LONDON – Scientists have found high levels of arsenic in the hair of King George III and say the deadly poison may be to blame for the bouts of apparent madness he suffered.
In 1969, researchers proposed the strange behavior of the monarch who reigned during the American Revolution resulted from a rare hereditary blood disorder called porphyria.
However, a study this week in the Lancet medical journal found high concentrations of arsenic in the king’s hair and contends the severity and duration of his episodes of illness may have been caused by the toxic substance.
The 18th-century king, under whose reign Britain mastered the oceans, defeated Napoleon and expanded its empire to superpower dimensions, was best remembered for the humiliating loss of the American colonies and for the periods when he lost his mind.
While on the throne, George had five episodes of prolonged and profound mental derangement. At the time, his malady was thought to be a psychiatric disorder.
But in 1969, psychiatrists investigating his documented symptoms such as lameness, acute abdominal pain, red urine and temporary mental disturbance, proposed he suffered from porphyria. Subsequent studies that examined records of his ancestors, descendants and other relatives refined the diagnosis to a certain type of porphyria.
Martin Warren, a professor of biosciences at the University of Kent in England, led the latest study. Warren and his team set out to examine a sample of the king’s hair on display at London’s Science Museum for traces of mercury or lead, metals known to make porphyria worse.
“What surprised us was there were very high levels of arsenic. Arsenic is also known to push porphyric patients into a worse state,” Warren said. The semi-metallic element was found to be at 17 parts per million in the hair. Levels are normally found at less than one part per million.
Arsenic interferes with the production of heme, a key element of blood and the central problem of porphyria. The blood then gets toxic, which can cause mental disturbance and severe pain.
John Henry, a toxicologist at Imperial College in London, said he was cautious about interpreting the findings. “He may have accumulated significant amounts in the last few months of his life, but that doesn’t prove it caused his illness all his life,” Henry said. “It’s a nice theory, but it’s just that – a theory.”