Copper is an important trace mineral. We need it for normal growth, bone strength, immune function, and cardiovascular health. However, too much of it can be toxic. Read this post to learn more about the health benefits of copper, harmful effects of copper overload, and ways to change your copper absorption.
How is Copper Used in the Body?
Copper is an integral part (cofactor) of a group of enzymes called cuproenzymes (R), which are important for:
- Energy production in the cell (cytochrome C oxidase) (R)
- Formation of strong and flexible connective tissue (lysyl oxidase) (R)
- Iron metabolism (multi-copper oxidases, ferroxidases) (R)
- Normal function of the brain and nervous system (dopamine β-hydroxylase, cytochrome C oxidase) (R)
- Antioxidant activity (superoxide dismutase, ceruloplasmin) (R)
- Formation of the pigment melanin (tyrosinase) (R)
Health Benefits of Copper Supplementation
1) Copper is Important for Proper Immune Function
Copper plays an important role in white blood cell growth and function.
One month of copper supplementation in infants with copper deficiency significantly increased the ability of white blood cells to engulf pathogens (R).
In the 19th century, workers exposed to copper salts did not develop cholera during the cholera epidemics (R).
2) Copper is Important for Bone Health
Copper plays an important role in bone formation (R).
Copper supplementation reversed bone abnormalities in copper-deficient infants (R).
In copper-deficient elderly patients, copper supplementation improved copper status and markers of bone resorption and formation (R).
3) Copper is Essential for Heart and Blood Vessels Health
Copper is essential for the strength and integrity of the heart and blood vessels (R, R2). Copper supplementation improves altered heart function, and promotes the regression of heart enlargement caused by copper deficiency (R, R2, R3, R4).
A study in healthy young women found that supplementation with 6mg of copper for 4 weeks led to a 30% reduction in plasminogen activator inhibitor-1 (PAI-1), thus decreasing a risk for atherosclerosis (R, R2).
In rats, copper supplementation decreased blood levels of total cholesterol, triglycerides, and “bad” LDL–cholesterol while slightly increasing “good” HDL-cholesterol (R). This was because copper increased the body’s own antioxidant defenses, by increasing total antioxidant levels and glutathione peroxidase enzyme activity (R).
A clinical study confirmed this finding (R), which suggests that copper supplementation can be used in the treatment of patients with high triglycerides and cholesterol.
4) Copper May Prevent Neurodegenerative Diseases
Copper is important for the activity of enzymes that are crucial for brain development and function (R).
5) Copper May Protect Against Cancer
6) Copper Improves the Well-Being of the Skin
Copper oxide, due to its antimicrobial and antifungal properties, can be used for treating athlete’s foot infections when used as copper-impregnated socks (R).
Cooper used in wound dressings can help enhance wound healing by increasing skin regeneration and formation of new blood vessels (R). In addition, the copper in wound dressings also has potent antimicrobial properties, which can reduce the risk of wound contamination (R).
These copper oxide products are non-irritating and safe to use both on intact and damaged skin (R).
7) Copper May Heal Stomach Ulcers
8) Copper May Reduce Anxiety and Depression During Pregnancy
The Bad: Copper overload
Causes of copper excess
- Inflammation (R)
- Infection (tuberculosis, leprosy, viral hepatitis, pneumonia and chicken pox) (R, R2, R3)
- Hematologic diseases (iron deficiency anemia, aplastic and pernicious anemia, sickle cell anemia, and beta-thalassaemia) (R, R2)
- Diabetes (R)
- Heart and blood vessel disease (R, R2)
- Malignant diseases (acute and chronic leukemia, Hodgkin’s disease, multiple myeloma, breast and lung cancer) (R, R2, R3, R4)
- Liver disease (cirrhosis, hepatitis, obstruction to bile flow) (R, R2)
- Contraception (oral contraceptive use, copper intrauterine device) (R, R2)
- Pregnancy (R)
- Drugs (water pills) (R)
Signs of Copper Overload
Acute Copper Toxicity
Copper toxicity occurs with the ingestion of copper compounds usually with suicidal intent, or with accidental consumption of copper-contaminated foods, or water.
Ingestion of more than 1 g of copper can cause copper toxicity. However, this is only a rough threshold for toxicity and depends on individual factors (R).
Symptoms include stomach ache, nausea, vomiting, diarrhea, dizziness, and muscle pain. More serious signs of copper toxicity include severe liver and kidney damage, hemolytic anemia, massive gut bleeding, and even death (R, R2, R3).
