A helping of an orange coloured sweet potato just twice a week could save lives in Mozambique. This is no ordinary sweet potato - it has been bred to have a high beta-carotene content, a compound rich in vitamin A, which is found naturally in the root, hence the more intense orange colour. The human body is unable to synthesise vitamin A and has to obtain it from external sources.
“We find that children under five [years of age] reported consuming orange sweet potato [OSP] twice a week when available. They tend to eat OSP boiled, and the amount of beta-carotene consumed between OSP and other sources then exceeds the US recommended daily allowance for vitamin A when averaged over the week,” said Alan de Brauw, a senior research fellow at the International Food Policy Research Institute (IFPRI), who managed the impact evaluation of a three-year study which ended in 2009.
The study was published in the British Journal of Nutrition, and showed that OSP is effective in providing vitamin A to malnourished women and children in Mozambique, where the prevalence of vitamin A deficiency (VAD) is very high. The research was part of a HarvestPlus project, a programme run by the Consultative Group for International Agricultural Research.
VAD globally, and in Mozambique
VAD is the leading cause of preventable blindness in children, and increases the risk of disease and death from severe infections. In pregnant women VAD causes night blindness and may heighten the risk of maternal mortality.
Globally, an estimated 250,000 to 500,000 vitamin A-deficient children become blind every year, and half of them die within 12 months of losing their sight, the World Health Organization has noted.
In Mozambique an estimated 2.3 million children below the age of five years are vitamin-A-deficient, according to a study funded by Helen Keller International and published in the peer-reviewed journal, Public Health Nutrition, in 2004.
The study warned that in the absence of appropriate policy and programme action, VAD will cause over 30, 000 deaths annually among children younger than five, representing 34.8 percent of all-cause mortality in this age group.
A 2010 analysis by the UN Children’s Fund (UNICEF) said about one in every six children dies before she or he reaches their fifth birthday. In 2004 it was estimated that the total number of deaths among children under the age of five was 117,000 - about 320 child deaths every day.
Malaria and acute respiratory infection (ARI) are the two main immediate causes of mortality among young children in Mozambique, with AIDS emerging as a major killer. UNICEF says malnutrition is a significant underlying cause of child mortality.
Studies have shown that in areas where VAD is prevalent, vitamin A repletion reduces child mortality by 23 percent on average.
Grow it yourself
Vines bearing the beta-carotene enhanced potato were distributed to more than 10,000 households in Zambezia Province, northern Mozambique, which has the country’s highest number of children living in poverty. Many of these households traditionally grew and ate yellow or white sweet potato, which are poor sources of vitamin A.
IFPRI’s De Brauw reported that by the end of the project, “We found women consuming more OSP (and vitamin A), and by-and-large, households were consuming OSP they produced themselves.“
He said they are planning to do another survey in 2012 to find out how much OSP has been retained by households that participated, to see if the vitamin A in the diet is still adequate three years after the project took place.
When the project ended, OSP was providing more than 70 percent of all dietary vitamin A and was the third most important food in the diet (after maize and rice) for young children. OSP also provided more vitamin A than other local foods such as pumpkin, leafy green vegetables, or mango, according to HarvestPlus. “Available for about 3 months of the year, or longer in other regions, OSP can help close the VAD gap when other vitamin A-rich foods or supplements are not available,” the project said in a release.
Researchers across the world have been studying this hardy root, trying to develop other uses for it.
The sweet potato is a rich source of complex carbohydrates, vitamins A, B1 and B2, calcium, and fibre, and also produces more edible energy per hectare than wheat, rice, or cassava. Around 130 million tons of it are produced annually in more than 100 countries, including China and many parts of Africa, and the CIP says it is the world’s fifth most important food crop by weight.
It is drought-tolerant, and therefore has tremendous potential as a nutrition source in countries where water for irrigation is likely to become scarce as the impact of climate change unfolds, said Genoveva Rossel, curator of the sweet potato collection at the International Potato Centre (CIP) in Peru. The sweet potato is likely to have been grown in Peru over 5,000 years ago.
The CIP, in partnership with the International Livestock Research Institute (ILRI), in Kenya, has been experimenting with the sweet potato to position it as an alternative to napier grass - also known as elephant grass - a primary livestock feed in Kenya’s dairy industry.
East Africa has the highest per capita consumption of livestock products such as meat and milk in sub-Saharan Africa.
Expanding populations have increased the competition for grains as food for people as well as animals, making it scarcer and more expensive, especially in the dry season. Napier grass requires significant allocations of land and is currently suffering a disease outbreak.
The sweet potato could change this. Apart from using it as animal feed, the CIP is working directly with pig and dairy farmers in Kenya and Rwanda to test the feasibility of using sweet potato vines as silage and leaf protein supplements. Valerie Gwinner, spokeswoman for CIP, commented: “The researchers call it the ‘cow cafeteria’.”
This article was produced by IRIN News while it was part of the United Nations Office for the Coordination of Humanitarian Affairs. Please send queries on copyright or liability to the UN. For more information: https://shop.un.org/rights-permissions