The Americas and Africa's Ancient Foodways

In Mesoamerica, maize was domesticated from teosinte, a wild grass native to the Balsas River valley in southwestern Mexico, in a process that genetic studies now suggest began as early as 9,000 years ago, considerably earlier than the roughly 5,000 to 7,000-year estimates once derived primarily from macrobotanical remains. Because teosinte bears little resemblance to modern maize, with small ears encased in hard casings, its identification as maize's wild ancestor was itself a major achievement of twentieth-century botany and genetics. Once domesticated, maize spread across Mesoamerica and beyond, becoming the foundation of diets from the Olmec through the Maya and Aztec civilizations. Its nutritional limitations, low levels of usable niacin and certain essential amino acids, were addressed through nixtamalization, a process in which dried maize kernels are soaked and cooked in an alkaline solution, traditionally made with lime or wood ash, which loosens the hull, softens the grain for grinding into masa, and crucially releases bound niacin, preventing the vitamin-deficiency disease pellagra among populations reliant on maize as a dietary staple. The precise antiquity of nixtamalization remains debated, with some archaeological evidence, including lime-processing equipment, suggesting the technique may be considerably older than once assumed.