Chronic Copper Overload
The long-term copper toxicity is not frequent in individuals who do not have inherited disorders of copper metabolism.
Chronic ingestion of copper supplements taken in a dose of 30-60 mg/day during 3 years caused severe liver disease (R).
Negative Health Effects of Copper Excess
1) Excess Copper Causes Oxidative Damage
Excess free copper is toxic (R).
2) Copper Overload is Associated with Alzheimer’s Disease
Copper is thought to contribute to AD since alterations in copper levels tend to precede symptoms of AD in some, but not all patients (R).
3) Copper Excess May Increase Risk of Parkinson’s Disease
Free copper has the ability to produce free radicals, and increase Lewy body formation, the hallmark of Parkinson’s disease (R).
4) Copper Excess Alters Immune System Function
High intakes of copper significantly reduced the number of neutrophils, levels of IL-2, and levels of antibody level against the Beijing strain of influenza.
5) Copper Increases Risk of Hearth and Blood Vessel Disease
Copper levels in the blood and in the blood vessel wall are elevated in individuals with atherosclerosis.
6) Copper Levels May Be Associated with Diabetes
7) Copper May Be Associated with Depression
Sources of Copper
Food Sources of Copper
- Liver (especially calf, lamb, beef)
- Seafood (oysters, squid, lobster, crab)
- Fruit and vegetables (dark leafy vegetables, potatoes, mushrooms, avocados, dried fruit)
- Seeds (sesame, sunflower, pumpkin)
- Nuts (cashew, hazelnuts, Brazil nuts, walnuts),
- Beans (chickpeas, soybeans, adzuki),
- Goat cheese
- Soy products (tofu, tempeh, soy milk, soy powder)
- Chocolate, cocoa
- Wheat bran cereals and whole-grain products
A number of copper supplements are available in the form of copper oxide, copper chloride, copper gluconate, copper sulfate, and copper amino acid chelates (R).
Although copper is essential to health, copper supplementation is unnecessary for most healthy individuals (R).
Copper supplementation should not be used in individuals with genetic disorders affecting copper metabolism:
- Wilson’s disease (R)
- Idiopathic copper toxicosis (R)
- Childhood cirrhosis syndromes (Indian childhood cirrhosis, idiopathic copper toxicosis) (R, R2)
The Recommended Dietary Allowance (RDA) for copper (R):
- Children 0.3-0.9 mg/day (depending on age)
- Adults 0.9 mg/day
- Pregnancy and lactation 1-1.3 mg/day
The average intake of copper from food in the United States is approximately 1.0 to 1.6 mg/day for adult men and women.
The Tolerable Upper Intake Level, the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects for almost all individuals, for adults is 10 mg/day (R).
The human body is somewhat protected from copper deficiency and toxicity because the body can balance copper absorption with physiological needs and elimination.
Copper absorption becomes more efficient with reduced dietary copper intake, and vice versa (R). When measured in humans, copper absorption was only 12% when the intake was 7.5 mg/d, but it increased to 36% when the intake was 1.7 mg/d (R).
The balance of copper in the body is also maintained by copper excretion. The excretion of copper is low when dietary copper is low, whereas excretion increases as dietary copper increases (R).
In the liver, copper is either incorporated into the proteins and enzymes or secreted into the bile (R).
Most of the copper (70-95%) is bound to ceruloplasmin, the main copper carrier in blood, while the remaining 10% is bound to albumin or carried as amino acid-bound copper, and transported into various tissues (R, R2).
Organs with a high copper content include liver, brain, kidneys and heart (R).
Approximately 80-90% of dietary copper is excreted in the feces. The amount of copper excreted in urine, hair, and sweat is negligible (R).
Dietary copper is partially absorbed in the stomach. However, the largest portion of copper is absorbed in the beginning region of the small intestine (R).
Absorption of copper ranges from 15–97%, depending on several factors including age and sex of the individual, levels of dietary copper, forms of the copper, and composition of the diet.
Ways to Increase Copper Absorption
Ways to Decrease Copper Absorption
Zinc supplementation increases metallothioneins, proteins which bind copper and prevent its absorption.
Adequate copper blood level is necessary for normal iron metabolism and red blood cell formation (R).
Copper absorption may be influenced by the type of carbohydrate consumed.
Dietary fiber may decrease copper absorption (R).