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Other common
name(s): none
Scientific/medical
name(s): Cu, cupric oxide, copper sulfate, copper
gluconate, copper picolinate, cupric acetate, alkaline copper carbonate
Description
Copper is a required nutrient. It is found naturally in foods
such as seafood, liver, green vegetables, whole grains, wheat bran,
lentils, and nuts. 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.
Overview
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. More extensive human studies are needed
to determine what role copper may play in the prevention or treatment
of cancer.
How is it promoted for use?
There are claims that copper aids in the healing process,
helps to expel toxins from the body, and helps prevent heart problems.
Copper is also used in some preparations of Iscador, a commercially
prepared mistletoe extract sold as a complementary therapy in Europe
for tumors of the liver, gallbladder, stomach, and kidneys.
There are also claims that copper actually promotes cancer
growth. Proponents of this theory recommend a diet low in copper and
the use of chelating agents that bind to copper and promote its
elimination 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 supplements. However, 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. Some copper is also present in drinking water, and copper pipes
can leach extra copper into the water they carry.
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, to help
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, 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 is needed to form new blood vessels, and
because cancer needs new blood vessels in order to grow, some
researchers are interested in copper’s possible impact on
cancer. One group of researchers looked at whether a copper-lowering
drug 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.
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 found to be no more effective at relieving
pain than sham gel, although the copper gel produced more rashes.
Further research may help determine whether any form of copper might be
helpful in arthritis.
One laboratory study showed that the white blood cells of men
who had been on a low-copper diet did not attack germs as effectively
as they had when the same men were receiving enough copper. An older
study in a group of children recovering from malnutrition showed that
those who got copper supplements had significantly fewer lung
infections than those who got sham supplements. While severe copper
deficiency is known to result in poorer immune function, further
studies are needed to find out what effect, if any, milder deficiency
might have. These studies are hindered by the fact that copper levels
in the blood do not always reflect nutritional status.
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. However, 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, large population studies 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. Supplements may be helpful
for 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?
This product is sold as a
dietary supplement in the United States. Unlike companies that produce
drugs (which must provide the FDA with results of detailed testing
showing their product is safe and effective before the drug is approved
for sale), the companies that make supplements do not have to show
evidence of safety or health benefits to the FDA before selling their
products. Supplement products without any reliable scientific evidence
of health benefits may still be sold as long as the companies selling
them do not claim the supplements can prevent, treat, or cure any
specific disease. Some such products may not contain the amount of the
herb or substance that is written on the label, and some may include
other substances (contaminants). Though the FDA has written new rules
to improve the quality of manufacturing processes for dietary
supplements and the accurate listing of supplement ingredients, these
rules do not take full effect until 2010. And, the new rules do not
address the safety of supplement ingredients or their effects on health
when proper manufacturing techniques are used.
Most such
supplements have not been tested to find out if they interact with
medicines, foods, or other herbs and supplements. Even though some
reports of interactions and harmful effects may be published, full
studies of interactions and effects are not often available. Because of
these limitations, any information on ill effects and interactions
below should be considered incomplete.
Copper toxicity is rare, and copper supplements are considered
safe when taken in recommended amounts. However, adults are advised not
to take more than 10 milligrams per day due to increased risk of liver
damage. The maximum recommended dosage is lower for children, depending
on age. 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 containing 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 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 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.
Additional Resources
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-ACS-2345).
References
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
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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
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Copper. PDRhealth Web site.
http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/cop_0083.shtml.
Accessed June 4, 2008.
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
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Eaton-Evans J, Mellwrath EM, Jackson WE, McCartney H, Strain
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Finefrock AE, Bush AI, Doraiswamy PM. Current status of metals
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Kumar N, Gross JB Jr, Ahlskog JE. Copper deficiency myelopathy
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Mártin-Lagos F, Navarro-Alarcón M,
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Percival SS. Copper and immunity. Am J Clin Nutr.
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Redman BG, Esper P, Pan Q, Dunn RL, Hussain HK, Chenevert T,
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Renault E, Deschatrette J. Alterations of rat hepatoma cell
genomes induced by copper deficiency. Nutr Cancer.1997;29:242-247.
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copper toxicosis. Am J
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Shackel NA, Day RO, Kellett B, Brooks PM. Copper-salicylate
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Spencer JW, Jacobs JJ.
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heart disease and cancer. Br
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Wu T, Sempos CT, Freudenheim JL, Muti P, Smit E. Serum iron,
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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 Medical Review: 11/01/2008
Last Revised: 11/01/2008
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