Other common name(s): none
Scientific/medical name(s): Cu, cupric oxide, copper sulfate, copper gluconate, copper picolinate, cupric acetate, alkaline copper carbonate
Copper is a required nutrient. It is found naturally in foods such as shellfish, beef liver, whole grains, beans, peas, nuts, potatoes, green vegetables, and chocolate. Copper helps regulate blood pressure and heart rate and is needed to absorb iron from the gut. It is used to make many important compounds in the body.
Some laboratory and animal studies have found that copper has antioxidant properties and may have some anti-cancer effects. Other studies have found that high copper levels in the blood were linked with cancer and other diseases. Newer studies are looking at whether depriving the body of copper can help stop cancer growth. More extensive human studies are needed to learn what role copper may play in preventing or treating cancer.
How is it promoted for use?
Scientists know, based on many studies, that copper is a trace element needed to support nerve function and help the body use iron. It is important to a number of enzyme systems, and helps produce energy and skin color (melanin).
There are also claims that copper helps healing, helps to expel toxins from the body, prevents thyroid problems, promotes healthy skin and hair, and helps prevent heart problems. A few maintain that it can cure slipped discs, aneurysms, and even hemorrhoids.
On the other hand, some claim that copper promotes cancer growth. Proponents of this theory recommend a diet low in copper and the use of chelating agents that bind to copper and help remove it from the body (see our document, Chelation Therapy).
What does it involve?
Copper supplements are available in pill or capsule form. Copper is often added to vitamin and mineral supplements. But most people are able to get enough copper in their bodies by eating balanced meals. Fruits and vegetables can provide up to 30% of a person's total copper intake. Copper is often present in drinking water, mainly from copper pipes that leach it into the water as it flows through.
The minimum recommended dietary allowance (RDA) for copper is 0.9 milligrams per day for most adults, 1 milligram for pregnant women, and 1.3 milligrams for women who are breast-feeding. The RDA is enough to meet the needs of most people in these groups.
Some people may not get enough copper from foods, especially if they take zinc supplements, which can partly block copper absorption. Large doses of vitamin C supplements can also block copper uptake. People who take zinc supplements or large doses of vitamin C may need to take extra copper to absorb enough. Those with malabsorption diseases or malnutrition may also need extra copper.
What is the history behind it?
While research into the antioxidant properties of copper is quite recent, healing properties have long been attributed to copper in folk medicine. Some people wear copper bracelets, for example, because they believe it helps with arthritis. Today, many multivitamins and other herbal and mineral supplements include copper.
What is the evidence?
Copper is a trace mineral that is needed for many important body processes. Animal studies have shown that copper is useful in maintaining antioxidant defenses. Antioxidants block the actions of free radicals, which are activated oxygen molecules that can damage cells. While the role of copper in the cancer process is still unclear, copper complexes have been shown to have anti-cancer properties in laboratory studies.
Other laboratory and animal studies suggest that high copper levels may be linked to liver cancer and brain tumors. More recently, many studies have shown that patients' blood copper levels are higher in several types of cancer and other diseases. To add to the confusion, blood tests can show high copper levels even when there is little copper in the tissues. These high copper levels may be due to injury, disease, or inflammation. Because copper levels in the blood do not always reflect nutritional status, it's hard to design or find good studies of copper.
Copper is needed to form new blood vessels, and because cancer needs new blood vessels in order to grow, some researchers are lowering copper levels to see if it will help slow tumor growth. In effect the researchers are trying to use low copper levels to starve the tumor of nutrients by keeping it from building new blood vessels (anti-angiogenesis). One group of researchers looked at whether a copper-lowering drug, tetrathiomolybdate (or TM), could help patients with advanced kidney cancer. Some patients' cancer stopped growing during the 6-month treatment period. A few people had low white blood counts during treatment, requiring that treatment be stopped until they recovered. This was a small study, and further research is needed to find out whether copper can help more people with advanced cancer.
More study of TM and a related drug (ATN-224) is taking place to find out if lower copper levels can help other anti-cancer treatments work better. Though most of the studies so far have been in the lab, early clinical trials in people with solid tumor cancers look promising. People taking copper-lowering drugs with cancer treatment have had problems with anemia, tiredness, and low white blood cell counts.
