Cohort studyindependent cross-checkabstract only checked★ key study I-VEG-06 in-depth review
Vegetable-rich diet and kidney stones
DASH-style diet associates with reduced risk for kidney stones.
Overview
Taylor EN et al.. J Am Soc Nephrol 2009 · PMID 19679672 · DOI 10.1681/ASN.2009030276
People with a diet rich in vegetables, fruit and legumes had about 40-45% fewer kidney stones.
Does the study support the specific claim? No · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
DASH and stones
- How was the study done?
Cohorts
- How many people, animals or samples were studied?
~240,000
- What was actually found?
Fewer stones
- How large was the observed effect?
RR 0.55-0.60
- What do the results mean in everyday life?
Vegetables protect rather than harm.
- What are the study's limitations?
Observational
- What does it say about Elawady's specific claim?
Contradicts claim
- Do the results apply to Germany and Europe?
Moderate
- What can explicitly not be concluded from this study?
Cannot prove causation.
Scientific in-depth review
1. Full reference
- Authors
- Taylor EN et al.
- Journal
- J Am Soc Nephrol
- Year
- 2009
- Identifier
- PMID 19679672 DOI 10.1681/ASN.2009030276
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
NIH funding
2. Research question
DASH-style diet and kidney stones.
3. Study design and population
- Study design
- Cohort study – Three prospective cohorts
- Population
US health professionals
- Country
USA
- Period
14-18 years
- Sample size
~241,766; 5,645 stones
- Inclusion and exclusion criteria
Cohort participants
4. Methods and endpoints
- Exposure / intervention
DASH score (high fruit, vegetables, nuts, legumes, low-fat dairy, whole grains)
- Comparator
Lowest quintile
- Endpoints
Incident kidney stones
- Statistical methods
Cox regression
5. Actual results
- Results
Highest vs lowest DASH quintile: RR 0.55 (0.46-0.65) men, 0.58 (0.49-0.68) older women, 0.60 (0.52-0.70) younger women; higher DASH had higher oxalate intake.
- Absolute risks
not reported
- Authors' conclusion
DASH-style diet associated with marked decrease in stone risk.
6. Strengths
- Large
- Long follow-up
7. Weaknesses
- Observational
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Confounding possible.
9. Assessment of the statistical interpretation
Large relative reduction.
10. Relevance to the specific claim
Contradicts C-VEG-05, C-LEG-13, C-VEG-16.
11. Independent contrary findings
None.
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Important nuance: vegetable-rich diet despite more oxalate.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | some concerns |
| Precision of results | high |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Causality.
15. Linked fact checks
- Legumes as a whole (fava beans, lentils, chickpeas, beans, cowpeas, peas, lupin, peanuts) are harmful and should be fully forbidden. – Studies contradicting or limiting the claim
- Oxalate-rich greens (spinach, beet greens, chard) cause kidney stones; each 100 mg of dietary oxalate raises urinary oxalate by about 2.7 mg. – Studies contradicting or limiting the claim
- Avoiding (nearly) all vegetables, salads and legumes is compatible with good health. – Studies contradicting or limiting the claim