Honey

In medicine
For at least 2700 years, honey has been used by humans to treat a variety of ailments through topical application, but only recently have the antiseptic and antibacterial properties of honey been chemically explained.

Wound gels that contain antibacterial raw honey and have regulatory approval for wound care are now available to help conventional medicine in the battle against drug resistant strains of bacteria MRSA. As an antimicrobial agent honey may have the potential for treating a variety of ailments. One New Zealand researcher says a particular type of honey (Manuka honey) may be useful in treating MRSA infections. Antibacterial properties of honey are the result of the low water activity causing osmosis, hydrogen peroxide effect, high acidity, and the antibacterial activity of methylglyoxal.

Honey appears to be effective in killing drug-resistant biofilms which are implicated in chronic rhinosinusitis.

Osmotic effect
Honey is primarily a saturated mixture of two monosaccharides. This mixture has a low water activity; most of the water molecules are associated with the sugars and few remain available for microorganisms, so it is a poor environment for their growth. If water is mixed with honey, it loses its low water activity, and therefore no longer possesses this antimicrobial property.

Hydrogen peroxide
Hydrogen peroxide is formed in a slow-release manner by the enzyme glucose oxidase present in honey. It becomes active only when honey is diluted, requires oxygen to be available for the reaction (thus it may not work under wound dressings, in wound cavities or in the gut), is active only when the acidity of honey is neutralised by body fluids, can be destroyed by the protein-digesting enzymes present in wound fluids, and is destroyed when honey is exposed to heat and light. Honey chelates and deactivates the free ion, which starts the formation of oxygen free radicals produced by hydrogen peroxide and the antioxidant constituents in honey help clean up oxygen free radicals present.


 * C6H12O6 + H2O + O2 → C6H12O7 + H2O2

When used topically (as, for example, a wound dressing), hydrogen peroxide is produced by dilution with body fluids. As a result, hydrogen peroxide is released slowly and acts as an antiseptic.

In diabetic ulcers
Topical honey has been used successfully in a comprehensive treatment of diabetic ulcers when the patient cannot use other topical antibiotics.

Acidity
The pH of honey is commonly between 3.2 and 4.5. This relatively acidic pH level prevents the growth of many bacteria.

Methylglyoxal
The non-peroxide antibiotic activity is due to methylglyoxal (MGO) and an unidentified synergistic component. Most honeys contain very low levels of MGO, but manuka honey contains very high levels. The presence of the synergist in manuka honey more than doubles MGO antibacterial activity.

Nutraceutical effects
Antioxidants in honey have even been implicated in reducing the damage done to the colon in colitis. Such claims are consistent with its use in many traditions of folk medicine.

For throats
Honey has also been used for centuries as a treatment for sore throats and coughs, and according to recent research may in fact be as effective as many common cough medicines. It is important to remember however that this is an initial study with a small sample size.

Other medical applications
Some studies suggest that the topical use of honey may reduce odors, swelling, and scarring when used to treat wounds; it may also prevent the dressing from sticking to the healing wound.

Honey has been shown to be an effective treatment for conjunctivitis in rats.

Though widely believed to alleviate allergies, commercial honey has been shown to be no more effective than placebos in controlled studies of ocular allergies. However, a recent study has shown pollen collected by bees to exert an anti allergenic effect, mediated by an inhibition of IgE immunoglobulin binding to mast cells. This inhibited mast cell degranulation and thus reduced allergic reaction.

Honey mixed with water and vinegar was also used as a vermifuge. The concoction was called Oxymellin.

A review in the Cochrane Library suggests that honey could reduce the time it takes for a burn to heal - up to four days sooner in some cases. The review included 19 studies with 2,554 participants. Although the honey treatment healed moderate burns faster than traditional dressings did, the author recommends viewing the findings with caution, since a single researcher performed all of the burn studies.

Potential health hazards
Because of the natural presence of botulinum endospores in honey, children under one year of age should not be given honey. The more developed digestive systems of older children and adults generally destroy the spores. Infants, however, can contract botulism from honey. Medical grade honey can be treated with gamma radiation to reduce the risk of botulinum spores being present. Gamma radiation evidently does not affect honey's antibacterial activity, whether or not the particular honey's antibacterial activity is dependent upon peroxide generation.

Infantile botulism shows geographical variation. In the UK, there have only been six cases reported between 1976 and 2006, yet the USA has much higher rates 1.9 per 100,000 live births, 47.2% of which are in California. Although honey has been implicated as a risk factor for infection, it is household dust that is the major source of spores. Therefore the risk honey poses to infant health is small, if uncertain.

Honey produced from the flowers of rhododendrons, mountain laurels, sheep laurel, and azaleas may cause honey intoxication. Symptoms include dizziness, weakness, excessive perspiration, nausea, and vomiting. Less commonly, low blood pressure, shock, heart rhythm irregularities, and convulsions may occur, with rare cases resulting in death. Honey intoxication is more likely when using "natural" unprocessed honey and honey from farmers who may have a small number of hives. Commercial processing, with pooling of honey from numerous sources, generally dilutes any toxins.

Toxic honey may also result when bees are in close proximity to tutu bushes (Coriaria arborea) and the vine hopper insect (Scolypopa australis). Both are found throughout New Zealand. Bees gather honeydew produced by the vine hopper insects feeding on the tutu plant. This introduces the poison tutin into honey. Only a few areas in New Zealand (Coromandel Peninsula, Eastern Bay of Plenty and the Marlborough Sound) frequently produce toxic honey. Symptoms of tutin poisoning include vomiting, delirium, giddiness, increased excitability, stupor, coma, and violent convulsions. To reduce the risk of tutin poisoning, humans should not eat honey taken from feral hives in the risk areas of New Zealand. Since December 2001, New Zealand beekeepers have been required to reduce the risk of producing toxic honey by closely monitoring tutu, vine hopper, and foraging conditions within 3 km of their apiary.

source: http://en.wikipedia.org/wiki/Honey#In_medicine