Biofortification: Evidence and lessons learned linking agriculture and nutrition

Biofortification, the process of breeding nutrients into food crops, provides a comparatively cost-effective, sustainable, and long-term means of delivering more micronutrients. The biofortification strategy seeks to put the micronutrient-dense trait in those varieties that already have preferred agronomic and consumption traits, such as high yield and disease resistance. Marketed surpluses of these crops may make their way into retail outlets, reaching consumers first in rural and then urban areas. Progress to date in breeding and delivering biofortified crops is discussed. The nutrition evidence on bioavailability and efficacy is growing. Completed nutrition studies for each crop are briefly discussed. Human studies have included a variety of technologies, including stable isotope methods, which are among the most powerful to measure bioavailability and efficacy. Efficacy and effectiveness studies are available for orange-fleshed sweetpotato (OFSP); full evidence is not yet available for biofortified maize, cassava, or golden rice, but initial bioavailability and efficacy results are promising. Efficacy trials have been completed for iron crops (beans and pearl millet) and evidence for zinc biofortification is still developing. Food-based approaches to improve nutrition face challenges in providing rigorous evidence that they can deliver nutrition improvements in a cost-effective and timely manner. The experience of delivering OFSP is reviewed and discussed, including the challenges of marketing a visible trait and changing perceptions of OFSP as merely a food security crop. Whether implementing or integrating OFSP programs, strong and effective partnering practices are required; strategies for successful implementation of cross-sectoral nutrition sensitive programming are discussed. Biofortification is yet to be fully scaled-up in a single country, but much evidence and experience has been assembled to support its eventual effectiveness. Policies to support crosssectoral implementation at all levels, as well as increasing the evidence base, will contribute to making biofortification a cost-effective investment in a more nourishing future.