Copper benefits and side effects

Copper is a part of an enzyme called cytochrome C oxidase which is responsible for producing energy in the body.

Cytochrome oxidase is a part of the electron transport chain in the mitochondria membrane—every cell in the body has a powerhouse called mitochondria where glucose and oxygen are converted into energy in the form of ATP.

This enzyme helps generate electrical gradients across the membrane of the mitochondria, which, in turn, produces ATP, the energy currency of the cell.

Our body needs copper for both the development and maintenance of the immune system. Though the exact mode of action of copper remains unknown, studies show that a deficiency of copper affects both our innate immunity (the one we are born with) and our acquired immunity (the one we develop after exposure to pathogens).  

A deficiency of copper can lead to a condition called neutropenia, which refers to the reduction in the number of neutrophils, a type of white blood cells. Copper deficiency has also been shown to reduce the function of neutrophils. Similar effects have been noted on macrophages in copper-deficient animals. Macrophages are immune system cells that engulf pathogens and destroy them.

Animal studies show that copper deficiency increases the risk of infection and mortality and mitigating the deficiency improves immune function. 

The effects of copper deficiency on macrophages and other immune system cells have also been shown in malnourished infants and copper-deficient adults in small-scale studies. (Read more: How to improve immunity)

Finally, copper is shown to play a role in the inflammation process. The levels of copper are seen to increase in the body during active inflammation. Inflammatory cytokines are suggested to be copper-dependent. (Read more: Cytokine storm)

Apart from helping the immune system to fight harmful microbes, copper also plays a direct role in fighting pathogenic (harmful) bacteria that enter the body. 

It is suggested that the phagocytic cells use the antibacterial effects of copper to kill harmful bacteria. Our body uses the copper ions in cells as antioxidants to neutralise the free radicals formed during an infection. These radicals, if left as is, may damage body tissues. At the same time, copper depletes the antioxidants in the bacteria, which leads to bacterial death.

Additionally, copper also affects certain iron-dependent metabolic pathways in bacteria, which stop bacterial growth and kill them.

Read more: Bacterial infection symptoms

Copper has an important role in iron metabolism. Copper affects iron metabolism at almost every level, starting with the absorption of iron from the gut, movement of iron from cells, synthesis of heme from iron and reuse of iron in reticuloendothelial cells.

Reticuloendothelial cells mainly include monocytes and macrophages—two types of white blood cells that are crucial for our immune system. These cells store all the extra iron in the body. They also play a role in breaking down red blood cells (RBCs) and recycling the iron present in them. 

Low copper levels may cause the body to absorb less iron, which can lead to anaemia. So when your iron levels go down, your body sends copper to various areas of your body to increase their iron levels.

Copper containing enzymes convert iron from its ferrous to ferric state so that it can be transferred to various areas of the body through the transferrin protein.

Copper is involved in the synthesis of heme through cytochrome oxidase. Heme is an iron-containing compound present in RBCs that binds to and carries oxygen and carbon dioxide. (Read more: What is haemoglobin?)

It is not just copper deficiency but also copper excess that affects iron metabolism. Excess copper can reduce iron reutilisation from reticuloendothelial cells.

Various enzymes that are needed for brain function are dependent on copper. Copper is needed for the formation and maintenance of the myelin sheath in nerve cells. This sheath covers brain cells and helps in the quick transfer of signals through the brain. Copper is also needed for the synthesis of various neurotransmitters, chemical messengers in the brain.

Studies show that imbalance in copper levels may play a role in the pathogenesis of Alzheimer's disease. Alzheimer’s patients have a higher level of free copper in their serum as compared to healthy individuals. Copper is thought to play a role in the formation of brain plaques (a characteristic of Alzheimer’s) and increase oxidative stress in the brain leading to brain damage.

An excess of copper is also associated with prion diseases, as cellular prion protein is dependent on copper. Cellular prion protein (PRPC) plays an important role in reducing oxidative stress and transmembrane signalling between neurons. When PRPC converts into its PRPSC form, it leads to neurodegenerative prion diseases.

Additionally, Wilson’s disease and aceruloplasminemia (a genetic disorder marked by the absence of copper from blood and accumulation of iron in the brain) are associated with cognitive impairment and dystonia (repeated and involuntary contraction of muscles) like that in Parkinson’s disease. Copper is also associated with the pathophysiology of Parkinson’s, though the evidence is not clear.

Hence, copper balance is said to be highly important to maintain good brain health.

Copper is involved in the development and maintenance of bones. Copper deficiency is associated with decreased bone mineral density and increased risk of bone fractures. 

Copper deficiency is the cause of osteoporosis in people with Menkes disease. Menkes disease is a genetic disorder which occurs due to mutation in a gene—ATP7A—which is involved in the regulation of copper levels in the body. Low copper levels in those with Menkes leads to other problems such as kinky hair and nervous system dysfunction.

A study done in 11 healthy men showed that intake of about 0.7 mg of copper per day was found to improve bone resorption within six weeks.

In a randomized double-blind study, postmenopausal women were found to have less bone loss when given copper, zinc, and manganese supplements. 

According to a study published in the journal Osteoporosis International, copper deficiency also causes wearing down of teeth enamel in adults. Though the exact mode of action is still unknown.