By Stephanie Pain for nature. For thousands of years cannabis has been valued as a versatile herbal medicine. In the twentieth century, prescription gave way to proscription. Might this ancient remedy be about to regain its healing reputation? By Stephanie Pain
Earliest evidence: ~2700 BC
Cannabis sativa is thought to have been grown for at least 12,000 years, initially for fibre and grain. “The plant arose in Central Asia, but once people began growing it, it spread very quickly,” says Ethan Russo, a psychopharmacologist at biotechnology firm Phytecs, based in Los Angeles, California, and a historian of medical cannabis. The earliest use of cannabis as a medicine is attributed to the legendary Chinese Emperor Shen Nung (pictured), who is thought to have lived around 2700 BC. His teachings were passed down by word of mouth before appearing in writing in the Shen Nung Pen-ts’ao Ching, a second-century Chinese book of herbal remedies.