Assessing the Potential of Biofortified Cassava for Improving Indices of Vitamin A Status: Update on Human Studies

Abstract

Objectives: Cassava usually contains essentially no beta-carotene (BC). However, cassava is being bred to increase its BC content. Our objective was to test how effective biofortified cassava is at increasing BC and vitamin A (VA) concentrations in healthy adult women. Methods: Ten American women participated in a cross-over trial.  They ate 3 treatments in random order: a breakfast containing 100 g boiled biofortified cassava, with or without 15 mL oil; or 100 g white cassava with 15 mL oil.  Carotenoid concentrations in cassava were measured by HPLC, spectrophotometry, and colorimetry. VA and BC concentrations in triacylglycerol-rich plasma were measured by HPLC, before and after each dietary intervention. Results: Carotenoid concentration differences in cassava preparations were monitored successfully by spectrophotometry and colorimetry as well as by the more expensive HPLC. VA and BC increased after both biofortified cassava treatments. BC concentration increases in triacylglycerol-rich plasma varied >10-fold between women, for unknown reasons. VA conversion was very good, approximately 4 µg β-carotene: 1 µg retinol, for both biofortified cassava treatments. Data from this study were used to predict BC intakes for African women if biofortified cassava replaced white cassava in their diet. The model predicts that completely replacing white with biofortified cassava provides recommended VA intakes for 92% (Nigeria) to 100% (Congo) of adult women where cassava is a staple crop. Conclusions: These results suggest that current varieties of biofortified cassava, when boiled gently, could be a useful intervention for improving VA status. This research was supported by grant 8227 from HarvestPlus.