Farm Raised Salmon

The topic I have chosen to discuss is the dangers of farm raised Salmon. Farm raised salmon have been fed a food mixture of canthaxanthin, a chemical fed to them to produce their natural pink color. This chemical is used to keep the fish from turning an unhealthy gray from the food that they are given on the farm, since they do not get the natural krill diet that they are meant to have. This chemical is mostly banned in Australia, due to its effect on the retina, a part in the eye vital to sight. What I found interesting, however, was that this same chemical is used in self tanning pills, an oral medication which darkens skin tone. These pills are banned in the United States, yet salmon raisers are allowed to give it to the fish we will eventually ingest? I guess my real question is, why would the FDA approve it for use in our food, but not in a medication that could possibly prevent skin cancer through tanning beds? This medication has proven successful in countries such as Canada, therefore using it in the United States should have the similar effect.
Tristan Meadows

http://www.webmd.com/vitamins-supplements/ingredientmono-846-CANTHAXANTHIN.aspx?activeIngredientId=846&activeIngredientName=CANTHAXANTHIN