How The Humble Orange Sweet Potato Won Researchers The World Food Prize

By Dan Charles

Published June 28, 2016 at 5:58 PM EDT

Sweet potato evangelist Maria Isabel Andrade drives around Mozambique in her orange Toyota Land Cruiser in 2012. She is one of four researchers honored with the World Food Prize for promoting the crop to combat malnutrition.

One summer day in 2012, on a long drive through northern Mozambique, I saw groups of men standing beside the road selling buckets filled with sweet potatoes. My translator and I pulled over to take a closer look. Many of the sweet potatoes, as I'd hoped, were orange inside. In fact, the men had cut off the tips of each root to show off that orange color. It was a selling point.

This may not sound like much. In the United States, most sweet potatoes are orange-fleshed varieties. But in Africa, that's unusual and new. Traditionally, sweet potatoes grown in Africa have had white flesh. It's the result of historical accident: Centuries ago, white-fleshed varieties made the voyage to Africa, and became popular, especially in East Africa.

Those orange-fleshed sweet potatoes along the road that day represented the triumph of a public health campaign to promote these varieties — which, unlike their white-fleshed counterparts, are rich in Vitamin A. Today, that campaign got some high-level recognition at a ceremony at the U.S. State Department. Four of the main people behind it will receive the 2016 World Food Prize. This prize is billed as the foremost international recognition of efforts to promote a sustainable and nutritious food supply.

This year's laureates are Maria Andrade, Robert Mwanga, Jan Low and Howarth (Howdy) Bouis. Three of them — Andrade, Mwanga and Low — worked at the International Potato Center, which is based in Peru, but has satellite operations in Africa. Bouis worked at the International Food Policy Research Institute in Washington, D.C., and was an early advocate of efforts to improve the nutritional quality of staple crops.

I met Andrade during my trip to Mozambique. She drove to our meeting in a bright orange truck painted with slogans promoting the high-Vitamin A sweet potatoes. She's a tireless and completely convincing evangelist for the cause. And in recent years, researchers have documented health improvements among villagers in Mozambique and Uganda, simply because they chose to eat sweet potatoes with orange flesh.