Copper — Health Benefits, Foods List, and Supplements

by Jack Yacoubian | Last updated on March 25, 2024

Medically reviewed by Victoria Mazmanyan

Summary

Copper is an essential mineral that is important for numerous body functions. These functions often involve enzymatic reactions important in anti-oxidation, iron absorption, and maintaining a normal nervous system.
Copper is essentially consumed from beef liver and a variety of nuts. There are different copper requirements for each age category.
If the copper in our bodies is higher or lower than normal, it often presents as a pathological condition that a physician must treat.

Introduction

Copper is an essential trace mineral that plays a crucial role in various physiological functions in the body. It is involved in oxidation, elimination of free radicals, iron absorption, bone and connective tissue health, and nervous system function.

Copper is a cofactor for numerous enzymes necessary for energy production, antioxidative reactions, and iron metabolism (1).

This article will focus on the nutritional and health aspects of copper.

The nutritional part will discuss which foods are the richest in copper. We will also discuss how to keep copper levels at healthy amounts and avoid copper deficiency or toxicity.

We will also deep dive into the health aspects of copper, discussing acquired and genetic causes of metabolic problems related to copper, such as Wilson's Disease and Menke's Disease.

Daily Copper Requirement

The recommended daily allowance (RDA) for copper is the same for women and men. However, the amounts of copper needed per day differ based on age.

The table below shows the RDA of copper based on gender, age, pregnancy, and lactation (2).

Age	Male and Female	Pregnancy	Lactation
Birth to 6 months	0.2 mg
7–12 months	0.22 mg
1–3 years	0.34 mg
4–8 years	0.44 mg
9–13 years	0.7 mg
14–18 years	0.89 mg	1 mg	1.3 mg
19+ years	0.9 mg	1 mg	1.3 mg

Copper is a trace mineral, meaning minimal amounts of copper are needed to satisfy the body’s physiological functions.

Foods Rich in Copper

Copper sources are very diverse. They range from animal products to nuts and seeds. In the table below, we will list the top foods containing copper.

Food	Copper Content (per 100g)
Beef liver	14.28 mg
Oyster	4.29 mg
Sesame	4.08 mg
Cashew	2.195 mg
Brazil nut	1.743 mg
Hazelnut	1.725 mg
Walnut	1.586 mg
Lobster	1.349 mg
Pistachio	1.3 mg
Peanut	1.14 mg

Dietary restrictions do not significantly affect copper intake since copper is found in many foods.

Factors Affecting Copper Absorption

According to the American Journal of Clinical Nutrition, we absorb 30 to 40% of our dietary copper. Many factors affect the absorption of copper, ranging from physiological needs to the other nutrients found in the food.

Copper is absorbed in an ionic form, Cu+. However, copper is found in salt forms or bound to other organic compounds in food. Thus, the digestive system renders this copper into a bioavailable form.

Often, copper is in Cu2+ form, which must be reduced to Cu+ for the intestinal cells to absorb it (3, 4).

Macronutrients and Copper

Proteins and soluble carbohydrates increase copper absorption and bioavailability.

In comparison, fiber has an indirect effect on copper absorption. Fiber can increase or decrease nutrients that affect copper absorption. Thus, the indirect association can be positive or negative.

Vitamin C and Copper

Intake of vitamin C supplements or foods rich in vitamin C along with copper decreases the bioavailability of copper; combining both together negatively impacts our health. The health section will discuss how vitamin C and copper can negatively impact our health (5).

Minerals and Copper

Other minerals such as iron, manganese, and zinc can inhibit and decrease copper absorption. Thus, long-term supplementation with zinc or iron without regular follow-ups from a physician can cause copper deficiency.

Copper is essential for iron absorption. Copper deficiency may lead to reduced iron levels (6)(7).

Naturally, malabsorption of different origins in the digestive tract can lead to decreased copper absorption and copper deficiency.

Considering all the factors above, paying attention to which types of foods are consumed together and which should be separated is essential.

For example, we should eat copper-rich foods and soluble carbs or protein to increase our copper intake.

Copper Levels, Metabolism, and Absorption

Normal copper levels in the blood range between 10 to 25 mcmol/L (63.5–158.9 mcg/dL).

Most copper absorption occurs in the stomach and upper part of the small intestine, and most of the body's copper is stored in the liver, muscles, and bones (8).

Most of the copper in the blood is bound to a protein called ceruloplasmin. Thus, testing for copper in the blood is frequently done by measuring ceruloplasmin levels.

A smaller portion of copper in the blood is free or bound to other compounds, such as albumin.

Physiological and Biochemical Functions of Copper

Copper has several physiological and biochemical functions crucial for everyday health. Copper acts as a cofactor for different enzymes (cuproenzymes) in energy production, connective tissue synthesis, neurotransmitter synthesis, and iron metabolism (9).

In addition, copper is essential for normal immune system functioning, angiogenesis, gene expression, and defense against oxidative stress by superoxide dismutase enzyme (10).

Copper, iron, and magnesium are crucial for red blood cell formation.

As mentioned above, copper is essential in iron absorption (6,7).

Health Impacts of Copper

This section is a deep dive into the health impacts of copper. Considering the normal reference range and the physiological functions of copper, we will discuss copper deficiency and high levels of copper or toxicity.

Wilson's Disease

Wilson's Disease is a genetic disease that causes copper accumulation in the body. The copper accumulates in the liver, brain, and other organs. This build-up of copper leads to hepatitis and liver damage, neurological problems, and psychiatric issues.

