Whole wheat flour in tef injera tripled iron absorption in young women
What it found
Replacing 10% of the tef flour with whole wheat flour during fermentation tripled how much iron young women absorbed from the bread.
The test was done in people.
What they found
Studies in people
Whole wheat flour boosted iron
When 10% of the tef flour was replaced with whole wheat flour, the women took in about 5.3% of the iron in the meal. That was more than three times the 1.5% they took in from pure tef flatbread.
Added enzyme also helped
Adding an isolated enzyme from a fungus raised iron uptake to 3.6%. This was better than pure tef but not significantly different from using whole wheat flour.
Another iron form failed
Swapping some of the added iron for a different iron compound did not improve how much iron the women took in. The authors think the ratio of ingredients was too low to work.
Other findings
Phytic acid dropped sharply
Pure tef flatbread contained 0.62 g of phytic acid per meal. Adding 10% whole wheat flour lowered this to 0.20 g per meal, and adding a lab enzyme lowered it to 0.02 g per meal.
What the authors conclude
- They conclude that replacing 10% of tef flour with whole wheat flour during fermentation tripled iron uptake in young women.
- They suggest this simple change could be a practical way to improve iron nutrition in Ethiopia.
How it was done
Iron deficiency is a major problem in Ethiopia, where people eat a lot of tef injera flatbread. A natural compound called phytic acid in the grain blocks the body from taking in iron.
Researchers tested two groups of healthy young women aged 21 to 29 in Switzerland, with 17 finishing each study. The women ate different versions of tef injera flatbread over three mornings after fasting overnight. Blood samples taken 14 days later measured how much iron their bodies had taken in.
What it can’t tell you
- The study only included healthy young women in Switzerland, so scientists do not yet know if the results would be the same for children or men.
- Each woman ate the test meals for just three days, so this cannot show what happens to iron levels over months or years of eating this bread.
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 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error