Enhancing Iron Status in Young Girls: The Impact of Iron-Fortified Lentils

In a recent publication within The Journal of Nutrition, researchers conducted an evaluation of the efficacy of incorporating iron-fortified lentils (IFLs) into the dietary habits of rural Bangladeshi adolescent females regarding their body iron (Fe) levels.

Background: Iron deficiency (ID) presents as a prevalent micronutrient concern globally, particularly affecting females in low-income regions. Sustainable strategies, like iron fortification, offer promise in addressing these deficiencies by targeting vulnerable populations in a cost-effective manner.

Research indicates that meals fortified with iron can enhance iron status indicators across different age groups. Lentils, being protein-rich legumes, serve as effective candidates for Fe fortification, augmenting both iron content and bioavailability. Given their high protein and iron content, lentils emerge as a favorable choice for micronutrient enrichment.

Study Overview: In this double-blinded, community-based, randomized controlled trial, researchers scrutinized the effects of IFL consumption on the body iron status of adolescent females in Bangladesh.

The study enrolled 1,195 females aged 10 to 17 years. Participants, comprising 48 members of the BRAC Adolescent Club (27 girls per club), were randomly assigned to intervention, comparator, and control groups.

The intervention arm received 200 grams of cooked iron-enriched lentils, while the comparator arm received an equivalent quantity of cooked lentils lacking iron fortification (NIFLs). The control group maintained their regular diet without additional lentil intake.

All participants were non-pregnant, non-breastfeeding, nulliparous, and healthy non-smokers. The lentils utilized in the study were Saskatchewan-grown small red lentils fortified with 16 parts per million (ppm) of iron per 100 mg of lentils.

The intervention, administered five days a week for 85 days, supplied 8.6 mg of iron per serving of iron-fortified lentils and 2.6 mg from non-fortified lentils.

Blood samples collected on days 0, 42, and 85 were assessed for iron and inflammatory biomarker levels, including serum ferritin (sFer), soluble transferrin receptor (sTfR), total body iron (TBI), C-reactive protein (CRP), and complete blood count (CBC).

Data on socio-demographics and dietary intake were obtained via self-reported questionnaires and the seven-day diet recall (7DDR) questionnaire from the 2011–12 Bangladesh National Micronutrient Survey.

The researchers employed linear mixed and multinomial logistic regression models for analysis, with upazilas or sub-districts of Bangladesh considered as the effect variable.

Participants were categorized as responders and non-responders to iron status variables to ascertain whether differences in iron status between groups stemmed from response to group assignment.

Results: While all study groups exhibited declining iron levels over time, the intervention group demonstrated a significantly attenuated reduction in serological ferritin (-7.20 µg/L, 22%) and TBI (-0.5 mg per kg) compared to the comparator (sFer, -14 µg per L and total body iron, -1.4 mg per kg) and control (sFer, -13 µg per L and total body iron, -1.3 mg/kg) groups.

Furthermore, the intervention group exhibited a 57% (odds ratio, 0.4) lower risk of iron deficiency (sFer below 15 µg/L) compared to the control group.

IFL consumption prevented a deterioration in Fe status (sFer and TBI) among intervention group members, contrasting with the comparator and control groups.

The most notable enhancements in sFer, Hgb, and TBI levels among IFL consumers were observed within the initial two months of consumption. Adolescent girls consuming iron-fortified lentils manifested a significant elevation in serum ferritin (5.7 µg/L) compared to the control group after 85 days.

Total body iron increased by 0.8 mg/kg in the intervention group versus the control group. Adolescents consuming iron-fortified lentils exhibited a 42% (odds ratio, 0.6) and 77% (odds ratio, 0.2) lower likelihood of developing mild and moderate anemia, respectively, compared to controls.

Over the four-month period, the intervention group experienced a considerably smaller decline in hemoglobin levels (0.2 g/dL) compared to the comparator and control groups. Similarly, the intervention group demonstrated a protective effect against TBI compared to the comparator group (0.9 mg/kg) and the control group (0.8 mg/kg).

No significant alterations in sFer, hemoglobin, or TBI levels were observed in the comparator group relative to the control group.

The intervention group exhibited a higher proportion of sFer responders (14% vs. 7.6% and 7.5%), hemoglobin responders (17%), and TBI responders (13% vs. 6.9% and 8.4%), indicating a more robust response to the intervention.

Conclusion: The study underscores the significant impact of iron-fortified lentils on the iron status of adolescent females in Bangladesh. The IFL intervention emerges as an effective and well-received food-based approach for addressing the needs of vulnerable groups.

These findings hold potential for informing future public health campaigns centered on lentils and other food-based interventions to combat iron deficiency globally. National and international non-governmental organizations (NGOs) and humanitarian groups can leverage IFL as a public health commodity to benefit individuals affected by iron deficiency and iron deficiency anemia (IDA), as well as those at risk thereof, particularly in resource-constrained settings.

Moreover, these study findings can guide the formulation of future lentil policies and other food fortification strategies, contribute to the scientific understanding of IFLs, and foster the development of a market for iron-fortified lentils.