Methylglyoxal (MGO)
The compound responsible for manuka honey's non-peroxide antibacterial activity, and the number most manuka is priced on.
Definition
Mānuka nectar contains dihydroxyacetone, which converts non-enzymatically into methylglyoxal over weeks and months as the honey matures. Most honeys contain only trace amounts. Its significance is that it produces antibacterial activity in vitro that does not depend on hydrogen peroxide — and peroxide activity, which every honey has, is destroyed by catalase present in human tissue. MGO ratings on a jar state the concentration in milligrams per kilogram.
Where the word gets used loosely
A high MGO number is a laboratory measurement, not a health outcome. There is no clinical evidence that eating higher-rated manuka produces a proportionally greater effect in a person, and price rises far faster than the rating does. The established medical use of honey is topical wound care with sterilised, regulated products under supervision — a different context that does not transfer to a kitchen jar. Note also that whether anyone independently verified the number is a separate question from whether the measurement is objective.
See also
Other chemistry terms
Sources
Sources
- Identification of methylglyoxal as the dominant antibacterial constituent of manuka honey — Molecular Nutrition and Food Research / Carbohydrate Research (2008) · Peer-reviewed article
- UMF grading and the New Zealand manuka honey definition — UMF Honey Association / New Zealand Ministry for Primary Industries · Industry body
How sources are selected and weighted is set out in the sources and evidence policy.