What is the best way to cook a sweet potato in order to preserve its nutritional value? These test results give us a clear answer.
The ORAC value, which is a test of total in vitro antioxidant content, revealed that when they're boiled without the skin, their value is 766 (as reflected above).
Now contrast that to a baked sweet potato with skin intact, which tests out to be 2,115.
Conclusion? The healthiest way to cook a sweet potato is baking it in the skin.
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010