Copper has been known to be an essential trace mineral for some time. In recent years there has been more concern about copper toxicity than about getting the small amounts we need to make hemoglobin and perform other functions. Copper is present in all body tissues. The total amount in our bodies is about 75-100 mg., less than that contained in a copper penny.
Copper is found in many foods in small amounts (oysters and nuts are the richest sources). The standard amount available in our diet, whether or not it is excessive or deficient, is a controversial topic; the naturalist in me feels that if it is in wholesome foods, it must be the right amount. This mineral is present in water that flows through copper piping. Increases in estrogen hormone levels, from taking birth control pills or during pregnancy, for example, often increase serum copper levels to more than double normal values, while red blood cell levels, where copper is important, may actually be lower. This may contribute to some of the psychological or other symptoms seen during pregnancy or with birth control pill use. Increased copper levels have been associated with schizophrenia, learning disabilities, and senility, although none of these associations have been demonstrated with certainty. Depression and other mental problems, premenstrual syndrome, and hyperactivity have also been correlated with high copper levels, often in combination with low zinc levels.
Zinc and copper have a seesaw relationship in the body, competing with each other for absorption in the gut. Both zinc deficiency and copper toxicity have increased since the switch from zinc (galvanized) to copper water pipes. We can avoid this problem by not drinking tap water. Some studies of schizophrenics have revealed high blood copper with low urinary copper (showing that copper is being retained) and low blood zinc. In some of these cases, zinc was helpful as an antianxiety agent.
About 30 percent of copper intake is absorbed into the body from the stomach and upper intestine; it is fairly rapidly absorbed, usually within 15 minutes. Copper is transferred by albumin across the gut wall and carried to the liver, where it is formed into ceruloplasmin, a copper-protein complex. About 90 percent of the average 100 mcg. of copper in the blood is in the form of ceruloplasmin. As a balancing mechanism to minimize copper toxicities, absorption of copper is decreased when ceruloplasmin levels are adequate. Vitamin C, zinc, and manganese all interfere with copper absorption. Protein and fresh vegetable foods have been shown to improve copper absorption.
About 100 mg. of copper are stored in the body, with the highest concentrations in the liver and brain tissues, which account for about one-third of the total. Muscles contain approximately another third, with the remaining copper in the other tissues. At birth, a high amount is contained in the liver; by about age ten, the normal adult level of copper is reached, both in the liver and the rest of the body. Excess copper is eliminated mainly through the liver into the bile and is lost through the intestines. A minimal amount is excreted in the urine.
Sources: Copper is available in most natural foods. Some authorities believe that our average intake is higher than our actual needs, that low intakes are uncommon, and that toxicity is a potential problem. The other school of thought holds that low intake is common because soil depletion has decreased the copper level in many foods and because many people avoid natural, copper-containing foods.
Foods with good supplies of copper are the whole grains, particularly buckwheat and whole wheat; shellfish, such as shrimp and other seafoods; liver and other organ meats; most dried peas and beans; and nuts, such as Brazil nuts, almonds, hazelnuts, walnuts, and pecans. Oysters have high amounts, about five times as much as other foods. Soybeans supply copper, as do dark leafy greens and some dried fruits, such as prunes; cocoa, black pepper, and yeast are also sources. In addition to food sources, copper can come from water pipes and cookware.
Functions: Copper is important as a catalyst in the formation of hemoglobin, our oxygen-carrying molecule. Copper in the red blood cells is bound to erythrocuprein, a substance thought to have superoxide dismutase (SOD) activity, which is energy enhancing. Copper is also part of the cytochrome system for cell respiration, an energy-releasing process. It also helps oxidize vitamin C and works with C to form collagen (part of cell membranes and the supportive matrix in muscles and other tissues), especially in the bone and connective tissue. It helps the cross-linking of collagen fibers and thus supports the healing process of tissues and aids in proper bone formation. An excess of copper may increase collagen and lead to stiffer and less flexible tissues.
