A new study demonstrates the detriments of high-heat cooking.  The study compared the effects of 2 diets--one based on "mild steam cooking", and the other on "high-temperature cooking".  The following was observed after only one month:

In comparison with the mild-steam group, the high-heat group had;

Lower insulin sensitivity (the beginning of the type 2 diabetes process)

Lower blood levels of omega-3's (read my omega-3 paper)

Lower blood levels of vitamins C and E

Higher levels of triglycerides

This study demonstrates that in addition to the quality of ingredients that you buy, how you cook your food makes a HUGE difference.  The authors of the study blame the negative effects of high-heat cooking primarily on "MRP's", which are formed as carbohydrates and amino acids interact; "Upon heat treatment of foods, a characteristic browning and taste compounds are generated by the so-called Maillard reaction. The Maillard reaction is any reaction between a reducing carbohydrate and an amino acid and occurs in foods during storage and heat treatment, with the rate and diversity of chemical reactions accelerating as the temperature increases. Maillard reaction products (MRPs) are chemically highly diverse and comprise taste- and flavor-active molecules and health-beneficial compounds. In contrast, potent carcinogens are also generated, such as acrylamide or heterocyclic amines."

How do you know if you are producing MRP's?  If your food is browning as you cook it, you're creating them!  Consider having a baked potato or mashed potatoes instead of hash browns, chips, and french fries, consider steaming instead of frying your vegetables, and turn your toaster down so that your bread gets warm without turning brown.

Read the abstract of the study here.