Iron-fortified lentils and thinking skills in Bangladeshi girls
What it found
Teenage girls in Bangladesh who ate iron-fortified lentils for four months did better on some thinking and reaction-time tasks than girls who ate ordinary lentils or no lentils.
The fortified lentils also helped protect their iron levels from falling.
What they found
Studies in people
Thinking tasks
At the end, girls who ate iron-fortified lentils performed better on at least one measure in four of the five thinking tasks compared with the other two groups. The only task with no difference was the go/no-go task.
Iron levels
Iron levels dropped in all groups over the four months, but the drop was smallest in the girls who ate iron-fortified lentils. At the end, their iron levels were better than those of girls who ate ordinary lentils or no lentils.
Link to iron change
Girls whose iron levels improved also tended to do better on the thinking tasks. Those whose iron levels stayed the same or fell did not improve or did worse.
Who responded
More girls in the fortified lentil group saw their iron levels improve compared with the other groups. Girls who started with the lowest iron levels were the most likely to improve.
What the authors conclude
“the provision of iron-fortified lentils provided a protective effect on iron status in the context of declines in iron status and supported higher levels of cognitive performance for adolescent girls at-risk of developing iron deficiency.”
Also in their conclusions
- They conclude that providing iron-fortified lentils offered protective or beneficial effects on both thinking performance and iron status.
- They say the fortified lentils may prevent a decline in iron status and that this benefits thinking skills.
- They suggest that adding fortified staple foods is an effective alternative to iron supplements where diets lack enough iron.
How it was done
Iron deficiency is common in South Asia, especially among women and children in Bangladesh. Poor iron levels can harm thinking and learning.
They studied 359 adolescent girls aged 10 to 17 in Bangladesh. The girls were split into three groups: one got iron-fortified lentils, one got ordinary lentils, and one got no lentils. The girls in the two lentil groups ate about 200 g of cooked lentils five days a week for 85 feeding days. The researchers measured iron levels in blood and gave five computer-based thinking tasks at the start and end.
What it can’t tell you
- The study lasted only four months, so it cannot show what happens over a longer time.
- The girls were generally healthy and few had iron deficiency at the start, so the results may not apply to girls who are already iron deficient.
- The study cannot rule out that other differences between the groups affected the results.
Who paid
- Funding
- Funded by Nutrition International (from the PubMed record).
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- The University of Oklahoma, USA; The University of Saskatchewan, Canada; Dalhousie University, Canada
The paper
- Title
- The Effect of Iron-Fortified Lentils on Blood and Cognitive Status among Adolescent Girls in Bangladesh
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Barnett AL, Wenger MJ, Yunus FM, Jalal C, DellaValle DM (2023). The Effect of Iron-Fortified Lentils on Blood and Cognitive Status among Adolescent Girls in Bangladesh. Nutrients. doi:10.3390/nu15235001Free full textPubMed 38068859DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error