The Science Behind Honey's Antibacterial and Anti-Inflammatory Properties
How honey fights bacteria and calms inflammation at a molecular level, and what the clinical evidence actually supports.
Why honey resists bacteria in the first place
Honey is one of the few foods that almost never spoils, and the same chemistry that keeps it shelf-stable is what makes it hostile to bacteria. Ripe honey has a water activity of around 0.5-0.6, far below the 0.91 or higher that most bacteria need to grow, so microbes are effectively dehydrated on contact. Its sugar concentration, typically 80% or more, creates an intensely hypertonic environment that draws water out of bacterial cells through osmosis.
On top of this physical hostility, honey is naturally acidic, usually sitting between pH 3.2 and 4.5, which is low enough to inhibit many common pathogens outright. These three factors together, low water activity, high osmolarity and acidity, mean that even honey diluted with wound fluid or saliva retains meaningful antibacterial pressure long after it leaves the hive.
The hydrogen peroxide system
Bees add an enzyme called glucose oxidase to nectar as they process it into honey. When honey is diluted, this enzyme converts glucose into gluconic acid and hydrogen peroxide, a mild antiseptic that is released slowly over hours rather than all at once, which is one reason honey-based wound dressings are considered gentler on tissue than direct hydrogen peroxide solutions.
This peroxide activity varies enormously between honey types and can be destroyed by heat, light and the enzyme catalase, which some bacteria produce as a countermeasure. It is also the component most affected by processing, so raw, minimally heated honey generally retains more peroxide-based antibacterial capacity than pasteurised supermarket honey.
Non-peroxide activity and manuka honey
Some honeys, most famously manuka honey from New Zealand and Australia, retain strong antibacterial action even after the peroxide system is neutralised. This is largely attributed to methylglyoxal (MGO), a compound derived from dihydroxyacetone found in manuka nectar, which accumulates in the honey over time and is stable to heat and light in a way peroxide is not.
Manuka honey is graded commercially by Unique Manuka Factor (UMF) or MGO content, and clinical-grade medical honeys used in wound dressings are standardised and irradiated to ensure a consistent, sterile antibacterial dose. This distinguishes them from ordinary jarred honey, which is not sterile and is not licensed as a medical product.
How the anti-inflammatory effect works
Honey's anti-inflammatory reputation comes mainly from its polyphenol and flavonoid content, plant-derived compounds such as chrysin, pinocembrin and various phenolic acids that vary by floral source. Laboratory studies suggest these compounds can dampen the activity of pro-inflammatory signalling molecules and reduce oxidative stress, which is one proposed mechanism behind honey's traditional use for sore throats and minor irritation.
Its physical properties matter too. Honey is viscous and forms a protective, slightly acidic barrier over a wound or mucous membrane, which can reduce moisture loss, limit further irritation, and create favourable conditions for the body's own healing processes. This dual action, biochemical and physical, is why honey has been used topically for millennia.
What the clinical evidence actually shows
Systematic reviews of honey for wound care, including work published through the Cochrane Collaboration, generally find that honey can be helpful for certain wound types, particularly partial-thickness burns, where it may speed healing compared with some conventional dressings. Evidence for chronic wounds such as venous ulcers is more mixed, and honey is not a substitute for proper medical debridement or infection control in serious wounds.
For sore throats and coughs, honey has reasonably good evidence as a short-term symptom soother, comparable in some trials to over-the-counter cough suppressants, and UK guidance from NICE and Public Health England recommends honey as a first-line option for adults and children over one year before reaching for antibiotics in mild upper respiratory infections. It is not, however, a treatment for underlying bacterial infection, arthritis or serious inflammatory disease, and should never be applied to open surgical wounds without clinical guidance.
Frequently Asked Questions
Is all honey equally antibacterial?
No. Antibacterial strength varies widely by floral source, processing and freshness. Manuka and a handful of other monofloral honeys test far higher than typical blended supermarket honey, and heating or prolonged storage reduces peroxide-based activity.
Can I use ordinary honey on a wound at home?
For very minor cuts and grazes, food-grade honey has some supporting evidence, but it is not sterile. For anything beyond a superficial wound, use a licensed medical-grade honey dressing or seek clinical advice rather than jar honey from the cupboard.
Does honey cure infections if eaten?
There is no good evidence that eating honey treats internal bacterial infections. Its antibacterial action is best supported topically on skin, wounds and mucous membranes, not systemically through digestion.
Why is manuka honey more expensive?
Its non-peroxide antibacterial activity from methylglyoxal is unusually stable and strong, it is graded and lab-tested for potency (UMF/MGO), and genuine manuka nectar is regionally limited to New Zealand and parts of Australia, all of which drive up cost.
Are honey's anti-inflammatory effects proven in humans?
There is reasonable evidence for topical and throat-soothing effects. Broader claims about treating systemic inflammatory disease are not well supported by robust clinical trials and should be treated cautiously.