rather than infection as contemporary medical opinion would suggest. goldberger believed that the root cause of pellagra amongst southern farmers was limited diet resulting from poverty, and that social and land reform would cure epidemic pellagra. his reform efforts were not realized, but crop diversification in the southern united states, and the accompanying improvement in diet, dramatically reduced the risk of pellagra. goldberger is remembered as the "unsung hero of american clinical epidemiology". though he identified that a missing nutritional element was responsible for pellagra, he did not discover the specific vitamin responsible. in 1937, conrad elvehjem, a biochemistry professor at the university of wisconsin-madison, showed that the vitamin niacin cured pellagra (manifested as black tongue) in dogs. later studies by dr. tom spies, marion blankenhorn, and clark cooper established that niacin also cured pellagra in humans, for which time magazine dubbed them its 1938 men of the year in comprehensive science. research conducted between 1900 and 1950 found the number of cases of women with pellagra was consistently double the number of cases of affected men. this is thought to be due to the inhibitory effect of estrogen on the conversion of the amino acid tryptophan to niacin. some researchers of the time gave a few explanations regarding the difference. gillman and gillman related skeletal tissue and pellagra in their research in south africans. they provide some of the best evidence for skeletal manifestations of pellagra and the reaction of bone in malnutrition. they claimed radiological studies of adult pellagrins demonstrated marked osteoporosis. a negative mineral balance in pellagrins was noted, which indicated active mobilization and excretion of endogenous mineral substances, and undoubtedly impacted the turnover of bone. extensive dental caries were present in over half of pellagra patients. in most cases, caries were associated with "severe gingival retraction, sepsis, exposure of cementum, and loosening of teeth". united states corn grits, yellow unenriched, drynutritional value per 100 g (3.5 oz)protein8.8 gtryptophan0.062 g vitaminsquantity %dv†niacin (b3)8% 1.2 mg units μg = micrograms • mg = milligrams iu = international units †percentages are roughly approximated using us recommendations for adults. peanut, valencia, rawnutritional value per 100 g (3.5 oz)protein25 gtryptophan0.2445 g vitaminsquantity %dv†niacin (b3)86% 12.9 mg units μg = micrograms • mg = milligrams iu = international units †percentages are roughly approximated using us recommendations for adults. pellagra was first reported in 1902 in the united states, and has "caused more deaths than any other nutrition-related disease in american history", reaching epidemic proportions in the american south during the early 1900s. poverty and consumption of corn were the most frequently observed risk factors, but the exact cause was not known, until groundbreaking work by joseph goldberger. a 2017 national bureau of economic research paper explored the role of cotton production in the emergence of disease; one prominent theory is that "widespread cotton production had displaced local production of niacin-rich foods and driven poor southern farmers and mill workers to consume milled midwestern corn, which was relatively cheap but also devoid of the niacin necessary to prevent pellagra." the study provided evidence in favor of the theory: there were lower pellagra rates in areas where farmers had been forced to abandon cotton production (a highly profitable crop) in favor of food crops (less profitable crops) due to boll weevil infestation of cotton crops (which occurred randomly). the whole dried corn kernel contains a nutritious germ and a thin seed coat that provides some fiber. there are two important considerations for using ground whole-grain corn. the germ contains oil that is exposed by grinding, thus whole-grain cornmeal and grits turn rancid quickly at room temperature and should be refrigerated. whole-grain cornmeal and grits require extended cooking times as seen in the following cooking directions for whole-grain grits: "place the grits in a pan and cover them with water. allow the grits to settle a full minute, tilt the pan, and skim off and discard the chaff and hulls with a fine tea strainer. cook the grits for 50 minutes if the grits were soaked overnight or else 90 minutes if not." most of the niacin in mature cereal grains is present as niacytin, which is niacin bound up in a complex with hemicellulose which is nutritionally unavailable. in mature corn this may be up to 90% of the total niacin content. the preparation method of nixtamalization using the whole dried corn kernel made this niacin nutritionally available and reduced the chance of developing pellagra. niacytin is concentrated in the aleurone and germ layers which are removed by milling. the milling and degerming of corn in the preparation of cornmeal became feasible with the development of the beall degerminator, which was originally patented in 1901 and was used to separate the grit from the germ in corn processing. however, this process of degermination reduces the niacin content of the cornmeal. casimir funk, who helped elucidate the role of thiamin in the etiology of beriberi, was an early investigator of the problem of pellagra. funk suggested that a change in the method of milling corn was responsible for the outbreak of pellagra, but no attention was paid to his article on this subject. pellagra developed especially among the vulnerable populations in institutions such as orphanages and prisons, because of the monotonous and restricted diet. soon pellagra began to occur in epidemic proportions in states south of the potomac and ohio rivers. the pellagra epidemic lasted for nearly four decades beginning in 1906. it was estimated that there were 3 million cases, and 100,000 deaths due to pellagra during the epidemic. in popular culture george sessions perry's 1941 novel hold autumn in your hand – and jean renoir's 1945 film adaptation of it, the southerner – incorporates pellagra ("spring sickness") as a major plot element in the story of an impoverished texas farm family.