Since copper mainly accumulates in the liver and nervous system, Wilson's Disease manifests in vomiting, jaundice, pruritus (itchiness), and swelling in the legs and abdomen (ascites). The neurological symptoms include tremors, muscle stiffness, anxiety, and psychiatric changes (11).

Menke's Disease

Menke's disease is a genetic disease leading to copper deficiency. This disease starts during infancy, usually after a couple of weeks from birth. The symptoms include a weak muscle tone, brittle hair, seizures, neurodegeneration, and failure to thrive.

Menke's disease requires treatment with copper injections. Simply increasing dietary copper does not fix the deficiency (12).

Neurological Diseases

Altered levels of copper are hypothesized to be associated with an increased risk of Alzheimer's disease. Defective areas of the brain have a very low copper content (13).

In addition, there is a link with Parkinson's disease as well. However, these diseases can exist without altering copper levels (14).

Type 2 Diabetes

Altered copper levels are linked with oxidative stress and cellular damage linked with an increased risk of type 2 diabetes. In addition, data indicated that altered copper levels during type 2 diabetes increase the risks of complications due to diabetes (15).

However, more data and research are needed to establish proper causation.

Kidney Disease

Combining vitamin C and copper in high amounts causes a Fenton reaction, which can damage our kidneys and cause kidney injury due to oxidative stress.

It is best not to consume them together, especially in higher doses (16).

Individuals with kidney disease should be careful of foods high in vitamin C and copper.

Copper Deficiency

Copper levels should be below 63.5 mcg/dL to diagnose copper deficiency. Clinicians must also test the ceruloplasmin levels. However, in clinical cases, symptoms of copper deficiency start showing when copper levels are even lower, as low as 5 mcg/dL (17).

Symptoms of Copper Deficiency

Copper deficiency can have many symptoms. Some are listed below (18):

Anemia
Low body temperature
Bone fractures and osteoporosis
Low white blood cell count
Irregular heartbeat
Loss of pigment from the skin
Thyroid problems

Causes of Copper Deficiency

The leading causes of copper deficiency are the following (18):

Gastric bypass and gastrectomy - bariatric surgeries
Inflammatory bowel disease
Cystic fibrosis
Celiac disease
Overuse of zinc supplements
Denture cream ingestion
A diet low in copper

Gastrectomy and gastric bypass surgeries are the leading causes of acquired copper deficiency. However, it takes several years for copper stores in the body to deplete after the surgery (7).

It is rare to have copper deficiency due to nutrition when there are no pathological underlying issues. Yet, it can still happen.

Consuming low amounts of copper for a long duration can lead to a deficiency. Note that this takes years to manifest and cause symptoms.

In addition, even when we consume adequate levels of copper, sometimes zinc supplements or other medications discussed below can contribute to a copper deficiency.

Thus, knowing nutrients and medications that can interact with copper is essential. Keeping consumption to recommended daily allowance levels is also important.

Copper Overload

Copperiedus is also known as copper toxicity. It can either be primary due to a genetic problem or secondary due to an underlying pathology regarding the metabolism of copper, such as excretion (19).

Excessive amounts of copper induce oxidative stress, DNA damage, and inhibition of new cell formations.

To diagnose copper intoxication, a panel of tests should be done, but mainly, the blood copper levels should be higher than 158.9 mcg/dL. The higher the number, the more severe the symptoms and manifestation.

Symptoms of Copper Intoxication

Abdominal pain
Vomiting with blood
Diarrhea
Dark, bloody stool (melena)
Anorexia
Severe thirst
Blue-green pigmentation in feces or vomit

In severe forms, copper intoxication can lead to hepatitis and hepatic cell death (necrosis), cardiac failure, kidney failure, encephalopathy, hemolysis (destruction) of red blood cells, coma, and death (20).

High Copper Consumption

Consuming copper in high amounts over long periods or misuse of copper supplements can cause copper intoxication (7)(8).

However, this is rare since the upper limit of daily copper consumption is high.

The table below demonstrates the upper limit of copper consumption per day.

Ages	Upper Limit
Birth to 12 months	Not Established
Children 1–3 years	1 mg
Children 4–8 years	3 mg
Children 9–13 years	5 mg
Teens 14–18 years	8 mg
Adults	10 mg

Copper Supplementation

Copper supplementation and dietary copper consumption can cause an overload in copper if not done correctly. This can cause an acquired form of copper intoxication, which can cause hepatitis and neurological symptoms similar to the ones mentioned in the section above.

It's advised that copper supplements should be recommended by a doctor who bases them on need and indication.

Forms of copper supplements (21):

Copper oxide
Copper sulfate
Copper chelate
Copper gluconate

The most bioavailable forms of copper supplements are copper chelate and copper gluconate.

Interactions with Medications

There is a list of medications that can interact with copper. Thus, it is essential to inform your doctor if you are taking copper supplements or mention your clinical history of copper-related problems (18).

The medications are:

Birth control pills and estrogen following menopause
NSAIDS like ibuprofen
Penicillin antibiotics
Allopurinol (Zyloprim)
Cimetidine (Tagamet)
Nifedipine (Adalat or Procardia)
Zinc

References

Author name: Jack Yacoubian

Education: Haigazian Medical University

Last updated: March 25, 2024

Medically reviewed by Victoria Mazmanyan