Researchers from Wrocław Medical University reconstructed the diet and eating habits of nearly 200 people who lived in the city between the late 17th and early 19th centuries, using a combination of medicine and bioarchaeology.

Their analysis of teeth and dental plaque also provided clues about dental health, childhood development and how long children were breastfed.

The research was based on human remains recovered from a large cemetery discovered during construction work at Bulwary Książęce following the demolition of the former Józef Babiński Provincial Hospital.

The cemetery was associated with the parish of St. Barbara and All Saints Hospital, which once stood in this part of the city. Less wealthy residents were buried there. Archaeologists recovered hundreds of skeletons as well as objects linked to the everyday lives of the people who lived in Wrocław at the time.

The remains were examined at the Laboratory of Paleosteology and Paleohistology at Wrocław Medical University by a team led by Paweł Dąbrowski, PhD.

Much of the evidence about the residents’ diet was preserved in dental plaque. Poor dental hygiene helped plaque accumulate and mineralise, paradoxically providing researchers with valuable material for reconstructing the diet of the city’s former residents.

The mineralised plaque contained microscopic food remains, including starch particles and phytoliths — silica structures formed in plant tissues that can survive long after the plant itself has decomposed.

By examining their shape, size and structure, scientists can identify the plants that were consumed.

The researchers found traces of wheat, rye, millet and barley, as well as peas and beans. They also found evidence of animal products, including pork, game and poultry.

Chickens provided both meat and eggs, while broths made from them may have been given to weakened people and to children moving from breast milk to solid food.

One particularly interesting discovery was corn, which originated in the New World and was still relatively new in Europe during the period studied.

“Its presence shows that average residents of Wrocław also had access to products delivered to the city thanks to the development of overseas trade,” the researchers said.

Dental plaque also contained micro-remains of plants from the pepper and nightshade families, associated with spices and the appearance of new foods such as potatoes in the local diet.

Sea fish, particularly Baltic herring, was also an important part of the diet. The fish was mainly imported from Szczecin and, despite being brought in from elsewhere, was not restricted to the tables of the wealthiest residents.

The researchers say the overall diet of the people studied was relatively varied.

The teeth also provided clues about the effects of diet on dental health.

One important indicator was dental caries, which is associated, among other factors, with the consumption of foods rich in easily digestible carbohydrates.

“At the threshold of industrialization, food gradually became more and more processed. With the development of grain milling and cleaning techniques, some residents could afford bread baked from lighter, more thoroughly purified flour. It was more expensive and perceived as a higher quality product. But from a dental point of view, a diet based on such flour was not necessarily more beneficial,” Dąbrowski said.

The researchers say finely ground flour contained less bran, plant fibre and particles from stone milling. Less wealthy residents more often ate darker bread made from cheaper, less refined flour, which could contain fragments of bran and mineral particles from the grinding process.

They suggest that these differences may have contributed to a striking contrast in dental health. Wealthier residents may have experienced less tooth wear, but their greater consumption of refined flour products may also have made them more vulnerable to cavities.

“Wealthier individuals may have had less tooth wear, but, due to their more frequent consumption of heavily processed flour products with high starch content, they were more susceptible to caries. Therefore, wealth did not translate into better dental health in those times,” the researchers said.

The teeth also preserved a record of childhood development.

Enamel forms gradually, layer by layer, creating a chronological record of the development of the dental crown that can be compared with the growth rings of a tree.

“Enamel is not formed in a single step. It is deposited cyclically, layer by layer, according to a specific biological rhythm. The microstructural growth of enamel prisms creates a chronological record of the development of the dental crown during early ontogeny, which can be compared to the growth of tree rings,” Dąbrowski said.

Because enamel does not undergo secondary remodelling once it has formed, disruptions during childhood can remain visible in the teeth decades after death. Researchers can therefore identify periods when normal development was interrupted by physiological stress.

The analysis also found that children were breastfed for an average of around 24 to 30 months. The researchers found no significant differences between boys and girls in feeding and care practices.

The research was carried out as part of the interdisciplinary project “On the Threshold of Industrialization – An Interdisciplinary Assessment of the Well-Being of the Residents of Modern Wrocław”. (PAP)

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