Researchers at the University of Edinburgh have determined that doctors from ancient Greece and China were right: cool kills pain.
A paper from the university says that a small percentage of nerve cells in the human skin contain a protein, called TRPM8, that is activated by cooling chemicals applied to the skin (such a mint oil) or cool temperatures. The protein then inhibits pain messages from getting to the brain. In ancient China, doctors prescribed mint oil for localized pain. Similarly, Hippocrates advised on using cold water to soothe arthritis.
The university is working on a synthetic compound similar to mint oil which researchers believe could be safer than current pain medications because it would only be applied externally. It wouldn't have to be digested.
Not all ancient pharmaceuticals, however, have passed the test of time. In ancient Rome, for instance, some believed gladiator sweat was an aphrodisiac.