Iron-biofortified Beans Research Articles

Phytic Acid Concentration Influences Iron Bioavailability from Biofortified Beans in Rwandese Women with Low Iron Status

Background:The common bean is a staple crop in many African and Latin American countries and is the focus of biofortification initiatives. Bean iron concentration has been doubled by selective plant breeding, but the additional iron is reported to be of low bioavailability, most likely due to high phytic acid (PA) concentrations. Objective:The present study evaluated the impact of PA on iron bioavailability from iron-biofortified beans. Methods:Iron absorption, based on erythrocyte incorporation of stable iron isotopes, was measured in 22 Rwandese women who consumed multiple, composite bean meals with potatoes or rice in a crossover design. Iron absorption from meals containing biofortified beans (8.8 mg Fe, 1320 mg PA/100 g) and control beans (5.4 mg Fe, 980 mg PA/100 g) was measured with beans containing either their native PA concentration or with beans that were ∼50% dephytinized or >95% dephytinized. Results:The iron concentration of the cooked composite meals with biofortified beans was 54% higher than in the same meals with control beans. With native PA concentrations, fractional iron absorption from the control bean meals was 9.2%, 30% higher than that from the biofortified bean meals (P < 0.001). The quantity of iron absorbed from the biofortified bean meals (406 μg) was 19% higher (P < 0.05) than that from the control bean meals. With ∼50% and >95% dephytinization, the quantity of iron absorbed from the biofortified bean meals increased to 599 and 746 μg, respectively, which was 37% (P < 0.005) and 51% (P < 0.0001) higher than from the control bean meals. Conclusions:PA strongly decreases iron bioavailability from iron-biofortified beans, and a high PA concentration is an important impediment to the optimal effectiveness of bean iron biofortification. Plant breeders should focus on lowering the PA concentration of high-iron beans. This trial was registered at clinicaltrials.gov as NCT01521273.

Iron biofortified beans improve iron status in Rwandan University women: results of a feeding trial (646.1)

Objective: To examine the efficacy of an iron biofortified bean intervention on iron status in iron depleted young women.Methods: 257 Rwandan university women (18‐27 y) with screening ferritin &lt;20 μg/L were randomized to consume ~155 g/d, dry wt. of either iron biofortified beans (Fe=78 mg/g) or control beans (Fe=59 mg/g) per day for 135 days. Iron status (hemoglobin‐Hb, ferritin‐Fer, transferrin receptor‐TfR, body iron‐BI), inflammation (CRP, AGP), and anthropometric indices were determined at enrollment, 7 random midpoints and after 135 days. Difference‐in‐difference analysis plus repeated measures ANOVA and linear and binomial regression models were used to evaluate the effect of the intervention on iron status.Results: At baseline, for the 231 study subjects who completed the study, 34% were anemic (Hb &lt;120 g/L), 73% had Fer &lt;15.0 μg/L) and 48% had negative BI stores (Cook’s algorithm). After 135 days of feeding, there was significant group difference in change in Hb (difference=3.5 g/L, p&lt;.001) and BI (difference=0.45 mg/kg, p=.033) in the high iron compared to control group. Also, 54 of 109 women with negative BI at baseline increased their BI by 1.5 mg/kg, with 30% more responders in the high iron compared to the control group.Conclusions: Consumption of iron‐biofortified beans over 4.5 months improved iron status in iron depleted Rwandan women.Grant Funding Source: HarvestPlus/IFPRI

Unanticipated weight gain during a dietary intervention designed to improve iron status (804.20)

Objective: To quantify the effect on weight gain of a 4.5 months feeding trial intended to replace the subjects’ regular meals.Methods: 145 Rwandan women (18‐26 years) in a double‐blind feeding trial were randomized to receive either iron‐biofortified beans or traditional beans daily for 4.5 months. During the feeding period, the subjects were served 175 g of beans per meal, for lunch and dinner, plus ad libitum consumption of side dishes; they were allowed to consume more beans if desired. Blood biomarkers and anthropometry were measured before and after the feeding period. General linear models were used to evaluate the effect of the intervention on weight gain.Results: On average, the women consumed 200 g of beans (358 kcals) per meal. After the 4.5 months feeding period, 25% of the women gained 蠅 3 kg in body weight. Both the control and the treatment group consumed the same amount of beans per meal, with the treatment group having a significantly (p&gt;.001) greater increase in iron status. The more beans consumed per meal, the more weight the subjects gained (F= 3.94, p=.05), regardless of iron intake. Women in the upper quartile of the BMI distribution (BMI &gt; 24.2) gained the most weight (F=3.09, p=0.03).Conclusion: Providing lunch and dinner in a feeding trial to improve micronutrient status resulted in a net addition of calories and subsequent weight gain, especially in women with higher BMI.Grant Funding Source: Supported by HarvestPlus

Inflammation, weight status, and iron status in Mexican children in a randomized controlled iron‐biofortified bean feeding trial

Overweight is increasing in transition countries, but iron deficiency remains prevalent. Ferritin is a common marker or iron stores; however, in populations with chronic inflammation, ferritin values may be artificially increased in the presence of real iron deficiency. This study examines the relationship between BMI and markers of iron status and inflammation in children age 9–12 (n = 347) using data from a randomized, placebo‐controlled trial of iron biofortified beans in 20 Mexican boarding schools. Dependent variables are iron status (hemoglobin, ferritin, and sTfR) expressed as continuous or categorical variables (iron deficient and anemic). BMI is expressed as a continuous or categorical variable (normal, overweight, obese). Inflammation was assessed by CRP and AGP. Covariates, such as age, sex, school, amount of fortified beans consumed were controlled. Overweight was observed in 17.6% of the children, 13.5% were anemic (hemoglobin &lt;120 g/L), 9.8% had elevated CRP (&gt;3 mg/L) and 11.0% had elevated AGP (&gt;1 g/L). Inflammation status of the school, obesity, and individual baseline CRP predicted elevated ferritin at baseline (p =0.003; p=0.022; p&lt;0.001, respectively). In boarding schools given the control beans, those with high morbidity showed a positive change from baseline in corrected log ferritin (p = 0.0074) compared to those with low morbidity. Supported by HarvestPlus and AgroSalud

Iron-Biofortified Beans Intervention in Mexico

Iron-Biofortified Beans Intervention in Mexico