Osteoarthritis (OA): A Modern Disease of the Anthropocene Era

In this paper we discuss recent studies that have unravelled important roles for modern-day environmental factors in the pathogenesis of osteoarthritis (OA). OA is a relatively modern disease in terms of human evolution. While our ancestors have been around for about six million years, modern humans (Homo sapiens) only evolved about 200,000 years ago. Early humans did not live long enough to suffer from age-related musculoskeletal conditions such as OA and arthritic diseases are thought to have been extremely rare in early Natufians and Egyptians, but this is probably because of an underrepresentation of older adults in the skeletal records. Examination of Egyptian skeletal records from burial sites provides some evidence of arthritic diseases such as OA, but mainly in the mummified remains of pharaohs and high-ranking officials, viziers, priests and nobles. Examination of the skeletal records in Roman burial ground does reveal more evidence of arthritic diseases but the evidence is sketchy and we can only assume that arthritic diseases were more prevalent in the slave population in ancient Egypt and the Roman Empire. Recent studies indicate that independent risk factors for knee OA either arose or have become amplified in the post-industrial era, suggesting that the prevalence of OA has gradually increased since the industrial revolution. Alarmingly, the incidence of knee OA has doubled since the middle of the 20thcentury, suggesting that OA is a modern disease of the Anthropocene era and there may be unknown environmental factors that have led to its increased incidence since industrialization.