This study was done to see if the common food colors tartrazine (Yellow 5), metanil yellow (a non-permitted color often used illegally) and sunset yellow (Yellow 6) may play a part in liver disease.
The researchers used 4 groups of 6 Swiss albino rats; one group was the control, given no dyes. The others were given various amounts of the 3 colors for a month. Several tests were then done to see if their livers had been damaged. They were. Not only did the tests show damage, but this damage included dead liver cells and vacuolation (liquid-filled holes or blisters in the cells), and a “drastic alteration” in the antioxidant defense system.
NOTE: Even if you think you are avoiding food dyes, you may be fooled. Looking up metanil yellow, it became clear that although this dye is not approved, it is still used. In India, it is used to color lentils, turmeric, and other things. Who would think a lentil or bean would be colored? For the turmeric, it is scary, because the yellow color is added to cover up adulteration with chalk or other powders. FDA, are you watching? This is not really new information – there was a study published by Food and Chemical Toxicology a while back (Nagaraja 1993) about metanil yellow and what it does to the central nervous system, the brain, and learning ability. There are numerous other studies about testing for colors that are either unapproved or unlabeled. Obviously, there are a lot of people out there trying to pull a fast one on a trusting public, and there are others out there (we hope) trying to catch them.
An interesting book some of you might like is called Sorting the Beef from the Bull: The Science of Food Fraud Forensics by Richard Evershed and Nicola Temple. I have just downloaded it from Amazon as a Kindle for $1.99 – but you can get it as a hard cover, a paperback, or an audio book, as well. I can’t say whether it is a great book, as I haven’t read it yet. Their chapter headings are certainly very cute, however. Here is a quote from the Foreward: “For as long as food has been prepared and sold there has been cheating. Looking at the history of food fraud is a wonderful way to explore the darker side of human nature.”