Captain James Lancaster 1601
The first controlled medical trial in world history was staged in 1601 by a British ship captain named James Lancaster.
Four ships were traveling from England to India around the Cape of Africa, Lalvani explained, when Lancaster decided to give the sailors on his ship three teaspoons of lemon juice every morning. No doubt Lancaster was acting on reports that had come from Sir Richard Hawkins during a voyage to the South Pacific, eight year earlier, when Hawkins had observed that the most effective protection against scurvy appeared to be "sour oranges and lemons."
As the chart shows, the hypothesis proved correct: by the end of the voyage, 40 percent of the sailors on the three ships where no one received their Vitamin C had come down with scurvy and perished. On Lancaster's ship, no one died of the disease. Although the medical evidence was compelling, the British Navy finally put it to good use, making sure that all sailors on long voyages received sufficient vitamin C beginning in 1795--194 years after Lancaster's voyage!