The common saying, “too much of a good thing,” does have a place in nutrition. Like Goldilocks, the body prefers a happy medium, and too little and too much of many essential vitamins and minerals can lead to imbalances and health problems. Many nutrients also work as antagonists with one another, which can mean that when one is too high, it causes the other to become too low, which could increase your susceptibility to certain acute or chronic conditions.
No pair better exemplifies this than zinc and copper. When your copper to zinc ratio becomes too high, it can lead to health problems. Before we go too far into the relationship of these two essential minerals, let’s review the basics.
Zinc plays numerous roles in the body, which might be why one prediction states that at least 10 percent of the human proteome, or the proteins an organism expresses, codes for zinc proteins! There are more than 3,000 zinc proteins in the human body, some of which are key enzymes, and some whose functions are currently unknown. Zinc ions also work as signalers in the body. The body requires specific cellular concentrations of this mineral to ensure the zinc reactions can take place without disrupting the work of other essential ions. Although considered a trace element, in the cell itself, zinc is actually incorporated as a cofactor more often than many other essential vitamins and the concentration is almost as high as that of ATP, the energy of the cell.
The most common uses of zinc in the body include:
– Cell division
– DNA synthesis
– Growth and development
– Immune function
– Protein synthesis
– Wound healing
The recommended dietary allowance (RDA) in the U.S. per the Food and Nutrition Board is 11 mg per day for adult males and 8 mg per day for adult females. Pregnant and lactating women, teenagers, children, and infants have different requirements. It is important to continually consume zinc, as there is no specific storage space for zinc. Although it is essential to health, supplementing in high doses can lead to adverse side effects.
Other than a lack of intake, risk factors for a zinc deficiency include poor absorption, increased requirements, and increased losses. Those with gastrointestinal diseases might have difficulty absorbing zinc. Vegetarians might also have a lower intake, since meat is a more bioavailable source than plant-based foods. In some estimates, vegetarians require 50 percent more zinc than non-vegetarians.
Signs of deficiency include:
– Alzheimer’s disease
– Cognitive impairment
– Delayed wound healing
– Eye and skin lesions
– Growth retardation
– Hair loss
– Hypogonadism in males
– Impaired immune function
– Loss of appetite
– Mental lethargy
– Taste abnormalities
– Weight loss
Copper also plays a role as a cofactor in enzymes or other functions in several biochemical processes, including redox reactions, iron metabolism, antioxidant defense, immune function, and neuropeptide synthesis.
Although rarer than for zinc, deficiency and insufficiency of copper can happen. Deficiency of copper in developing fetuses might lead to issues with the development and formation of the skeletal system, the cardiovascular system, the immune system, and the neurological system. Chronic insufficiency might lead to issues with cholesterol metabolism. There are genetic diseases, such as Menke’s disease, which causes copper deficiency. Other signs of copper deficiency include:
– Impaired growth
– Neurological symptoms
– Osteoporosis and bone development abnormalities
Despite its importance, copper has the potential to be toxic at high doses. High levels of copper can also contribute to excessive oxidative stress, which can damage the cell and cause it to die. High copper levels can lead to an increased risk for heart disease and cognitive decline.
The RDA for copper is 900 ug/day for adult men and women. As with zinc and most other nutrients, the levels for pregnant and lactating women, teenagers, children, and infants differ. In addition to food sources, you might also ingest copper through your drinking water, depending on the pipes and groundwater makeup.
The Importance of the Zinc/Copper Ratio
Copper and zinc are antagonists, which means they work against one another and compete for binding sites. Excess zinc can lead to a copper deficiency and vice versa. When you have an imbalance in the two, it can lead to health problems. A study in the 1990s found a correlation between oxidative stress and the copper to zinc ratio, independent of health status, age, and gender. However, the older participants did have a higher level of oxidative stress and a higher copper to zinc ratio. In the healthy elderly population, the higher ratio was due to higher levels of copper, while in those who were disabled, this was due to a lower level of zinc and high levels of copper.