Another study noted high copper levels in the blood of people who died from heart disease. It is not known whether the laboratory tests accurately reflected copper levels in the body tissue or exactly what caused the high levels. In contrast, a recent study gave copper supplements to healthy women with no signs of copper deficiency. Their cholesterol and triglyceride levels improved, as did some other markers of heart disease risk. This small study did not look at actual heart disease, however. Further research is required to determine whether copper can affect heart disease risk.
Many people wear copper bracelets for their arthritis, and some people report improvements in their arthritis symptoms. However, available scientific evidence does not support claims that the bracelets are effective. A gel form of copper salicylate (an aspirin-copper compound) was no better for pain relief than sham gel, although the copper gel produced more rashes.
One lab study showed that the white blood cells of men who had been on a low-copper diet were less effective attacking germs than they were when the same men were getting enough copper. An older study in a group of children recovering from malnutrition showed that those who got copper supplements had fewer lung infections than those who got sham supplements. While these studies suggest that severe copper deficiency results in poorer immune function, further studies are needed to find out what effect, if any, milder deficiency might have.
There is some evidence that trace metals, including copper, iron and zinc, may have a role in forming the brain plaques associated with Alzheimer's disease. There is not enough evidence to define the role of copper in this process.
At this time, it is hard to say how each nutrient or nutrient combination affects a person's risk of cancer. On the other hand, studies looking at large groups of people have shown that those whose diets are high in vegetables and low in animal fat, meat, and/or calories have lower risks for some of the most common types of cancer.
Until more is known about this, the American Cancer Society recommends eating a variety of healthful foods -- with most of them coming from plant sources -- rather than relying on supplements. In certain situations, supplements may help some people, such as pregnant women, women of childbearing age, and people with restricted food intakes. If a supplement is taken, the best choice for most people is a balanced multivitamin/mineral supplement that contains no more than 100% of the "Daily Value" of most nutrients.
Are there any possible problems or complications?
Adults are advised not to take more than 10 milligrams of copper per day due to the risk of liver damage. The recommended maximum dosage is lower for children, depending on age.
Copper toxicity is rare, and copper supplements are considered safe when taken in recommended amounts. Copper overdoses can cause serious problems such as liver damage, kidney failure, coma, and death. Early symptoms of overdose may include nausea, vomiting, diarrhea, abdominal pain, problems with coordination or movement, and sleepiness. There may also be behavioral problems, such as trouble concentrating or emotional disturbances.
People with Wilson's disease (a genetic disorder that allows copper to build up in the body) should not take copper supplements or multivitamins that contain copper. Diabetics should also avoid these supplements because copper can affect blood sugar levels.
Problems may also happen when a person has too little copper. Copper is required for iron to be absorbed into the body and is necessary for babies to develop normally. Osteoporosis (thinning bones) can develop in infants and adults with too little copper. In adults, low copper levels can result in anemia and low white blood cell counts. Low copper levels in adults have been reported to cause muscle spasms in the legs and trouble walking.
Copper supplements can interfere with some medicines. Talk with your doctor or pharmacist about all medicines, herbs, and supplements that you are taking.
Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.
More information from your American Cancer Society
The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-227-2345).
The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management
Araya M, Olivares M, Pizarro F, Méndez Ma, González M, Uauy R. Supplementing copper at the upper level of the adult dietary recommended intake induces detectable but transient changes in healthy adults. J Nutr. 2005;135:2367-2371.
Bügel S, Harper A, Rock E, O'Conner JM, Bonham MP, Strain JJ. Effect of copper supplementation on indices of copper status and certain CVD risk markers in young healthy women. Br J Nutr. 2005;94:231-236.
Cassileth B. The Alternative Medicine Handbook: The Complete Reference Guide to Alternative and Complementary Therapies. New York, NY: W.W. Norton; 1998.
Castillo-Durán C, Fisberg M, Valenzuela A, Egaña JI, Uauy R. Controlled trial of copper supplementation during the recovery from marasmus. Am J Clin Nutr. 1983;37:898-903.
Copper. PDRhealth Web site. Accessed at www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/cop_0083.shtml on June 4, 2008. Content no longer available.
