbonated mineral water 1.5 L/day x improved functional dyspepsia — Evidence Grade C·40. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/gut/carbonated-mineral-water-functional-dyspepsia/ · 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.