Potatoes help fight the scourge of vitamin A deficiency

Posted: 12 September 2000

New ways have recently been found to add vitamin A to the diets of families in sub-Saharan Africa where three million children under the age of five suffer blindness caused by Vitamin A Deficiency (VAD).

Many of those who don't get enough vitamin A die as a result of increased vulnerability to infection. Women are far more likely to die during pregnancy if they lack vitamin A.

For many years the United Nations has been running a programme to distribute vitamin A capsules and this has led to a two-thirds reduction in VAD-related child blindness. By 1997 some 12 million children were receiving vitamin A supplements in Africa. However, in remote rural areas which are not served by the program vitamin A deficiency remains a serious problem.

Now help is at hand in the shape of a beta-carotene-rich sweet potato. A native of South America, sweet potatoes have become a staple food in many African countries, but these are the white-fleshed variety which contain little or no beta-carotene, which when eaten by humans converts to vitamin A.

For many years development experts believed that African consumers would shun the orange-fleshed beta-carotene-rich varieties, which were thought to be too moist and sweet for African tastes. However, scientists have now developed a sweet potato which has high levels of beta-carotene and passes African consumer taste tests.

The hope is that this can be introduced to remote parts of the continent for people to grow their own source of vitamin A. "This project demonstrates that research geared to promote grassroots changes on the farm and in the family kitchen can provide a straightforward solution to a serious problem," says Dr Wanda Collins of the International Potato Centre, a Peru-based organisation which has been involved in the project.

Meanwhile, biotechnology researchers recently announced that they have incorporated into rice genetic material from a daffodil which has the ability to manufacture beta-carotene. Of the three billion people who depend on rice as their staple food, an estimated 10 per cent suffer some level of vitamin A deficiency. The research team has also added a gene from a French bean to rice, thus doubling its iron content.

Plant breeders at the International Rice Research Institute say that once the new transgenic rice varieties have been approved by national biosafety authorities, they will be distributed free of charge to farmers, who will have unrestricted rights to them.