Is too much MGO bad for you? Unpacking the potential risks of high Methylglyoxal intake

December 31, 2025 •

4 min read

While methylglyoxal (MGO) is praised for giving Manuka honey its potent antibacterial properties, the accumulation of high concentrations of MGO has been linked to numerous health issues in scientific literature. This raises questions about the long-term safety of consuming high-MGO products.

Quick Summary

Methylglyoxal (MGO) is a reactive compound found in Manuka honey that offers antibacterial benefits. However, high levels of MGO are associated with cellular damage, chronic diseases, and vascular complications via the formation of Advanced Glycation End Products (AGEs).

Key Points

MGO forms toxic AGEs: High levels of methylglyoxal (MGO) react with proteins to form advanced glycation end products (AGEs), which cause cellular damage and oxidative stress.
Linked to chronic diseases: Accumulation of AGEs from high MGO exposure is associated with cardiovascular disease, diabetes complications, and neurodegenerative disorders.
Vascular and diabetic risks: Studies show high MGO is implicated in vascular dysfunction, insulin resistance, and β-cell damage, which contributes to diabetes progression.
Risks differ by intake: While dietary intake from moderate Manuka honey is likely safe, prolonged high consumption or use of high-potency products warrants caution, especially for individuals with underlying health conditions.
High-MGO for topical use: High-grade Manuka honey is generally reserved for targeted therapeutic uses like wound care, where its antibacterial properties are most needed.

What is MGO (Methylglyoxal)?

Methylglyoxal, or MGO, is a naturally occurring compound key to Manuka honey's antibacterial efficacy. It develops from dihydroxyacetone (DHA) in Manuka flower nectar as the honey matures. Higher MGO concentrations lead to stronger antibacterial properties and are reflected in the honey's grading system. Topical use of Manuka honey for wounds and burns is particularly noted for its antibacterial effects.

The Dark Side of High Methylglyoxal

Despite MGO's benefits, high concentrations pose health risks. A 2017 study connected MGO accumulation to harmful effects on vascular function and chronic diseases. This is mainly due to MGO promoting the formation of Advanced Glycation End Products (AGEs). AGEs form when sugars react with proteins or lipids, and their buildup contributes to cellular damage, oxidative stress, and inflammation.

Potential Health Risks of Excessive MGO Exposure

Vascular Dysfunction and Cardiovascular Disease: MGO accumulation can harm vascular function and contribute to atherosclerosis by inducing apoptosis in vascular endothelial cells.
Diabetic Complications: High MGO levels are strongly linked to type 2 diabetes and its vascular issues, potentially causing insulin resistance and β-cell dysfunction.
Neurodegenerative Diseases: MGO and AGEs have been associated with conditions like Alzheimer's and Parkinson's disease.
Cellular and Genetic Toxicity: Studies indicate high MGO concentrations can be toxic to cells and damage genetic material, raising concerns about long-term consumption of very high-MGO products.
Oxidative Stress: MGO increases reactive oxygen species (ROS) production, leading to oxidative stress and cellular damage implicated in chronic inflammatory diseases.

Navigating MGO in Manuka Honey: Benefits vs. Risks

Consumers weigh the therapeutic benefits of high-MGO Manuka honey against potential cellular risks. It's crucial to distinguish between controlled topical medical use and general dietary intake.

MGO in Manuka Honey vs. MGO from Other Sources

Studies on MGO toxicity often use high, isolated concentrations, which may not fully reflect the effects of MGO within the complex matrix of honey. Some research suggests that the body's natural defenses may mitigate potential risks, but this is an ongoing area of study.

Comparison: Benefits vs. Risks of High MGO Honey


Feature	Benefits of MGO (Manuka Honey)	Risks of High MGO Exposure (Scientific Studies)
Mechanism	Antibacterial properties via MGO.	Formation of Advanced Glycation End Products (AGEs).
Therapeutic Use	Topical treatment for wounds, burns, and skin infections.	Linked to diabetic complications and vascular dysfunction.
Bodily Effects	Promotes immune response and soothes minor infections.	Induces oxidative stress and cellular damage.
Disease Links	Anti-inflammatory potential for digestive health.	Associated with neurodegenerative diseases and cancer risk.
Oral Consumption	Typically moderate intake recommended for general wellness.	Long-term high dietary exposure linked to exacerbated disease pathogenesis.

