Kathryn wrote:Can you expand on the idea of "glycotoxins"? (glyco-sugar?).
Advanced glycoxidation end products (AGEs), derivatives of glucose-protein or glucose-lipid interactions, are implicated in the complications of diabetes and aging. Diet can be a significant environmental source of AGEs, which may constitute a chronic risk factor for cardiovascular and kidney damage.
AGEs are produced endogenously from the nonenzymatic (haphazard, not requiring enzymes) glycation of proteins, lipids, and nucleic acids. AGEs can also form from lipid peroxidation, to form advanced lipoxidation end products (ALEs). Recent studies have measured that about 10% of diet-derived AGEs are absorbed and correlate with circulating and tissue AGE levels. Dietary AGE restriction resulted in significant reduction of circulating AGE levels and disease progression in animal models of atherosclerosis and diabetes, as well as in diabetic patients with normal renal function and in nondiabetic patients with renal failure. These findings suggest that dietary AGEs may constitute a chronic environmental risk factor for tissue injury.
In the following table, foods were prepared for standard cooking times with commonly used cooking methods: boiled in water (100°C), broiled (225°C), deep fried (180°C), oven fried (230°C), and roasted (177° C).
Food item AGE (kU/g or /mL of food)
Almonds, roasted 66.5 kU/g
Oil, olive 120 kU/mL
Butter 265 kU/g
Mayonnaise 94 kU/g
Chicken breast, broiled×15 min 58 kU/g
Chicken breast, fried×15 min 61 kU/g
Beef, boiled×1 h 22 kU/g
Beef, broiled×15 min 60 kU/g
Tuna, roasted×40 min 6 kU/g
Tuna, broiled×10 min 51 kU/g
Cheese, American 87 kU/g
Cheese, Brie 56 kU/g
Egg, fried 27 kU/g
Egg yolk, boiled 12 kU/g
Tofu, raw 8 kU/g
Tofu, broiled 41 kU/g
Bread, whole-wheat center 0.54 kU/g
Pancake, homemade 10 kU/g
Milk, cow, whole 0.05 kU/mL
Milk, human, whole 0.05 kU/mL
Enfamil (infant formula) 4.86 kU/mL
Apple 0.13 kU/g
Banana 0.01 kU/g
Carrots 0.1 kU/g
Green beans 0.18 kU/g
It can be seen that cooked fats are highest in AGEs, uncooked carbohydrates lowest, and cooked proteins, intermediate. Uncooked proteins are also relatively low in AGEs compared to cooked proteins. Using this knowledge regarding AGE sources enables individuals to reduce a previously unrecognized dietary risk factor that contributes to the pathologies in normal aging, diabetes, and kidney disease.
AGEs (advanced glycation end products, either exogenous--preformed from the diet, or endogenous--produced in the body) accumulate in the dermis and accelerate photaging. Denatured (cooked) proteins are more likely to glycate once ingested. Cooked fats are worse,
Advanced glycation end-products (AGEs) have been reported to accumulate in the dermal skin. AGEs hastened photoaging of the skin by means of active oxygen species such as *O(2)(-), H(2)O(2), and *OH, generated during UVA irradiation.
AGEs decrease both hyaluronic acid (HA) synthesis and activity of elastase-type matrix metalloproteinase (ET-MMP).
Goldberg T, Cai W, Peppa M, Dardaine V, Baliga BS, Uribarri J, Vlassara H, Advanced glycoxidation end products in commonly consumed foods, Am Diet Assoc. 2004 Aug; 104 : 1287-91, PMID: 15281050
Okano Y, Masaki H, Sakurai H., Dysfunction of dermal fibroblasts induced by advanced glycation end-products (AGEs) and the contribution of a nonspecific interaction with cell membrane and AGEs., J Dermatol Sci. 2002 Sep;29(3):171-80
There are many more studies. You can google or search pubmed for exogenous glycation or glycosylation. The ill-effects tend to be much more pronounced in diabetics than in normals.