There is also good biochemical evidence that supports the hypothesis that plants in disturbed areas are likely to have more chemicals in them for defense, said Stepp.
The possible placebo effects from the medicinal plants is unclear, but Stepp said that 30 percent of the effects of all medicines, including pharmaceuticals, have been found to be placebo effects in some studies. What is clear is that most of the plants used by the Maya do have biologically active compounds that have been shown by generations to be effective against specific disorders. "The rainforests should be conserved for many intrinsic and economic reasons," said Stepp. "But the reason that we should save them primarily to use the medicinal plants found there is not a very good one."
The idea of medicinal plants and self-treatment is somewhat alien to many Western cultures where going to the doctor and being given a prescription is the standard. The vast majority of people in the world, however, take care of themselves and use healing plants that have been used for hundreds of generations.
The discovery that easy-to-find weeds may be more important as medicinal plants than exotic species "hidden" deep in the rainforests may catch some people by surprise, Stepp said. In a class he taught at the University of Georgia, Stepp took students to the side of a nearby railroad track and collected all the plants in the area. Of the 60species collected, an astonishing 38 are already listed as having medicinal properties.
"We think the evidence supports a closer examination of the relationship between weeds and medicinal floras," said Stepp. "We may find that the next plant-derived pharmaceutical is in the abandoned lot down the street."
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Contact: John Stepp
rstepp@arches.uga.edu
706-227-9553
University of Georgia
15-Mar-2001