Understanding Methylglyoxal (MGO)
Methylglyoxal (MGO) is unique to Manuka honey, setting it apart from other types of honey. It forms from dihydroxyacetone (DHA), abundant in the nectar of the Manuka bush. The MGO concentration directly links to the honey's antibacterial activity. A higher MGO rating indicates stronger antibacterial effects.
How MGO is Created and Graded
- Origin: MGO in Manuka honey comes from DHA found in the Manuka flower's nectar.
- Development: DHA levels decrease while MGO levels increase as the honey matures.
- Rating System: The MGO concentration (mg/kg) determines the honey's potency. Ratings can range from MGO 30+ to over MGO 1000+.
Proven Benefits of MGO in Manuka Honey
Extensive research has shown significant health benefits from the high MGO content in Manuka honey.
- Antibacterial Action: Manuka honey, and its MGO, effectively combats a wide range of bacteria, including antibiotic-resistant strains like MRSA. It hinders bacterial growth and biofilm formation, which is valuable in treating infections.
- Wound Healing: Manuka honey, approved by the FDA for wound treatment, helps heal cuts, burns, and chronic wounds by fighting infection and promoting tissue regeneration.
- Digestive Health: Manuka honey may support digestive health by fighting harmful gut bacteria related to IBS and C. difficile.
- Oral Health: MGO's antibacterial effect combats bacteria causing plaque and gum disease.
- Skin Care: Applied topically, Manuka honey can treat acne and eczema, thanks to its antibacterial and anti-inflammatory properties. It also hydrates the skin.
The Potential Risks: Concerns and AGEs
MGO has faced scrutiny due to concerns regarding its reactivity and connection to Advanced Glycation End Products (AGEs). The majority of these concerns stem from in vitro (lab-based) studies using high MGO concentrations.
- AGE Formation: MGO is a precursor to AGEs, which have been linked to oxidative stress and inflammation. The accumulation of AGEs is associated with chronic conditions like heart disease, diabetes, and neurodegenerative diseases.
- Cytotoxicity: In lab settings, high MGO concentrations have shown cytotoxicity and genotoxicity, raising concerns about long-term consumption of high-MGO honey.
- Diabetic Ulcer Caution: Some researchers have raised a specific concern that applying high-MGO honey on diabetic ulcers could potentially impair the healing process due to MGO's reactivity. More clinical research is needed in this area.
Low Bioavailability: The Reality of Consumption
It's important to distinguish between MGO's effects in the lab versus its impact after consumption. Studies show that the human digestive system effectively processes and neutralizes dietary MGO, making its systemic bioavailability very low.
- The gut rapidly breaks down ingested MGO, so very little enters the bloodstream.
- The MGO from a serving of Manuka honey is a small fraction of what the body naturally produces through its own metabolism.
- Therefore, in vitro studies with high concentrations do not accurately reflect the effects of eating Manuka honey.
Comparison: Dietary MGO vs. Endogenous MGO
This table compares MGO consumed through Manuka honey with MGO produced by the body.
| Feature | Dietary MGO from Manuka Honey | Endogenous MGO (Body's Metabolism) |
|---|---|---|
| Typical Amount | Small, a few milligrams per serving | Larger, up to 3 mmol daily in a healthy adult |
| Bioavailability | Very low; quickly degraded in the intestine | Produced internally, 100% bioavailable, managed by the body's glyoxalase system |
| Health Context | Generally managed by the body, low risk for healthy individuals | Higher levels linked to diabetes and renal failure when not properly managed |
| Effect on AGEs | Minimal contribution due to low systemic presence | Primary internal driver of AGE formation if not effectively neutralized |
Who Should Be Cautious?
While safe for most, some individuals should be cautious with Manuka honey.
- Diabetics: Manuka honey's high sugar content can affect blood sugar levels. Diabetics should consult a doctor before using it.
- Infants: Honey should not be given to children under 12 months old because of the risk of infant botulism from Clostridium botulinum spores.
- Individuals with Allergies: Those with allergies to honey, pollen, or bees should avoid Manuka honey to prevent allergic reactions.
The Role of Antioxidants
Manuka honey contains antioxidants like polyphenols and flavonoids, contributing to its health benefits and helping to counteract oxidative stress. These antioxidants may work alongside MGO, though MGO might not be the primary antioxidant. Manuka honey is a rich source of these beneficial compounds.
Conclusion: The Balanced View on Methylglyoxal in Manuka Honey
Concerns about methylglyoxal in Manuka honey being bad are largely unfounded for healthy people consuming it in moderation. Lab studies demonstrating potential toxicity do not reflect what happens in the human body. The digestive system's low bioavailability and the body's metabolic processes mean dietary MGO has a minimal impact. Manuka honey's antioxidants and other beneficial compounds often outweigh theoretical risks. For health conditions like diabetes, consulting a healthcare professional is always advised. The benefits of Manuka honey, particularly for topical and minor internal uses, continue to be supported by scientific evidence, while risks associated with moderate consumption appear negligible.
