Are Beans High In Iron

Are Beans High in Iron?

Iron Content in Common Beans

Common beans (Phaseolus vulgaris L.) are a staple food in many regions, particularly in Latin America and Eastern-Southern Africa, where iron deficiency is prevalent. Studies have shown that the average iron concentration in common beans is around 55 mg/kg. Efforts to biofortify beans to increase their iron content have been ongoing, with breeding targets set to achieve higher iron levels than local varieties.

Biofortification and Iron Absorption

Biofortification of beans has shown promise in increasing iron intake. For instance, iron-biofortified beans (Fe-Beans) have been developed with significantly higher iron content compared to standard beans. In a study conducted in Rwanda, women consuming Fe-Beans with 86 mg Fe/kg showed significant improvements in iron status markers such as hemoglobin and serum ferritin compared to those consuming standard beans with 50 mg Fe/kg. Similarly, a study in Mexico with school children found that while both Fe-Beans and control beans improved iron status, the Fe-Beans did not show a significant advantage over control beans in terms of iron biomarkers.

Challenges in Iron Bioavailability

Despite the higher iron content, the bioavailability of iron from beans can be limited by the presence of phytic acid (PA) and polyphenols (PP), which inhibit iron absorption. Studies have shown that reducing PA in beans can significantly increase iron absorption. For example, low-phytic acid (lpa) beans have been shown to improve iron absorption in women, with a 90% reduction in PA leading to a substantial increase in bioavailable iron. However, these lpa beans can cause adverse gastrointestinal symptoms, which may affect their overall acceptability and consumption.

Comparative Studies and Efficacy

Comparative studies using animal models and in vitro methods have demonstrated that biofortified beans can provide more bioavailable iron than standard beans. For instance, biofortified red mottled beans were found to deliver more bioavailable iron for hemoglobin synthesis in poultry compared to standard beans. Additionally, yellow beans, which are known for their fast cooking properties, have shown higher iron bioavailability compared to other bean varieties in animal studies.

Impact on Health and Cognitive Function

The consumption of iron-biofortified beans has not only improved iron status but also had positive effects on cognitive performance. In a study involving Rwandan female college students, those who consumed iron-biofortified beans showed significant improvements in cognitive tasks related to memory and attention compared to those who consumed control beans. This highlights the potential broader health benefits of consuming iron-biofortified beans beyond just addressing iron deficiency.

Conclusion

In summary, common beans are a good source of iron, and biofortification efforts have successfully increased their iron content. However, the presence of iron absorption inhibitors like phytic acid and polyphenols can limit the bioavailability of this iron. Strategies to reduce these inhibitors, such as developing low-phytic acid bean varieties, have shown promise in improving iron absorption. Overall, iron-biofortified beans can play a significant role in combating iron deficiency and improving health outcomes, particularly in populations that rely heavily on beans as a dietary staple.

Summary

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