Linked beriberi to diet, revealing "accessory food factors"
Christiaan Eijkman, working in the Dutch East Indies, made a crucial observation: chickens fed polished (white) rice developed symptoms identical to beriberi — a devastating disease causing nerve damage and heart failure. When fed unpolished (brown) rice, they recovered. Eijkman initially believed white rice contained a toxin that brown rice's outer layer neutralized. His colleague Gerrit Grijns correctly interpreted the findings: the rice bran contained an essential "protective substance." This substance — thiamine (vitamin B1) — wasn't isolated until 1926. Eijkman received the Nobel Prize in 1929.
Polyneuritis in Chickens
1897
Proved diseases could be caused by nutritional deficiency; Nobel Prize 1929