In fact, the copper to zinc ratio might just be a marker for inflammation that predicts all-cause mortality, at least in an elderly population. Higher ratios were associated with low serum albumin, high CRP and ESR levels, and high IL-6, all markers for inflammation. The patients who died had a significantly higher copper to zinc ratio than those who were still living at the follow-up. There was also an association between stable cardiovascular disease and BMI with the copper to zinc ratio. In fact, many of the studies demonstrate that the copper to zinc ratio was more important as a marker of insufficiency, deficiency, or imbalance than the serum levels of the individual minerals. In the elderly, ratios above 2.0 appear to correlate with an increased inflammatory response.
Does the imbalance of the copper to zinc ratio lead to inflammation and oxidative stress, or is it the other way around? Well, one study points to inflammation and oxidative stress influencing the copper to zinc ratio, generally through increasing copper levels and decreasing zinc levels. Impaired insulin balance and other hormone imbalances might also contribute to an increased copper to zinc ratio. Part of the normal immune response depletes infected tissues of zinc to starve the pathogens from this essential metal while also moving the zinc to other locations to support the immune response. Copper increases to also assist in the immune response, as it has been known to regulate macrophage (white blood cells, especially in response to infection) pathways. Many of these changes are not related to nutritional or supplemental intake of the metals.
Because many of these actions also relate to the changes that occur in aging, one group of researchers postulate the ratio might provide a biomarker of aging. They also propose that acute high copper to zinc ratio might actually help the body in fighting issues, ultimately delaying health problems. Alternatively, it might cause more rapid deterioration. More studies will point to the role it plays in aging.
What role does it play in other areas of health?
Zinc is well known for its immune-modulating effects, but copper plays a role, too, especially the copper to zinc ratio. A balanced copper to zinc ratio, which is between 0.7 to 1.0, based on the studies discussed here, plays a role in maintaining the immune system, helping resist infectious diseases, and it has the potential to be used as an indicator of oxidative stress.
Studies have found that during stages of chronic inflammation and poor health, there is a lower level of zinc and a higher level of copper, leading to an imbalance in the ratio. Both copper and zinc create the superoxide dismutase (SOD) enzyme that counteracts oxidative stress. In a study reviewing serum levels of copper, zinc, SOD, and other markers in 15 IBD patients and 30 controls, zinc levels were significantly lower (23 percent lower), as was SOD activity (7.3 percent), in IBD patients. The reduction in SOD activity relates to a lower ability to scavenge free radicals, which can lead to excessive oxidative stress. The copper levels were significantly elevated in women (17.6 percent) but not all patients (5.9 percent higher but not significant). In the IBD patients, the copper to zinc ratio was 0.73 in men and 0.87 in women, compared to 0.64 and 0.51 in the respective controls.
In a prospective and experimental study, researchers took samples of serum copper and zinc levels in 100 patients with multidrug resistant pulmonary tuberculosis (TB) and determined their copper to zinc ratio. At the onset of treatment, the participants had a very high copper to zinc ratio, which experienced a significant drop when treated at the three and six-month marker after being treated with second-line TB drugs. Copper levels remained normal, while the zinc levels continued to be lower than that of the controls. The lower levels of zinc due to the disease led to a higher copper to zinc ratio, which in turn contributed to the immune system dysfunction and an increase of oxidative stress in patients. The researchers postulate that zinc supplementation might increase the efficacy of TB treatment through restoring the copper to zinc ratio and improving the body’s antioxidant capacity.
The copper to zinc ratio also plays a role in brain health. A recent meta-analysis found that Alzheimer’s disease patients had high serum copper levels and low serum zinc levels compared to controls. The mean difference in copper levels was 9.27 (95% CI 5.02 – 13.52), which was significant, while the mean difference in zinc levels was -6.12 (95% CI -9.55 to -2.69), which was also significant. Children with ADHD might also have a higher copper to zinc ratio. In one study reviewing 58 children with ADHD and 50 healthy controls, there were significantly lower levels of zinc and a higher copper to zinc ratio in the children with ADHD. The median zinc level in the ADHD group was 10.63 umol/L, compared to 11.32 umol/L, and the copper to zinc ratio was 1.78, compared to 1.61 in the control group. Although the children also had a higher level of copper, it was not significant. There was also a correlation with inattention based on a teacher-rated score.
