Mud, marvellous mud

We scold our children for playing in it and lament it trodden into the carpet, but mud has long been celebrated for its healing benefits. Widely used for its skin-perfecting properties, research also suggests it could hold the key to significant advances in medicine and antibiotic resistance.

Words JO JUKES

There are more living things in one teaspoon of soil than there are people on the planet, according to the James Hutton Institute, a scientific research institute based in Scotland.

It’s no secret that mud is often used in baths and facials to soften the skin, but research also suggests that elements of mud may hold answers for the future of medicine, pain relief and antibiotic resistance.

And it’s not just physical health that mud can benefit; a bacterium commonly found in soil has been found to alter the behaviour of laboratory mice in the same way as antidepressants, and could pave the way for a future “stress vaccine” to help minimise the effects of post-traumatic stress disorder (PTSD) and other mental health conditions.

Since the pandemic, many of us have become clean fanatics. But when dirt holds the key to many health benefits, we shouldn’t be afraid get our hands dirty.

What is mud?

By definition, mud can be a mixture of soil, clay, silt, minerals and earth; when mixed with water it takes a liquid form. Clay is a soft rock-based compound and is often one of the elements that come together to make mud.

You have probably come into contact with some of the more common types of clay, like French green clay or bentonite clay, both of which have purifying properties and are often utilised in skincare products to help balance oily or acne-prone skin.

Centuries of healing

The use of mud in health and beauty treatments isn’t new. Cleopatra is perhaps the most famous mud-enthusiast; the Queen of Egypt founded the world’s first spa, located by the Dead Sea, and was allegedly said to use mud-wraps to keep her skin looking youthful. Today, people still travel from around the world to float in the Dead Sea and lather themselves in mud in the name of smooth, glowing skin.

Closer to home, New Zealand Māori have used geothermal muds and sulphurous waters in traditional healing practices for centuries to soothe their battle-scarred bodies. New Zealand is home to some of the most active geothermal activity in the world, and the Rotorua region on the North Island is home to Hell’s Gate, the country’s only geothermal mud spa.

Mud baths

Mud baths are perhaps the most common way to reap the benefits of mud. I visited the Hell’s Gate mud spa for exactly that reason. Holding my breath a little to avoid the smell of rotting eggs (caused by the mineral-rich sulphur water), I immersed myself in the warm water, slathering clumps of mud onto my arms, back and face. Washing it off some 20 minutes later, my skin felt softer and smoother, with a slight tingle. Was it just a placebo? Science suggests not.

Mark Frazer is a tour guide at Hell’s Gate. According to Frazer, the mud at the geothermal spa is so healing that it’s medically certified and was once supplied to a local hospital. “[Hell’s Gate] used to supply black mud to a hospital in Rotorua, which treated people with ailments like arthritis and rheumatism,” says Frazer.

The key mineral that helps ease aches and pains is magnesium, but the geothermal mud also contains silica, alumina, calcium, iron, titanium, sulphur, phosphorous, sodium and potassium. Such minerals are also beneficial for acne-prone skin, particularly the bactericidal properties of sulphur, which kills bacteria and assists in the prevention and elimination of acne. “We had a young fellow here three years ago,” says Frazer, “working during the summer for a couple of months. He had chronic acne. We put him on a program of using the mud on his face once a day, and when he left, that acne was virtually clear.”

The benefits of mud baths aren’t unique to New Zealand. In 2010, a study published in the Rheumatology International journal explored the efficacy of mud packs and baths as a treatment for patients suffering from knee osteoarthritis. Researchers based at Rome’s Sapienza University separated patients into two groups; one underwent three cycles of mud-based spa therapy over the course of a year, and the other did not. Overall, the mud-bath therapy remarkably improved the clinical conditions of patients with knee arthritis and significantly reduced the frequency and severity of symptoms.

Mud baths are not recommended for pregnant people, those with high or low blood pressure or with certain health conditions. If you’re unsure then consult with your doctor before taking one.

Injuries and trauma

Mud and clay are also used to help heal and soothe trauma sites on the body. Mud-packing is an alternative therapy that has been used for centuries to help heal injuries, old wounds, aches and pains. Clay is mixed with herbal fluids to increase its detoxification properties and it’s applied to specific areas of the body such as scars and surgery or pain sites, and left on for around 10 minutes before being washed off.

Gary Beck is a naturopath who has been practising for over two decades and specialises in mud-packing. “Mud-packing is a tool used to help overcome some form of trauma or blockage in the body,” says Beck. “More specifically, it’s used to unblock energy flow in areas that have become blocked or traumatised. The term I use is that the trauma has caused an ‘interference field’. If you can envisage the meridian system used in acupuncture or Traditional Chinese Medicine, you may get a feel for how an area at one end of your body may in fact be affecting another part of your body.”

Practitioners believe that trauma blocks the flow of energy and disrupts how that energy communicates with organs, hormones and the body’s nervous system and energy centres, and that mud-packing treatments can help alleviate these issues.

Mineral-rich mud

In 2002, the Journal of Clinical Rheumatology reported the results of a small study conducted with mud pack treatments for knee arthritis. A group treated with natural mineral-rich mud compresses had a significant reduction in knee pain, but another group, given mineral-depleted mud compresses, had no significant change.

