Copper is a mineral found throughout your body. It’s a nutrient that your body needs in small amounts to function properly.
Other heavy metals, like lead, mercury, and arsenic, aren’t good for you. But getting copper in trace amounts is essential. Getting too much or not enough of it can cause health problems.
What does copper do?
Copper has an important role in a number of functions, including the:
- production of red blood cells
- regulation of heart rate and blood pressure
- absorption of iron
- prevention of prostatitis, or inflammation of the prostate
- development and maintenance of bone, connective tissue, and organs like the brain and heart
- activation of the immune system
Possible benefits of copper
Copper is a vital component for your body, but you need just the right amount. Copper supplements may improve some health conditions, though these are usually associated with a copper deficiency.
For example, a 2015 studyTrusted Source found that post-menopausal women with low bone density had very low levels of copper and other minerals in their blood. The study recommended copper supplements as a potential treatment to help improve bone density.
Some experts have also suggested that copper supplements may improve heart failure. But findings are mixed, with a 2014 study indicating that a supplement containing copper didn’t benefit people with heart failure.
Other studies have also linked higher copper intake to mortality from cardiovascular disease. Overall, more research should be done to assess any benefits of copper in this area.
Copper’s role in Alzheimer’s disease is similarly unclear. According to research from 2017Trusted Source, some studies associate Alzheimer’s disease with copper deficiency and recommend increasing copper levels, while others link the disease to overly high levels of copper.
Additional research is needed to explain the potential benefits of copper supplements for different health conditions.
Copper and cancer
Copper’s role in cancer is complex and is still being studied.
According to research from 2015, high concentrations of copper in the blood are linked to several kinds of cancer, including breast and lung cancer.
The article also noted that copper may play a role in the development of tumors, and that some types of cancer cells have elevated copper levels.
As a result, many current studies focus on copper chelation therapy. Copper chelators bind to copper ions to reduce their activity, remove them from cells, or transport them between cells.
Research from 2018 suggested that copper chelation may be effective when combined with other cancer treatments.
Copper may also be used to kill cancer cells more directly. A 2019 study Trusted Source indicated that treatment with copper nanoparticles delayed the growth of pancreatic tumors in mice.
Another study from 2014 found that copper compounds caused the death of colon cancer cells in test tubes.
Overall, more studies are needed to explore copper’s role in cancer.
Copper bracelets
Magnetic therapy bracelets are sometimes promoted as wearable treatment for arthritic pain. British scientists put copper bracelets to the test in a placebo-controlled trial.
The results, published in the journal PLoS ONE Trusted Source, found that the bracelets offered little or no therapeutic benefit. Furthermore, several study participants experienced skin irritation from the bracelets.
Where do you get copper?
Because your body needs so little copper, it may seem that you’d get enough through your diet.
But according to research from 2018, at least one-quarter and possibly much more of the U.S. population doesn’t eat the daily average requirement of copper. As a result, the study notes that the risk of copper deficiency may be common.
Copper-rich foods
One easy way to make sure you’re getting enough copper is to eat foods that contain it. You can find copper in shellfish and organ meats, like liver.
You can also get a good amount of copper by eating vegetables, grains, and seeds, like:
- potatoes
- peas
- beans
- green vegetables
- whole grains
- sunflower seeds
Peanut butter and dark chocolate also contain copper.
When you might need copper supplements
According to research in the Annals of HematologyTrusted Source, people with sufficient levels of iron can still be anemic. If blood test results show that you’re not getting enough copper, your doctor may recommend that you take supplements.
Copper supplements are available as pills and capsules. You can also get copper intravenously, or through your veins. You shouldn’t take copper supplements and zinc supplements at the same time — you should take these supplements at least 2 hours apart.
Copper deficiency
Symptoms
If you’re in good health, you’re not likely to have low levels of copper. Symptoms of copper deficiency may include:
- tremors
- a tingling sensation
- an unstable gait
- numbness
- fatigue
- anemia
- a loss of vision
Conditions that may lead to copper deficiency
Most people get enough copper from their diet. But if you have one of the following conditions, you may need supplemental copper.