There is also an association with autism and a poor copper to zinc ratio. In one study, the zinc to copper ratio decreased (which relates to an increased copper to zinc ratio) as the severity of autism increased, demonstrating a negative relationship between the two. The children had a significantly higher level of copper and a significantly lower level of zinc than the controls. The children with autism had a mean serum zinc level of 78.7 ug/dl compared to 87.7 ug/dl in the controls. For copper, the children with autism had a serum level of 129.9 ug/dl compared to 121.2 ug/dl in the controls. This led to a 0.608 zinc to copper ratio in children with autism compared to 0.727 in the controls. There was also an association between severity of the disease and the copper to zinc ratio. The researchers postulate that this ratio could be an early indicator of the disease.
Other Health Effects
There are many other ways in which this ratio affects health. Your copper to zinc ratio might also affect your sleep patterns. Higher levels of copper than between 1.10 mg/l and 1.12 mg/l correlate with a reduction in sleep duration, which in turn contributes to oxidative stress and inflammation. In one study, researchers looked at the link between inflammation (hs-CRP), serum zinc levels, and serum copper levels with sleep duration in older men. Those who slept 6 hours or less a night had the lowest levels of zinc at 0.91 mg/l, while the participants with the highest levels of zinc slept 9.5 hours a night with a serum zinc level of 0.96 mg/l. The group that slept under six hours at night had an elevated hs-CRP at 3.23 mg/l, compared to 1.92 – 2.85 mg/l for those sleeping between 6.5 and 9.5 hours at night. Sleeping over 10 hours at night raised the hs-CRP to 3.77 mg/l. The serum copper levels were highest in those sleeping less than six hours at 1.13 mg/l, those sleeping 9 hours at 1.14 mg/l, and those sleeping more than 10 hours at 1.17 mg/l, compared to between 1.10 and 1.12 mg/l for the other sleep duration groups. After accounting for certain confounders, only the copper and hs-CRP levels remained significant.
In another study on elderly patients, a higher copper to zinc ratio, and a lower zinc level and antioxidant capacity, correlated with a higher risk of physical disability. The patient group had a 47.5 percent lower level of serum zinc compared to the control, and they had a 10.8 percent higher copper level and a 112.5 percent higher copper to zinc ratio compared to the control. The researchers concluded that the copper to zinc ratio is a reliable parameter for determining the physically disabled patients compared to the controls.
One study found that in patients with heart failure, copper levels were higher. Both acute heart failure patients and chronic heart failure patients had significantly higher blood copper levels than controls, although the levels did not differ significantly between the two. Conversely, the serum zinc levels were significantly lower in both sets of heart failure patients compared to the control. This was independent of other risks for heart disease.
The ratio also plays a role in metabolic health. In patients with type-1 diabetes, which is known to contribute to oxidative stress, the level of serum zinc was significantly lower and the level of serum copper was significantly higher in patients with diabetes, especially those with poor glycemic control. This led to a higher copper to zinc ratio, as well as higher levels of SOD. The researchers in this study also found a correlation between the HbA1C levels and the copper to zinc ratio, with a higher ratio correlating with a higher HbA1C.
Zinc and copper work hand in hand in many of their beneficial tasks, which is why it is important to not only concern yourself with just the amount of zinc or copper you consume. You also want to ensure you retain a good copper to zinc ratio to avoid the potential health risks discussed. If you are concerned, you can ask your doctor to perform a blood test to assess your serum copper and serum zinc levels. One way to do this is to ensure you consume adequate amounts of both minerals, primarily through diet. If you supplement with one, then you want to ensure you supplement with the other, unless you already have an imbalanced ratio.
Getting Your Recommended Zinc and Copper
As with most nutrients, the best place to start to get your zinc and copper is through food sources. The best food sources of zinc, from highest to lowest, include:
– Organic, grass-fed beef
– Sesame seeds
– Pumpkin seeds
– Adzuki beans
– Wild rice
– Pine nuts
– Cashew nuts
– Navy beans
– White beans
– Sunflower seeds
– Black beans
– Split peas
The best food sources of copper, also from highest to lowest, include:
– Sesame seeds
– Cocoa powder
– Cashew nuts
– Sunflower seeds
– Brazil nuts
– Adzuki beans
– Kidney beans
– White beans
– Mung beans
– Pine nuts
As you can see from the list, many foods have both zinc and copper, making it easy to maintain your ratio. Some of the foods with the best copper to zinc ratio include oysters, sesame seeds, cashew nuts, and sunflower seeds. Foods in the nuts, seeds, and legume families often are rich sources of both zinc and copper, and they also have many other benefits. For example, Brazil nuts, known for their high selenium content, also are rich in other minerals, including zinc and copper. The average concentration of zinc in 100 grams of Brazil nuts is 4.7 mg, and the same serving has an average 2.0 mg of copper. Granted, an average serving is more often closer to one ounce or 6 nuts, which has 1.15 mg of zinc and 0.494 mg of copper. In addition to these nutrients, you also get healthy fat, protein, fiber, phytonutrients, selenium, magnesium, calcium, and phosphorus. These work synergistically to further promote optimal health.
