Orange Sweet Potato improves Vitamin A deficiency in Uganda, Mozambique

BY EDMUND SMITH-ASANTE

Cooked orange sweet potato. Credit Harvestplus

A study published Wednesday, August 8, 2012 by the International Food Policy Research Institute (IFPRI) in the Journal of Nutrition, has established that orange sweet potato (OSP) given to malnourished Ugandan and Mozambican children and women, has resulted in significant increases of vitamin A and that a modest improvement in vitamin A levels in the body was measurable in some cases.

According to the study, 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, adding, in Africa, VAD prevalence is estimated at 42% among children under five.

Uganda, it says, is among the African countries reported to be at high risk, with 28% of children and 23% of women estimated to be vitamin A deficient, hence the embarking on a project by HarvestPlus and its partners to stem the tide.

IFPRI says HarvestPlus and its partners were moved to act because VAD can impair immunity and cause eye damage that can lead to blindness and even death, stating that annually, up to 500,000 preschool children go blind from VAD, while about two-thirds will die within months of going blind.

Thus, from 2007–2009, HarvestPlus and its partners disseminated new orange sweet potato (OSP) varieties to more than 10,000 farming households in Uganda and Mozambique for whom sweet potato is a key staple food, to see if VAD could be reduced to more than 24,000 households in both Mozambique and Uganda.

During project’s implementation in Mozambique, it was found that the country showed even higher levels of adoption - and consumption - of OSP by vulnerable households.

Basically, 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 and can be a rich and steady source of vitamin A.

As said by IFPRI, although traditionally white or yellow sweet potato varieties are grown and eaten in Africa, these provide little, or no vitamin A, and so bio fortified OSP was conventionally bred, not just to provide more vitamin A but also to make it high yielding and drought tolerant. 

Biofortification is the process of breeding new varieties of foods crops that contain higher amounts of nutrients to improve nutrition and public health and agricultural approaches, such as biofortification, are now being looked upon to fill the nutritional gap for vitamin A and other nutrients.

Meanwhile, the project resulted in 61% of households which were also willing to substitute more than one-third of their traditional white and yellow sweet potato consumption with OSP, adopting the vitamin A-rich OSP to grow on their farms.

The study found that 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. 

Further, vitamin A intake increased by two-thirds for older children and nearly doubled for younger children and women by project end, while for children six to 35 months, who are especially vulnerable, OSP contributed more than 50% of their total vitamin A intake.

The IFPRI study maintains that as a result of the project’s success, the high prevalence of inadequate vitamin A intake among a subset of children 12 - 35 months who were no longer breastfeeding, also fell from nearly 50% to only 12%.

“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,” said IFPRI in a statement.

The press statement said researchers were also able to measure a small positive impact of eating OSP on the amount of vitamin A in the blood among children 5–7 years that had lower levels of vitamin A at the start of the project.

It added that at project end, researchers also found that women who got more vitamin A from OSP had a lower likelihood of having marginal VAD but Vitamin A deficiency was unexpectedly low among the women sampled in the study, which made it hard to detect changes.

Confirming results of the nutrition study, Dr. Christine Hotz, former HarvestPlus Nutrition Head who led in its conduction said, “Overall, these results add to the growing evidence base that OSP provides large amounts of vitamin A in the diet,” adding, “We were also able to show a modest increase in vitamin A blood levels among children, despite this being challenging to measure, given the changing nutritional landscape over two years under real-world conditions."

Also commenting on the study’s findings, senior IFPRI economist, Dr. Daniel Gilligan stated; "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.”

For now, HarvestPlus is now scaling-up OSP to reach another 225,000 households by 2016, while the International Potato Centre (CIP), plans to scale-up OSP to reach more than 600,000 households in 10 countries by 2015, including 120,000 households in Mozambique.

HarvestPlus,  an organisation that is part of the CGIAR Research Programme on Agriculture for Improved Nutrition and Health and coordinated by CIAT and the International Food Policy Research Institute (IFPRI), leads a global effort to breed and disseminate staple food crops that are rich in vitamins and minerals to improve nutrition and public health.