Oct 20 / Star Khechara

Endogenous Glycation: The Inside-Out Cause of Skin Ageing

What Is Endogenous Glycation?

Endogenous glycation refers to the formation of Advanced Glycation End Products (AGEs) inside the body. It happens when blood glucose levels stay elevated for too long and sugar molecules attach themselves to proteins or fats, forming sticky, dysfunctional structures. These AGEs accumulate over time and accelerate the ageing process, particularly in collagen-rich tissues such as the skin.

For practitioners, this internal mechanism explains why some clients experience premature loss of firmness, elasticity and radiance, even with an effective topical routine. The issue is not only what touches the skin but also what happens beneath it.
Saturated Fat increases insulin
resistance by 10%
Diabetologia 2001

The Role of Blood Sugar Regulation

The body maintains tight control over blood glucose through a hormonal feedback system led by insulin and glucagon. After eating, insulin helps move glucose from the blood into cells, where it’s used for energy or stored as glycogen. When blood sugar falls, glucagon triggers the release of glucose from the liver to restore balance.

However, this finely tuned system can become disrupted by modern dietary habits. Frequent consumption of refined sugars and processed foods creates sudden blood sugar spikes, followed by sharp drops, a rollercoaster effect that stresses the system. Over time, this contributes to insulin resistance, a condition where cells stop responding properly to insulin.

Insulin Resistance and the Fat Connection

Contrary to common belief, sugar isn’t the sole driver of insulin resistance. Research shows that dietary fat, especially saturated fat, plays a far more damaging role. High levels of fat in the bloodstream interfere with glucose transport into the cells, leaving excess sugar circulating in the blood. This state of hyperglycaemia is the ideal breeding ground for glycation.

Meals high in fat and protein demand more insulin to manage blood glucose levels. If this pattern continues, the pancreas overproduces insulin, but glucose remains trapped in the blood. This metabolic imbalance triggers the formation of AGEs and promotes inflammation, both of which degrade collagen and elastin in the dermis.
For the skin, insulin resistance manifests as dullness, loss of tone and accelerated wrinkling. The skin becomes less able to repair itself and microcirculation slows, depriving cells of oxygen and nutrients.

How much fat is too much fat?

  • Experts working with insulin resistance say 7- 15% of calories from fat in a meal or in the overall diet prevents insulin resistance.
  • The Mastering Diabetes authors say 15%
  • and Dr Barnard says 10%

The Endogenous Glycation Cascade & Skin Ageing

The chain reaction is straightforward yet destructive:

  1. High-fat diets promote insulin resistance.
  2. Insulin resistance causes persistent hyperglycaemia.
  3. Hyperglycaemia drives glycation and AGE accumulation.
  4. AGEs cross-link collagen and elastin fibres, reducing skin elasticity.
  5. The resulting stiffness and inflammation accelerate visible ageing.


AGE build-up also activates Matrix Metalloproteinases (MMPs), enzymes that degrade collagen and hyaluronic acid, key components of firm, hydrated skin.

AGE accumulation leads to accelerated collagen ageing and an increase of MMPs, matrix metalloproteinases which degrade the extracellular matrix proteins: collagen and elastin. And degrade the Hyaluronic acid in the dermis
...a low-fat, plant-based, whole-food diet
containing approximately 10% fat outperformed a
conventional diabetes diet based on the 2003
American Diabetes Association guidelines.
Diabetes Care. 2006

Anti-Glycation Dietary Strategies

The most effective way to reduce endogenous glycation is through a low-fat, wholefood plant-based diet. This approach keeps blood sugar stable, minimises circulating fatty acids and naturally reduces insulin resistance.

Ideal anti-glycation foods include:

  • Fruits and vegetables rich in fibre and antioxidants
  • Legumes, beans and gluten-free whole grains for slow, steady energy release
  • Small amounts of wholefood fats like avocado, olives, or nuts


In contrast, foods to limit or avoid include animal fats, fried and processed foods, dairy and added oils, all of which contribute to insulin dysfunction and glycation.

Healthy fats

Even these need to be kept to under 15% of total Kcal. 

Nuts and seeds

Whole coconuts

Avocados

Olives

Fats to restrict or avoid

Meats

Eggs

Junk food

Butter

Key Takeaways for Practitioners

  •  Endogenous glycation is driven by blood sugar imbalance and dietary fat overload.
  •  Insulin resistance is the main metabolic trigger behind AGE formation.
  •  A plant-based, low-fat diet can dramatically reduce glycation and improve skin integrity.
  •  Educating clients on the metabolic roots of ageing empowers long-term results that go beyond topical care.

Conclusion

Endogenous glycation is the unseen force behind much of the skin’s structural decline. By guiding clients toward a low-fat, wholefood, plant-based diet, practitioners can help slow collagen degradation, improve skin resilience and promote a more youthful complexion from the inside out.

