I was in Berkeley, California a couple of weeks ago, and was struck by the prevalence of Starbuck’s coffee and marijuana among the fine citizens of that liberal city. And as luck would have it, there have recently been research findings presented on the topics of caffeine and marijuana and their effects upon patients with rheumatoid arthritis.

There have always been concerns that caffeine, found in tea, coffee, colas and chocolate might adversely impact the efficacy of methotrexate. Caffeine...