Hypothesis: tobacco use is a risk factor in rheumatoid arthritis.

Rheumatoid arthritis (RA) has been described in 3000-5000 year-old skeletal remains from North America by Rothschild, Turner and DeLuca (1). RA was first described unambiguously in Europeans in 1800 (1). Tobacco was introduced into Europe from the New World in the 1600s, and Rothschild, Turner and DeLuca include tobacco among variables that could be responsible for the appearance of RA in Europe. Primary and secondary exposure to tobacco smoke could be etiological, along with other causal variables. Tokuhata found cigarette smoking correlated with reduced fertility in women (2). I have hypothesized that RA is a disease with initial symptoms to the gamete and gonad (3). The hypothesis predicts a significant positive correlation between primary and secondary exposure to smoking and RA.