Whole wheat flour in injera triples iron absorption
What it found
In 17 young women, replacing 10% of tef flour with whole wheat flour during injera fermentation increased iron absorption from fortified injera about threefold.
The same women absorbed very little iron from plain tef injera.
What they found
Studies in people
Iron absorption from plain injera
In study A, the women absorbed a median of 1.5% of the iron from plain tef injera. In study B, the median was 3.3%.
Whole wheat flour boosts absorption
Adding 10% whole wheat flour to the tef during fermentation raised median iron absorption to 5.3%, about 3.5 times higher than plain injera.
Added phytase boosts absorption
Adding an isolated phytase from Aspergillus niger raised median iron absorption to 3.6%, about 2.4 times higher than plain injera.
NaFeEDTA did not help
Replacing 50% or 75% of the FeSO4 with NaFeEDTA did not significantly change iron absorption.
Other findings
Phytic acid breakdown
Phytic acid in the injera dropped from 0.62 g per meal to 0.20 g with 10% whole wheat flour and to 0.02 g with added phytase.
What the authors conclude
“Replacing 10% tef with whole wheat flour during injera fermentation tripled FIA in young women and should be considered as a potential strategy to improve iron status in Ethiopia.”
Also in their conclusions
- They conclude that replacing 10% of tef with whole wheat flour during injera fermentation tripled iron absorption in young women.
- They say this should be considered as a potential strategy to improve iron status in Ethiopia.
- They note that adding whole wheat flour could be a simple and potentially sustainable approach.
How it was done
Iron deficiency is a public health concern in Ethiopia, where the diet is based on tef injera. Iron absorption from injera is low because of its high phytic acid content.
Two studies gave single test meals to healthy women aged 21 to 29. Study A (17 women) compared plain tef injera with injera made with 10% whole wheat flour or with added Aspergillus niger phytase. Study B (17 women) tested replacing part of the iron fortificant FeSO4 with NaFeEDTA.
What it can’t tell you
- The study lasted only a few days and measured iron absorption from single meals, so it cannot show whether this practice improves iron status over time.
- The women were healthy Swiss students, so the results may not be the same for other groups, such as young children or people in Ethiopia.
- The fermentation was not controlled and phytic acid breakdown can vary, so the size of the effect may differ in home settings.
Who paid
- Authors work at
- Institute of Food, Switzerland
The paper
- Title
- Addition of Whole Wheat Flour During Injera Fermentation Degrades Phytic Acid and Triples Iron Absorption from Fortified Tef in Young Women
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Herter-Aeberli I, Fischer MM, Egli IM, Zeder C, Zimmermann MB, Hurrell RF (2020). Addition of Whole Wheat Flour During Injera Fermentation Degrades Phytic Acid and Triples Iron Absorption from Fortified Tef in Young Women. The Journal of nutrition. doi:10.1093/jn/nxaa211Free full textPubMed 32805002DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error