- a diet consisting of white rice lacks in vitamin B1, which causes a debilitating disease called "beriberi"
- a naval officer named Kanehiro Takaki discovered this (indirectly) using epidemiology techniques, determining that those who ate more balanced diets did not catch the disease
- mixing barley in with rice basically eliminated the disease from the Japanese navy
- due to some combination of politics, and worry that the solution was "superstition" (ie, it was similar to a folk remedy, and was not laboratory-tested; many Japanese academics of the time did not trust epidemiological/statistical techniques) the Japanese army rejected the solution and continued to have serious beriberi outbreaks, up until 1905 when they finally decided to give it a chance