When we hear the word copper, for most of us we think of a brownish metal used in pipes or coins. But copper is more than a metal. It is one of the essential minerals our body needs to stay healthy. Although we need it in small amounts, it plays an important role in maintaining a healthy body. Our main source of copper is from the foods we eat. Copper is naturally found in various plant and animal-based foods. A small amount is stored in our body with about two-thirds found in the bones and muscles.
The Role of Copper in the Body
Copper is involved in various processes in the body.
Sources of Copper
Dietary foods that are rich in copper include shellfish, seeds, nuts, organ meats, whole grain products and chocolate. Some beverages can also contain copper but the amount varies. The average daily recommended dose of copper is 900 mcg. As copper is present in many daily foods, most healthy adults can meet this need just based on diet alone. Below are some foods and the content of copper. Foods do not need to contain 100% of the daily requirement individually. The content of copper from different foods can easily add up to meet the daily requirement.
DV means Daily Value, based on 900 mcg of copper per day for adults. Values are approximate. Source:NIH
Copper Deficiency
Even though most adults meet the daily requirement of copper from their regular diet, certain medical conditions and supplements can affect how much copper is absorbed by the body. Let us look at some of these cases that have a higher risk copper deficiency.
If you fall in of these groups, consider discussing with your health care provider about the risks of copper deficiency and whether additional testing or supplementation is needed.
What a Copper Deficiency Actually Looks Like
In the Journal of Neurology in 2010, a review described 55 cases of copper deficiency myelopathy. This is where too little copper injures the spinal cord and leads to symptoms such as numbness, weakness and difficulty walking. These symptoms can be almost indistinguishable from B12 deficiency myelopathy. This review included mostly women (three times as many as men) in their fifties and sixties. The usual risk factors were the ones in the section above: earlier surgery on the stomach or upper intestine, excess zinc intake, or a malabsorption disorder.
In a fifth of cases, the cause remained unknown. Blood tests showed abnormalities in 78 percent of cases, most commonly anemia. The authors noted that in some cases it is possible the diagnosis of a bone marrow disorder was made when really a nutrient deficiency was to blame. Copper deficiency myelopathy is diagnosed with a blood test and is characterized by low levels of copper and of a protein called ceruloplasmin that carries copper. Treatment consists of copper supplements and correcting the underlying disorder, if possible. Blood counts can be expected to respond, but neurological symptoms often only partially improve.
As bariatric surgery is on the rise, physicians should be on the lookout for copper deficiency myelopathy, especially before difficulty walking sets in. Doctors have known for more than 50 years that copper deficiency can cause anemia and a decreased white blood cell count. It has only been more recently described as a cause of spinal cord disease. Since copper deficiency is rare, it’s easy to assume it’s not serious. But like B12 deficiency, the earlier it’s caught, the better.
Source: Copper deficiency myelopathy, Journal of Neurology 2010
The Denture Cream Problem
In 2008 a team of neurologists reported on four patients who presented with nerve damage, low copper, high zinc and no explanation for either. The authors of that case report wondered why these four patients were ingesting so much zinc. None of them was taking zinc supplements. But all of them wore dentures and used huge amounts of denture adhesive.
Far more than the directions call for, over a long period. The researchers had the various adhesives analyzed and found that two of the most popular brands (Poli-Grip and Fixodent) contained between 17,000 and 34,000 micrograms of zinc per gram of cream at the time. This would add up to a zinc supplement’s worth if one used plenty of the stuff multiple times a day. When three of the patients stopped using denture adhesive their blood zinc levels dropped. Two patients that were given copper experienced some improvement in their neurological problems.
When used as directed denture adhesive is not a problem, but if you are using a lot of it, it could be worth mentioning to your dentist or pharmacist, especially if you are also taking a zinc supplement. This is an easy one to rule in or out with a simple zinc and copper blood test.
Copper Toxicity: How much is too much?
While copper is essential for health, like any other mineral, too much can be harmful. According to the NIH, chronic exposure to high levels of copper can result in liver damage and gastrointestinal symptoms like nausea and vomiting. Based on copper levels associated with liver damage, the Food and Nutrition Board (FNB) reports the tolerable upper intake level for copper, adults (19+) are 10,000 mcg. This is the highest daily intake that will likely not result in harmful effects. Even though this is the highest limit, the goal should not be reaching this amount. Copper toxicity is rare but certain situations like contaminated water or rare genetic disorders like Wilson’s disease can increase risk of copper toxicity.