Although several common foods contain copper, those following the typical “SAD” diet might still risk deficiency. The number of people presenting with copper deficiency is increasing, which might be due to a reduction in copper intake. It might also be from an increase in zinc consumption, which causes an imbalance in the ratio that might present as copper deficiency.
What You Need to Know About Supplementing
Zinc has a reputation for being healthy, including supporting the immune system and acting as an antioxidant. This has led to many people supplementing with high doses of zinc. Zinc is also found in many cough drops and other cold remedies. Because of the potential toxicity of copper, many people stay away from supplemental doses of it. Where does this leave you? With a risk of an out of balance zinc to copper ratio, which as discussed above can cause problems. So, what do you do?
For one, do not supplement with high levels of just one of these minerals, such as zinc, without knowing your serum levels and/or ratio, which can be done with various lab tests. The most common is a blood draw for serum zinc and copper levels, which most doctors can perform. You might have to calculate your own copper to zinc ratio using the results for your serum zinc and copper levels. You need to make sure that both are in the same units, which is generally ug/dL. You might receive results with the units as umol/L, which requires you to divide the zinc by 0.153 and the copper levels by 0.157. If you have units such as L or mg, then you will have to perform metric conversions, which is usually multiply or dividing by a factor of 10. For example, to get from g/L to ug/dL, you would multiply by 100,000. You can also use an online conversion tool. Once they are in the same units, you simply divide the copper level by the zinc level. Some specialty labs will perform this for you.
In those with high copper levels, supplementing with just zinc might be fine. In one study, supplementing with 10 mg of zinc gluconate helped to improve the copper to zinc ratio, which in turn helped to normalize oxidative stress and inflammation biomarkers in hemodialysis patients.
It seems self-evident that if your zinc/copper ratio is off balance, supplementing with one will help. However, work with a healthcare practitioner so you will not end up altering the balance the other way. Often, using a supplement with both zinc and copper ensures you retain a good ratio.
High levels of either mineral also come with other risks. Taking excessive amounts of zinc in supplemental form can lead to side effects, including vomiting, diarrhea, and abdominal cramps. Using nasal sprays might also disrupt your sense of smell. The tolerable upper intake level (TUL) for zinc is 40 mg for adult women and men. Excessive copper intake through supplementation also comes with its risks, including altering the copper to zinc ratio and toxicity. The TUL for copper is 10,000 ug/day for adults. You will want to check for the TUL for other age groups, as well as pregnant and lactating women.
In some cases, you might need high doses, such as in cases of malabsorption. However, you do not want to undertake this alone. As always, discuss supplementing with your doctor or other healthcare professional. They will work with you to determine a level of zinc and/or copper supplementation that ensures you have adequate amounts of both to retain the right ratio based on your situation and health concerns.
It is important you consider all of your sources of both zinc and copper beyond food and supplements when determining if you are at risk of an imbalance. For example, a patient using excessive amounts of denture adhesive that contained zinc presented with severe copper deficiency symptoms. Additionally, copper might leech from any pots and pans, and you might also find it in your drinking water. If you have well water and are concerned about your drinking water, you can contact your state certification officer to perform a test for free. Those not on a well, you can purchase testing kits from a variety of places that are simple to use and do not cost a lot of money.
The copper and zinc relationship is just another example of the delicate balance that the essential minerals—and micronutrients in general—play with one another for our maximal health. Recognizing the ways in which nutrients interact with others will help you formulate a better plan to maintain your optimal health through your diet and supplements.
Rainbow Foods & Supplement Course
Are you ready to learn even more about the balance of minerals in your body? Then I invite you to join me this January for the Rainbow Foods & Supplements Course, where I’ll teach you even more about the emerging, trending health findings and scientific research in the food, eating, and supplement fields!