Chewing gum in stomach:
http://www.mayoclinic.org/digestive-system/expert-answers/faq-20058446
A 1998 paper describes a four-year-old boy being referred with a two-year history of constipation. The boy was found to have "always swallowed his gum after chewing five to seven pieces each day", being given the gum as a reward for good behavior, and the build-up resulted in a solid mass which could not leave the body. A 1½-year-old girl required medical attention when she swallowed her gum and four coins, which got stuck together in her esophagus.
MSG:
http://www.businessinsider.com/is-msg-sodium-in-chinese-food-safe-to-eat-2014-8
https://www.youtube.com/watch?v=VJw8r_YWJ9k&feature=youtu.be
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2222.2009.03221.x/abstract
Wooden spoon:
http://food-hacks.wonderhowto.com/how-to/why-does-wooden-spoon-stop-pasta-from-boiling-over-0151541/
Salt to boiling water:
http://chemistry.about.com/od/foodcookingchemistry/f/Why-Do-You-Add-Salt-To-Boiling-Water.htm
Steak searing
https://www.youtube.com/watch?v=Pt2iNwuTKHM
On Food and Cooking (Revised Edition). cGee, Harold (2004). Page 161, "The Searing Question"
Raspberry flavoring
http://www.ncbi.nlm.nih.gov/pubmed/17365147
http://voices.nationalgeographic.com/2013/10/01/beaver-butts-emit-goo-used-for-vanilla-flavoring/
http://www.npr.org/sections/thesalt/2014/03/26/293406191/does-beaver-tush-flavor-your-strawberry-shortcake-we-go-myth-busting
Cocaine Cola:
http://www.nytimes.com/1988/07/01/business/how-coca-cola-obtains-its-coca.html
Dr. Pepper Crack:
Not true, couldn’t find a recorded mention of crack in Dr. Pepper
Surge yellow 5:
Pollock, Ellen Joan. "Why Mountain Dew Is Now the Talk of the Teen Circuit." The Wall Street Journal. 14 October 1999
Foods that give nightmares
http://firstwefeast.com/eat/how-does-food-influence-our-dreams/
http://bodyodd.nbcnews.com/_news/2013/02/15/16965956-can-spicy-food-really-give-you-nightmares
http://www.foxnews.com/health/2012/04/13/10-foods-to-avoid-before-bed.html
Grapefruit
http://www.ajcn.org/cgi/pmidlookup?view=long&pmid=16685052
Honey for infants
http://kidshealth.org/parent/infections/bacterial_viral/botulism.html
Pork and Trichinosis: http://www.latimes.com/world/la-fg-japan-blowfish1-2009apr01-story.html
http://www.cdc.gov/parasites/trichinellosis/gen_info/faqs.html