Copper in Your Tap Water
The EPA notes that most lead and copper contamination in drinking water comes from plumbing materials, specifically from the pipes and fittings in or around your home (not at the treatment plant). Water that sits in copper pipe can pick up some of the metal.
The Lead and Copper Rule has an action level for copper, which requires water systems to take additional actions to control corrosion in the distribution system if more than 10 percent of tap samples collected from customers exceed 1.3 parts per million of copper. Health effects the EPA associates with both metals range from stomach upsets to brain damage, although for copper alone, according to the NIH, these mostly consist of nausea and vomiting, and potentially liver problems from long-term exposure. If you get your water from a public water system, chances are this has already been taken care of, since your utility samples customer taps for it and publishes the results.
But if you use a private well, have had copper plumbing installed recently, or notice a blue-green stain in your sink (copper making itself visible), you may want to have your water tested. Home test kits or services offered by your water utility can give you peace of mind for just a few dollars.
Source: Lead and Copper Rule, U.S. Environmental Protection Agency
Copper-Related Health Products
Some copper related products have been promoted for their supposed health benefits.
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Overall, there is no sufficient scientific evidence to support claims that copper bottles and bracelets provide additional health benefits.
Where Copper Really Does Kill Germs: Hospital Rooms
The antibacterial claim behind the copper water bottle is real; it is just pointed at the wrong target. Bacteria, yeasts and viruses die on contact with bare copper. Microbiologists call this phenomenon contact killing, and a 2011 review estimated it kills seven to eight logs per hour (i.e. pretty much everything, if it sticks around long enough). The EPA even registered copper as the first antimicrobial solid material, leading to copper-alloy doorknobs, bed rails, and bathroom fixtures in some hospitals.
But does it actually work? In a randomized trial in three hospital intensive care units (July 2010 – June 2011), patients were randomly assigned to rooms where six commonly-touched surfaces were made of copper-alloy, versus not. This led to fewer hospital-acquired infections or colonizations with MRSA or VRE (0.071 versus 0.123), and also fewer infections overall (0.034 versus 0.081). The authors recommend further trials in other healthcare settings, but this one is a pretty solid start.
However, there are two caveats. First, in 2020 researchers reported lab-adapted strains of E. coli and MRSA that were 12 and 60 times more resistant to copper, respectively, indicating that copper objects will still need to be regularly cleaned in order to maintain their antimicrobial properties. Second, and more importantly for us, this has nothing to do with drinking water out of a copper bottle. The surface kills what lands on it; it does nothing for the person holding it.
Sources: Metallic copper as an antimicrobial surface, Applied and Environmental Microbiology 2011 · Copper surfaces reduce the rate of healthcare-acquired infections in the intensive care unit, Infection Control & Hospital Epidemiology 2013 · Mutant strains of E. coli and MRSA obtained by laboratory selection to survive on metallic copper surfaces, AEM 2020
Take Away
The full numbers
Daily Value is based on 900 mcg of copper per day for adults. Values are approximate. Source: NIH Office of Dietary Supplements.
Selam Melka, PharmD, is a pharmacist with more than ten years of experience in clinical pharmacy and acute care.
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I decided I would try copper bracelets and rings that had magnets too. I did not expect them to help, but they were pretty so I figured what the heck. Within three weeks the severe pain in my hands and feet was greatly diminished and I no longer wake up in the middle of the night in pain. I never believed it would help, and all other “miracle cures” were worthless, so this was not a placebo effect. I don’t understand why it helps but it does. I have fibromyalgia and am under a doctors care.
Melody, thank you for sharing this, and we’re glad the pain in your hands and feet has eased. Fibromyalgia pain that wakes you up at night is exhausting, and three weeks of better sleep is no small thing.
One point worth adding for anyone reading along: the trial we cite in the article tested copper bracelets and magnetic straps in people with rheumatoid arthritis, which is a different condition. It did not study fibromyalgia, so we can’t say the research rules out what you’re experiencing. We also wouldn’t tell you to second-guess relief that’s real to you. Copper bracelets and magnets have no known downside, so if they’re helping and your doctor knows you’re using them, there’s no reason to stop.
Keep working with your doctor, keep doing what’s working, and thanks again for reading!