by Margaret Coulombe

Clay is most commonly associated with the sublime experience of the European spa. Visitors have been masked, soaked, and basted with this touted curative since the Romans ruled. But go back further still and you’ll find that clay has had a role in human health as ancient as man.

The first proof of the therapeutic use of clays was incised on clay tablets in Mesopotamia around 2500 B.C. However, some scholars believe that prehistoric ancestors such as Homo erectus and Homo neanderthalensis used ochres to cure wounds as well as paint caves. Ochres are a mixture of clay and iron hydroxides.

In Egypt, Cleopatra used clays to preserve her complexion. But the Pharaohs’ physicians used the material as anti-inflammatory agents and antiseptics. It was also an ingredient used for making mummies.

Despite a long history of use, some very fundamental questions remain about the benefits of clay.

Can clays cure? At Arizona State University, geochemist Lynda Williams and microbiologist Shelley Haydel have teamed up to find out. If their research into the antibacterial properties of clays realizes its full potential, smectite clay might one day rise above purely cosmetic use. It might take its place comfortably with antibacterial behemoths like penicillin.

“People are interested in natural cures and I think that there is a lot of nature that we don’t understand yet,” Williams says. “What if we unearth a mechanism for controlling microbes that had never been discovered before? It is these avenues, at the boundaries of scientific discovery, at the edges of my field and knowledge (and Shelley’s), where such discoveries are made.”

Williams and Haydel’s research is an unusual pairing. Both work in the College of Liberal Arts and Sciences. But both are pursuing different lines of scientific discovery.

Williams is an associate research professor in the School of Earth and Space Exploration. She studies clay geochemistry. Haydel is an assistant professor in the School of Life Sciences and with the Center for Infectious Disease and Vaccinology in the Biodesign Institute. She studies tuberculosis.

This disparate duo is attempting to tease apart the mechanisms that allow two clays mined in France to heal Buruli ulcer. The flesh-eating bacterial disease is found primarily in central and western Africa.

source: Arizona State University: