by Bruce M. Rothschild, Professor of Medicine & Biomedical Engineering, Northeastern Ohio Universities College of Medicine, and Research Associate, The Carnegie Museum of Natural History
Arthritis afflicts 40 million Americans. It always bothered me that one variety, rheumatoid arthritis, is especially common among American Indians. Why were Indians apparently singled out for this affliction? Rheumatoid arthritis was thought to be a recent disease, since the oldest instance of it occurred in the Old World in 1785. This recent appearance contrasts with other earlier forms of arthritis, documented in European, Asian, and African skeletons.
Although the onset of rheumatoid arthritis was blamed on the industrial revolution, its appearance in Europe also coincided with the New World invasion by Europeans (also referred to as colonization). A question naturally arose: was rheumatoid arthritis a New World disease, which subsequently spread to the Old World? If so, perhaps definition of its original location and spread would allow identification of its cause. Although theories have been suggested, we really have had no idea what actually causes rheumatoid arthritis. If we knew the cause, perhaps we could treat it more effectively or at least prevent it.
Rheumatoid arthritis is an erosive disease. It produces excavations, or holes, in bone in the areas where bones meet and movement occurs (joints). These joint areas of bones are covered by cartilage and surrounded by a capsule. Rheumatoid arthritis initially attacks the bone between the capsule and the cartilage. The bone appears as if something had gnawed into it. Actually, the lining cells of the joint do “gnaw” into the bone, leaving a damage pattern. That pattern of damage is specific to rheumatoid arthritis.
The pattern of disease (rheumatoid) has been described in skeletons of early twentieth century Cleveland (presumably not Indians, although some may have played for another team) inhabitants. Investigation of the skeletons of American Indians revealed that rheumatoid arthritis did exist in the New World prior to the voyages of Columbus, and even those attributed to the Vikings. The arthritis in ancient American Indians of Tennessee (more than 4,000 years ago) is indistinguishable from contemporary rheumatoid arthritis. The female predominance (3:1), nature of bone involvement, x-ray appearance, and distribution of joint involvement are identical to that found in living patients, confirming that the diagnosis is correct. Only examination of skeletons allowed the antiquity of rheumatoid arthritis to be recognized.
It is highly significant that we were able to identify numerous occurrences of rheumatoid arthritis in prehistoric North American skeletal remains, while no such occurrences have been found in Old World skeletal remains. Rheumatoid arthritis apparently started as a disease of American Indians, who are still predisposed to this potentially crippling disease. The study of over 20,000 skeletons has now identified its spread in North America and subsequently, to Europe. Current data indicate the presence of rheumatoid arthritis in a very small area of southwestern Kentucky, west-central Tennessee, and northwestern Alabama in the Archaic period (5000-500 BC), a minor spread to Ohio in the Woodland period (500 BC-AD 1000), and an explosive spread after the late 18th century.
Evidence of this spread in the New World and then its “penetration” into the Old, suggests a vector-transmitted disease. The study of the distribution of another vector-transmitted disease, Lyme arthritis, allowed identification of its cause and even its cure. It is hoped that further study of skeletal remains will allow us to similarly identify the cause of this disease of American Indians and, therefore, improve their quality of life.