|A clay used for medicinal purposes|
Public domain photo by Morn the Gorn at Wikimedia Commons
Clays have had a long use in traditional medicine and have been used both externally and internally. They were once popular treatments for wounds and digestive problems and were also used to kill parasites. Some people use clays medicinally today.
Scientists are now finding that at least some of the traditional uses of clays have validity. Kaolin clay helps the blood clotting process during bleeding, for example. The Arizona State University research has shown that some clays can kill bacteria "in vitro". This term means that the experiment was carried out in lab equipment and not in living things. The research results may also be valid for animals and humans, but this won't be known until appropriate tests are performed.
The researchers obtained four different clays and made water extracts of their minerals. They tested the extracts against both E. coli and MRSA. The researchers discovered that metal ions attached to the clay minerals killed the bacteria. They found that at suitable concentrations copper, zinc, nickel and cobalt ions were effective against E.coli. Copper, zinc and cobalt ions were effective against MRSA. However, the antibacterial activity of the metal ions depended on other factors, such as pH and temperature.
While the idea of using clays to kill bacteria is exciting, it's important to realize that they may contain toxic substances as well as potentially helpful ones. The Arizona State University researchers point out that the composition of clays must be "standardized" before they're used therapeutically.