- celiac disease
- cystic fibrosis
- Crohn’s disease
Menkes syndrome
Menkes syndrome can also cause a copper deficiency. If you have Menkes syndrome, you can absorb copper from the food you eat. But your body doesn’t release it into your bloodstream properly.
As a result, your body doesn’t get the copper it needs. Instead, copper tends to build up in the small intestine and kidneys. Menkes syndrome is a rare genetic disorder. People who have it are usually diagnosed when they’re babies.
This condition is commonly called Menkes kinky hair syndrome because one of its characteristics is sparse, kinky hair.
Risk factors for copper deficiency
The following situations can sometimes increase the risk of having a copper deficiency:
- Gastric bypass surgery makes some people more prone to deficiency.
- Premature babies are more likely to have a copper deficiency than full-term babies.
- Taking supplemental zinc can make it difficult for your body to absorb enough copper.
Copper toxicity
Just as copper is necessary for survival, too much copper can be toxic. The tolerable upper intake level for copper has been set at 10 milligrams per day Trusted Source.
Symptoms of copper toxicity
A larger amount of copper can cause toxicity symptoms, including:
- vomiting
- diarrhea
- jaundice
- muscle pain
In severe cases, toxic levels of copper can cause:
- liver damage
- heart failure
- kidney failure
- death
A condition that can lead to copper toxicity
Wilson’s disease is an inherited disorder in which the liver is unable to get rid of excess copper. Copper then builds up in organs like the brain, liver, and eyes, which causes damage over time. Wilson’s disease can be life-threatening if you don’t get treatment for it.
The takeaway
Copper has an essential role in keeping you healthy. Most people get enough copper by eating a healthy diet. Certain conditions, like Crohn’s disease, or gastric bypass surgery may make you more prone to copper deficiency.
Not having enough copper in the body is more common than having too much copper in the body. Copper toxicity can cause problems as well, including liver damage or heart and kidney failure.
Be sure you get enough copper, but not too much. Talk with your doctor if you notice the symptoms of either copper deficiency or toxicity.
8 Foods That Are High in Copper
Copper is a mineral that your body requires in small quantities to maintain good health.
It uses copper to form red blood cells, bone, connective tissue and some important enzymes.
Copper is also involved in the processing of cholesterols, the proper functioning of your immune system and the growth and development of babies in the womb (1Trusted Source).
Though it’s only needed in tiny amounts, it’s an essential mineral — meaning that you must obtain it from your diet because your body cannot produce it on its own.
It’s recommended that adults get 900 mcg of copper per day.
However, if you’re pregnant or breastfeeding, you should get slightly more — 1 mg or 1.3 mg per day, respectively.
Here are 8 foods high in copper.
1. Liver
Organ meats — such as liver — are extremely nutritious.
They provide good amounts of many nutrients, including vitamin B12, vitamin A, riboflavin (B2), folate (B9), iron and choline (2).
Liver is also an excellent source of copper.
In fact, one slice (67 grams) of calf liver gives you 10.3 mg of copper — a whopping 1,144% of the Reference Daily Intake (RDI) (3).
To add flavor and zest to liver, try pan-frying it with onions or mixing it into burger patties and stews.
However, the high amounts of vitamin A in liver can harm unborn babies. Therefore, pregnant women should avoid foods extremely high in vitamin A, including liver (4Trusted Source).
2. Oysters
Oysters are a type of shellfish often considered a delicacy. They can be served cooked or raw, depending on your preference.
This seafood is low in calories and high in many essential nutrients like zinc, selenium and vitamin B12.
In addition, oysters are a good source of copper, providing 7.6 mg per 3.5 ounces (100 grams) — or 844% of the RDI (5).
You may be concerned about eating oysters and other shellfish due to their high cholesterol content.
However, unless you have a certain, rare genetic condition, dietary cholesterol found in foods like oysters is unlikely to significantly raise your blood levels of cholesterol (6 Trusted Source).
It should be noted that high dietary intake of zinc can interfere with copper absorption, and because oysters are also very high in zinc, 154mg per 100g, this may interfere with the amount of copper absorbed (7 Trusted Source).