Is MGO a Risk Factor for Everyone?

The risk from MGO varies. The body has natural detoxification processes, but these can be less effective in some individuals. Factors that increase vulnerability include:

Pre-existing Conditions: Diabetes or impaired kidney function can increase risk due to reduced ability to regulate metabolic byproducts like MGO.
Dosage: The amount and frequency of consumption matter. Standard daily servings of Manuka honey are typically safe, but very high or long-term intake of high-MGO products without medical guidance should be cautious.
Dietary Context: MGO in honey is part of a complex mix including antioxidants that may lessen negative effects, unlike isolated MGO from other sources.

Conclusion

While MGO in Manuka honey offers significant antibacterial benefits, particularly for topical use, potential risks from high MGO levels at a cellular and systemic level are noteworthy. Research indicates high MGO accumulation contributes to AGE formation, linked to vascular issues, diabetic complications, and neurodegeneration. Moderation and context are key. Standard grades of Manuka honey in a balanced diet are likely safe, but awareness of the scientific findings on excessive MGO exposure is important. Consult a healthcare professional for therapeutic use or high-potency varieties. A balanced approach respects both the benefits and potential long-term impacts of high exposure.

How to responsibly consume Manuka honey

Choose lower MGO grades for daily use: MGO 150+ or 250+ is adequate for general wellness.
Follow dosage guidelines: Adhere to the recommended 1-2 teaspoons daily.
Consult a professional: Seek medical advice if you have health conditions, especially diabetes, or plan therapeutic use of high-grade honey.
Use high-grade honey for specific purposes: Reserve very high-MGO varieties (MGO 1000+) for targeted, short-term uses like topical wound application.
Prioritize a balanced diet: Honey is a supplement; it should complement a diet rich in antioxidant-rich fruits and vegetables.

External Reference

For further reading on the complex and sometimes conflicting research surrounding methylglyoxal's effects, consult a reliable scientific review. A key study on the topic can be found via the National Institutes of Health. ^1

Frequently Asked Questions

Methylglyoxal (MGO) poisoning is not a recognized risk from consuming Manuka honey, as long as it's done in moderation. Most studies showing toxicity use extremely high, isolated doses not found in a normal diet. The body's natural defense system can process typical dietary levels of MGO.

Yes, methylglyoxal (MGO) is a common metabolic byproduct in the body, primarily from glucose degradation. It is also found exogenously in many cooked foods. The MGO in Manuka honey is chemically identical, though its concentration is significantly higher than in other foods and it is part of a complex natural matrix.

Most Manuka honey producers and health experts recommend consuming 1 to 3 teaspoons (approximately 14-42g) daily for general wellness. High consumption is typically not recommended due to the high sugar content.

There is no evidence that moderate consumption of Manuka honey causes diabetes. However, studies show that high levels of MGO accumulation are associated with insulin resistance and can worsen diabetic complications in individuals who already have the disease. People with diabetes should consult a doctor before adding it to their diet.

Topical application of medical-grade Manuka honey for wounds and burns is considered safe and effective. It's a key use of high-grade Manuka honey, and the MGO's antibacterial properties aid in healing. The risks associated with high MGO levels primarily relate to systemic accumulation from ingestion.

Individuals with diabetes, kidney problems, or other metabolic disorders should be most cautious. Pregnant women, children under one year old (due to botulism risk), and those allergic to bees or honey should also avoid it.

Yes, research indicates that high concentrations of MGO can increase the production of reactive oxygen species (ROS), leading to oxidative stress and cellular damage. The formation of AGEs, which MGO accelerates, also contributes to inflammation and oxidative stress.