AGEs stand for advanced glycation end products, and they are a family of compounds formed when there’s a chemical reaction forming a link/attachment between sugar and proteins (or lipids). AGEs are associated with diabetes, cardiovascular disease, kidney disease, and neurodegenerative diseases. AGEs can also promote aging and literally make you "age."
How are AGEs produced?
AGEs are produced both exogenously (come from outside of the body) and endogenously (produced within the body).
Exogenous AGEs
Exogenous AGEs mostly come from our diet and cigarette smoking. Cooking meats under dry high heat creating Maillard reaction will produce AGEs. Deep frying, roasting, grilling; and broiling of meats, meat-substitutes and foods high in fat and protein tend to produce high levels of AGEs. The amount of AGEs in foods cooked under dry high heat is up to 100 folds above that in uncooked foods. Foods cooked under higher temperature, drier environment and higher pH (more alkaline) will yield a higher level of AGEs. Broiled beef, pan fried beef, stir fried beef, deep fried chicken, roasted/BBQ chicken, fried bacon are among the foods with highest level of AGEs.
Endogenous AGEs
AGEs are also formed within the body, but at a lower temperature than in foods. Diabetic patients tend to have higher level of endogenous AGEs due to a higher sugar/glucose level within the body. Aging is also associated with higher level of endogenous AGEs level, so the older we get, the higher amount of AGEs we have.
Health impacts of high AGEs
We all have AGEs formed inside our body and consumed from our diet. But when the amount of AGEs is beyond what our body's antioxidant capacity can balance out, damages to our body can happen.
High levels of AGEs in our body are associated with an increased risk and increased severity of:
Insulin resistance
Type 1 and type 2 diabetes
Complications of diabetes (e.g. diabetic skin ulcers, infections, non-healing wounds)
Cardiovascular diseases (e.g. atherosclerosis)
Neurodegenerative diseases (e.g. Alzheimer’s disease)
Kidney diseases (e.g. renal fibrosis, renal dysfunction), related or non-related to diabetes
Cataracts
Accelerated ageing process
Skin problems (yellowing and browning of skin, decreased elasticity, wrinkles)
AGEs can damage our skin barrier and delay the self-repair of the barrier
AGEs also promote the production of melanin in melanocytes, which can cause darkening of the skin
AGEs can accumulate in collagen and cause collagen to brown, which can turn our skin yellow
The underlying mechanism of AGEs leading to these health conditions are increased oxidative stress and inflammation. Individuals with high AGEs intake from the diet and high AGEs levels in the body also have higher levels of inflammatory markers.
Benefits of low AGE diet
Many research studies have compared the health impacts of a high vs low AGEs diet. While a high AGEs diet is associated with the above-mentioned health conditions, a low AGEs diet has been shown to have these benefits:
Decreased inflammatory markers
Decreased oxidative stress
Improved insulin sensitivity
Reduced cholesterol level
Less oxidized and glycated LDL (oxidized LDL are associated with higher risk of atherosclerotic plaques and other cardiovascular diseases)
Higher blood level of omega-3 fatty acids, vitamin C and vitamin E (a diet low in AGEs is often prepared with a lower heat, which can preserve more heat sensitive nutrients like vitamin C and E)
Accelerated wound healing
How to prepare a low AGE diet?
Besides quitting cigarette smoke and controlling blood sugar level, reducing the amount of AGEs in our diet is one the most effective way of reducing AGEs in our body. Below are methods of food preparation that yield lower level of AGEs:
Cook foods, especially meats and meat products under a lower heat and a higher moisture level – e.g. steaming, boiling, poaching, stewing.
Marinate the meats with acidic solutions like lemon juice or vinegar to lower the pH. Research has shown that by marinating beef with lemon juice and vinegar for 1 hour before cooking, the amount AGEs had lowered by more than 50%.
Replace foods that yield higher AGEs with foods that yield lower AGEs.
Foods that yield higher AGEs: beef, cheeses, high-fat spreads (butter, cream cheese, margarine, mayonnaise), fatty meats, full-fat dairy products, processed foods.
Foods that yield lower AGEs: vegetables, fruits, fish, legumes, whole grains, and low-fat milk products.
References
Singh, R. B. A. M., et al. "Advanced glycation end-products: a review." Diabetologia 44.2 (2001): 129-146.
Uribarri, Jaime, et al. "Advanced glycation end products in foods and a practical guide to their reduction in the diet." Journal of the American Dietetic Association 110.6 (2010): 911-916.
Poulsen, Malene W., et al. "Advanced glycation endproducts in food and their effects on health." Food and Chemical Toxicology 60 (2013): 10-37.
Chen, Chun-yu, et al. "Advanced Glycation End Products in the Skin: Molecular Mechanisms, Methods of Measurement, and Inhibitory Pathways." Frontiers in Medicine 9 (2022).