What is Methylglyoxal (MGO)?
Methylglyoxal, or MGO, is an organic compound that is widely recognized for its potent antibacterial properties, most famously associated with Manuka honey. It is a reduced derivative of pyruvic acid and forms naturally in honey over time from another compound, dihydroxyacetone (DHA), which is found in nectar. While MGO is a natural byproduct of certain metabolic pathways in organisms, its presence in food products like honey is influenced by the source material and processing.
MGO Levels in Normal Honey vs. Manuka Honey
The primary difference between standard supermarket honey and Manuka honey lies in their respective MGO concentrations. Multi-floral or conventional honeys, which come from a variety of floral sources, have very low MGO levels, typically ranging from 0.4 to 5.4 mg/kg. In contrast, Manuka honey, sourced specifically from the Manuka tree (Leptospermum scoparium) nectar, contains exceptionally high levels of DHA, which converts into MGO during storage and maturation. As a result, Manuka honey can have MGO concentrations that are up to 100 times higher than conventional honeys, often ranging from 100 mg/kg to over 800 mg/kg in high-grade products. It is this high concentration that gives Manuka its unique, non-peroxide antibacterial activity.
How Does Methylglyoxal Form in Honey?
Methylglyoxal formation in honey is a process that begins with the nectar collected by bees. The precursor to MGO, dihydroxyacetone (DHA), is a compound found in varying quantities in the nectar of different plant species. Once honey is made and stored, a slow, non-enzymatic reaction occurs in which DHA is converted into MGO. This process explains why raw, freshly harvested honey typically has lower MGO levels, and why the concentration tends to increase over time with proper maturation. Research has demonstrated that storing honey at warmer temperatures can accelerate this conversion.
Factors Influencing MGO Levels
Several factors determine the final MGO content of any given honey. These include:
- Floral Source: This is the most critical factor. The concentration of DHA in the nectar is the single greatest determinant of the final MGO level. Manuka flowers have particularly high DHA levels, which is why their honey is so potent.
- Geographic Origin: The specific growing conditions and genetics of the plants can vary by region, impacting the DHA content of the nectar.
- Storage Time and Temperature: The conversion of DHA to MGO is a time-dependent process that is accelerated by heat. Proper storage is crucial for managing the honey's MGO content.
- Processing: Excessive heat, such as that used during pasteurization, can damage some of the beneficial enzymes and compounds in honey, potentially affecting MGO levels. Raw, unprocessed honey is generally best for preserving natural compounds.
Comparison of Normal Honey vs. Manuka Honey
| Feature | Normal Honey (e.g., Clover, Wildflower) | Manuka Honey |
|---|---|---|
| Floral Source | Nectar from a variety of flowers (multi-floral). | Predominantly from the nectar of the Manuka tree (Leptospermum scoparium). |
| Primary Antibacterial Factor | Hydrogen peroxide, created by the enzyme glucose oxidase. This is easily degraded by heat and enzymes in the body. | Methylglyoxal (MGO), which is more stable than hydrogen peroxide, and other unique compounds. |
| MGO Concentration | Very low levels, typically 0.4–5.4 mg/kg. | High to very high concentrations (e.g., MGO 150+ to 800+ mg/kg). |
| Potency and Use | Mild antibacterial properties suitable for general use. | Strong, non-peroxide antibacterial activity, often used for therapeutic applications like wound care and digestive health. |
| Cost | Generally more affordable and widely available. | Significantly more expensive due to its unique properties and limited geographical source. |
The Bottom Line: MGO in Your Honey
So, does normal honey have methylglyoxal? The definitive answer is yes, but the concentration is the key distinction. While all honey is a natural product with its own health benefits, it’s the exceptionally high and stable MGO content in Manuka honey that sets it apart for specific therapeutic uses. DHA, a precursor to MGO, is present in the nectar of various floral sources, not just the Manuka plant, confirming that trace amounts of MGO can be found across many types of honey. When considering antibacterial properties, Manuka's non-peroxide activity, driven largely by MGO, is significantly more potent than the hydrogen peroxide-based activity of most conventional honeys.
For those seeking the strongest potential antibacterial benefits, a Manuka honey with a certified MGO rating is the clear choice. However, for everyday use and for those who enjoy honey for its flavor and general health benefits, any normal honey is a perfectly healthy and delicious option. As with any food product, heat can affect the natural compounds, so if you are interested in preserving the full spectrum of beneficial compounds, consider raw, unprocessed honey and avoid boiling it. Further research into the unique compositions of different honeys continues to provide a more nuanced understanding of their properties.
Visit the NIH for more on methylglyoxal's role in Manuka honey's properties.
Conclusion
In summary, methylglyoxal (MGO) is not a compound exclusive to Manuka honey; it is present in small quantities in all types of honey. The significant difference lies in the concentration. Manuka honey contains dramatically higher levels of MGO, which it develops from a high concentration of dihydroxyacetone (DHA) in its nectar during storage. This results in Manuka's powerful non-peroxide antibacterial properties, a characteristic not found in normal honey. Standard honeys offer their own health benefits, primarily from hydrogen peroxide, but are less potent and less stable than Manuka. Ultimately, the presence of MGO is universal in honey, but its therapeutic significance is a matter of concentration.
