Zeolites are fascinating crystals possessing microscopic pores and metal binding abilities. They are usually formed naturally in lava flows but they can also be made in the laboratory [1, 2]. Since their discovery the crystals have attracted considerable interest from scientists due to their ability to organize themselves into hundreds of useful shapes. Right now, various forms of zeolite are being explored for their use in areas as diverse as water purification, oil refining, cosmetics and medical therapies.

 

Traditional Uses of Zeolite

Zeolites are essentially molecular sieves that are able to bond with a variety of metals and it is these properties that have made them extremely useful in the past. Historically, the minerals have been used to decontaminate water since they can capture a wide range of toxic metals and pollutants directly from the water supply. When added to water, harmful pollutants like lead and ammonia are locked away inside the zeolite crystals and replaced by harmless metals like calcium, which are released from the zeolite pores [3, 4]. Zeolite also plays a major role in the petrochemical industry where it is similarly used to remove metals from crude oils and to help break them down into fuels like petroleum [5]. One of the most noted use of zeolite today is as animal feed additive due to its anti-caking properties.

 

Modern Uses of Zeolite

More recently, zeolites are being studied for their potential use in a variety of medical and cosmetic applications, including whole body detoxification. Some of these applications are really exciting, whereas others could be considered misleading.  Most importantly, these modern applications mean that people will be directly exposed to zeolite and this could potentially be dangerous[6]. The danger arises because there are some toxic forms of zeolite, containing harmful metals that may be released inside your body when eaten [7]. The full risks associated with ingesting zeolite are currently unknown since no sole toxicological studies have looked at zeolite ingestion in humans. However, most studies do show that only very small particles (below 200 nano-meter) can actually make it across the small intestine and into the body, meaning that zeolite is definitely too big to make it into your bloodstream [8]. It is therefore highly unlikely that zeolite is able to perform any ‘detoxifying’ effects outside of the gut. This is fortunate trait, since insoluble silica based nano-particle in bloodstream would wreak havoc resulting in over-stimulation of immune system and potentially death. Therefore, beware of the misleading “DETOX” zeolite claims, particularly when promoted in context of size. Be sure to check supplier certificates and zeolite origin.

 

The Future

On a more positive note, the fact that zeolites are retained in the gut does make them useful for variety of applications. Certain zeolites such as clinoptilolite are actually very useful for delivering medications to where they are needed inside the body. Scientists are been developing and shaping zeolites to deliver drugs like painkillers and vaccines and there are some promising studies ongoing [9]. One of these exciting trials has shown that zeolites can be used to selectively release arthritis treatments inside the intestine, which avoids damaging the stomach [10]. Additionally, the demonstrated ability of zeolite to interact with bacteria revealed that they are also capable of increasing the amount of beneficial bacteria in our gut [11], just like probiotic yogurts are designed to do. Due to gut microbiome complexity this research might lead to new direction uncovering yet unseen unique zeolite characteristics.

Powdered, synthetic zeolites are known to irritate the eyes and inside the nose, but most forms are non-irritating to the skin and do not provoke the immune system [7]. The non-toxic reports of zeolite on skin contact do mean that zeolite can also be used safely in cosmetics that are applied to the surface of the skin. Additionally, because zeolite is too large to pass across the skin and into the body then there is an even smaller risk of toxicity. Since zeolites have been used to safely trap toxins and pollutants from water and air for many years then there is no evidence to suggest that they will not do the same when applied to your skin. The best part is that there is no harm in trying them.

 

References:

  1. Khodayar, M. and H. Franzson, Fracture pattern of Thjórsárdalur central volcano with respect to rift-jump and a migrating transform zone in South Iceland. Journal of Structural Geology, 2007. 29(5): p. 898-912.
  2. Li, J., A. Corma, and J. Yu, Synthesis of new zeolite structures. Chemical Society Reviews, 2015. 44(20): p. 7112-7127.
  3. Pandey, P.K., S.K. Sharma, and S.S. Sambi, Removal of lead(II) from waste water on zeolite-NaX. Journal of Environmental Chemical Engineering, 2015. 3(4, Part A): p. 2604-2610.
  4. Wang, S. and Y. Peng, Natural zeolites as effective adsorbents in water and wastewater treatment. Chemical Engineering Journal, 2010. 156(1): p. 11-24.
  5. Choudary, N.V. and B.L. Newalkar, Use of zeolites in petroleum refining and petrochemical processes: recent advances. Journal of Porous Materials, 2011. 18(6): p. 685-692.
  6. Boranic, M., [What a physician should know about zeolites]. Lijec Vjesn, 2000. 122(11-12): p. 292-8.
  7. Thomas, J.A. and B. Ballantyne, Toxicological Assessment of Zeolites. Journal of the American College of Toxicology, 1992. 11(3): p. 259-273.
  8. O’Hagan, D.T., The intestinal uptake of particles and the implications for drug and antigen delivery. Journal of Anatomy, 1996. 189(Pt 3): p. 477-482.
  9. Rimoli, M.G., et al., Synthetic zeolites as a new tool for drug delivery. J Biomed Mater Res A, 2008. 87(1): p. 156-64.
  10. Elham, K., et al., Synthetic Zeolites as Controlled‐Release Delivery Systems for Anti‐Inflammatory Drugs. Chemical Biology & Drug Design, 2016. 87(6): p. 849-857.
  11. Prasai, T.P., et al., Zeolite food supplementation reduces abundance of enterobacteria. Microbiological Research, 2017. 195: p. 24-30.