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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 the body in functions such
as the healing process, expelling toxins from the body, and preventing
heart problems. Copper is also used in some preparations of Iscador (a
species of European mistletoe) 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 low copper diet and use
of chelating agents that bind to copper and promote its elimination
from the body (see Chelation
Therapy). Available scientific evidence does not
support these claims.
What does it involve?
Copper supplements are available in pill or capsule form.
Copper is often added to multiple 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 (mg) per day for most adults, 1 mg for pregnant women,
and 1.3 mg for
women who are breastfeeding. 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. 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. Antioxidant compounds block the
action of activated oxygen molecules, known as free radicals, which can
damage cells. While the involvement of copper in the cancer process via
antioxidant effects is still unclear, copper complexes have been shown
to have anti-cancer properties in lab studies.
Other lab and animal studies suggest that high copper levels may be
linked to liver cancer and brain tumors. More recently, many studies
have shown that blood copper levels are higher in several types of
cancer as well as in 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, one group
of researchers used a copper-lowering drug to find out if it helped
patients with advanced kidney cancer. Some patients' cancers 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 if it can help more people with advanced cancer.
Another study measured copper levels in the blood of people
who died from heart disease, and noted that their levels were high. It
is not known whether the lab testing truly reflected copper levels in
the body tissues, 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 see if copper can affect heart disease risk.
Many people wear copper bracelets for their arthritis, and
some people report that their arthritis symptoms are better. 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 no better than sham gel, although
the copper gel produced more rashes. Further research on copper may
help determine if any form of copper might be helpful in arthritis.
One lab 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 had received 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 of
Alzheimer disease. However, there is not enough evidence to define the
role of copper intake 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 of 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. Choose whole grains over
refined grains and sugars. Limit high-fat and processed meats. Select
foods that help maintain a healthy weight. It is also important to
engage in moderate to vigorous physical activity for 30 to 60 minutes 5
or more days per week. For most people, this will help keep weight
under control, reduce risk of some cancers, and reap many other health
benefits. While it is best to get vitamins and minerals from foods,
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 drugs (which must be tested before being allowed to be sold),
the companies that make supplements are not required to prove to the
Food and Drug Administration that their supplements are safe or
effective, as long as they don't 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). Actual amounts per dose may vary
between brands or even between different batches of the same brand.
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 supplements are considered safe when taken in
recommended amounts. Copper toxicity is rare. However, adults are
advised not to take more than 10 mg per day due to increased risk of
liver damage. (The maximum is lower for children, depending on age.)
Copper overdoses can cause serious problems such as liver
damage, kidney failure, coma, and death. Earlier symptoms of overdose
may include nausea, vomiting, diarrhea, abdominal pain, and problems
with coordination or movement. There may also be behavior problems,
such as trouble concentrating, emotional disturbances, or sleepiness.
Copper can interfere with some medicines, so it is helpful to
talk with your doctor or pharmacist about all medicines, herbs, and
supplements that you are taking.
People with Wilson 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 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. Infants and adults with too
little copper can have osteoporosis (weak bones.) In adults, low copper
levels can result in anemia (low red blood count) and low white blood
cell counts. Low copper levels in adults have been reported to cause
muscle spasms in the legs and trouble walking.
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 ordered
from our toll-free number (1-800-ACS-2345).
References
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at the upper level of the adult dietary recommended intake induces
detectable but transient changes in healthy adults. J Nutr.
2005;135:2367-2371.
Bugel S, Harper A, Rock E, et al. 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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Castillo-Duran C, Fisberg M, et al. Controlled trial of
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Davis CD, Feng Y. Dietary copper, manganese and iron affect
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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.
Revised: 06/26/2007
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