Copper in a nutshell
Copper is a common metal that is used in hundreds of enzymes in our bodies – that means hundreds of reactions require copper. It is also needed to help iron bind to hemoglobin (the molecule that carries oxygen in the blood) and it is part of an enzyme that stops allergic reactions.
Best source of Copper for Juicers
Copper is found in various nuts, but for juices, add carrots, garlic, ginger and turnips.
Copper is an essential element in human nutrition that most of us overlook. Too much copper, however, can be just as detrimental as too little.
Alternative names: Copper; chemicals beginning with the terms “cupric” or “cuprous.”
What Is Copper?
Copper is the familiar reddish metal that we use in our homes. It is a great conductor of heat and electricity and is used in electrical wiring and heating elements. Because it is extremely ductile, we also using it in copper piping to carry water around the home.
Copper is also widely used in alloys, like bronze and brass.
What Does Copper Do in the Human Body?
Nutritionists tend to classify oxidants as “bad” and antioxidants as “good,” but the oxidation caused by copper enzymes is essential to human health. Every cell in the human body uses a copper-containing enzyme called cytochrome c oxidase to store energy that is released in the mitochondria. This enzyme is essential for making the energy-storage molecule ATP. But it's hardly the only essential enzyme the body makes with copper.
One enzyme the body makes with copper (diamine oxidase), for instance, stops the action of histamine and ends an allergic reaction. Another enzyme the body makes with copper (monoamine oxidase) breaks down excess serotonin in the brain and helps the body remove and recycle the hormones released during stress. And another enzyme the body makes with copper (lysine oxidase) forms cross-links in collagen that make skin and tendons stronger.
Without copper-containing ceruloplasmin, the body cannot oxidize iron into a form that binds it into hemoglobin, the protein that carries oxygen through the bloodstream. Copper, along with vitamin C, is a cofactor for an enzyme called dopamine beta-monooxygenase, which converts one brain chemical, dopamine, into another, norepinephrine. And copper also is key to the creation of one of the body's most important antioxidant enzymes, superoxide dismutase (one form of it).
The body absorbs copper through the stomach and the small intestine. A small amount of copper “leaks” through the lining of the stomach into the bloodstream. Most of the copper the body absorbs from food has to be “pumped” through specialized receptors in the small intestine. Anything that interferes with the function of the small intestine, such as celiac disease, severe constipation, or overgrowth with bacteria, can also interfere with the body's ability to absorb copper. Even under the best conditions, the body only absorbs about 50% of the first 5 milligrams of copper digested out of food or supplements in a single day, and only about 20% of any copper released from food or supplements after that.
Most of the body's copper is stored in the bones and skeletal muscles, but most of the conversion of copper into critical enzymes takes place in the liver. The liver releases excess copper into bile salts that are mixed with stool and evacuated with bowel movement. Only about 0.1% of the copper excreted by the body goes into the urine.
What Happens When We Don't Get Enough Copper?
Copper deficiencies are relatively rare. They can occur in infants who are exclusively fed formula that does not contain copper, or who are fed a high-iron formula for anemia. (Ironically, iron interferes with copper absorption and copper is essential for the formation of hemoglobin, so using too much iron to treat anemia in infants can cause anemia in infants.)
Copper deficiencies can occur in people who receive parenteral nutrition (all their nutrients through an IV) with a formula that does not contain copper. And because zinc competes with copper for absorption into the body, copper deficiencies can occur in people who take 75 mg of zinc a day or more for longer than two weeks.
Infants deprived of copper sometimes develop osteoporosis. They may also develop leukopenia or neutropenia, which are shortages of white blood cells. Adults who suffer low copper levels due to excess consumption of zinc sometimes develop a variety of symptoms that may include:
- Anemia. Without enough copper the body cannot create hemoglobin for red blood cells. These red blood cells appear normal in other respects except they lack the full capacity to carry oxygen.
- Pancytopenia. Without enough copper the body cannot create enough white blood cells, especially the neutrophils (which kill pathogenic microorganisms with inflammation) and leukophils (which create more white blood cells).