References

  1. Book: Mastering Diabetes
  2. Theories of Aging: https://www.physio-pedia.com/Theories_of_Aging
  3. https://en.wikipedia.org/wiki/Maillard_reaction
  4. Skin Therapy Lett. 2015 Nov;20(6):1-5. Sugar Sag: Glycation and the Role of Diet in Aging Skin. Nguyen HP, Katta R.
  5. J Am Diet Assoc. 2010 Jun; 110(6): 911–16.e12. Advanced Glycation End Products in Foods and a Practical Guide to Their Reduction in the Diet. Jaime Uribarri et al.
  6. Postepy Dermatol Alergol. 2017 Apr; 34(2): 97–103. Melanin and lipofuscin as hallmarks of skin aging Anna Skoczyńska et al.
  7. Suji, G., & Sivakami, S. (2004). Glucose, glycation and aging. Biogerontology, 5(6), 365-373.
  8. Oettlé, G.J., Emmett, P.M., & Heaton, K.W. (1987). Glucose and insulin responses to manufactured and whole-food snacks. The American Journal of Clinical Nutrition, 45(1), 86-91.
  9. Pageon, H., Bakala, H., Monnier, V., & Asselineau, D. (2007). Collagen glycation triggers the formation of aged skin in vitro.. European journal of dermatology : EJD, 17(1), 12-20.
  10. Vessby, B., Uusitupa, M., Hermansen, K., Riccardi, G., Rivellese, A., Tapsell, L., Nälsén, C., Berglund, L., Louheranta, A., Rasmussen, B., Calvert, G., Maffetone, A., Pedersen, E., Gustafsson, I., & Storlien, L. (2001). Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU study. Diabetologia, 44(3), 312-319.
  11. Barnard, N.D., Cohen, .J., Jenkins, D.J., Turner-McGrievy, .G., Gloede, .L., Green, .A., & Ferdowsian, .H. (2009). A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-wk clinical trial. The American Journal of Clinical Nutrition, 89(5),
  12. Guenther Boden; Role of Fatty Acids in the Pathogenesis of Insulin Resistance and NIDDM. Diabetes 1 January 1997; 46 (1): 3–10
  13. M. Roden et al., “Mechanism of Free Fatty Acid-Induced Insulin Resistance in Humans.” The Journal of Clinical Investigation 97, no. 12 (June 15, 1996): 2859–65.
  14. Howard A. Wolpert et al., “Dietary Fat Acutely Increases Glucose Concentrations and Insulin Requirements in Patients with Type 1 Diabetes Implications for Carbohydrate-Based Bolus Dose Calculation and Intensive Diabetes Management.” Diabetes Care 36, no. 4 (April 1, 2013): 810–16
  15. Kirstine J. Bell et al., “Impact of Fat, Protein, and Glycemic Index on Postprandial Glucose Control in Type 1 Diabetes: Implications for Intensive Diabetes Management in the Continuous Glucose Monitoring Era.” Diabetes Care 38, no. 6 (June 1, 2015): 1008–15
  16. https://nutritionfacts.org/video/what-causes-insulin-resistance/
  17. Wright, N., Wilson, L., Smith, M. et al. The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease or diabetes. Nutr & Diabetes 7, e256 (2017)
  18. Whitcomb EA, Chiu CJ, Taylor A. Dietary glycemia as a determinant of health and longevity. Mol Aspects Med. 2015 Dec;46:14-20
  19. Ludwig, D. (2013). Examining the Health Effects of Fructose. JAMA, 310(1), 33-34.
  20. Papandreou, D., Magriplis, E., Abboud, M., Taha, Z., Karavolia, E., Karavolias, C., & Zampelas, A. (2019). Consumption of Raw Orange, 100% Fresh Orange Juice, and Nectar- Sweetened Orange Juice—Effects on Blood Glucose and Insulin Levels on Healthy Subjects. Nutrients, 11(9),
  21. Scheffers, F., Wijga, A., Verschuren, W., van der Schouw, Y., Sluijs, I., Smit, H., & Boer, J. (2020). Pure Fruit Juice and Fruit Consumption Are Not Associated with Incidence of Type 2 Diabetes after Adjustment for Overall Dietary Quality in the European Prospective Investigation into Cancer and Nutrition–Netherlands (EPIC-NL) Study. The Journal of Nutrition, 150(6), 1470-1477.
  22. Kuzma, J., Schmidt, K., & Kratz, M. (2017). Prevention of metabolic diseases: fruits (including fruit sugars) vs. vegetables. Current Opinion in Clinical Nutrition & Metabolic Care, 20(4), 286-293.

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Article by Star Khechara

Professional agehacker, author, speaker, founder of skin nutrition institute
About me
Ex-skincare formulator and beauty author turned skin-nutrition educator: Star distilled her 20+ years of skin-health knowledge into the world’s first international accredited skin-nutrition school to teach skin therapists, facialists, face yoga practitioners and estheticians how to help their clients feed the skin from within for cellular-level rejuvenation and vibrant beauty. 
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