Copper is a reddish-brown metal used for thousands of years in coinage, tools, and jewelry. The practice of wearing copper jewelry, particularly bracelets, persists due to the belief that it delivers specific health benefits. These purported effects often include reducing inflammation and easing the pain associated with conditions like arthritis. This article investigates the science behind these popular claims, examining how the body handles copper and evaluating the evidence for wearing the metal as a therapeutic practice.
Copper’s Essential Functions in Human Biology
Copper is an essential trace mineral, required in small amounts to support numerous metabolic processes. It functions primarily as a cofactor for cuproenzymes, which facilitate chemical reactions throughout the body. These enzymes are involved in cellular energy production and the regulation of iron metabolism, helping the body absorb and transport iron.
Copper is also directly involved in forming and stabilizing connective tissues, such as collagen and elastin, which provide structure to the skin, bones, and blood vessels. Copper-containing enzymes, including lysyl oxidase, help cross-link these proteins. Furthermore, copper plays a role in antioxidant defense as a component of superoxide dismutase, an enzyme that manages harmful free radicals.
The average adult requires about 900 micrograms of copper daily, typically obtained through foods like nuts, seeds, whole grains, and organ meats. The body uses precise homeostatic mechanisms, mainly regulated by the liver, to balance copper levels by increasing absorption when intake is low and excreting excess through the bile.
Comparing Skin Absorption and Dietary Intake
The central question regarding copper jewelry is whether the metal can be effectively absorbed through the skin, known as transdermal absorption, to reach systemic circulation. The skin acts as a robust barrier, making the transfer of copper from a bracelet into the bloodstream highly inefficient compared to ingesting the mineral.
When copper jewelry is worn, the metal reacts with the salts and acids in sweat and skin oils, causing minute amounts of copper ions to leach onto the skin surface. This reaction creates the characteristic green or blue-green stain often seen under the jewelry, which is a harmless copper salt. While minimal absorption can occur, the quantity is biologically insignificant.
Studies suggest that the amount of copper absorbed through intact skin is likely only a few micrograms per day. This is substantially less than the 500 to 1,000 micrograms of copper the body typically absorbs from food daily. Consequently, wearing copper is considered an ineffective method for supplementing copper requirements or delivering a therapeutic dose.
Scientific Evaluation of Pain and Inflammation Claims
The most common health claim associated with wearing copper bracelets is the ability to alleviate pain and reduce the inflammation characteristic of conditions like rheumatoid arthritis and osteoarthritis. This belief suggests that the small amounts of copper absorbed transdermally exert a measurable anti-inflammatory effect. However, controlled clinical trials have consistently failed to support this hypothesis.
A 2013 randomized, double-blind, placebo-controlled crossover trial investigated the effects of copper bracelets on patients diagnosed with active rheumatoid arthritis. Participants wore four different devices, including a copper bracelet and a non-magnetic control device, for five-week periods. The study measured outcomes including pain levels, physical function, and objective inflammation markers like C-reactive protein.
The analysis found no statistically significant difference between the copper bracelet and the control device across any clinical or biological measures. Copper did not reduce pain, decrease joint swelling, or lower inflammatory markers in the blood. The reported benefits experienced by some users are largely attributed to the well-documented placebo effect.
The placebo effect occurs when a person experiences a perceived improvement in symptoms simply because they believe the treatment will work. Since the symptoms of chronic conditions like arthritis naturally fluctuate, a patient may coincidentally put on a bracelet when symptoms are severe and credit the jewelry when symptoms naturally lessen. This belief can influence the perception of pain, even without a physiological change caused by the copper.
Dermatological and Systemic Safety Considerations
For most individuals, wearing copper jewelry poses minimal health risk, though skin reaction and systemic exposure require consideration. The most frequent observation is skin discoloration—the green residue resulting from the chemical reaction between copper and skin secretions. This substance is copper acetate and is not harmful.
A more concerning dermatological reaction is contact dermatitis, an allergic skin reaction. Copper is a known contact allergen, and sensitive individuals may develop localized redness, itching, or irritation where the jewelry touches the skin. If this reaction occurs, the use of the copper item should be discontinued.
The systemic absorption of copper from jewelry is too low to cause copper toxicity (copper overload). The body’s homeostatic mechanisms are capable of managing and excreting the minute amounts that enter the bloodstream. However, individuals with rare genetic disorders that impair copper regulation, such as Wilson’s disease, should exercise caution with any copper exposure, including jewelry, as their bodies cannot process the metal efficiently.