Meta-analysisindependent cross-checkabstract checked I-LEG-113 standard review
Pulses and blood sugar: 65 trials
Pulse consumption improves indices of glycemic control in adults with and without type 2 diabetes: a systematic review and meta-analysis of acute and long-term randomized controlled trials.
Overview
Hafiz MS et al.. Eur J Nutr 2022 · PMID 34585281 · DOI 10.1007/s00394-021-02685-y
Eating beans, lentils or chickpeas lowered blood sugar after meals and improved long-term glucose markers.
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?
Pool RCTs on pulses and glucose.
- How was the study done?
Meta-analysis.
- How many people, animals or samples were studied?
65 RCTs, 2,102 adults.
- What was actually found?
Lower glucose and HbA1c.
- How large was the observed effect?
HbA1c -0.17 in T2D.
- What do the results mean in everyday life?
Legumes help blood sugar control.
- What are the study's limitations?
Heterogeneous, short trials.
- What does it say about Elawady's specific claim?
Contradicts 'legumes are toxins'.
- Do the results apply to Germany and Europe?
Applicable.
- What can explicitly not be concluded from this study?
It does not show fewer diabetes complications.
Scientific in-depth review
1. Full reference
- Authors
- Hafiz MS et al.
- Journal
- Eur J Nutr
- Year
- 2022
- Identifier
- PMID 34585281 DOI 10.1007/s00394-021-02685-y · PMC8854292
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref works API
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
No conflicts declared.
2. Research question
Does pulse consumption improve glycaemic control in adults with and without T2D?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and meta-analysis of RCTs (acute and long-term)
- Population
Normoglycaemic adults and adults with T2D
- Country
International
- Period
Not stated in abstract
- Sample size
65 RCTs, 2,102 participants
- Inclusion and exclusion criteria
RCTs of pulse interventions reporting glycaemic outcomes.
4. Methods and endpoints
- Exposure / intervention
Pulses (beans, lentils, chickpeas, peas)
- Comparator
Control meals/diets
- Endpoints
Post-prandial glucose, fasting glucose, HbA1c, HOMA-IR
- Statistical methods
Random-effects meta-analysis; meta-regression
5. Actual results
- Results
Acute: peak post-prandial glucose ES -2.90 (95% CI -4.60 to -1.21) in T2D and -1.38 (-1.78 to -0.99) without T2D. Long-term in T2D: fasting glucose -0.54 (-0.83 to -0.24), HbA1c -0.17 (-0.33 to 0.00), HOMA-IR -0.47; normoglycaemic fasting glucose -0.06 (-0.12 to 0.00). I2 up to 93%.
- Absolute risks
Not applicable
- Authors' conclusion
Pulses reduce post-prandial glucose and improve long-term glycaemic control.
6. Strengths
- Large number of RCTs
- PROSPERO-registered
7. Weaknesses
- Very high heterogeneity
- Effect sizes reported as ES (units partly unclear in abstract)
- Short trials
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
Heterogeneity; small trials.
9. Assessment of the statistical interpretation
Direction consistent; magnitude uncertain because of heterogeneity.
10. Relevance to the specific claim
Contradicts claims that legumes 'deteriorate health' (C-LEG-01, C-LEG-13): trials show improved glycaemic markers.
11. Independent contrary findings
I-LEG-112 (no protective association with incident T2D).
12. Transferability to Germany and Europe
Applicable.
13. Overall methodological judgement
Consistent trial evidence of metabolic benefit.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Durability over years.
15. Linked fact checks
- Fava beans and lentils (together with flour products) are toxins that cause inflammation and deteriorate health; the fava bean hull is indigestible and the bean contains toxins that ferment 'dirtily'. – Studies contradicting or limiting the claim
- 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
- Plant lectins in legumes survive digestion, bind to intestinal cells and harm human health, so legumes are harmful even when eaten normally. – Studies contradicting or limiting the claim