Pellagra

The traditional food preparation method of corn (maize), nixtamalization, by native New World cultivators who had domesticated corn required treatment of the grain with lime, an alkali. It has now been shown that the lime treatment makes niacin nutritionally available and reduces the chance of developing pellagra.  When corn cultivation was adopted worldwide, this preparation method was not accepted because the benefit was not understood. The original cultivators, often heavily dependent on corn, did not suffer from pellagra. Pellagra became common only when corn became a staple that was eaten without the traditional treatment.

Pellagra was first described in Spain in 1735 by Gaspar Casal, who published a first clinical description in his posthumous "Natural and Medical History of the Asturian Principality" (1762). This led to the disease being known as "Asturian leprosy", and it is recognized as the first modern pathological description of a syndrome. It was an endemic disease in northern Italy, where it was named "pelle agra" (pelle = skin; agra = sour) by Francesco Frapoli of Milan. Because pellagra outbreaks occurred in regions where maize was a dominant food crop, the belief for centuries was that the maize either carried a toxic substance or was a carrier of disease, people also believed it was carried by insects. It was not until later that the lack of pellagra outbreaks in Mesoamerica, where maize is a major food crop (and is processed), was noted and the idea was considered that the causes of pellagra may be due to factors other than toxins.

In the early 1900s, pellagra reached epidemic proportions in the American South. There were 1,306 reported pellagra deaths in South Carolina during the first ten months of 1915; 100,000 Southerners were affected in 1916...

Photo via Wurzeltod.