Ionised jewellery appears in many shapes and sizes, usually peddled by homeopathic "healers" and similar charlatans, all with claims of relief from the symptoms of rheumatic pains caused by arthritis and various non-specific causes of inflammation. They have a basis in various forms of woo like Traditional Chinese Medicine, including "Qi". The evidence supporting the efficacy of ionised jewellery is very much similar to that surrounding magic crystals, etc.
Much of the "science" behind these claims seems to be based on the fact that metals display "magical" properties, such as magnetism, electro-conductivity, "being very shiny" and making wearers feel warm and fuzzy.
The way these charms 'work', is that a radioactive material, usually thorium or uranium is added to the item to cause it to emit beta particles. Beta particles are a form of ionizing radiation, and are able to create ions. However, the risks associated with low levels of radiation for long periods of time make them dangerous to wear. Even if ions had health benefits, there wouldn't be enough to have any effect. This kind of woo goes as far as, believe it or not, ionised football kits!
There are different variants of alternative health bracelets. Copper bracelets, for example, are usually worn by old people claiming to have arthritis — rather than just experiencing the effects of age-related conditions — who swear that when they do not wear the jewellery they suffer immense pain. Diet, exercise, and basic wellness measures have all been shown to relieve if not alleviate these conditions, but why put forth the time and effort to lead a healthy lifestyle when you could just buy one of these badboys? Similarly, magnetic therapy bracelets are said to restore the body's hypothetical "electromagnetic energy balance".
The same lack of evidence is exhibited by ionised bracelets which supposedly affect a wearer's "Qi". The mechanism of action for the different bracelets is now completely understood, thanks to double blind, randomised, placebo-controlled trials, some of them notably conducted by Jacksonville Florida Mayo Clinic in 2002, proving that no more than a placebo effect is apparent.
- "Effect of 'Ionized' Wrist Bracelets on Musculoskeletal Pain: A Randomized, Double-Blind, Placebo-Controlled Trial" Mayo Clinic Proceedings, 2002. 77:1164-1168.