In the past, I have often mentioned on this list the issue of heat-created toxins, particularly AGEs(advanced glycation end products).I did find out, over time, that people on vegetarian diets seemed to be more susceptible to AGEs despite, technically,eating diets lower in AGE-content than diets high in cooked animal foods:-
http://www.proteinpower.com/drmike/sugar-and-sweeteners/vegetarians-age-faster-2/
What I find interesting, though, is that I've now read another article which mentions carnosine's ability to nullify AGEs. I was thinking, therefore, that those who have no interest in going in for low-AGE raw animal food diets might well benefit from taking carnosine supplements as well:-
http://www.lef.org/magazine/mag2001/jan2001_report_carnosine_1.html
Obviously, there is also another method to reduce the formation of heat-created toxins, namely, heating at low temperatures while the food is soaked in a liquid.
Geoff