Activated charcoal: benefits, dosage, contraindications

Plant-based activated charcoal is a carbon-rich, porous material obtained by calcining wood (or other materials) heated to a very high temperature in the absence of air. The charcoal is then activated by increasing the number of pores, which increases its surface area. This is achieved by heating it at high temperature in the presence of steam or carbon dioxide, or with an activating agent such as phosphoric acid or zinc chloride. Activated charcoal is widely used to treat drug overdoses and poisonings. Activated charcoal can be prepared from plant byproducts such as coconut shells, cherry and olive pits, or date pits. The adsorptive power of activated charcoals is essentially attributed to porosity and specific surface area (surface area per unit mass, expressed in m²/g), representing the area available to adsorb a monolayer of molecules. The surface area developed by activated charcoal is substantial: 1 g of activated charcoal has a specific surface area between 400 and 2,500 m²/g. Activated charcoal demonstrated its ability to prevent toxicity when two of its early pioneers, Bertrand (1813) and Touéry (1831), publicly ingested arsenic and strychnine, respectively, with activated charcoal and survived. Subsequently, researchers demonstrated in vitro the action of activated charcoal on a wide range of toxins, notably morphine, barbiturates, salicylates, and other drugs. In addition to its role in the neutralizing toxins, activated charcoal has been shown to adsorb gases, which suggests it could play a role in reducing flatulence. Because of its adsorbent character (that is, attracting substances to the surface of the material), activated charcoal can help treat liver and kidney disorders. Oral intake of activated charcoal can lower cholesterol levels and reduce elevated bile acid levels.