Dr. Adam Drewnowski and colleagues at the University of Washington -- in a study funded by the industry group the U.S. Potato Board -- merged nutrient composition data from the United States Department of Agriculture Food and Nutrition Database for Dietary Studies with the USDA Center for Nutrition Policy and Promotion national food prices database.
The researchers used food frequency of consumption data obtained from the National Health and Nutrition Examination Survey and the Affordable Nutrition Index was the metric used to assess nutritional value per dollar for potatoes and for other vegetables.
Potatoes were the lowest-cost source of dietary potassium, a nutrient identified by the 2010 Dietary Guidelines as lacking in the American diet.
The high cost of meeting federal dietary guidelines for potassium, 4,700 milligram per person per day, presents a challenge for consumers and health professionals, but the cost of potassium-rich white potatoes was half that of most other vegetables, Drewnowski said.
"Potatoes deserve credit for contributing to higher diet quality and increasing vegetable consumption," Drewnowski said in a statement.