Randomised controlled trialindependent cross-checkabstract checked I-LEG-123 standard review

Iron-rich beans improved iron status

Consuming Iron Biofortified Beans Increases Iron Status in Rwandan Women after 128 Days in a Randomized Controlled Feeding Trial.

Overview

Haas JD et al.. J Nutr 2016 · PMID 27358417 · DOI 10.3945/jn.115.224741

Women eating iron-rich beans for 128 days had higher haemoglobin and iron stores than women eating ordinary beans.

Does the study support the specific claim? No · Methodological quality: high

Study explained simply

What did the researchers want to find out?: Test iron-biofortified beans.
How was the study done?: RCT.
How many people, animals or samples were studied?: 195 iron-deficient women.
What was actually found?: Better iron status.
How large was the observed effect?: Hb +3.8 g/L.
What do the results mean in everyday life?: Iron in beans is absorbed and useful, despite phytate.
What are the study's limitations?: Comparator also beans.
What does it say about Elawady's specific claim?: Limits C-LEG-08.
Do the results apply to Germany and Europe?: Indirect.
What can explicitly not be concluded from this study?: It does not compare beans with no beans.

Do iron-biofortified beans improve iron status in iron-depleted women?

Study design: Randomised controlled trial – Randomised controlled feeding trial (128 days)
Population: 195 Rwandan women aged 18-27 y with serum ferritin <20 ug/L
Country: Rwanda
Period: 128 days (NCT01594359)
Sample size: 195
Inclusion and exclusion criteria: Ferritin <20 ug/L.

Results: Both groups ate ~336 g wet beans/day; Fe-Beans group had greater increases in haemoglobin (3.8 g/L), log ferritin (0.1 log ug/L) and body iron (0.5 mg/kg); each 1 g Fe from beans over 128 days associated with +4.2 g/L haemoglobin.
Absolute risks: Not applicable
Authors' conclusion: Iron-biofortified beans significantly improved iron status.

Effect moderate; shows that bean iron is absorbed despite phytate.

Limits C-LEG-08: despite phytate, beans can improve iron status; supports legumes as an iron source rather than a reason to avoid them.

Indirect (biofortified varieties).

Strong evidence that bean iron is nutritionally available.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	high
Risk of bias	low
Precision of results	moderate
Directness	indirect
Reproducibility	partly replicated
Consistency with the overall evidence	consistent
Regional transferability	moderate
Adequacy of the interpretation (by the archive)	not applicable

Ordinary beans vs no beans.