Randomised controlled trialindependent cross-checkfull text checked★ key study I-WHT-118 in-depth review
Cutting sugar reduced acid reflux in a diet trial
The Effects of Modifying Amount and Type of Dietary Carbohydrate on Esophageal Acid Exposure Time and Esophageal Reflux Symptoms: A Randomized Controlled Trial.
Overview
Gu C et al.. Am J Gastroenterol 2022 · PMID 35973185 · DOI 10.14309/ajg.0000000000001889
In 98 veterans with reflux, a diet much lower in simple sugars reduced oesophageal acid exposure over 9 weeks compared with a high-sugar diet.
Does the study support the specific claim? Partly · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Carbohydrate type and reflux.
- How was the study done?
Randomised diet trial.
- How many people, animals or samples were studied?
98 veterans.
- What was actually found?
Less sugar, less acid exposure.
- How large was the observed effect?
AET -4.3% vs +3.1%.
- What do the results mean in everyday life?
Diet can help reflux.
- What are the study's limitations?
Mostly men; PPIs continued.
- What does it say about Elawady's specific claim?
Partly supports diet effects; not white-flour cure or stopping medicines.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
Cannot show that stopping white flour replaces medication.
Scientific in-depth review
1. Full reference
- Authors
- Gu C et al.
- Journal
- Am J Gastroenterol
- Year
- 2022
- Identifier
- PMID 35973185 DOI 10.14309/ajg.0000000000001889 · PMC9531994
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
VA Merit Award; no competing interests (full text).
2. Research question
Do amount and type of dietary carbohydrate affect oesophageal acid exposure and reflux symptoms?
3. Study design and population
- Study design
- Randomised controlled trial – Randomised controlled 2x2 diet trial (9 weeks)
- Population
US veterans with symptomatic GERD and overweight/obesity on PPI therapy
- Country
USA
- Period
not stated (trial NCT02384551)
- Sample size
98
- Inclusion and exclusion criteria
GERD diagnosis, PPI for >=3 months, BMI 25-45; excluded Barrett's oesophagus, strictures, motility disorders (full text)
4. Methods and endpoints
- Exposure / intervention
High total/low simple, low total/high simple, low total/low simple carbohydrate diets
- Comparator
High total/high simple carbohydrate control
- Endpoints
24-h pH acid exposure time (AET), reflux episodes, GERDQ, GSAS
- Statistical methods
ANCOVA, regression; PPIs stopped 7 days before pH testing (full text)
5. Actual results
- Results
Significant diet effect on AET (P=0.001) and reflux episodes (P=0.003). AET change: high total/low simple -4.3% +/- 3.8 vs control +3.1% +/- 3.7 (P=0.04). Simple sugar reduced by ~62 g/day. Symptom ratings improved in all carbohydrate-modification groups.
- Absolute risks
not reported
- Authors' conclusion
Substantially reducing simple sugars improved pH monitoring outcomes and GERD symptoms.
6. Strengths
- Randomised
- Objective pH endpoint
- Prepared foods
- Full text read
7. Weaknesses
- Mostly men (veterans)
- Short (9 weeks)
- Tested sugar, not white flour
- Did not test stopping PPIs
8. Risk of bias
- Orienting tool
- RoB 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Diet adherence uncertain; small groups.
9. Assessment of the statistical interpretation
Between-group AET difference 7.4 percentage points (stats/C-WHT-08).
10. Relevance to the specific claim
Partial support that carbohydrate modification helps reflux; the effective change was reducing simple sugars (which the system allows), not removing white flour; participants remained on PPIs.
11. Independent contrary findings
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Best direct trial; indirect for the specific claim.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | indirect |
| Reproducibility | not replicated |
| Consistency with the overall evidence | unknown |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
White-flour-specific trials; PPI withdrawal.
15. Linked fact checks
- Stopping all white-flour products for about 5-10 days (in one video: within seven days) resolves reflux so that acid-reducing medicines are no longer needed. – Studies with mixed or unclear results
- Reflux (heartburn) and irritable bowel syndrome are largely driven by eating habits; removing white/baladi bread, baked goods and soft drinks can improve symptoms. – Studies supporting the claim
- Stopping bread and baked goods for five days will improve 85% of reflux and IBS symptoms within at most ten days; both diseases can be eliminated completely. – Studies with mixed or unclear results