The evidence was that poor people were the only ones who were getting Pellagra. Because of their poor diet.
Pellagra
Joseph Goldberger believed that pellagra was caused by a nutritional deficiency, particularly a lack of niacin in the diet. He conducted studies showing that pellagra could be prevented and treated by adding foods rich in niacin, such as meat and milk, to the diet.
Joseph Goldberger, a physician in the U.S. government's Hygienic Laboratory, the predecessor of the National Institutes of Health, discovered the cause of pellagra and stepped on a number of medical toes when his research experiments showed that diet and not germs (the currently held medical theory) caused the disease.
because they thought it was caused by a bacteria(germs) or either a bug or insect
Dr.Goldberger did an experiment to see what caused pellagra
Dr.Goldberger did an experiment to see what caused pellagra
Looking at the southern people's diet and how it was a horrible diet, which made him think that pellagra is caused by a lack of nutrition
Dr. Goldberger took a bunch of healthy prisoners (prisoners without Pellagra) to a sanitary building with screens on the doors and windows so no insects could get in. The building was cleaned every week and the prisoners diet was changed to one consisting of corn and fatback (a piece of meat with a bunch of fat). After a week or two seven out of nine prisoners had Pellagra.
picnic
pellagra
people of the south thought pellagra was caused by eating corn, or that it was a contagious disease carried by insects or bacteria. Pellagra is caused by lack of certain diets, but people in america don't have to worry about it today, because all the vitamins used to prevent pellagra are in flour.
Niacin