- Neurological problems. People who become copper deficient often develop spasticity, muscles which are simultaneously stiff and weak. They may lose sensation in their arms and legs and have difficulty walking, standing, and picking up objects.
It's usually safe to take zinc for a cold for up to two weeks. Most of the people who have developed copper deficiencies severe enough to require hospitalization (and treatment with blood transfusions and copper supplement injections) have used overdoses of zinc to treat sinus problems.
How Can You Be Sure of Getting Enough Zinc from Your Diet?
The kinds of symptoms that occur when people take too much zinc (blocking the absorption of copper) can also occur if an adult diet does not supply at least 900 micrograms (just a little under a milligram) of copper per day. For the USA, the recommended daily allowances for copper are as follows:
- For infants up to 6 months of age, at least 200 micrograms per day.
- For infants 6 months to 1 year of age, at least 220 micrograms per day.
- For children aged 1 to 3, at least 340 micrograms per day.
- For children aged 4 to 8, at least 440 micrograms per day.
- For children aged 9 to 13, at least 700 micrograms per day.
- For teens age 14 to 18, at least 890 micrograms per day.
- For most adults, 900 micrograms per day.
- For women who are pregnant, 1000 micrograms per day.
- For women who are breastfeeding, 1300 micrograms per day.
Generally speaking, a copper supplement that contains 2 or 3 milligrams (2000 to 3000 micrograms) of copper once a day, about 50% of which is absorbed into the bloodstream, can prevent copper deficiency for any person in any age group. It's also possible to get all the copper you need from food.
- A 3-1/2 ounce or 100 gram serving of beef, lamb, or veal liver contains 15,000 micrograms of copper.
- A 3-1/2 ounce or 100 gram serving of chicken or goose livers contains 8,000 micrograms of copper.
- A 3-1/2 ounce or 100 gram serving of oysters or mussels contains 8,000 micrograms of copper.
- A 3-1/2 ounce or 100 gram serving of dark chocolate contains 3,000 micrograms of copper.
- A 3-1/2 ounce or 100 gram serving of cashew nuts, sunflower seeds, walnuts, hazelnuts, soy nuts, calamari, lobster contains 2,000 micrograms of copper.
- A 3-1/2 ounce or 100 gram serving of yard long beans (green beans), fava beans, pinto beans, potatoes boiled in their skins, potatoes baked in their skins, rye bread, leeks, hearts of palm, chestnuts, almonds, pecans, peanuts, peanut butter, pistachio nuts, pine nuts, lentils, tofu, crab, dried apricots, chocolate candy, or feta cheese contain 1,000 micrograms of copper.
And although we can't recommend it as a regular item in your diet, KFC extra-crispy fried chicken (probably due to the spices in the batter) is also an excellent source of copper.
Using Copper to Support Recovery from Disease
Osteoarthritis and osteoporosis respond to the use of copper supplements.
Wearing a copper bracelet is an age-old remedy for osteoarthritis. Taking 1 to 3 mg of copper in supplements each day may relieve symptoms.
In one study, women who took 1 to 3 mg of copper with other mineral supplements for osteoporosis (calcium, manganese, and zinc) experienced fewer fractures of the spine over the two years of the study. Copper by itself has little or not effect on osteoporosis but it may help the bones use other mineral elements more effectively.
Can You Get Too Much Copper?
The main way people overdose copper is by drinking too many soft drinks that contain copper. A liter of carbonated soft drink contains about 3 milligrams of copper. It takes about 5 mg of copper from soft drinks, or a little more than 1-1/2 liters per day, to cause stomach upset, usually bloating, flatulence (which is also aggravated by the bubbles in the soft drinks), and “acid stomach.”
People who have a condition called Wilson's disease suffer liver damage after consuming excessive copper. Liver damage has also been noted in one person who took 60 milligrams of copper per day for two years, consuming enough copper for two lifetimes in two years. Consuming up to 10 milligrams per day (which is not recommended) is not likely to cause liver disease in people who are otherwise healthy.