Although people have adorned themselves with copper since prehistory, the marketing of copper bracelets as a treatment for arthritis pain appears to date back only to the 1970s.
Proponents of copper bracelets often cite the research of Werner Hangarter (1904–1982), a German doctor of internal medicine. Hangarter evangelized for copper’s therapeutic possibilities after hearing that copper miners in Finland seldom developed rheumatism while laboring in the copper-rich environment of the mines.
Hindsight reveals several problems in Hangarter’s research. Based on inference and anecdote, he assumed a chain of causation — that exposure to environmental copper helped miners ward off RA — where the reverse is actually far more likely: No active miners had RA because individuals who developed the condition quit the profession.
So even the effects of copper in solution are ambiguous: What about topical copper? The effectiveness of wearing copper, rather than ingesting it, is based on the idea that trace amounts of the metal can be effectively absorbed through the skin. But there’s little evidence for this claim, and in any case the occasional peanut-butter sandwich or chocolate bar would be a more efficient way to get the stuff into your system than a $25 bangle.