Honey is most commonly used in dermatology applications for its antimicrobial properties, which are thought to be due to the enzymatic release of hydrogen peroxide from the honey. While the hyperosmolarity of honey impedes bacterial growth, the inhibines, which include hydrogen peroxide, flavonoids and phenolic acids, produce antibacterial effects directly.3
As a result of these properties, one of the most widely investigated applications of honey is in wound healing. Numerous studies have looked at the ability of honey to aid in the skin’s healing process as well as to inhibit and eradicate bacteria, including community-associated methicillin-resistant Staphylococcus aureus found on the skin.4
One study showed greater efficacy of honey over silver sulphadiazine for treating superficial and partial-thickness burns in patients.5 Another study looked at Medihoney—an FDA-cleared, gamma-irradiated, commercially available active manuka honey—and its effect on chronic pressure ulcers in patients with spinal cord injury, showing a significant improvement in wounds and decrease of bacterial growth.6
Manuka honey is often the honey of choice for medical application and is available as a medical device. Manuka honey comes from the honeybees feeding on the manuka tree (Leptospermum scoparium), which grows natively in New Zealand and Southeastern Australia.
The antibacterial action of manuka honey is not clearly understood, but in vitro studies have shown that methylglyoxal is one of the key phytochemical factors that lend manuka honey it antibacterial properties. It is thought that the amount of methylglyoxal in the honey correlates with the strength of the antibacterial activity. It is also hypothesized that the honey has an osmotic effect, drawing moisture from the environment and dehydrating bacteria.
READ: Indigo Naturalis
In addition, the pH of the honey is between 3.2 and 4.5, and it is thought that the acidic nature of the honey inhibits the growth of microorganisms.7 Manuka honey, in vitro, has been shown to affect biofilms of Streptococcus pyogenes resulting in significant cell death and dissociation of cells from the biofilm.8
While manuka honey is the current popular medical honey, Ulmo honey from Chile has also been shown to be effective against methicillin-resistant Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Ulmo honey was shown to be potentially more effective than manuka in a study funded by the honey producers.9 Other honeys may have medical use and one study showed healing utility from three different honeys, though the selection of rhododendron honey as one of the three may be considered a strange choice.10, 11