The fun childhood tradition of trick-or-treat yields a bounty of sugary treats. But the most frightening part of Halloween could be what’s behind the candy wrappers. Synthetic food dyes derived from petroleum are found in many major brands of candy, drinks and cereal to make them visually appealing. Some studies done over the past decade have linked artificial food dyes to attention deficit hyperactivity disorder and tumors in laboratory rodents. 

The Center for Science in the Public Interest, founded in 1971, is a science-based consumer advocacy organization dedicated to improving the food system to support healthy eating. Their report, Food Dyes: A Rainbow of Risks (http://cspinet.org/sites/default/files/attachment/food-dyes-rainbow-of-risks.pdf) breaks down some of the most commonly used dyes in candy: 

Red Dye 40: One of the most frequently used food dyes in everything from candy to cosmetics, Red Dye 40 is also listed as Red no. 40, FD&C Red 40, Allura Red, Allura Red AC, C.I. 1603 and C.I. Food Red 17. Studies have linked Red Dye 40 to triggering hyperactivity in children. 

Red No. 3: Found in candy, cake decorating sprinkles, maraschino cherries and frozen pops, Red no. 3 is also known as erythrosine B. Red 3 was partially banned in 1990 by the U.S. Food & Drug Administration citing research that high doses have caused cancer in rats. 

Yellow No. 5: Also known as tartrazine, it’s commonly found in chips, soft drinks, gelatin and other foods. Some studies have linked Yellow 5 to severe hypersensitivity reactions in a small number of people and other behavioral effects on children. 

Blue No. 1: Commonly found in ice cream, candy, drinks and mouthwash, this dye is also known as Brilliant Blue. The dye can cause hypersensitivity reactions. 

Blue No. 2: Also known as Indigotine or Indigo Carmine, it’s widely used to color candy and beverages. The Rainbow of Risks study reports statistically significant incidence of tumors in male rats. 

The July-Sept 2012 issue of the International Journal of Occupational and Environmental Health, one of the more recent reports available on this issue, states, “nine currently U.S.-approved dyes raise health concerns of varying degrees,” including cancer in lab animals. Three dyes—Red 40, Yellow 5, and Yellow 6—have been found to be contaminated with benzidine or other carcinogens. At least four dyes, Blue 1, Red 40, Yellow 5 and Yellow 6 could cause hypersensitivity reactions.