Keep in mind also that raw oysters do carry a risk of food poisoning, so are not recommended for pregnant women or people with compromised immune systems (8 Trusted Source).
3. Spirulina
Spirulina is a powdered food supplement made from cyanobacteria, or blue-green algae.
Once consumed by the ancient Aztecs, it reemerged as a health food after NASA successfully used it as a dietary supplement for astronauts on space missions (9Trusted Source, 10).
Gram for gram, spirulina is extremely nutritious. A single tablespoon (7 grams) contains just 20 calories but packs 4 grams of protein, 25% of the RDI for vitamin B2 (riboflavin), 17% of the RDI for vitamin B1 (thiamine) and around 11% of the RDI for iron (11).
The same amount provides 44% of the RDI for copper.
Spirulina is often mixed with water to make a greenish beverage. However, if you don’t like its unusual taste, you can add it to stock, smoothies or cereal to disguise the flavor.
4. Shiitake Mushrooms
Shiitake mushrooms are a type of edible mushroom, native to East Asia, that have a strong umami flavor.
Four dried shiitake mushrooms (15 grams) offer 44 calories, 2 grams of fiber and a host of nutrients, including selenium, manganese, zinc, folate and vitamins B1, B5, B6 and D (12).
This portion also knocks out an impressive 89% of the RDI for copper.
5. Nuts and Seeds
Nuts and seeds are tiny powerhouses of nutrition.
They’re high in fiber, protein and healthy fats, as well as a wide range of other nutrients.
Although different nuts and seeds contain different nutrients, many hold substantial amounts of copper.
For example, 1 ounce (28 grams) of almonds or cashews boasts 33% and 67% of the RDI, respectively (13, 14).
Additionally, a tablespoon (9 grams) of sesame seeds packs 44% of the RDI (15).
You can enjoy nuts and seeds as a standalone snack, atop a salad or baked into a bread or casserole.
6. Lobster
Lobsters are large, muscular shellfish which live on the seabed.
Their succulent flesh makes them a popular addition to soups and bisques, though they can also simply be served on their own.
Lobster meat is low in fat, high in protein and loaded with vitamins and minerals, including selenium and vitamin B12.
It’s also an excellent source of copper.
In fact, a 3-ounce (85-gram) serving of lobster contains a phenomenal 178% of the RDI (16).
Interestingly, though low in fat, lobster is also quite high in cholesterol.
However, dietary cholesterol has little effect on blood cholesterol levels in most people, so the amount in lobster shouldn’t be a concern (17 Trusted Source).
7. Leafy Greens
Leafy greens like spinach, kale and Swiss chard are extremely healthy, boasting nutrients like fiber, vitamin K, calcium, magnesium and folate in a minimal number of calories.
Many leafy greens contain sizeable amounts of copper.
For example, cooked Swiss chard provides 33% of the RDI for copper in a single cup (173 grams) (18).
Other greens have similar amounts, with a cup (180 grams) of cooked spinach also holding 33% of the RDI (19).
These greens can be enjoyed raw in a salad, cooked into a stew or added as a side to most meals to boost both their nutrient and copper content.
8. Dark Chocolate
Dark chocolate contains higher amounts of cocoa solids — as well as less milk and sugar — than regular chocolate.
Dark chocolate boasts antioxidants, fiber and several nutrients.
For example, a 3.5-ounce (100-gram) bar of dark chocolate — with 70–85% cocoa solids — provides 11 grams of fiber, 98% of the RDI for manganese and 67% of the RDI for iron (20).
The same bar also packs a massive 200% of the RDI for copper.
What’s more, consuming dark chocolate as part of a balanced diet is linked to improvements in several heart disease risk factors (21 Trusted Source, 22 Trusted Source, 23 Trusted Source).
However, take care to not overeat dark chocolate. It’s still a high-calorie food loaded with fat and potentially sugar.
The Bottom Line
Copper — which is vital to your health — is found in a wide range of foods, from meat to vegetables.
Particularly good sources include oysters, nuts, seeds, shitake mushrooms, lobster, liver, leafy greens and dark chocolate.
To avoid a deficiency, be sure to include a variety of these sources in your diet.
