Honey and charcoal, used by medical practitioners since ancient times, still persist in modern hospitals. Not every medicine has to be sophisticated.
Most medicines are boring: a single compound that interacts with a particular target (usually a protein of some variety) in the human body to bring about a beneficial effect. For the modern-day drug developer, this simplicity is desirable. A mixture of compounds, such as is found in herbal remedies, can hit multiple targets and produce many effects, some of which may be unwanted.
For all the benefits of keeping medicines straightforward in their composition and actions, there remains a place for those which act non-specifically. Two of our oldest medicines, honey and charcoal, are still found in hospital supply cabinets precisely because of their crudeness.
Honey begins its life as nectar, the sugary solutions that plants make in their flowers as a lure for pollinators. Foraging bees take the bait, consume the nectar, and store it in their honey crop, a specialised structure just beyond the oesophagus and separated from the stomach and intestines by a valve. Inside the crop, enzymes break apart sucrose in the nectar into the simpler sugars glucose and fructose. Back at the hive, this digested nectar is regurgitated and stowed away in the cells of honeycomb. There, evaporation gradually reduces its water content, ultimately producing the viscous, sugary goo we know as honey.
Honey is mostly water and simple sugars, but it also contains an assortment of proteins, organic acids, vitamins, trace elements and plant-produced phenolic compounds. This messy mixture confers the sugary goo with a unique set of abilities beneficial to wound healing.
Firstly, and most importantly, honey is hostile toward bacteria. Its high sugar content limits the availability of life-enabling water (this is why jams and marmalades keep so well), while its acidity hinders the growth of most disease-causing bacteria. The presence of the enzyme glucose oxidase means the slow yet steady generation of bacteria-destroying peroxides, the actions of which are complemented by a collection of flower- or bee-derived antibacterial compounds.
Components of honey also appear to inhibit biofilm formation (a key step in the infection of a wound by bacteria), limit the tissue damage and swelling associated with inflammation, and help close off a wound and replace it with normal tissue by recruiting reparative white blood cells and boosting growth factor production.
Currently, honey is used in hospitals in specialised dressings applied to external wounds — be they burns, bed sores, diabetic ulcers, or surgical incisions — to stave off bacterial infections while promoting healing. Honey has also been investigated as a treatment for bacterial gastroenteritis (stomach flu), as a substitute for glucose in oral rehydration fluid used to counter diarrhea.
Charcoal is made by carefully cooking down ground up organic material in the absence of oxygen to remove everything but the element carbon. It’s been manufactured from such varying source materials as blood, fish, kelp, peat, coconut shells, coal, bone and wood. Humans have been making charcoal since we started working with metals, as you can achieve much higher fire temperatures with less smoke using charcoal in place of wood (since there’s no water to take away heat when it boils off). At the start of the 20th century, a Russian scientist by the name of Raphael von Ostrejko introduced the idea of activating charcoal by reacting it, while hot, with an oxidising gas (usually steam, air, or carbon dioxide). This additional step creates numerous tiny pockets within the charcoal, vastly increasing its surface area.
Unlike honey, activated charcoal is used internally, introduced into the stomach and intestines via the mouth to sop up a wide range of accidentally or intentionally ingested poisons. In general, it’s good at binding organic compounds but not so much strong acids and bases, ethanol or heavy metals. Activated charcoal is typically used when a patient has taken overdoses of highly toxic substances or a sustained release medication.
But like honey, charcoal is a mixture (albeit one of molecules consisting solely of carbon) that acts in a nonspecific manner when used as a medicine. As a result of the weak van der Waals forces that act between nearby molecules, a wide range of substances will stick to the surfaces of the carbon structures making up charcoal. This makes charcoal a general antidote in cases where a person has recently ingested a poison or too much of a drug, as it will bind up the harmful substance and thereby limit how much of it gets outside of the digestive tract.
In addition to being able to capture many drugs and poisons, the tremendously large surface area of activated charcoal ensures that a relatively small dose can adsorb a great deal of the poison. When toxicologists write about the surface area of single doses of activated charcoal, they speak in terms of football fields. Specifically, 50 grams of activated charcoal possesses seven fields’ worth of poison-adsorbing surface.
Honey and charcoal share a similar early history. The ancient Egyptians applied charcoal to festering wounds in an effort to reduce their stench. The Edwin Smith papyrus, a medical text dating back at least three thousand years, includes a recipe for a honey-based wound salve. The Greek physician Hippocrates included honey in the formulations he prescribed for pain, fever, and wounds. He and his contemporaries viewed charcoal as an effective treatment for such disparate conditions as anemia, epilepsy, and anthrax.
Two thousand years later, European scientists discovered the ability of charcoal to adsorb gases and organic compounds from liquids, which led to investigations into its usefulness as an antidote. After successful trials with various mammals, charcoal made its way into hospitals in the early decades of the 19th century. This adoption was likely spurred by at least two famous instances where the utility of charcoal in avoiding certain death by poisoning was publicly demonstrated — the first involving arsenic, and the second, strychnine. As long as the demonstrator ingested charcoal alongside an otherwise lethal dose of the poison, no harm befell them.
Charcoal became increasingly popular in the early 20th century, and advertisements lauded it as a cure for numerous ailments. All the while, the administration of charcoal to recently poisoned individuals remained relatively uncommon until the 1960s, when this approach to detoxification received a particularly glowing review in a medical journal. It has since become commonplace in the emergency rooms of the world.
Although it has enjoyed a longstanding popularity in traditional medicines throughout the world, honey did not undergo scientific vetting until the late 19th century. Its ability to inhibit the growth of bacteria was first reported in 1892, and it saw action among wounded Russian and Chinese soldiers during the First World War. However, the utility of honey in the treatment of infected wounds wasn’t documented until the mid-20th century. Even then, unable to compete with sulfa drugs and other antibiotics, honey was largely ignored until the 1980s.
As of late, honey has caught the eye of those seeking a way to counter the rise of antibiotic resistance among bacteria around the world. It appears to be good at killing resistant bacteria such as MRSA that are associated with wound infections and hasn’t become the target of resistance itself. Unlike antibiotics, which attack a single target within bacteria and can be shrugged off fairly easily with the right mutation, honey is challenging for bacteria to develop resistance against because its antimicrobial actions occur via several distinct mechanisms.
Charcoal remains relevant because it is inexpensive, effective and relatively safe to use. The most common issue with giving someone charcoal is that they vomit it back up. Not coincidentally, the most serious concern with charcoal is a person can aspirate it into their lungs if they vomit while unconscious.
Our oldest medical treatments tend to be the crudest ones. They’re the survivors of a modern drug development gauntlet focused on simplicity. While most medicines are individual compounds with highly specific mechanisms of action, honey and charcoal each work more generally. This lack of precision is what keeps these ancient medicines relevant today.
Edited by Timothy Newport and Diana Crow