Cytotoxins break down DNA and attack the aging process by the way�so are not to be ingested.
The use of fry pans - a brief high temp frying of some chicken rather than a long period immersion frying on an industrial scale - will not be a problem at home for some cooking. The downside comes from using old oil - because of the breakdown of the proteins to undesirable products as well as having poor taste in the oil itself.
The frying process is also about the starches in food - i.e carbihydrates - being affected by heating processes so that they become gelatinous so causing a change in both the surfaces and content of the food. In food terms this is: '..thermal energy affecting the structure development through starch gelatinization and protein denaturation..' or cooking a doughnut to you and me....but not the cooking oil barons of this world.
I would suggest that in summary :- deep frying whilst suiting some cooking styles is to be done sparingly; flash frying with minimal or no oils is best but won't provide the optimum results in all recipes; use of a wok or similar which cooks foods rapidly but evenly is also another positive method.
Frying introduces lipids into the human system so as above we need some to function but too many causes a lot of negatives.
If you fancy some info on other chemicals in the food processing and other fields, this is a good link:
http://www.health-report.co.uk/index.html and there are umpteen resources to trawl through on the web if you want further info.
Hope this helps..? And not too much waffle here o apologies if its longwinded but this is a broad field to go over.