Medicinal Clay Properties, Health Benefits, and Precautions
Medicinal and Cosmetic Clays
Clay has been used medicinally for a very long time. It's been eaten to treat gastrointestinal problems and other diseases, used to remove toxins and kill parasites, packed into wounds to stop bleeding, and spread over the skin to treat surface ailments or improve the skin's condition. It's still a popular material. Interestingly, scientists are finding evidence that supports some of the traditional beliefs about the health benefits of clay.
Medicinal and cosmetic clays are often sold as a powder, which may be white, grey, pink, red, green, blue, brown, or black in color. The color depends on the identity of the minerals that are present as well as the substances that are mixed with the clay, such as plant material. Edible clays are generally mixed with liquid to form a drink and are found in some health food markets. Cosmetic clays are found in a wider variety of stores.
What Is Clay?
Clay deposits are made of minerals belonging to a family known as aluminum phyllosilicates."Phyllo" means that the minerals are arranged in leaf-like layers. Different types of clay contain different aluminum phyllosilicates.
Clay minerals come from weathered and eroded rocks. They exist as very fine particles which are less than two micrometers in size, according to the definition of "clay" in geology. A micrometer is a thousandth of a millimeter. The minerals may exist on their own or mixed with other materials in soil.
Most clay minerals can absorb a great deal of water and may swell as they do so. Many can also bind ions at their surface (a process known as adsorption) and then release the ions later when the environment changes. An ion is an electrically charged particle consisting of an atom or a group of atoms. Clay minerals tend to have negative charges, so many of the ions that they attract are metal ions, which are positive. In nature, opposite charges attract each other.
The practice of eating clay is a type of geophagia. Geophagia, or geophagy, is the eating of materials that come from the earth, such as clay, chalk, or soil. Geophagia is in turn a type of pica, which is the ingestion of non-food substances.
Pica is usually considered to be abnormal and pathological. It may be a symptom of iron-deficiency anemia, for example. However, scientists are beginning to think that geophagia may be an adaptation to satisfy a nutritional need instead of being pathological.
More than two hundred species of animals are known to eat soil, including gorillas, chimpanzees, elephants, deer, and birds. Humans have eaten soil and especially clay since at least the time of Ancient Greeks.
Some pregnant women develop an urge to eat soil in the early stage of their pregnancy, often when they have morning sickness. Women in some cultures traditionally eat clay at this time. The reason why the women are attracted to the material is uncertain. It may provide minerals needed by the mother or fetus or it may remove toxins (and perhaps bacteria and viruses) that could hurt the fetus.
Eating untreated earth materials from nature may be dangerous due to the presence of contaminants.
Clay Licks and Animals
A clay lick is an area that animals visit in order to feed on clay. Parrots in the Amazon basin are frequent visitors to the licks. There are many theories as to why they need to eat clay. One idea is that it provides nutrients that the birds lack, such as calcium, sodium, or iron. Another is that it detoxifies poisons in the seeds and unripe fruits that they eat.
There is evidence supporting the ideas that soil and clay can detoxify poisons in parrots and other animals. In the 1990s, Dr. James Gilardi observed that Peruvian parrots regularly fed on a particular patch of soil instead of on another patch nearby that contained more minerals. He decided to investigate the reason for this preference.
Gilardi performed an experiment in which he fed parrots a toxic substance called quinidine. Some of the parrots were also fed their favorite soil, while others weren't. Gilardi then tested the level of quinidine in the parrots' blood. The birds who had eaten the preferred soil had a sixty percent lower level of quinidine in their blood than the other birds. The amount of clay in the soil wasn't reported. Investigations of chimpanzees and baboons have shown that clay ingestion reduces toxin absorption in their bodies, however.
Scarlet Macaws and Medicinal Clay
Humans use many different types of clay for medicinal and cosmetic purposes. Bentonite and kaolin are two clays that are used medicinally.
What Is Bentonite?
Bentonite is a clay produced by the weathering of volcanic ash. Its main componment is a mineral called montmorillonite. The two main types of bentonite are calcium bentonite, in which the dominant metallic ion is calcium, and sodium bentonite, which is rich in sodium ions.
Bentonite is used in the food processing industry to clarify liquids and as an ingredient in food packaging materials, so very tiny amounts enter most of our bodies on a regular basis.
Bentonite is not absorbed in the intestine and is a GRAS (Generally Recognized As Safe) substance when ingested in small amounts, according to an FDA report. It's important to note that while small to moderately small quantities of ingested bentonite are considered to be harmless, large quantities may be harmful.
Possible Health Benefits of Bentonite
In natural and alternative medicine, bentonite clay is often recommended for detoxification. Scientific evidence supporting this benefit is lacking, however. Just because some types of clay appear to prevent toxin absorption in a bird or another animal doesn't mean that bentonite does the same in humans, although this is a possibility. Even if bentonite is potentially useful for this purpose, researchers need to identify the concentration that is both effective and safe for removing toxins.
Bentonite is sometimes used as a laxative. Since it absorbs water and bulks up the contents of the intestine, it can trigger defecation. The amount of bentonite that is eaten is of critical concern, however. Bentonite may absorb so much water and swell to such a large extent that it blocks the intestine.
