Tiny particles of plague removed from the teeth help decode ancient dietary patterns, reveals study.
G. Richard Scott, associate professor of anthropology at the College of Liberal Arts, University of Nevada, Reno, obtained samples of dental plaque from 58 skeletons buried in the Cathedral of Santa Maria in northern Spain dating from the 11th to 19th centuries to conduct research on the diet of this ancient population.
After his initial findings met with mixed results, he decided to send five samples to Simon R. Poulson at the Nevada University's Stable Isotope Lab, in the expectation they might contain enough carbon and nitrogen to allow them to estimate stable isotope ratios, said a university statement.
"It's chemistry and is pretty complex," Scott explained. "But basically, since only protein has nitrogen, the more nitrogen that is present, the more animal products were consumed as part of the diet. Carbon provides information on the types of plants consumed."
Scott said that once at the lab, the material was crushed, and then an instrument called a mass spectrometer was used to obtain stable carbon and nitrogen isotope ratios.
"It was a long shot," he said. "No one really thought there would be enough carbon and nitrogen in these tiny, five to 10 mg samples to be measurable, but Dr. Poulson's work revealed there was," added Scott.