Changes in Iron Status Are Related to Changes in Brain Activity and Behavior in Rwandan Female University Students: Results from a Randomized Controlled Efficacy Trial Involving Iron-Biofortified Beans.
Study Goal
The researchers aimed to determine whether iron-biofortified beans improve iron status, brain dynamics, and cognitive performance in women with low iron status.
Results Summary
The study found that consuming iron-biofortified beans significantly improved iron status (hemoglobin, ferritin, body iron), cognitive performance (speed, memory retrieval), and brain activity (EEG measures) compared to a control group. Mediation analysis supported that brain activity changes linked iron status improvements to cognitive enhancements.
Population
55 women aged 18-27 years with low iron status (serum ferritin <20 µg/L).
Effective Dosage
Daily consumption of iron-biofortified beans (86.1 ppm iron) vs. comparison beans (50.1 ppm iron).
Duration
18 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
iron-biofortified beans | increase | hemoglobin | 55 women aged 18-27 y with low iron status (serum ferritin <20 µg/L) | η2 = 0.16 | significant improvements | #1 |
iron-biofortified beans | increase | ferritin | 55 women aged 18-27 y with low iron status (serum ferritin <20 µg/L) | η2 = 0.17 | significant improvements | #2 |
iron-biofortified beans | increase | body iron | 55 women aged 18-27 y with low iron status (serum ferritin <20 µg/L) | η2 = 0.10 | significant improvements | #3 |
iron-biofortified beans | increase | speed of responding in attentional and mnemonic tasks | 55 women aged 18-27 y with low iron status (serum ferritin <20 µg/L) | η2 = 0.04-0.29 | significant improvements | #4 |
iron-biofortified beans | increase | sensitivity and efficiency of memory retrieval | 55 women aged 18-27 y with low iron status (serum ferritin <20 µg/L) | η2 = 0.12-0.55 | significant improvements | #5 |
iron-biofortified beans | increase | measures of EEG amplitude and spectral power | 55 women aged 18-27 y with low iron status (serum ferritin <20 µg/L) | η2 = 0.08 to 0.49 | significant improvements | #6 |
iron-biofortified beans | increase | behavioral performance and brain activity | female university students | - | resulted in improvements | #7 |
BACKGROUND: Evidence suggests that iron deficiency (ID) affects cognitive performance, as measured in behavior. Although such effects must be mediated by changes in the brain, very few studies have included measures of brain activity to assess this relation. OBJECTIVE: We tested the hypothesis that provision of iron-biofortified beans would result in improvements in measures of iron status, brain dynamics, and behavior. METHODS: A double-blind, randomized, intervention study was conducted in 55 women aged 18-27 y with low iron status (serum ferritin <20 µg/L). Women were randomly assigned to consume iron-biofortified (86.1 ppm iron) or comparison beans (50.1 ppm iron) daily for 18 wk. Iron status was assessed by hemoglobin, ferritin, transferrin receptor, and body iron; cognitive performance with 5 computerized tasks; and brain dynamics by concurrent electroencephalography (EEG). All measures were taken at baseline and endline. RESULTS: The groups did not differ on any measures at baseline. Intention-to-treat analyses revealed significant (all P < 0.05) improvements in hemoglobin (partial effect size attributable to the independent variable, η2 = 0.16), ferritin (η2 = 0.17), and body iron (η2 = 0.10), speed of responding in attentional and mnemonic tasks (η2 = 0.04-0.29), sensitivity and efficiency of memory retrieval (η2 = 0.12-0.55), and measures of EEG amplitude and spectral power (η2 = 0.08 to 0.49). Mediation models provided evidence in support of the hypothesis that changes in iron status produce changes in behavior by way of changes in brain activity. CONCLUSIONS: Behavioral performance and brain activity, as measured by EEG, are sensitive to iron status, and the consumption of iron-biofortified beans for 18 wk resulted in improvements in measures of both, relative to what was obtained with a comparison bean, in a sample of female university students. Furthermore, the results support the conclusion that changes in brain activity resulting from consumption of biofortified beans mediate the relations between changes in iron biomarkers and changes in cognition. Clinical trial registry: ClinicalTrials.gov Reg No. NCT01594359.