News

New sweet potato could help combat blindness in Africa

Claire Wallerstein, Lima

A new variety of sweet potato selected by scientists in Peru could help to prevent millions of cases of blindness and disease among children in Africa.

A simple deficiency of vitamin A is the leading cause of childhood blindness in developing countries, where around 251million children are vitamin A deficient, 10 million have xerophthalmia, or "dry eye," 500000 are irreversibly blinded, and three million die of vitamin A deficiency-related illnesses.

The new bright orange sweet potato, known as SPK 004, is rich in b carotene, which is converted by the body into vitamin A. It has been selected by the Lima based International Potato Center (CIP) from 5000 varieties kept in the centre's genebank. The agricultural research institute was set up in 1971 and is funded by, among others, the World Bank and the UK government's Department for International Development.

It is hoped that the project, which will start next year, will act as a backup for Unicef's vitamin A supplement programmes. These programmes have reduced severe vitamin A deficiency among mothers and children worldwide by two thirds since 1980.

But they have limitations. They are generally carried out during measles immunisation campaigns, which in some countries are non-existent. In others the infrastructure has been disrupted by war or is beyond the reach of families in far flung rural areas, who may never hear about the campaigns in the first place.

The potato institute's $3.2m (£2.3m) project will plant 5000 hectares with the new variety of sweet potato by 2004 in an effort to enable people in sub-Saharan east Africa to avoid vitamin A deficiency.

People in west Africa use red palm oil, which is rich in b carotene, in cooking, so rarely develop vitamin A deficiency. Importantly, the project will not involve actually changing diets, as sweet potato is already a staple food in the target area. The current variety, however, is white fleshed and fills a child's stomach without containing any micronutrients. Just 100 g of the institute's variety will provide a day's requirements of b carotene, as well as vitamins B and C and iron.

Meanwhile, scientists in the Philippines are also working to wipe out blindness with genetically modified "golden rice," containing a yellow daffodil gene that is rich in b carotene.