Not all mud is made equal. You can’t simply scoop a handful of mud from your garden and expect magical results; the key is mineral-rich mud.

Dr Zara Celik, a chiropractic doctor and owner of Melbourne’s Amara Wellness Centre, explains that high-quality mud is essential. Mud products can be purchased directly from professionals, but if you’re keen to make your own, Dr Celik recommends buying certified organic mud or clay, which you can mix with water or food-grade rosewater to form a paste. Massage onto your skin, leave to dry for oily skin, or almost dry for dehydrated skin, and wash off with a warm damp cloth.

Depending on what you want to achieve with your skin, you can add extra elements to the clay for a nourishing facial boost. “We sell certified organic clay here at the Wellness Centre. [Clients] can just mix it with water and apply, or they can put serum in it if their skin’s really dehydrated and dry,” says Dr Celik. “I also recommend using raw aloe vera gel extract, blended and added to the clay, for skin that is dehydrated or very itchy, particularly for eczema or rosacea.”

Opioid alternative

One of the newer and more innovative breakthroughs in using mud for health purposes has nothing to do with slathering it on your skin, but its potential for the future of antibiotics and pain relief medicine. In 2019, a sample of estuarine mud taken in Tasmania 16 years before has yielded a potential new class of painkiller as potent as opioids, but without their disadvantages. The properties of the mud’s marine fungi have the potential to bypass many of the negative side effects associated with traditional pain relief, including increased tolerance and addiction.

Professor Rob Capon is one of the researchers who made the discovery. Professor Capon is a professorial research fellow at the University of Queensland’s Institute for Molecular Bioscience. His research specialises in the search for molecules from nature that can be used to solve important scientific issues.

The potential of the findings from the Tasmanian mud are still being explored and, unfortunately, Capon’s research faces many obstacles. “It’s very expensive to get a new analgesic (painkiller) onto the market,” Professor Capon explains. “A lot of the large pharmaceutical companies have stepped away from even trying on the grounds they don’t want to run the risk of failure. They would rather focus on a different type of drug, which has a higher risk to market profile. So it’s a commercial challenge to get a new analgesic funded through the development phase.”

After the initial discovery, Professor Capon’s findings have now been passed onto researchers at the University of Sydney who have expertise in pharmacology and neuroscience for the next phase of experiments. Capon is hopeful that the researchers can put a strong enough case together to approach a major pharmaceutical company in the future.

Antibiotic resistance

Pain relief isn’t the only discovery found in the study of mud; it could also pave the way for new antibiotics. As superbugs becoming increasingly resistant to antibiotics and threaten to cause 10 million deaths per year worldwide by 2050, researchers are desperately looking for answers.

“One of the other [findings] we have, which is progressing even better, comes from a soil sample from a desert region in North Queensland,” says Professor Capon. “It gave us a bacterium on that occasion, rather than a fungus, and produced molecules that we discovered are very effective at killing tuberculosis, including multidrug-resistant strains of tuberculosis.”

Research is still ongoing, and Professor Capon’s team also runs the Soils for Science program, inviting Australians to donate samples of mud from their backyard so the researchers can study them to see what other medical advances could be made. Details can be found on their website.

Stress buster

That feeling of joy you get after an afternoon of digging in the garden isn’t just the satisfaction of a hard day’s work — there’s a science behind it. Good bacteria in soil form part of the microbiomes that build our resistance to illness and fight the bad bacteria that causes infection, and the good bacteria also have the potential to boost our mood.

In 2007, researchers from Bristol University and University College London carried out experiments using laboratory mice, and discovered that a “friendly” soil-dwelling bacterium called Mycobacterium vaccae activated brain cells to produce serotonin (“the happy hormone”) and altered the mice’s behaviour in a similar way to antidepressants.

Another study, published in the Proceedings of the National Academy of Sciences in 2016, showed that injections of M. vaccae prior to a stressful event could prevent a “PTSD-like” syndrome in mice, fending off stress-induced colitis and making the animals behave in a less anxious manner when stressed again later. This study was led by Christopher Lowry, associate professor in the Department of Integrative Physiology and Center for Neuroscience at the University of Colorado Boulder. Associate Professor Lowry hopes this bacterium could potentially be used to develop a microbe-based “stress vaccine”.

“We are hoping that M. vaccae NCTC 11659 [a strain of the bacterium] could be used for prevention of PTSD,” says Professor Lowry. “For example, by initiating a treatment regimen after trauma. Alternatively, M. vaccae NCTC 11659 could be used for prevention in individuals with a high risk of future trauma exposure, such as active military personnel, first responders or nurses in COVID-19 intensive care units.” Research is ongoing and showing positive results to date, and once funding is secured, researchers are planning to take their findings to clinical trials.

Mud is more than just a nuisance when it’s trailed through the house. It holds an array of health and wellbeing benefits, some of which are paving the way for the future of medicine — something to remember next time you’re digging in the dirt or clapping the mud off your shoes. A teaspoon of soil holds endless possibilities for health and wellbeing.