Title: Modelling potential ß-carotene intake and cyanide exposure from consumption of biofortified cassava Authors
Submitted to: Journal of Nutritional Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 30, 2012
Publication Date: March 1, 2013
Citation: Katz, J.M., Lafrano, M.R., Winter, C.K., Burri, B.J. 2013. Modelling potential ß-carotene intake and cyanide exposure from consumption of biofortified cassava. Journal of Nutritional Science. 2(e6):1-8. DOI:10.1017/jns.2012.30. Interpretive Summary: Vitamin A deficiency causes disability and mortality in Asia and Sub-Saharan Africa. Cassava is a staple crop in Africa that normally contains no vitamin A or vitamin A-forming carotenoids. Recently cassava varieties have been bred that are good sources of the vitamin A-forming carotenoid beta-carotene. We conducted a human study that showed that one of these biofortified cassava varieties increased beta-carotene and vitamin A concentrations in healthy adult women. The purpose of this study was to model whether this variety of biofortified cassava would provide enough vitamin A to meet vitamin A requirements if it replaced ordinary white cassava completely in the diet of major consumers in Sub-Saharan Africa. We calculated that consuming beta-carotene enhanced cassava would meet recommended VA intakes for the following percentages of individuals from 6 African countries: Angola (95%), Central African Republic (95%), Congo (~100%), Ghana (99%), Mozambique (99%), and Nigeria (92%). This study demonstrates that consuming current varieties of biofortified cassava, processed to maintain beta-carotene and remove cyanide, could theoretically increase VA intake for African populations and other areas of the world where cassava is a staple crop.
Technical Abstract: Background: Vitamin A (VA) deficiency causes disability and mortality. Cassava, a staple crop in Africa, can be crossbred to improve its pro-vitamin A (PVA) content and used as an alternative to capsule supplementation. However it contains cyanide and its continued consumption may lead to chronic disability. Objective: To estimate the risk-benefit of consuming PVA enhanced cassava to increase VA intake in developing countries. Design: Ten American women were fed typical and PVA enhanced cassava. PVA and cyanide data from the feeding study were combined with African cassava consumption data to model the potential daily carotenoid intake and cyanide exposure of African women if their cassava were replaced by the PVA enhanced form. Results: Consumption of typical white cassava did not contribute to daily VA intake. Consumption of PVA enhanced cassava could meet recommended VA intakes for the following percentages of populations in 6 African countries: Angola (95%), Central African Republic (95%), Congo (~100%), Ghana (99%), Mozambique (99%), and Nigeria (92%). Cyanide intake after minimal preparation of PVA cassava would be 13 to 32 times the reference dose (RfD), a toxicological exposure reference, but was completely undetectable after extensive soaking. Conclusions: This study demonstrates that consumption of PVA enhanced cassava, processed to maintain PVA and remove cyanide, could theoretically increase VA status in African populations and other areas of the world where cassava is a staple crop.