Case-control studycited by the Tayebat archiveabstract only checked A-SOD-13 standard review
Cola and kidney disease
Carbonated beverages and chronic kidney disease.
Overview
Saldana TM et al.. Epidemiology 2007 · PMID 17525693 · DOI 10.1097/EDE.0b013e3180646338
People with kidney disease more often reported drinking two or more colas a day; authors called this preliminary.
Does the study support the specific claim? Partly · Methodological quality: low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Are carbonated beverages (cola) associated with CKD?
- How was the study done?
Case-control study.
- How many people, animals or samples were studied?
465 cases; 467 controls; Newly diagnosed CKD patients and community controls
- What was actually found?
>=2 colas/day OR 2.3 (1.4-3.7); regular colas 2.1 (1.3-3.4); artificially sweetened colas 2.1 (0.7-2.5 as printed); non-cola 0.94 (0.4-2.2).
- How large was the observed effect?
OR 2.3 (1.4-3.7)
- What do the results mean in everyday life?
Possible signal only.
- What are the study's limitations?
Case-control: recall and selection bias; Old data; Small
- What does it say about Elawady's specific claim?
Only evidence for C-SOD-09.
- Do the results apply to Germany and Europe?
Low.
- What can explicitly not be concluded from this study?
That cola damages kidneys.
Scientific in-depth review
1. Full reference
- Authors
- Saldana TM, Basso O, Darden R, Sandler DP
- Journal
- Epidemiology
- Year
- 2007
- Identifier
- PMID 17525693 DOI 10.1097/EDE.0b013e3180646338 · PMC3433753
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
No COI statement; NIH intramural
2. Research question
Are carbonated beverages (cola) associated with CKD?
3. Study design and population
- Study design
- Case-control study – Case-control study.
- Population
Newly diagnosed CKD patients and community controls
- Country
USA (North Carolina)
- Period
1980-1982
- Sample size
465 cases; 467 controls
- Inclusion and exclusion criteria
not stated in abstract
4. Methods and endpoints
- Exposure / intervention
Cola and non-cola carbonated beverages
- Comparator
<2 colas/day
- Endpoints
CKD
- Statistical methods
Adjusted OR
5. Actual results
- Results
>=2 colas/day OR 2.3 (1.4-3.7); regular colas 2.1 (1.3-3.4); artificially sweetened colas 2.1 (0.7-2.5 as printed); non-cola 0.94 (0.4-2.2).
- Absolute risks
not applicable
- Authors' conclusion
These preliminary results suggest cola consumption may increase CKD risk.
6. Strengths
- Specific hypothesis
7. Weaknesses
- Case-control: recall and selection bias
- Old data
- Small
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- high
- Rationale
Recall bias likely.
9. Assessment of the statistical interpretation
The CI printed for artificially sweetened cola (0.7-2.5) does not contain its point estimate 2.1, indicating a reporting error in the abstract.
10. Relevance to the specific claim
Only evidence for C-SOD-09.
11. Independent contrary findings
None reviewed.
12. Transferability to Germany and Europe
Low.
13. Overall methodological judgement
Weak, preliminary.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | high |
| Precision of results | low |
| Directness | direct |
| Reproducibility | not replicated |
| Consistency with the overall evidence | unknown |
| Regional transferability | low |
| Adequacy of the interpretation (by the archive) | taken out of context |
14. Open questions
Prospective evidence.
15. Linked fact checks
- Cola consumption damages the kidneys (chronic kidney disease). – Studies with mixed or unclear results
Use by the Tayebat archive
Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.
- What the archive says about the study
Listed in the archive bibliography only (no archive interpretation card).
- A. What was actually studied?
Cola and CKD.
- B. What did the authors find?
OR 2.3 for >=2 colas/day.
- C. What conclusions do the authors themselves draw?
Preliminary.
- D. What does the archive derive from it?
Summary includes 'kidneys' among cumulative harms.
- E. Is this derivation scientifically justified?
Presents a preliminary case-control finding as established.
- Adequacy of the interpretation (by the archive)
- taken out of context