It's amazing how many food sources listed in their raw form aren't themselves guilty, but the industrial manufacturing processes and additives used to enhance them are.
What really pisses me off in general is adding useless stuff to things that make said things worse. For example coloring agents in food, but the same goes for superfluous features in software.
Edit: I can't help myself. Some examples:
Bacon causes cancer: "High doses of inorganic phosphate salts – which are used to enhance the texture and flavour of processed meats..." http://www.dailymail.co.uk/health/article-1102368/Additives-...
Eggs cause cancer: "The chemicals, residue from drugs given to chickens..." http://www.dailymail.co.uk/news/article-50995/Cancer-chemica...
Rice causes cancer: "Cotton production relied heavily on arsenic pesticides. It left residues in the soils which are still there and is being picked up by the rice." http://www.dailymail.co.uk/health/article-444222/Rice-tainte...
Spices cause cancer: "...foreign producers are colouring spices to boost prices and profits." http://www.dailymail.co.uk/health/article-347287/Cancer-chec...