Systematic reviewindependent cross-checkabstract only checked★ key study I-SOD-01 in-depth review
Fizzy drinks and reflux: systematic review
Systematic review: the effects of carbonated beverages on gastro-oesophageal reflux disease.
Overview
Johnson T et al.. Aliment Pharmacol Ther 2010 · PMID 20055784 · DOI 10.1111/j.1365-2036.2010.04232.x
Fizzy drinks briefly lower acidity in the food pipe, but there is no direct evidence that they cause reflux disease.
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Do carbonated beverages affect oesophageal pH, motility, damage, GERD symptoms and complications?
- How was the study done?
Systematic review (qualitative).
- How many people, animals or samples were studied?
Not stated in abstract; Not stated in abstract
- What was actually found?
Very short decline in intra-oesophageal pH; possible transient reduction of LES basal pressure; no evidence of direct oesophageal damage; not consistently shown to cause GERD symptoms; no evidence of GERD complications or oesophageal cancer.
- How large was the observed effect?
Not pooled
- What do the results mean in everyday life?
Fizzy drinks are not a proven cause of reflux disease.
- What are the study's limitations?
Old (2010); Limited primary evidence; No meta-analysis
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
That nobody gets symptoms from them.
Scientific in-depth review
1. Full reference
- Authors
- Johnson T et al.
- Journal
- Aliment Pharmacol Ther
- Year
- 2010
- Identifier
- PMID 20055784 DOI 10.1111/j.1365-2036.2010.04232.x
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Not stated in abstract
2. Research question
Do carbonated beverages affect oesophageal pH, motility, damage, GERD symptoms and complications?
3. Study design and population
- Study design
- Systematic review – Systematic review (qualitative).
- Population
Not stated in abstract
- Country
Multinational
- Period
not stated in abstract
- Sample size
Not stated in abstract
- Inclusion and exclusion criteria
not stated in abstract
4. Methods and endpoints
- Exposure / intervention
Carbonated beverages
- Comparator
Non-carbonated/none
- Endpoints
Oesophageal pH, LES pressure, damage, symptoms, complications
- Statistical methods
Narrative synthesis
5. Actual results
- Results
Very short decline in intra-oesophageal pH; possible transient reduction of LES basal pressure; no evidence of direct oesophageal damage; not consistently shown to cause GERD symptoms; no evidence of GERD complications or oesophageal cancer.
- Absolute risks
not applicable
- Authors' conclusion
No direct evidence that carbonated beverages promote or exacerbate GERD.
6. Strengths
- Systematic
7. Weaknesses
- Old (2010)
- Limited primary evidence
- No meta-analysis
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Qualitative synthesis.
9. Assessment of the statistical interpretation
Not applicable.
10. Relevance to the specific claim
Contradicts C-SOD-12, C-SOD-13, C-SOD-14.
11. Independent contrary findings
Transient physiological effects exist.
12. Transferability to Germany and Europe
High.
13. Overall methodological judgement
Best available summary on soda and GERD.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | not applicable |
| Directness | direct |
| Reproducibility | unknown |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Effects in GERD patients specifically.
15. Linked fact checks
- Soft drinks wreck digestion, trigger reflux and heartburn, disturb the stomach's acidity, and (Pepsi) are among the main causes of gastritis and ulcers. – Studies contradicting or limiting the claim
- Elawady: the harm of soda is the carbonated water itself, not the sugar or sweetener; one 300 ml Pepsi delivers more carbon dioxide than the body produces in a whole day, and colas contain sodium bicarbonate that neutralises stomach acid and increases reflux. – Studies contradicting or limiting the claim
- All carbonated waters of every kind (including unsweetened sparkling water) are harmful and must be avoided. – Studies contradicting or limiting the claim