The disease’s origins can be traced back a full 5,000 years, that is, to the Neolithic Age, and to the genetic traces left by the people of that time.
It is a large international research team, with experts from, among other places, Sweden, who have analyzed the DNA in the world’s largest gene bank to date and have been able to shed light on how ancient migrations and living conditions have left an imprint on the gene pool of modern humans. The findings are published in four articles in the journal Nature.
From the steppes in the east
Through the analyses, the researchers managed to trace the likely origin of the disease MS to the period when the cattle-herding Yamna (or Yamnaya) people group spread westward from the steppes of present-day Ukraine, southwestern Russia, and western Kazakhstan. They mixed with Eastern European farming groups, and the Corded Pottery culture emerged. Such cord ceramic groups then migrated north to Scandinavia. Still today, the jamna genes are strong in Scandinavia.
The Jamna people were exposed to zoonoses, that is, diseases that spread from animals to humans. The researchers’ hypothesis is that over time humans developed a stronger immunity to zoonoses – but that this happened at the price of an increased risk of developing MS. MS occurs when the immune system mistakenly attacks the body’s own nerve cells.
Good for farmers
– The protection against parasites and bacteria that can be transferred from animals was of great benefit as long as most people were farmers, until about 150 years ago. But with the modern lifestyle and improved hygiene, there was an imbalance. The immune system became idle, but still wanted to work and went to the body instead, explains Kristian Kristiansen, professor of archeology at the University of Gothenburg.
Kristiansen has participated in all four studies published in Nature, and has led one of them.
The question is how medical research can benefit from the new knowledge about multiple sclerosis.
– It is an obvious question that I myself have asked research colleagues. They are convinced that the findings can contribute to developing more precise treatments in the future, says Kristiansen.
He hopes that the research on the basis of the DNA bank can be taken further in a second stage.
– So far we have published findings based on analyzes from the Stone Age and the Early Bronze Age. We haven’t analyzed much from the Iron Age and the Middle Ages, which we hope to be able to do, says Kristian Kristiansen.