A chemical analysis of pottery feeding vessels from the Bronze and Iron Ages suggests prehistoric European babies and toddlers had diets supplemented with, and possibly replaced by, animal milk, in what’s potentially the earliest archaeological evidence of infant weaning.
New research published Wednesday in Nature is offering unprecedented insights into European Bronze Age and Iron Age cultural norms related to infant care and weaning practices. Chemical analysis of organic residues found in ancient German feeding vessels points to the use of animal milk as a supplementary or replacement food for infants and young children. The new research was led by a team from the University of Bristol.
The three ceramic vessels included in the study date to between 3,200 and 2,450 years ago (1200 to 450 BCE) and feature a spout through which a child could easily suck out a liquid. In a way, these pipe-like vessels are a precursor to modern baby bottles and sippy cups.
Spouted vessels like these have been found before, including older artefacts, also found in Germany, dating back to between 7,500 and 6,800 years ago. Because some of these Neolithic artefacts were found in child graves, archaeologists could reasonably assume they were used to feed infants. But as bioarchaeologist Siân Halcrow pointed out in a related Nature News & Views article, some scholars believe the drinking vessels, some of which were crafted to look like animals, were used to feed the elderly and infirm.
Crucial to understanding the purpose of these vessels would be knowing what substances once filled them, but archaeologists had previously struggled to pinpoint this. The “precious nature and often small openings of these vessels makes their sampling for organic residue analysis extremely challenging,” explained the authors in the study. Thankfully, the University of Bristol researchers recently gained access to vessels with an open bowl-like shape, allowing for a chemical analysis.
Two of the artefacts were found in an early Iron Age German cemetery dating to between 800 and 450 BCE, and the third artefact was found in a Late Bronze Age German necropolis, dating to between 1200 and 800 BCE. All items were found buried next to children, who ranged in age from a few months to six years old.
An isotope analysis was used to identify the organic lipid residues still present in these ancient artefacts. In two of the vessels, the fatty acids were traced to the milk from ruminant animals, a group that includes cows, sheep, and goats. The third exhibited fatty acids from the milk of a non-ruminant animal, possibly a pig or even a human. In all cases, the exact species of animal could not be established.
“The finding of these three obviously specialised vessels in child graves combined with our chemical evidence strongly points to these vessels having been used to feed animal milk to babies (instead of human milk) and/or children during weaning to supplementary foods,” wrote the authors.
That humans were drinking animal milk during this period is hardly a surprise. The earliest evidence of humans drinking milk from another animal dates to 6,000 years ago, according to research published earlier this year.
This new study is unique in that it presents the earliest known evidence of this dietary shift in infants and children, while also showing that prehistoric Iron Age and Bronze Age Europeans were supplementing their infants’ diets. Crucially, it’s also the earliest evidence of possible infant weaning from the mother’s breast, with animal milk being the substitute.
Halcrow, an associate professor from New Zealand’s University of Otago who wasn’t involved in the new study, said this is a surprising result, given the inferiority of animal milk compared to mother’s milk. As she explained in News & Views,
Human breast milk is a perfect baby food, containing carbohydrates, protein, fat, vitamins, minerals, digestive enzymes and hormones. It provides protection from infection because it contains numerous types of immune cell.
Some of the sugars it contains, although not digested by babies, support certain communities of gut microorganisms, which prevent disease-causing microbes from establishing a presence in the body.
By contrast, animal-milk products do not provide a complete nutritional source for infants. And the use of hard-to-clean bottles for animal milk poses a risk of exposure to life-threatening infections such as gastroenteritis. The introduction of milk in bottles... therefore, might have led to a deterioration in the health of some infants.
Halcrow said further research should be undertaken to further explore this dramatic dietary shift and the way it impacted the health and wellbeing of ancient European infants, which could be done by studying their remains.
As to why animal milk was introduced as a dietary supplement or replacement to mother’s breast milk remains an open question, but the University of Bristol researchers believe it had something to do with the transition from hunter-gatherer lifestyle to farming, and possibly the population growth spurts that resulted. In way, the consumption of animal milk was a function of modernity, as the authors described in the study:
The widespread use of animal milk, either to feed babies or as a supplementary weaning food source, became possible with the domestication of dairy animals during the European Neolithic, during which time generally improved nutrition contributed to an increased birth rate, with shorter interbirth intervals, that resulted in considerable growth of the human population: the so-called Neolithic demographic transition.
Broad trends identified from the Neolithic to Iron Age in Central Europe suggest that supplementary foods were given to babies at around six months of age and weaning was complete by two to three years of age.
Prior to the Neolithic period, therefore, it wasn’t really possible for humans to wean infants at an early age, due to the lack of viable supplementary food. This changed when farming and livestock were introduced. What’s more, and as Halcrow noted, “such early weaning could have helped to counteract the period of infertility that can occur while a mother is breastfeeding, and thus might have led to the increase in fertility and population size during the Neolithic demographic transition.”
Interestingly, the increase in birth rates is “evidenced, somewhat counter-intuitively, by an increase in the number of infants found at burial sites,” said Halcrow, “if more babies are born in a population, then more babies will also die, and be buried.”
Despite the health risks of substituting animal milk for mother’s milk — whether known or unknown to prehistoric Europeans — this finding offers a fascinating snapshot into the intimate details of ancient family life. Like all good archaeology, it’s yet another relatable touchpoint that connects us to our ancient past.