If you eat foods which contain synthetic dyes (food coloring), you are essentially eating crude oil - the colorings are synthesized from petroleum. They were originally made from coal tar oil, and are still referred to in the industry as "coal tar dyes".
(U.S. Food & Drug Administration)
Artificial flavors and colors have been associated with: respiratory allergic disorders, hives and angioedema, lesions of the tongue and buccal mucosa, digestive disturbances, headache and behavioral disturbances, including hyperkinesis in childhood. (Nelson's Textbook of Pediatrics, 1987)
~~ From my Feingold files (www.feingold.org)