Élie Metchnikoff was a pioneer in the field of immunology and won the 1908 Nobel Prize in physiology or medicine for his discoveries of how the body protects itself from disease-causing organisms. Later in life he became interested in the effects of nutrition on aging and health, which led him to advocate some controversial diet practices.

Metchnikoff, the youngest of five children, was born in the Ukrainian village of Ivanovka on May 16, 1845, to Emilia Nevahovna, daughter of a wealthy writer, and Ilya Ivanovich, an officer of the Imperial Guard in St. Petersburg. He enrolled at the Kharkov lycee in 1856, where he developed an especially strong interest in biology. At age 16, Metchnikoff published a paper in a Moscow journal criticizing a geology textbook. After graduating from secondary school in 1862, he entered the University of Kharkov, where he completed a four-year program in two years. He also became an advocate...