Nixtamalization and the Corn That Prevents Pellagra

Mesoamerican cooks had been simmering dried corn kernels in a solution of wood ash or slaked lime — calcium hydroxide — for at least 3,500 years before Europeans arrived. The process, now called nixtamalization, does something chemically dramatic: the alkaline solution breaks bonds in the corn's pericarp, releasing niacin (vitamin B3) from a bound form the human gut cannot absorb into a bioavailable one it can.

When Spanish colonizers brought maize back to Europe in the 16th century, they brought the grain but not the technique. European farmers grew corn successfully — it was calorie-dense and high-yielding — and many communities made it their dietary staple. Within a few generations, pellagra appeared: a disease marked by dermatitis, diarrhea, dementia, and, in severe cases, death. By the 18th and 19th centuries, pellagra was endemic across northern Spain, southern France, and the American South, wherever corn was eaten without the alkaline pre-treatment.

The connection was not made until the early 20th century. Joseph Goldberger, a U.S. Public Health Service physician, established in 1915 that pellagra was a nutritional deficiency, not an infectious disease — an argument the medical establishment resisted for years. The specific deficiency, niacin, was not confirmed until 1937.

Today, mass-market corn flour in many countries is enriched with synthetic niacin, solving the problem through a different route. But a proper corn tortilla still starts with nixtamal: kernels that have been cooked and steeped in lime water, then ground while wet on a metate or a mechanical mill. The texture is different — stickier, more cohesive — and so is the nutritional profile.