Copper is found in many enzymes; most important is the cytoplasmic superoxide dismutase. Copper enzymes play a role in oxygen-free radical metabolism, and in this way have a mild anti-inflammatory effect. Copper also functions in certain amino acid conversions. Being essential in the synthesis of phospholipids, copper contributes to the integrity of the myelin sheaths covering nerves. It also aids the conversion of tyrosine to the pigment melanin, which gives hair and skin their coloring. Copper, as well as zinc, is important for converting T3 (triiodothyronine) to T4 (thyroxine), both thyroid hormones. Low copper levels may reduce thyroid functions.
Copper, like most metals, is a conductor of electricity; in the body, it helps the nervous system function. It also helps control levels of histamine, which may be related to allergic and inflammatory reactions. Copper in the blood is fixed to the protein cerulosplasmin, and copper is part of the enzyme histaminase, which is involved in the metabolism of histamine.
Uses: Some nutritional doctors feel that copper should not be supplemented because of the narrow line between the therapeutic and toxic doses. Copper has, however, been used in cases of anemia, vitiligo, fatigue, allergies, and stomach ulcers where low levels of copper have been found. Whenever copper is deficient, which it can be for many reasons, it should be supplemented. Copper can be measured in the blood, both plasma and red blood cell levels, to help determine the amount of copper to be supplemented.
The use of copper bracelets in the treatment of arthritis has a long history, and wearers continue to claim positive results. The copper in the bracelets reacts with the fatty acids in the skin to form copper salts that are absorbed into the body. The copper salts may cause a blue-green stain on the skin, but this can be removed with soap and water. Recent research suggests that copper salicylate used to treat arthritis reduces symptoms more effectively than either copper or aspirin alone.
In a Danish study, arthritis patients who were treated with injections of superoxide dismutase, an enzyme containing copper (or manganese and zinc) that is found within the cells, obtained relief from many of their symptoms, such as joint swelling, pain, and morning stiffness. SOD is available in tablets in the United States; however, it is not thought to be stable in the stomach and small intestine, so it may not be of any help for arthritis when taken orally. Additional research with enteric-coated tablets of active SOD may provide new insights into oral SOD treatment of arthritis and other inflammatory disorders.
Deficiency and toxicity: Copper toxicity has been the subject of great concern in recent years. High copper levels, especially when associated, as they often are, with low zinc levels, have been described in a wide variety of conditions. Whether this is incidental, a cause of these problems, or a result of them is not known for certain. Problems of copper toxicity may include stress and anxiety states, joint and muscle pains, psychological depression, mental fatigue, poor memory, lack of concentration, insomnia, manic depression, schizophrenia, senility, epilepsy, autism, hypertension, stuttering, hyperactivity in children, premenstrual syndrome, preeclampsia of pregnancy, and postpartum psychosis. Until further research clarifies the problems of copper toxicity, it is wise to check levels of copper (and zinc) in people with these conditions as well as those with alcoholism, cancer, and infectious diseases. The World Health Organization (WHO) still states that copper is nontoxic.
Hair levels of copper are not very helpful in detecting increased body copper because external contamination from the fungicides and algicides used in swimming pools or hot tubs may leave copper on the hair, causing misleading test results. However, hair copper is suggestive of body state, such that if hair (or blood copper) levels are elevated, it is wise to check the 24-hour urine copper level or the blood ceruloplasmin level. Red blood cell copper levels may be a good test to measure increased copper levels as well; serum copper levels may be easier for detecting deficiency.