Anyone who is pregnant or who has a health problem should consult their doctor about the advisability of using medicinal clay.
Bentonite Clay Uses
Possible Dangers of Bentonite
Bentonite's powerful ability to absorb water is shown by the fact that bentonite cat litter can act as an intestinal obstruction if a pet dog decides to eat it. The litter may absorb liquids from swallowed food and from the digestive fluids, expanding and blocking the intestine.
A high dose of bentonite in our gut may absorb important nutrients, preventing us from using them. At higher concentrations it interferes with vitamin A absorption in lab animals and hinders the their growth. In addition, it can absorb the electrolytes that we need, such as potassium ions. It may also absorb medications, so it should be ingested at a different time from any other medicines.
Another reason why the clay may be dangerous is that it sometimes contains poisonous chemical impurities or microbes. The source and purity of a bentonite supplement are therefore very important.
It's also important that the dosage recommendation on a container of bentonite or any other medicinal clay isn't exceeded, even when a doctor agrees with its use. If the recommended dose doesn't help a health problem, it's time to visit the doctor again.
There is scientific evidence supporting some health benefits of clays. For example, researchers at Arizona State University have shown that at least some clays can kill bacteria in the lab.
The researchers made water extracts from four different types of clay to isolate the clay minerals. They then investigated the effects of the extracts on the MRSA bacterium and on Escherichia coli (or E. coli). MRSA, or methicillin-resistant Staphylococcus aureus, is resistant to common antibiotics, including methicillin. It's a serious problem in hospitals, care homes, and the general community. Although some strains of E. coli are helpful to humans, others can cause dangerous infections or cases of food poisoning.
The researchers found that metal ions attached to the clay minerals could kill bacteria. Their experiment showed that at certain concentrations copper, zinc, cobalt, and nickel ions killed E.coli. Copper, zinc and cobalt ions killed MRSA. In order for the metal ions to destroy the bacteria, however, the pH and temperature had to be suitable.
These results are very promising. The next step in the research is to see whether the clays have the same antibacterial benefits in living things and in situations outside the lab as they do in lab equipment.
Kaolin and Bleeding
An old belief is that clay can help wounds heal. Researchers have shown that in the case of at least one clay this claim is true. In fact, even the army is using gauze which is impregnated with the clay. The name of this very useful clay is kaolin and the gauze is called Combat Gauze. Combat Gauze is available for the general public as well as the military.
Kaolin helps blood to clot when someone is wounded, thereby preventing blood loss from the body. Blood clotting or coagulation is a normal process that happens when a person is wounded and blood vessels break. The blood must clot to prevent the person from bleeding to death and to prevent the entry of dangerous microbes into the body. Blood clotting happens via a chain of reactions called the coagulation cascade. Each reaction depends on the previous reaction in the chain in order to occur. Kaolin enters this cascade and triggers a vital step in the blood clotting process.
Kaolin and Diarrhea
Kaolin is used in some diarrhea medications because of its ability to absorb water. One popular brand of anti-diarrhea medication is Kaopectate. This used to contain kaolin and pectin but contains bismuth subsalicylate instead today. Kaolin continues to be used in some medications, however.
Kaolin may be helpful for diarrhea. Like bentonite, however, it may absorb certain nutrients and medications while in the gut. A combination of kaolin and pectin seems to be especially problematic in this respect.
Uncontaminated kaolin is considered to be safe when taken internally. It isn't absorbed from the intestine into the bloodstream. It should be noted that while clays such as bentonite and kaolin are generally safe when eaten (as long as an excessive amount isn't ingested), chronic inhalation of a clay in the form of a dust can be dangerous.
Clay and Skin Care
Clay reportedly removes oil and impurities from the skin. It's also said to exfoliate the skin, removing old cells from the skin surface to reveal younger ones underneath. In addition, it's said to help acne. These are all wonderful claims, but there isn't much scientific evidence to support them at the moment. This doesn't mean that they aren't true, however.
Perhaps in the future scientists will show that clay has skin benefits. For now, it's important to read reviews written by people who've actually used a particular clay product to see if it's useful and to discover possible side effects. After this, personal experience will enable someone to discover if the product is helpful for their skin.
There is one clay product that has shown that it can be helpful for the skin. Bentoquatam lotion contains bentonite. It's used to create a protective shield over the skin before exposure to the irritating oils of poison ivy, poison oak, or poison sumac. The lotion doesn't help a rash that has already developed due to exposure to these plants, but it can stop one from forming.
A bentoquatam lotion needs to be applied about fifteen minutes before the first potential exposure to an irritant and then every four hours after that.
Medicinal Clay in the Future
It's possible that clay has many medicinal benefits and that many old and current beliefs about its value are true. We won't know this for certain until more research is done, however. The discoveries so far are very interesting. It certainly seems that this ancient remedy is worth investigating further.
- A geophagia report from Scientific American
- Information about bentonite in food and medicines from the FDA (Food and Drug Administration)
- Clay and MRSA from Arizona State University
- Kaolin information from WebMD
- Benefits of a kaolin-based hemostatic pad from the Journal of Invasive Cardiology
- Bentoquatam lotion from MedlinePlus, National Institutes of Health
Questions & Answers
© 2013 Linda Crampton