Human diet traced over 9000 years thanks to skulls

DNA from tartar – preserved on the teeth of ancient skeletons – has shed new light on the dramatic changes in human diet and health from the Neolithic Age to the modern day.

For the first time an international team of experts, including scientists at Aberdeen University, have been able to chart how bacteria, trapped in dental calculus, have evolved through 9,000 years. And they think the results of their breakthrough study may help medical researchers gain a new understanding of the development of diseases which still threaten mankind – and possible treatments.

The research teams claim it may also be possible to use the ancient genetic record to tell archaeologists, for the first time, exactly which animals and plants Neolithic man was eating and to discover whether ancient man also suffered from diseases such as leprosy and tuberculosis.

The team was led by the University of Adelaide’s Centre for ACAD, together with experts at Aberdeen and the Sanger Institute at Cambridge.

Professor Keith Dobney, of the Chair of Human Palaeoecology at Aberdeen and the project’s co-leader, said the results of their research were “hugely significant”. He said: “The most amazing thing is that we can extract DNA from bacteria preserved over thousands of years. Nobody ever thought that was possible before. And it is already telling us a huge amount about evolutionary changes in our diet and our health.

“This provides us with a completely new window on how people lived and died in the past. Knowing the real genetic history of diseases we still suffer from today will help us better understand and even treat them.

“Being able to track them through time has huge implications for understanding the origins and history of human health – making the archaeological record extremely relevant and important to modern-day medics and geneticists.” Prof Dobney said the DNA had been extracted for the first time from the tartar – calcified dental plaque – from 34 skeletons discovered in the UK and Germany and covering a period from 9,000 years to 500 years ago. “We found a big change in the bacteria that live on their teeth once people took up farming and started eating lots of carbohydrates and cereals and another huge change at the end of the medieval period, leading to the Industrial Revolution, when we were eating tons and tons of refined sugar and flour,” he said.

“The last 200 years have given us a whole range of problems.”

Professor Alan Cooper, study leader and director of ACAD, said: “This is the first record of how our evolution has impacted the bacteria we carry and their important health consequences.

The findings have been published in the latest edition of the journal Nature Genetics.