Heavy Metal Detox, Explained

The basics

Your body already detoxes metals

Two organs do most of the work. Your kidneys filter some metals out of the blood and into your urine. Your liver handles others.

In the liver, a small molecule called glutathione does the grabbing. Your body makes it itself. Glutathione contains sulphur, and metals such as mercury and cadmium stick to sulphur. The liver then sends the pair out in bile, the digestive fluid that flows into your gut.

The leak

Your gut takes some of it back

Once the metal reaches the gut, it should leave with your stool. But the gut can absorb part of it again, and it goes back to the liver. Scientists call this loop enterohepatic cycling. It is one reason some metals, mercury from fish in particular, stay in the body for weeks or months.

So what does a "detox" try to do? Most detox ideas aim at this loop. They try to hold on to the metal inside the gut so that it leaves with your stool instead of being taken back in.

Breaking the loop

Binders, and how strong the evidence is

Fibre. Fibre from beans, lentils, oats and vegetables binds some substances in the gut and helps them leave with your stool. It is good for you anyway, so it is an easy first step.

Zeolite. A volcanic mineral (the type sold for this is called clinoptilolite). It is full of tiny cages with a negative charge. Positively charged metals such as lead and cadmium swap into those cages and get stuck. The mineral is not absorbed, so it leaves with your stool. Most of the evidence comes from animals; human studies are few. In the EU, there is no approved health claim for zeolite.

Probiotics. Some strains of good gut bacteria can bind metals such as cadmium, lead and arsenic on their surface, so that more leaves with your stool. A small study in pregnant women in Tanzania found that a probiotic yoghurt helped limit the rise of mercury and arsenic in their blood. It is an early, promising result.

Spirulina and curcumin. Spirulina is a blue-green algae. Curcumin is the active part of turmeric, the yellow spice. A small study in people with long-term arsenic exposure tested spirulina with zinc. Curcumin has mostly been studied in animals. Both are early.

What about glutathione pills, coriander or chlorella? Your body makes its own glutathione. A six-month trial found that glutathione pills raised the body's stores, but it did not measure metals. Coriander and chlorella have mostly lab and animal data. None of these is proven to remove metals in people.

What is proven

Start here

1. Cut the sourceThe biggest win is taking in less. Old paint and pipes, some fish, rice, some spices and cosmetics, cigarette smoke, certain jobs and hobbies. Our Hidden Metals Guide lists where each metal turns up.
2. Eat enough iron and calciumLead and cadmium enter the body through the same "doors" in the gut as iron and calcium. When your iron or calcium is low, your gut takes up more metal. Meat, beans, lentils and leafy greens bring iron; dairy, sardines, tofu and greens bring calcium.
3. Don't start high-dose iron on your ownToo much iron harms too. If you think you may be low, ask your doctor for a blood test first.
4. Add fibre every dayBeans, lentils, oats, vegetables and fruit. Useful for the loop, and good for you anyway.
5. Test the right wayIf you want to know your levels, use a test that is read correctly. See our Heavy Metal Test Prep guide.

A word of care

Chelation is for real poisoning

Chelation means taking a drug that grabs metals in the blood and pushes them out through the kidneys. It is a real treatment, but only for real metal poisoning, and only under a doctor. The US Food and Drug Administration has never approved any chelation product sold over the counter, and warns that chelation can cause dehydration, kidney failure and even death.

Be careful with "provoked" urine tests, where you take a chelating drug before the test. Almost anyone looks high that way. Our guide Heavy Metals, in Plain Words explains why.