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. 2133 · Search date 2026-08-04 · Methodology v0.6

Red or white wine 150 mL/day,
does it really help with Improved glycemic control in type 2 diabetes?

30-Second Summary
D
Evidence Grade D · 36 · Safety warning
Wine composition and selected HDL or genotype signals did not establish better glycemic control
Alcohol with insulin or glucose-lowering medication can produce delayed hypoglycemia and may add calories, triglyceride burden, or liver risk. Drinking should not be started for glucose control.
What the
research shows
The grade is D. A two-year trial randomized 224 near-abstinent adults with type 2 diabetes to water 83, white wine 68, or red wine 73. In the full groups, white wine improved fasting glucose and an insulin-resistance measure, while red wine mainly improved lipid markers such as HDL; neither wine established an overall HbA1c advantage.
What the
ads claim
The trial red wine contained 270.1 mg gallic-acid equivalents of total phenols per serving versus 38.5 mg in white wine; alcohol was 16.9 and 15.8 g. Those composition differences and the HDL result are real, but they do not establish better glycemic control.
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Useful facts when choosing a product

  • The red wine was 14.2% and 16.9 g alcohol per 150 mL; white wine was 13.3% and 15.8 g.
  • Total phenols were 270.1 mg versus 38.5 mg gallic-acid equivalents per 150 mL.
  • Controls were current near-abstainers, not confirmed lifetime abstainers.
Gap Measurement · Verdict 2133 · D 36
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

The trial randomized 224 adults aged 40-75 with type 2 diabetes who drank no more than one drink weekly to water 83, white wine 68, or red wine 73, with 194 providing two-year data. NCT00784433 registered glycemic control at six months as the primary outcome, whereas the paper reported two-year lipid and glycemic results; those time points and scopes must be distinguished. Allocation was open but laboratory outcomes were objective, and suppliers reportedly had no role in design or analysis.

02

Why this is classified as D (36)

White wine improved selected full-group glycemic measures, but neither wine improved full-group HbA1c, red wine's positive results were mainly lipid outcomes, and genotype interactions were supplementary, giving D with 36 points.

Counterpoint. D does not mean every laboratory marker was identical. Lipid and genotype findings remain, but overall glycemic control was not established.

Rejudgment record. Cross-check applied — In the two-year water-controlled trial, white wine improved fasting glucose and insulin resistance but not full-group HbA1c, while red wine's positive findings were mainly lipid outcomes

Scoring profile behind this grade
EndpointSSurrogate marker - laboratory or imaging measures
ReplicationR1Single confirmatory trial
IndependenceI1Mixed funding sources
Effect sizeE0Null
PrecisionC0The confidence interval leaves room for benefit

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
Improved glycemic control in the overall type 2 diabetes groupDThe full randomized groups did not show consistent improvement.
Improvement in selected glycemic markers among slow ADH1B metabolizersCThis genotype-subgroup signal cannot be generalized to the full population.

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 two-year randomized controlled trial194Public and foundation grants; in-kind wine and water from Golan Heights Winery and Mey-EdenHbA1c, fasting glucose, insulin resistance, and lipidsWhite wine improved fasting glucose and insulin resistance, while red wine mainly improved HDL; neither showed a full-group HbA1c advantage.Direct long-term water-controlled trial
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Receipt — 2 References

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

Gepner Y, Golan R, Harman-Boehm I, et al. Effects of Initiating Moderate Alcohol Intake on Cardiometabolic Risk in Adults With Type 2 Diabetes: A 2-Year Randomized, Controlled Trial. Ann Intern Med. 2015;163(8):569-579. PMID: 26458258. DOI: 10.7326/M14-1650.
checked
ClinicalTrials.gov. NCT00784433. The CArdiovasCulAr Diabetes & Ethanol Trial.
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

Red or white wine 150 mL/day x glycemic control in type 2 diabetes Evidence Grade D card
[Chamgap] Red or white wine 150 mL/day x glycemic control in type 2 diabetes — Evidence Grade D·36. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/blood-sugar/wine-type-2-diabetes-glycemic-control/ · 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.