Symptoms of mild copper toxicity may be classified as hypochondriac or “neurotic” ones. Fatigue, irritability, nervousness, depression, and learning problems are some common symptoms. Higher levels of copper intoxication can lead to nausea, vomiting, diarrhea, liver damage, gingivitis, dermatitis, or a discoloration of the skin and hair. In their book Trace Elements, Hair Analysis and Nutrition (Keats Publishing, 1983), Drs. Richard Passwater and Elmer Cranton describe a case of three women who lived together in a house with copper pipes. All presented symptoms of fatigue, irritability, muscle and joint aches, and headaches, and all had elevated copper levels. They were treated successfully with increased levels of zinc and manganese, which compete with copper for absorption and also help eliminate copper through the bile and urine. Carl Pfeiffer, M.D., suggests using zinc (50 mg.), manganese (3 mg.), and vitamin B6 (50 mg.) daily without supplemental copper to increase copper excretion. If copper levels are very high, treatment with penicillamine or chelation therapy with ethylenediaminetetraacetic acid (EDTA) may be needed. In Europe, a compound called Dimeval (di-mercapto-succinic acid) may be used to lower copper levels.
A genetic disorder called Wilson’s disease affects copper metabolism and leads to low serum and hair copper with high liver and brain copper levels. This can be a serious and even fatal problem unless treated by chelating agents; penicillamine is most often used as it binds copper in the gut and carries it out. A low-copper diet and more zinc and manganese in the diet and as supplements will also help reduce copper levels. Menke’s disease is a rare problem of copper malabsorption in infants. In this condition, which can often be fatal, decreased intestinal absorption causes copper to accumulate in the intestinal lining.
Copper deficiency has long been considered unlikely even with a suboptimal diet because it was thought to be readily available from foods. Newer surveys seem to suggest that, with soil deficiency and poor diet, the average dietary intake is now less than 1 mg. per day. Our bodies require more than this. A recent study revealed that 75 percent of those evaluated had less intake than the 2 mg. RDA. Many authorities feel that intake below 2 mg. is still sufficient, especially when drinking water from copper pipes.
Copper deficiency is commonly found together with iron deficiency, especially with iron deficiency anemia. Fatigue, paleness, skin sores, and edema may appear with this, as may slowed growth, hair loss, anorexia, diarrhea, and dermatitis. High zinc levels or intake can lead to lower copper levels and some symptoms of copper deficiency. The reduced red blood cell function and shortened red cell life span can influence energy levels and cause weakness and labored respiration from decreased oxygen delivery. Low copper levels may also affect collagen formation and thus tissue health and healing. Reduced thyroid function, weakened immunity, cardiovascular disease, increased cholesterol, skeletal defects related to bone demineralization, and poor nerve conductivity, including irregular heart rhythms, might all result from copper depletions. Copper deficiency results in several abnormalities of the immune system, such as reduced cellular immune response, reduced activity of white blood cells, and, possibly, reduced thymus hormone production, all of which may contribute to an increased infection rate. Infants fed an all-dairy (cow’s milk) diet without copper supplements may develop copper deficiency. Some children with iron deficiency show reduced levels of copper as well. It is also likely that during pregnancy copper will be deficient unless supplemented with at least 2 mg. daily.
Requirements: The RDA for copper in adults is 2 mg. (liberally, 2-3 mg.) per day. For children it is 1-2 mg. and for infants about 0.5-1 mg. The average adult intake had been estimated at 2.5-5 mg. per day, although recent reports suggest lower levels.
Many nutritionists do not supplement copper at all or at least not more than 2 mg. per day in a general supplement because of the concern about toxicity and because excess copper can interfere with absorption of zinc. Zinc deficiency can cause a great number of problems, such as hair loss, menstrual problems, and weakened immunity. If the soil in which our food is grown is known to be high in copper or if we drink water from copper pipes, we should probably avoid copper supplements. If we eat a diet that includes whole grains, nuts, and leafy green vegetables or eat much liver, we are probably obtaining sufficient levels from our diet. Overall, if we do supplement zinc, we should also take copper in a ratio of 15-30 mg. zinc to 2 mg. copper, unless of course, we are trying to reduce copper or correct a zinc deficiency. Likewise, if we take copper we should add zinc, unless we are treating high zinc levels or copper deficiency.