Introduction

Malnutrition presents an urgent development challenge. Zinc, iron and vitamin A deficiencies—essential for healthy growth and development—are among the most debilitating forms of undernutrition, and they disproportionately affect vulnerable populations, including women of childbearing age.

Potatoes and sweetpotatoes can provide important sources of these essential nutrients. Potato is a good source of zinc, iron, protein, potassium and vitamins C and B6, making an important contribution to diets in regions where resource-poor populations have limited access to other foods. Just 100g of boiled, unpeeled potato can provide up to 16% of the recommended daily intake of potassium and 30% of recommended vitamin C intake. Benefits like these are especially important in mountain regions of rural Africa and Latin America, where people eat 300–800g of boiled potatoes a day, accounting for almost 40% of their energy requirements.

While iron concentration in cooked potatoes is lower than in cereals and legumes, its bioavailability—the amount of iron available for use by the body—is proportionally higher than in wheat and beans, in part because vitamin C facilitates iron absorption.

Orange-fleshed sweetpotato (OFSP) contains high levels of beta-carotene, which is converted by the body into vitamin A. Just 125g of boiled OFSP can provide the recommended daily allowance of vitamin A for children and women who are not breastfeeding. In addition, OFSP contributes significant amounts of vitamins C, E and several B vitamins, as well as dietary fiber, iron and magnesium. Purple-fleshed varieties, on the other hand, are rich sources of antioxidants. Sweetpotato leaves are also rich in vitamins, beta-carotene, and functional compounds including protein, amino acids and complex carbohydrates.

Potatoes and sweetpotatoes offer cost-effective and sustainable opportunities to supplement diets. Even at low yield levels, a family of five can grow enough OFSP on a 500m2 plot to meet their vitamin A needs, while potatoes contain more protein per unit growing area than alternative staple crops.

Early-maturing improved varieties with elevated levels of essential nutrients can produce nutritious food before rice or wheat are ready for harvest. They can contribute to the diversified diets needed to address “hidden hunger”—a diet sufficient in quantity but lacking in essential micronutrients.

Crop breeders have prioritized the development of more nutritious, climate-resilient potato and sweetpotato varieties with the qualities desired by local growers and consumers—but this is not enough to encourage successful adoption by farmers. Farmers seek varieties that are pest-resistant and drought and heat tolerant, while consumers look at factors such as taste and texture. To meet these demands, CIP collaborates with businesses, model farmers and national agricultural research systems to establish seed systems that guarantee the availability of quality planting materials to farming households.

Building blocks

Breeding

Over the past 15 years CIP has cut the time needed for developing and releasing new sweetpotato varieties using conventional breeding from eight years to four or five, and new biofortified varieties have been released in at least 22 countries. Progress is also being made towards the goal of producing zinc- and iron-rich sweetpotato, which would be the first biofortified crop to deliver three essential nutrients.

Farmer adoption/ behavioral change

Two decades ago, few Africans grew OFSP as it was considered as poor people’s food. Today, education and awareness campaigns about the nutritional qualities of OFSP have successfully contributed to their increased production and consumption. In a 10-month pilot initiative in Kenya, community health workers provided nutrition advice to new and expectant mothers along with vouchers for OFSP planting material. When CIP researchers returned to the area a year later, 75% of the families who received both the nutrition advice and OFSP vouchers were growing those new varieties. Embedding nutrition education into interventions and enhancing access to OFSP varieties proved effective. Promotional activities through public health services have improved maternal health-seeking behavior, nutrition knowledge, dietary vitamin A intakes, and vitamin A levels.

Market development

Successful market development has played an important role in expanding consumption of pro-vitamin-A sweetpotato in Africa. CIP scientists developed and disseminated a method to produce vacuum-packed sweetpotato puree – with a shelf life of three-to-six months–that can be used to make varied baked or fried products. The puree can be substituted for 45 percent of the wheat flour in bread, reducing production costs and resulting in a more nutritious product. The sale of sweetpotato bread in various African countries has increased the amount of vitamin A in consumers’ diets, spawned new value chains from farmers to retailers, and created income opportunities for women and young people.