What medieval skeletons tell us about long-term health and life expectancy

Independent

2 days ago

Beneath churchyards in London and Lincolnshire lie the chemical echoes of famine, infection and survival preserved in the teeth of those who lived through some of the most catastrophic periods in English history.
In a new study, my colleagues and I examined over 270 medieval skeletons to investigate how early-life malnutrition affected long-term health and life expectancy.
We focused on people who lived through the devastating period surrounding the Black Death (1348-1350), which included years of famine during the Little Ice Age and the great bovine pestilence (an epidemic that killed two-thirds of cattle in England and Wales). We found that the biological scars of childhood deprivation during this time left lasting marks on the body.
These findings suggest that early nutritional stress, whether in the 14th century or today, can have consequences that endure well beyond childhood.
Children's teeth act like tiny time capsules. The hard layer inside each tooth, called dentine, sits beneath the enamel and forms while we're growing up. Once formed, it stays unchanged for life, creating a permanent record of what we ate and experienced.
As our teeth develop, they absorb different chemical versions (isotopes) of carbon and nitrogen from our food, and these get locked into the tooth structure. This means scientists can read the story of someone's childhood diet by analysing their teeth.
A method of measuring the chemical changes in sequential slices of the teeth is a recent advance used to identify dietary changes in past populations with greater accuracy.
When children are starving, their bodies break down their fat stores and muscle to continue growing. This gives a different signature in the newly formed dentine than the isotopes from food. These signatures make centuries-old famines visible today, showing exactly how childhood trauma affected health in medieval times.
We identified a distinctive pattern that had been seen before in victims of the great Irish famine. Normally, when people eat a typical diet, the levels of carbon and nitrogen in their teeth move in the same direction. For example, both might rise or fall together if someone eats more plants or animals. This is called 'covariance' because the two markers vary together.
But during starvation, nitrogen levels in the teeth rise while carbon levels stay the same or drop. This opposite movement – called 'opposing covariance' – is like a red flag in the teeth that shows when a child was starving. These patterns helped us pinpoint the ages at which people experienced malnutrition.
Lifelong legacy
Children who survived this period reached adulthood during the plague years, and the effect on their growth was recorded in the chemical signals in their teeth. People with famine markers in their dentine had different mortality rates than those who lacked these markers.
Children who are nutritionally deprived have poorer outcomes in later life: studies of modern children have suggested that children of low birth weight or who suffer stresses during the first 1,000 days of life have long-term effects on their health.
For example, babies born small, a possible sign of nutritional stress, seem to be more prone to illnesses such as heart disease and diabetes in adulthood than the population at large. These characteristics can also be passed to future offspring through changes in how genes are switched on or off, known as 'epigenetic effects' – which can endure for three generations.
In medieval England, early nutritional deprivation may have been beneficial during catastrophic times by producing adults of short stature and the capacity to store fat, but these people were much more likely to die after the age of 30 than their peers with healthy childhood dentine patterns.
The patterns for childhood starvation increased in the decades leading up to the Black Death and declined after 1350. This suggests the pandemic may have indirectly improved living conditions by reducing population pressure and increasing access to food.
The medieval teeth tell us something urgent about today. Right now, millions of children worldwide are experiencing the same nutritional crises that scarred those long-dead English villagers – whether from wars in Gaza and Ukraine or poverty in countless countries.
Their bodies are writing the same chemical stories of survival into their growing bones and teeth, creating biological problems that will emerge decades later as heart disease, diabetes and early death.
Our latest findings aren't just historical curiosities; they're an urgent warning that the children we fail to nourish today will carry those failures in their bodies for life and pass them on to their own children. The message from the medieval graves couldn't be clearer: feed the children now or pay the price for generations.
Julia Beaumont is a Researcher in Biological Anthropology at the University of Bradford.