For most people, “copper” calls to mind an important and increasingly rare commodity that’s found in a certain part of Zambia. Here, these mineral deposits were once so rich that the entire area was named Copperbelt Province. But copper isn’t just something that exists deep down in the earth. It’s closely and inextricably connected to life.

Read on to learn five fascinating facts about copper’s connection to humans’ health.

1. Copper is life

Virtually every single cell in the human body requires copper – not just for optimum health, but for our very survival. Healthy adult bodies are made up of approximately 0.0001% copper, which translates to between 50 and 80 milligrams, stored in our muscles, liver, and brain.

Think of the body as having copper “reserves” that the body draws on in precise amounts for optimum well-being. Copper is needed to make substances like melanin (in skin), bone, and connective tissue. It’s also vital for the normal functioning of our immune system, cardiovascular system, and nervous system – which, of course, includes the brain.

Virtually every single cell in the human body requires copper – not just for optimum health, but for our very survival.

2. Copper can make you more clever

There’s a reason that the brain is one of our major copper storage centres. From foetal development through to old age, copper continuously plays a role in maintaining brain health. Copper helps to create neurotransmitters, which are the chemical messengers that ensure efficient communication between nerve cells. It’s also involved in sending electrical impulses along our nerves, without which we wouldn’t be able to respond to sensations like pressure or heat. The trace element copper also interacts with other organic compounds to prevent epileptic seizures, a disorder of the central nervous system.

3. Copper in medicine is both ancient and cutting-edge

The first record of copper for medical purposes can be found in the Egyptian Smith Papyrus, one of the oldest books known to humankind. Written at some point between 2600 and 2200 BC, it refers to the use of copper in sterilizing chest wounds and drinking water.

Legend has it that Babylonian and Egyptian soldiers would use the filings from sharpening their swords – which were made of bronze (an alloy of copper and tin) – to sprinkle into their wounds, believing it reduced infection. They weren’t wrong.

Copper and its alloys exhibit powerful antibacterial, antiviral and anti-fungal properties. It’s no surprise that heavily-trafficked places like theme parks are replacing their most frequently touched surfaces with copper to help keep germs under control.

Fast-forward a few millennia to the 1800s, when copper’s role in the immune system was accidentally revealed during a series of cholera epidemics in Paris. Despite living amongst those who contracted the life-threatening disease, copper workers showed immunity.

Today, copper intrauterine coils (IUD) are one of the world’s most commonly-used methods of contraception, with copper acting as a spermicide within the uterus. Wearing copper bangles is believed to alleviate the symptoms of arthritis. Copper’s hygienic properties are steadily being recognised in hospitals, for preventing infection.

4. Copper grows on trees (if you know where to find it)

Copper is necessary to sustain life, but it isn’t manufactured in the body. Humans and animals need to obtain a healthy dose of this essential trace element from food or, occasionally, dietary supplements. Even plants require copper for normal growth.

Luckily, a number of different foods contain copper. Meat eaters can obtain substantial doses from seafood, liver, or other organ meats, while vegetarians can opt for chickpeas, beans, whole grains, nuts, or potatoes to ensure they get the copper required for a balanced diet. Many foods that are probably already a part of your diet include copper, like spinach, dried fruits, black pepper, yeast, and cocoa – and that includes dark chocolate! Depending on where you live, tap water from copper pipes may even contribute to your daily intake, although certain water filters remove all trace metals before they reach your lips.

According to the World Health Organisation, between 1 and 3 milligrams of copper per day is necessary to prevent copper deficiency in adults. Malnourished children, premature babies who do not receive nutritional supplements, the elderly, and lactating, pregnant or post-menopausal women are at highest risk of copper deficiency.

A lack of copper may lead to anaemia, heart and circulation problems, complications with the nervous and immune systems, and bone or connective tissue abnormalities. Copper deficiencies can also be caused by a rare genetic disorder called Menkes disease that interferes with copper absorption.

5. You can have too much of a good thing

Although humans have developed biological mechanisms to manage intake levels, too much copper can be toxic. Excess copper is usually excreted through the bowels and liver, but an unhealthy liver may lead to chronic copper poisoning, although it’s rare. Accidentally ingesting copper nitrate or copper sulphate solutions can cause acute copper poisoning.

A rare genetic disorder called Wilson disease causes copper to build up in certain organs and can disrupt the normal functioning of the kidneys, liver and brain. Birth control pills, infections, inflammation, stress, and pregnancy can all temporarily increase copper in the blood, but usually not beyond safe levels.

Copper is the future

Research into the potential for using copper complexes to treat patients undergoing certain types of radiation therapy for cancer – and, indeed, to treat the cancer itself – is ongoing. For otherwise healthy people who are exposed to radiation (such as astronauts) copper complexes also look promising.

From telecommunication to nerve cell communication, this naturally-occurring element has a deep and inextricable connection to our world, and its future.

See also: Five things you didn’t know about…emeralds