Davis CD, Feng Y. Dietary copper, manganese and iron affect the formation of aberrant crypts in colon of rats administered 3,2'-dimethyl-4-aminobiphenyl. J Nutr. 1999;129;1060-1067.
DiSilvestro RA, Sakamoto K, Milner JA. No effects of low copper intake on rat mammary tissue superoxide dismutase 1 activity and mammary chemical carcinogenesis. Nutr Cancer. 1998;31:218-220.
Eaton-Evans J, Mellwrath EM, Jackson WE, et al. Copper supplementation and the maintenance of bone mineral density in middle-aged women. J Trace Elem Exp Med. 1996;9:87-94.
Dwyer J. Nutritional requirements and dietary assessment. In Fauci AS, Braunwald E, Kasper DL, et al (eds) Harrison's Principles of Internal Medicine 17th Ed. New York: McGraw Hill Medical 2008; 449.
Finefrock AE, Bush AI, Doraiswamy PM. Current status of metals as therapeutic targets in Alzheimer's disease. J Am Geriatr Soc. 2003;51:1143-1148.
Ford ES. Serum copper concentration and coronary heart disease among US adults. Am J Epidemiol. 2000;151:1182-1188.
Higdon J. Copper. 2007. Linus Pauling Institute Micronutrient Information Center. Oregon State University Web site. Accessed at http://lpi.oregonstate.edu/infocenter/minerals/copper/ on December 13, 2010
Kelley DS, Daudu PA, Taylor PC, Mackey BE, Turnlund JR. Effects of low-copper diets on human immune response. Am J Clin Nutr. 1995;62:412-416.
Kumar N, Gross JB Jr, Ahlskog JE. Copper deficiency myelopathy produces a clinical picture like subacute combined degeneration. Neurology. 2004;63:33-39.
Lowndes SA, Adams A, Timms A, et al. Phase I study of copper-binding agent ATN-224 in patients with advanced solid tumors. Clin Cancer Res. 2008 Nov 15;14(22):7526-34.
Lowndes SA, Sheldon HV, Cai S, et al. Copper chelator ATN-224 inhibits endothelial function by multiple mechanisms. Microvasc Res. 2009 May;77(3):314-26.
Mártin-Lagos F, Navarro-Alarcón M, Terrés-Martos C, et al. Serum copper and zinc concentrations in serum from patients with cancer and cardiovascular disease. Sci Total Environ. 1997;204:27-35.
Milne DB, Nielsen FH. Effects of a diet low in copper on copper-status indicators in postmenopausal women. Am J Clin Nutr. 1996;63:358-364.
Pass HI, Brewer GJ, Dick R, et al. A phase II trial of tetrathiomolybdate after surgery for malignant mesothelioma: final results. Ann Thorac Surg. 2008 Aug;86(2):383-9.
Percival SS. Copper and immunity. Am J Clin Nutr. 1998;67:1064S-1068S.
Redman BG, Esper P, Pan Q, Dunn RL, et al. Phase II trial of tetrathiomolybdate in patients with advanced kidney cancer. Clin Cancer Res. 2003;9:1666-1672.
Renault E, Deschatrette J. Alterations of rat hepatoma cell genomes induced by copper deficiency. Nutr Cancer.1997;29:242-247.
Scheinberg IH, Sternlieb I. Wilson disease and idiopathic copper toxicosis. Am J Clin Nutr. 1996;63:842S-845S.
Shackel NA, Day RO, Kellett B, Brooks PM. Copper-salicylate gel for pain relief in osteoarthritis: a randomised controlled trial. Med J Aust. 1997;167:134-136.
Spencer JW, Jacobs JJ. Complementary/Alternative Medicine: An Evidence-Based Approach. St. Louis, MO: Mosby; 1999.
Strain JJ. Putative role of dietary trace elements in coronary heart disease and cancer. Br J Biomed Sci. 1994;51:241-251.
US Congress, Office of Technology Assessment. Unconventional Cancer Treatments: OTA-H-405. Washington, DC: US Government Printing Office; 1990.
Wu T, Sempos CT, Freudenheim JL, Muti P, Smit E. Serum iron, copper and zinc concentrations and risk of cancer mortality in US adults. Ann Epidemiol. 2004;14:195-201.
Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.
Last Revised: 03/07/2011