Why is there a high AGE-content in vegetable oils?
Can anybody give me an explanation why vegetable oils (e.g. olive, peanut or canola oil) are so rich in AGEs, even if they are almost carbohydrate-free and in a raw (non cooked) form? According to Uribarri's article in J Am Diet Assoc. 2010; 110(6) these oils have more than 10,000 AGE kilounits/100 g food (measured by ELISA with a monoclonal anti-CML antibody).
The reason for the high AGE content of vegetable oils is their high level of polyunsaturated fatty acids (PUFAs). These are easily oxidized and lead to the formation of AGEs (although they should be referred to as ALEs (advanced lipid peroxidation endproducts) because there are no sugars or sugar-derived molecules involved).
The second reason probably is a non-CML-directed activity of the antibody in Uribari's ELISA test System towards other acid and lipophilic compounds in fat and oils.
True, CML can be formed from lipoxidation products, but the second precursor needs be lysine. The protein content in fat and oils is quite low, so the CML content given by Uribarri would probably be higher than the actual lysine content.
One could analyse CML chromatographically and would obtain lower amounts.
Maybe the AGE-database, edited by the food chemistry department of TU Dresden, Germany, will help you to find valid information about CML contents in food (see link below)
Another database was recently published by the group of Schalkwijk, see attachement below.