Orange sweet potatoes reduce both the prevalence and duration of diarrhoea in young children, according to a study.

The orange sweet potatoes conventionally bred in Uganda, Rwanda, Tanzania, Ethiopia, Ghana and Mozambique provide more vitamin A in the diet.

A study conducted by scientists from the International Food Policy Research Institute and HarvestPlus, a global program to improve nutrition that funded the field research shows that just about 250 grams of the orange-fleshed sweet potatoes can provide the recommended daily requirement for vitamin A (600 µg).

The study conducted in Mozambique found a 42 per cent reduction in the likelihood that children under the age of five who ate orange sweet potatoes within the past week would experience diarrhoea. For children under three years of age who ate orange sweet potatoes, the likelihood of having diarrhoea was reduced by more than half (52 per cent).

The potatoes had an impact not only on reducing the incidence, but also the duration of diarrhoea. For children who had diarrhoea, eating the sweet potatoes reduced the duration of the illness by more than 10 per cent in children under five, and more than 25 per cent in children aged under three.

“The beta-carotene in orange sweet potatoes is converted into vitamin A the same day the potatoes are eaten,” says Erick Boy, the head of Nutrition at HarvestPlus. “This vitamin A is used by the cells lining the gut to help form a barrier to invading germs.

These cells are regenerated every few days, so cells that have been weakened due to lack of vitamin A are quickly replaced by healthy cells when there is enough vitamin A. It should be noted that access to clean water and sanitation, targeted immunisation, and breastfeeding are also important in helping to prevent diarrhoea.”

The orange sweet potatoes are an important source of beta-carotene, carbohydrates, fibre and vitamin A for children and breast-feeding mothers. This is particularly important in sub-Saharan Africa and Asia where vitamin A deficiency is a leading cause of blindness and premature death among children under five and pregnant women.

In Africa, more than 40 per cent of children under five are estimated to be at risk of vitamin A deficiency. This increases the risk of diseases such as diarrhoea, which is one of the leading causes of mortality in children, accounting for more than 350,000 lives of children under five in Africa every year.

“Both vitamin A supplements and vitamin A-rich foods like orange sweet potato can provide sufficient vitamin A. From a public health perspective, they are complementary — neither alone is able to reach every child who needs vitamin A,” says Alan de Brauw, a senior research fellow at the International Food Policy Research Institute.

“But vitamin A supplements can be expensive, as much as $2.71 per dose. Alleviating this deficiency worldwide through supplements alone would cost almost $3 billion per year. Using orange sweet potatoes to provide vitamin A is a fraction of that cost. Given the popularity of the potatoes — children especially love the taste — we think it’s a sustainable solution to improving nutrition and child health in many countries, complemented, of course, by supplementation where it is cost-effective.”