CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-04). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 2147 · Search date 2026-08-04 · Methodology v0.6

Caffeinated coffee, two to four cups daily,
does it really help with Prevention of symptomatic gallstone disease and cholecystectomy?

30-Second Summary
C
Evidence Grade C · 58 · Safety caution
Caffeinated coffee was inversely associated with symptomatic gallstones in male and female cohorts, without proof of causality
Four or more cups and high total caffeine intake can cause insomnia, anxiety, or palpitations and may require adjustment for pregnancy, medications, and individual sensitivity.
What the
research shows
The grade is C. Among 46,008 men, 1,081 symptomatic cases included 885 cholecystectomies; persistent intake gave 0.60 (0.42 to 0.86) at two to three cups/day and 0.55 (0.33 to 0.92) at four or more. A separate 80,898-woman cohort followed 7,811 cholecystectomies as a proxy for symptomatic gallstones and found 0.72 (0.62 to 0.84) at four or more cups. This was not randomized, giving C with 58 points.
What the
ads claim
Caffeinated and decaffeinated coffee differ in caffeine content. An observational association confined to caffeinated coffee still does not establish an individual preventive effect.
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Useful facts when choosing a product

  • Neither original article reported analyses by filtered, instant, or espresso preparation. Caffeinated-versus-decaffeinated analyses were reported, but these are not brewing-method analyses.
  • The baseline mean total caffeine intake in the four-or-more-cup group was 738 mg/day; this included all sources and was not a laboratory measurement of coffee.
  • The FDA reports that an 8-fl-oz decaf coffee typically contains 2 to 15 mg caffeine; this was not measured in cohort products.
Gap Measurement · Verdict 2147 · C 58
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

The male cohort included 46,008 men and recorded 1,081 symptomatic cases, including 885 cholecystectomies. Persistent-intake estimates were 1.00, 0.88 (0.67 to 1.14), 0.60 (0.42 to 0.86), and 0.55 (0.33 to 0.92). The separate female cohort followed 80,898 women for 20 years and recorded 7,811 cholecystectomies, used as a proxy for symptomatic gallstones. Its persistent-intake estimates were 1.00, 0.91, 0.78, and 0.72 (0.62 to 0.84).

02

Why this is classified as C (58)

Dose-response associations in large male and female cohorts, tempered by nonrandomized design and multiple observational limitations, give C with 58 points.

Counterpoint. The evidence does not show that coffee dissolves existing stones or treats biliary pain.

Rejudgment record. Cross-check applied — Large prospective male and female cohorts found dose-related inverse associations for symptomatic gallstone events, but randomized evidence is absent and observational limitations remain

Scoring profile behind this grade
EndpointHHard endpoint - actual events such as death
ReplicationR1Single confirmatory trial
IndependenceI2Decisive evidence is publicly or non-profit funded
Effect sizeE+Meets the clinically important threshold

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
Prevention of symptomatic gallstones in menCA dose-response inverse association was observed, but the evidence is observational.
Prevention of cholecystectomy in womenCA separate female cohort found the same direction.
Gallstone prevention with decaffeinated coffeeDThe pivotal cohorts did not show a preventive association.

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.
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Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Prospective male cohort1,081Public funding including NCI CA55075 and NHLBI HL35464Symptomatic gallstone disease and cholecystectomyPersistent two to three cups RR 0.60 (0.42 to 0.86); four or more RR 0.55 (0.33 to 0.92)Pivotal male event cohort
Study 2Prospective female cohort7,811U.S. public research-network supportCholecystectomyPersistent intake: 1.00, 0.91, 0.78, and 0.72 (0.62 to 0.84)Same-direction observation in a separate female population
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-08-04).

Leitzmann MF, et al. A prospective study of coffee consumption and the risk of symptomatic gallstone disease in men. JAMA. 1999;281:2106-2112. PMID: 10367821. DOI: 10.1001/jama.281.22.2106.
checked
Leitzmann MF, et al. Coffee intake is associated with lower risk of symptomatic gallstone disease in women. Gastroenterology. 2002;123:1823-1830. PMID: 12454839. DOI: 10.1053/gast.2002.37054.
checked
Yuan S, et al. Obesity, Type 2 Diabetes, Lifestyle Factors, and Risk of Gallstone Disease: A Mendelian Randomization Investigation. Clin Gastroenterol Hepatol. 2022;20:e529-e537. PMID: 33418132. DOI: 10.1016/j.cgh.2020.12.034.
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

Caffeinated coffee, two to four cups daily x symptomatic gallstone prevention Evidence Grade C card
[Chamgap] Caffeinated coffee, two to four cups daily x symptomatic gallstone prevention — Evidence Grade C·58. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/liver/caffeinated-coffee-symptomatic-gallstone-prevention/ · 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.