Dr. Peter Molan

Associate Professor of Biochemistry

Director of the Honey Research Unit

University of Waikato, New Zealand

Winter published in the journal Nature in 1962 his finding that wounds heal a lot faster if kept moist. There have been a lot of other publications added to this in the years since, and it has now become standard practice for medical practitioners expert in wound care, but not for all. The outer layer of the skin serves to stop water loss from the body, and thus keeps the deeper tissues moist. When the outer layer is damaged a crust of dried serum (a scab) forms to act as a barrier to water loss, but this is only partially effective. For re-growth of skin tissues at maximum rate to repair injury fully moist conditions are required.

Another problem with healing under a scab is that the outer layer of skin is restored by the cells growing across the wound from the edges. These cells will grow only in fully moist conditions so they grow across deeper down under the scab. The consequence, when the wound is healed is that there is a pitted scar left, where the new skin is below the level of the surrounding skin. Also there is the problem with leaving a wound dry of having the dressings stick to the surface of the wound. When dressings are changed this tears off the scab, not only causing pain but also tearing away newly re-grown skin tissue. Many of the modern high-tech "non-adherent" dressings still stick to some degree to the wound surface.

So why do many people still not keep wounds moist to get them to heal? Like the cells of the skin tissues, bacterial cells need moist conditions to grow. By keeping a wound fully moist this creates the best conditions for bacterial growth. Antiseptics are all damaging to skin tissues and slow the rate of healing. Antibiotics often cause adverse reactions, and are increasingly found to be ineffective as more and more bacteria develop resistance to them. Also, neither penetrate from the surface of a wound to get to bacteria infecting deeper tissue.

Honey creates moist healing conditions but will not allow bacteria to grow because of its antibacterial properties. Furthermore it will clear up any infection already developed. But honeys vary as much as 100-fold in their antibacterial potency. The Ancient Greek physicians were aware that only certain honeys were suitable for medical use, and this wisdom is also seen in present day folk medicine around the world.

It was because of the folk knowledge in New Zealand that manuka honey is particularly good for treating injuries that it was investigated at the University of Waikato and its unusual antibacterial component was discovered.

The major problem bacteria that infect wounds have been tested for their sensitivity to honey, using honeys in the middle of the range of potency. Such honeys are 10 to 50 times more potent than they need to be to completely halt the growth of these bacteria, including the antibiotic-resistant "superbugs".

In this testing the mid-range manuka honey and the mid-range honey with the usual type of antibacterial activity were found to be of similar potency. So what is special about manuka honey? Honeys other than manuka owe their antibacterial properties to hydrogen peroxide produced by enzyme action in the honey. Hydrogen peroxide is broken down by an enzyme that is in the body's tissues. The unidentified manuka factor ('UMF®') is not broken down, so on a wound (as opposed to laboratory testing) manuka honey would be a lot more strongly antibacterial than other honey. Also, in laboratory testing the honeys are diluted for comparison. The enzyme that produces hydrogen peroxide in honey does not work unless honey is diluted. Yet the 'UMF®' is active in undiluted honey. With undiluted honey there is maximum antibacterial action from manuka honey, and no production in other honey of the hydrogen peroxide that gives it its antibacterial action. Another important difference is that the 'UMF®' in manuka honey penetrates skin tissues very easily, so it can reach bacteria in deep-seated infections, but the hydrogen peroxide in other honey does not.

This is where the rating of the 'UMF®' is important. The higher the antibacterial potency on the surface, the deeper down into infected tissues there will be sufficient antibacterial activity to clear up infection. Also, where there is fluid oozing out from an open wound diluting the honey put on a wound, the higher the antibacterial potency at the start the longer there will be maintained sufficient potency to be effective.

A wound will not heal if infected. Bacteria produce toxins, and cause inflammation which itself stops healing, causes pain, and causes fibrotic scarring. A honey with sufficient antibacterial potency stops all of these problems.