Meta-analysisindependent cross-checkabstract checked★ key study I-LEG-111 in-depth review
Legumes, heart disease and diabetes (Nordic review)
Legume consumption in adults and risk of cardiovascular disease and type 2 diabetes: a systematic review and meta-analysis.
Overview
Thorisdottir B et al.. Food Nutr Res 2023 · PMID 37288088 · DOI 10.29219/fnr.v67.9541
Cohorts showed no clear link with heart disease or diabetes, while trials showed lower cholesterol and glucose with legumes.
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?
Assess legumes and cardiometabolic disease.
- How was the study done?
Systematic review and meta-analysis.
- How many people, animals or samples were studied?
31 cohorts, 16 trials.
- What was actually found?
Null hard endpoints; better LDL and glucose.
- How large was the observed effect?
LDL -0.19 mmol/L.
- What do the results mean in everyday life?
Eating legumes is not harmful and modestly improves blood fats and sugar.
- What are the study's limitations?
Low intakes in cohorts; heterogeneity.
- What does it say about Elawady's specific claim?
Contradicts the claim that legumes are harmful.
- Do the results apply to Germany and Europe?
Directly applicable.
- What can explicitly not be concluded from this study?
It does not prove that legumes prevent heart attacks.
Scientific in-depth review
1. Full reference
- Authors
- Thorisdottir B et al.
- Journal
- Food Nutr Res
- Year
- 2023
- Identifier
- PMID 37288088 DOI 10.29219/fnr.v67.9541 · PMC10243120
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref works API
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Partly funded by the Nordic Council of Ministers and Nordic food/health authorities; no conflicts declared.
2. Research question
Is legume consumption associated with CVD and T2D and their risk factors in healthy adults?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and meta-analysis of RCTs (>=4 weeks) and prospective cohorts (>=12 months) for the Nordic Nutrition Recommendations 2023
- Population
Healthy adults
- Country
International (mostly Western cohorts with low legume intake)
- Period
Searches to 16 May 2022
- Sample size
47 studies: 31 cohorts (2,081,432 participants), 14 crossover RCTs (448), 1 parallel RCT, 1 non-randomised trial
- Inclusion and exclusion criteria
Beans/lentils/peas/soybeans; excluded peanuts and legume products/flours/protein isolates.
4. Methods and endpoints
- Exposure / intervention
Legume intake
- Comparator
Lower intake / control diets
- Endpoints
CVD, CHD, stroke, T2D; lipids, glycaemic markers, blood pressure
- Statistical methods
Random-effects meta-analysis; RoB2, ROBINS-I, RoB-NObS; WCRF grading
5. Actual results
- Results
Cohorts: suggestive of null associations for CVD, CHD, stroke and T2D. RCTs: total cholesterol -0.22 mmol/L, LDL-C -0.19 mmol/L, fasting glucose -0.19 mmol/L, HOMA-IR -0.30; heterogeneity I2 52% (LDL) and >75% for others. Overall evidence 'limited - no conclusion'.
- Absolute risks
Not reported
- Authors' conclusion
Legume intake was not found to influence CVD/T2D risk in populations with low intake, but favourable risk-factor effects support recommending legumes within healthy diets.
6. Strengths
- Pre-specified, guideline-commissioned review
- Separate RCT and cohort synthesis
- Formal risk-of-bias tools
7. Weaknesses
- Low legume intake in cohorts limits contrast
- High heterogeneity
- Abstract only read
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Comprehensive search and RoB assessment; conclusions appropriately cautious.
9. Assessment of the statistical interpretation
Benefits on surrogates (LDL) are consistent with I-LEG-02; null hard-endpoint associations mean benefit is unproven, but no harm signal.
10. Relevance to the specific claim
Contradicts claims that legumes are harmful (C-LEG-13, C-LEG-01): no harm signal; modest risk-factor benefits. Also tempers claims of large benefit.
11. Independent contrary findings
I-LEG-01 (small mortality benefit), I-LEG-112 (weak positive T2D association in Europe).
12. Transferability to Germany and Europe
Directly relevant (Nordic/European context).
13. Overall methodological judgement
Balanced, high-quality synthesis: legumes are not harmful and modestly improve lipids and glucose markers.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Effects at high intakes typical of Egypt.
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
- Because of favism (and the other narrow risks), legumes should be excluded from everyone's diet. – Studies contradicting or limiting the claim