A study published in the latest edition of the Journal of Nutrition provides conclusive evidence that orange sweet potato (OSP) provided significant amounts of vitamin A to malnourished Ugandan children and women and that a modest improvement in vitamin A levels in the body was measurable in some cases.
Vitamin A deficiency (VAD) is a major public health concern in poorer countries and accounts for more than 600,000 deaths a year among children under five years of age. In Africa, VAD prevalence is estimated at 42 per cent among children under five. Uganda is among the African countries reported to be at high risk, with 28 per cent of children and 23 per cent of women estimated to be vitamin A deficient. VAD can impair immunity and cause eye damage that can lead to blindness and even death. Annually, up to 500,000 preschool children go blind from VAD, and about two-thirds will die within months of going blind.
Traditionally, white or yellow sweet potato varieties are grown and eaten in Africa, but these provide little, or no, vitamin A. OSP was conventionally bred, not just to provide more vitamin A but also to be high yielding and drought tolerant. From 2007–2009, HarvestPlus and its partners disseminated new OSP varieties to more than 10,000 farming households in Uganda for whom sweet potato is a key staple food. The project provided OSP vines for farmers to grow, as well as extension services and nutritional information so that farmers could incorporate OSP into their cropping systems. Since sweet potato is available for about 10 months a year, it can be a rich and steady source of vitamin A.
The project resulted in 61% of households adopting the vitamin A-rich OSP to grow on their farms. They were also willing to substitute more than one-third of their traditional white and yellow sweet potato consumption with OSP. This level of substitution was enough to push large numbers of children and women over the threshold, ensuring that their daily requirements for vitamin A were met.
Vitamin A intake increased by two-thirds for older children and nearly doubled for younger children and women by project end. For children 6–35 months, who are especially vulnerable, OSP contributed more than 50% of their total vitamin A intake. The high prevalence of inadequate vitamin A intake among a subset of children 12–35 months who were no longer breastfeeding fell from nearly 50% to only 12% as a result of the project. This is a very positive finding as young children who have recently stopped breastfeeding are at higher risk of VAD. This is because breast milk has been their primary source of vitamin A and their vitamin A needs continue to be high.
This project was undertaken concurrently in Mozambique where results showed even higher levels of adoption—and consumption—of OSP by vulnerable households. “We now have evidence from two very different countries and contexts that show that farming households are willing to adopt OSP, incorporate it in their diets, and get the vitamin A that they need,” says senior IFPRI economist, Dr. Daniel Gilligan.
HarvestPlus is now scaling-up OSP to reach another 225,000 households by 2016. The International Potato Center (CIP) plans to scale-up OSP to reach more than 600,000 households in 10 countries by 2015, including 120,000 households in Mozambique.