The Introduction of Orange-Fleshed Sweet Potato in Mozambican Diets
The Towards Sustained Nutrition Improvement (TSNI) action research project, initiated in 2002, worked to promote the cultivation and consumption of orange-fleshed sweet potatoes (OFSP) as a means to decrease the prevalence of Vitamin A deficiency (VAD) in Mozambique.
The Problem
Vitamin A is an essential micronutrient for human health, and VAD can limit growth, weaken immunity, cause xeropthalmia, leading to blindness, and increase mortality. VAD is widespread among young children in sub-Saharan Africa (SSA), and in Mozambique the problem is severe, with an estimated prevalence of 71 per cent in children 6–59 months of age.
Agrobiodiversity
There are two types of vitamin A available in foods: preformed retinol (vitamin A itself) typically found in animal foods such as eggs, liver, and milk; and provitamin A carotenoids found in plant foods such as dark green leafy vegetables and yellow and orange vegetables and fruits. β-carotene is the major pro-vitamin A carotenoid among plant sources and the bioavailability of that beta-carotene which is converted into vitamin A (retinol) varies considerably. Among plant sources, orange-fleshed sweet potatoes (OFSP) are rich in beta-carotene, which is highly bioavailable. Just 100–125 g of boiled or steamed OFSP meet the daily recommended intake levels of vitamin A for children under five years of age. Moreover, unlike many vegetables, the sweet potato has significant amounts of energy as well as vitamin A. Hence, OFSP is considered a biofortified staple food crop that can tackle the problem of inadequate caloric intake as well as VAD.
Sweet potato (Ipomoea batatas (L.)) exhibits a wide range of varietal diversity that results in it being grown from sea level to 2,300 m above sea level in SSA. Over 5,000 accessions are found in the germplasm bank, maintained at the International Potato Center in Lima, Peru. Flesh colors cover the gamut of white, cream, yellow, orange, and purple. In SSA, the dominant landraces grown are white-fleshed, lacking in beta-carotene.
The Project
The Towards Sustained Nutrition Improvement (TSNI) action research project was initiated in September 2002. Recognizing that the causes of VAD and undernutrition among young children are diverse an integrated approach was adopted with three distinct
- Agriculture:
- Introduction of a new source of vitamin A and energy bio-fortified OFSP
- Intervention farmers receive (primarily through gropups) planting material of high-yielding OFSP varieties, combined with lessons on how to improve crop management and storage practices to maximize the availability of OFSP in the diet throughout the year.
- Nutrition
- At the village level, principal caregivers, both women and men, are encouraged and enabled to improve infant and young child feeding practices, hygiene practices, and diversify the household diet.
- Demand creation efforts that focus on building awareness among the broader community to create:
- demand for the new OFSP cultivars and their derivatives and other vitamin A-rich foods
- a supportive environment to accelerate behavior change at the household level (e.g. signs in local markets)
The intervention lasted 18 months in two of the poorest districts in rural Zambézia, Mozambique.
Impact
The effectiveness of the intervention was evaluated after two agricultural cycles and findings published. In the second year:
- 90 per cent of intervention households produced OFSP.
- Vitamin A intakes among intervention children were much higher than those of control children.
- OFSP contributed to 35 per cent of the total vitamin A intake of all children in the intervention area and 90 per cent among those who had consumed it the previous day.
- Controlling for infection/inflammation and other confounding variables, a 15 per cent decline in the prevalence of VAD was attributable to the integrated intervention.
- OFSP was well accepted and liked by both adults and children.
In addition to these benefits, the use of food-based approaches and OFSP became recognized by the government of Mozambique as an excellent source of vitamin A in the government’s current nutrition strategy. The Mozambican experience, combined with findings from other studies in Uganda and Kenya, has provided vital evidence that is being used by members of the Vitamin A for Africa (VITAA) platform and others to attract funding for the development and use of locally adapted OFSP varieties and their promotions.
Lessons Learned
- All age groups enjoy consuming OFSP and it can make significant impacts on vitamin A intakes and status when it is available.
- Adults and children can differ in their varietal preferences. Adults generally prefer a more floury texture (higher dry matter content) than young children do.
- The most important constraint to expanded and sustained sweet potato production is the timely availability of quality planting material at the beginning of the rains.
- For sustained adoption, it is necessary to invest in actual breeding efforts in Africa in order to have materials that are sufficiently adapted to local conditions.
Scaling Up
While the TSNI case study had many successes, the cost per beneficiary was high. Therefore, the follow-up action research project, known as the Reaching End Users (REU) project (led by HarvestPlus), sought to lower the cost by introducing the use of village promoters and using existing church or farmers groups instead of engaging in new group formation. By working through promoters, extension personnel could reach a larger number of beneficiaries per extensionist and substantially reduce costs.
Also important to note is that currently 15 additional counties are actively engaged in OFSP-related activities (Kenya, Ethiopia, Uganda, Tanzania, Rwanda, Malawi, Zambia, Mozambique, Madagascar, DR Congo, Angola, South Africa, Burkina Faso, Ghana, Nigeria) and are exchanging information through the Sweet potato for Profit and Health Initiative (launched in October 2009) and the Sweet potato Knowledge Portal (www.sweetpotatoknowledge.org).
More Information
http://www.all-about-sweet-potatoes.com/vitaa-sweet-potato.html
http://www.ifpri.org/publication/reaching-end-users-reu-socioeconomic-endline-survey-2009-mozambique
http://www.sweetpotatoknowledge.org/
Contact
Mary Arimond, marimond(at)ucdavis.edu