Ancient DNA extracted from the bones and teeth of people who lived in Europe around 34,000 years ago is offering valuable insights into the origins of multiple sclerosis (MS), a neurological disease affecting the brain and spinal cord. Researchers found that genetic traits, which now elevate the risk of MS, initially served as protection against diseases transmitted by animals. The study involved analyzing DNA from 1,664 ancient individuals in Western Europe and Asia, comparing it to modern DNA from over 410,000 people in the UK Biobank.

One significant discovery highlighted a key migration event approximately 5,000 years ago, during the Bronze Age. The Yamnaya people, nomadic livestock herders from the region, including present-day Ukraine and southern Russia, introduced genetic traits that were beneficial at the time. These traits guarded against infections from their livestock. However, as hygiene conditions improved over time, these same genetic variants started increasing the risk of MS, especially in Northern Europeans. This helps explain why MS is more prevalent in Northern Europe, with double the occurrence compared to Southern Europe. The findings highlight how genetic traits, once beneficial, can turn harmful as conditions change. The research suggests that multiple sclerosis (MS), categorized as an autoimmune disorder, may arise from the immune system’s adaptation to historical challenges. The study unveils insights into European traits, including height differences between Northern and Southern populations, influenced by ancient genetic factors. These findings challenge conventional views on MS, emphasizing the need to recalibrate, not suppress, the immune system in treatment. The research has broader implications for understanding and addressing MS, considering the impact of the evolving environment on genetic predispositions.