Patients suffered from a slow, agonizing decline marked by severe pallor, extreme fatigue, a smooth and fiery red tongue, and irreversible neurological damage leading to paralysis, dementia, and death.

Hearing of this, Boston physicians George Minot and William Murphy decided to try feeding raw liver to human patients dying of pernicious anemia. To everyone's astonishment, patients forced to consume about a half-pound of raw liver daily made complete recoveries. Whipple, Minot, and Murphy shared the for this discovery. 2. Extrinsic vs. Intrinsic Factors

For decades, physicians could do nothing but watch their patients die. The breakthrough came from a series of accidental discoveries and brilliant deductions. 1. The Liver Diet Breakthrough (1920s)

Eating massive amounts of raw or lightly cooked liver was nauseating and difficult for patients to sustain. Scientists knew there was a specific compound in the liver curing the disease—the "antipernicious anemia factor"—but they didn't know what it was.

The is the historical scientific term for Vitamin B12 (cobalamin) . Before its chemical structure was mapped, this mysterious substance was recognized only by its life-saving ability to cure pernicious anemia—a condition that was once an absolute death sentence.