Rich people in the Middle Ages suffered from lead poisoning as a result of the fine glazed cups and plates they dined with, scientists have discovered. By analysing 207 skeletons from six cemeteries in northern Germany and Denmark, a team of researchers established lead is virtually non-existent in poorer and rural populations, while it was high in urban individuals.
Publishing their findings in the Journal of Archaeological Science: Reports, the scientists looked at the chemical and anthropological analysis of the skeletons to separate the rich from the poor, and the level of lead poisoning.
At the time, glazing for crockery was made of lead, which would find its way into the body if people ate acidic foods. And it was only the wealthy, urban-dwelling population that could afford to eat and drink from glazed pottery. In rural areas, glazed pottery was used far less often and it was hard to come by.
Kaare Lund Rasmussen, from the University of Southern Denmark, said: "In those days lead oxide was used to glaze pottery. It was practical to clean the plates and looked beautiful, so it was understandably in high demand. But when they kept salty and acidic foods in glazed pots, the surface of the glaze would dissolve and the lead would leak into the food."
The six cemeteries studied included three from what would have been wealthy medieval towns and three from rural populations. While elevated lead levels were present in the rural skeletons, they were substantially higher among those from towns.
"There really is a big difference in how much lead, the individuals from the cemeteries had in their bodies," Rasmussen said. "This depended on whether they lived in the country or in a town. We see almost no lead in the bones from rural individuals, while the levels of this toxic metal were high in urban individuals."
Lead poisoning is particularly dangerous for children, whose nervous system is still developing, as it can affect their learning ability and intelligence. It has previously been suggested that lead poisoning could have played a part in the fall of the Roman Empire, as it was commonly used during this period.
"In the Middle Ages you could almost not avoid ingesting lead, if you were wealthy or living in an urban environment," Rasmussen said. "But what is perhaps more severe, is the fact that exposure to lead leads to lower intelligence of children."