Things worth knowing about "AGEs"
AGEs (Advanced Glycation Endproducts) are compounds formed when sugars react with proteins in the body or in food, and are linked to aging and chronic disease.
What are AGEs?
AGEs (Advanced Glycation Endproducts) are chemical compounds formed when sugar molecules such as glucose or fructose react non-enzymatically with proteins, fats, or nucleic acids. This process is known as glycation or the Maillard reaction. AGEs can be produced naturally within the body or consumed through food.
How AGEs are Formed
Endogenous Formation (within the body)
AGEs are continuously produced in the human body when blood sugar interacts with body proteins. In conditions of elevated blood glucose – such as in diabetes mellitus – the rate of AGE formation increases significantly. Over time, AGEs accumulate in tissues including the skin, kidneys, blood vessels, and nerves.
Exogenous Intake (through diet)
Foods prepared at high temperatures contain particularly high amounts of AGEs. Common dietary sources include:
- Fried and grilled meat
- Deep-fried foods (e.g., french fries, potato chips)
- Roasted bread and baked goods
- Ultra-processed and packaged foods
- Caramelized sugar and confectionery
It is estimated that approximately 10–30 % of dietary AGEs are absorbed by the body.
Mechanism of Action and Biological Effects
AGEs bind to specific cell surface receptors, most notably the RAGE receptor (Receptor for Advanced Glycation Endproducts). This binding triggers a cascade of inflammatory responses and oxidative stress. Key biological consequences include:
- Protein cross-linking: AGEs bind proteins together, reducing the elasticity and flexibility of tissues.
- Chronic inflammation: Activation of inflammatory pathways, including the NF-κB signaling pathway.
- Oxidative stress: Increased production of free radicals, damaging cells and tissues.
- Impaired cellular signaling: Altered function of enzymes and receptors throughout the body.
Health Risks and Associated Conditions
Elevated accumulation of AGEs in the body is associated with a wide range of chronic diseases:
- Diabetes mellitus and its complications: Damage to the kidneys (nephropathy), eyes (retinopathy), and nerves (neuropathy).
- Cardiovascular disease: Arterial stiffening, atherosclerosis, and increased risk of heart attack.
- Kidney disease: Impaired renal function due to protein cross-linking in kidney tissue.
- Neurodegenerative conditions: A potential link to Alzheimer's disease and other forms of dementia is under investigation.
- Skin aging: Reduced skin elasticity, increased wrinkle formation, and premature aging of the skin.
- Bone degradation: Impaired bone structure and increased fracture risk.
Diagnosis and Measurement
The level of AGEs in the body can be assessed using several methods:
- Blood and urine tests: Measurement of specific AGE markers such as carboxymethyllysine (CML) or pentosidine.
- HbA1c value: A well-known marker in diabetic patients reflecting the glycation of hemoglobin, which indirectly indicates AGE burden.
- Skin autofluorescence: A non-invasive optical measurement technique that detects AGE accumulation in the skin.
Prevention and Reduction of AGEs
Dietary Measures
Dietary AGE intake can be reduced through the following strategies:
- Preferring gentle cooking methods such as steaming, boiling, or poaching over grilling and frying.
- Increasing intake of fruits, vegetables, and legumes.
- Reducing consumption of highly processed foods.
- Marinating meat in acidic liquids (e.g., lemon juice, vinegar) before cooking can reduce AGE formation during heating.
Lifestyle and Medical Approaches
- Blood sugar control: Particularly important for individuals with diabetes to minimize endogenous AGE formation.
- Antioxidant-rich diet: Vitamin C, Vitamin E, and polyphenols can counteract AGE-mediated oxidative damage.
- Regular physical activity: Improves insulin sensitivity and helps lower blood glucose levels.
- Pharmacological agents: AGE inhibitors such as aminoguanidine are being studied in research but are not yet routinely approved for clinical use.
References
- Vlassara, H. & Uribarri, J. (2014): Advanced Glycation End Products (AGE) and Diabetes: Cause, Effect, or Both? Current Diabetes Reports, 14(1), 453.
- Uribarri, J. et al. (2010): Advanced Glycation End Products in Foods and a Practical Guide to Their Reduction in the Diet. Journal of the American Dietetic Association, 110(6), 911–916.
- Ramasamy, R. et al. (2005): Advanced glycation end products and RAGE: a common thread in aging, diabetes, neurodegeneration, and inflammation. Glycobiology, 15(7), 16R–28R.