Uploaded January 2025 | Updated September 2026, 2 weeks ago
Judging by effusive media reports, you would think that a heavy yoke has been lifted from the neck of Americans with the banning of Red Dye #3 by the FDA. Actually, this amounts to no more than flicking a flea off the back of an elephant. The ban is not the result of some new research that implicates this dye as a felon lurking in the food supply. It is the result of years of legal wrangling about the application of an amendment to the 1938 Food, Drugs and Cosmetic Act known as the “Delaney Clause”. Sponsored by Congressman James Delaney of New York, the amendment states “that the Food and Drug Administration shall not approve for use in food any chemical additive found to induce cancer in man, or, after tests, found to induce cancer in animals.” That sounds like motherhood and apple pie, since it seems obvious that a carcinogen should not be purposefully added to the food supply. The Delaney Clause presents carcinogenesis as a white or black issue, however, science is hardly ever white or black, it is shades of gray. The Delaney Clause ignores the cornerstone of toxicology first voiced by the sage Paracelsus in the 16th century that only the dose makes the poison.
So, how poisonous is erythrosine, commonly known as Red Dye #3? Somewhat, if you are a male rat. The controversy over this food colourant began with a 1990 study in which rats were fed a daily dose of erythrosine amounting to 4% of their diet. That is a staggeringly large amount, hundreds of times greater than to what a human would be exposed. This resulted in an increase in thyroid cancer in the animals. There seemed to be some theoretical justification for this since erythrosine was found to increase levels of thyroid stimulating hormone (TSH) that is released by the pituitary gland and signals the thyroid gland to release hormones that regulate numerous body functions ranging from metabolism to heart rate and temperature. It is known that increased activity in the thyroid gland can also trigger cancer, but there is controversy about whether the mechanism by which thyroid activity is increased in a rat is also operative in humans. Furthermore, there was no increased risk of cancer in female rats or in other animals exposed to the dye. And there is absolutely no evidence of the dye causing cancer in people.
There have also been some studies implicating certain food dyes in behavioural problems in children with reference often being made to a 2008 study carried out at Southampton University in England that tested the effects of food additives including some dyes and preservatives on the behaviour of children but Red Dye #3 was not fingered. In any case, the food industry has been aware of the impending ban on erythrosine and has been replacing it in the food supply mostly with Red #40 (allura red), so contrary to claims, it is not found in thousands of foods. And wherever it does appear, it is in foods that fall into the highly-processed category, foods that we should not be encouraging the consumption of. Yet that is exactly what food dyes do. They serve only a cosmetic purpose without any nutritional value and generally attract consumers to highly processed foods that should be limited, not because of any perceived toxicity of food dyes, but because numerous studies have shown such ultra-processed foods to be detrimental to health.
For that reason, I do not favour the use of food dyes. I think the toxicity issue has no practical relevance, and replacing synthetic dyes with natural ones extracted from beets or berries does not make “junk” foods “safer.” Red dye #3 being synthesized from petroleum, as reported by fear-mongering bloggers, is a totally moot point. But I think that eating fewer foods that contain dyes signals an improvement in the overall diet.
Judging by effusive media reports, you would think that a heavy yoke has been lifted from the neck of Americans with the banning of Red Dye #3 by the FDA. Actually, this amounts to no more than flicking a flea off the back of an elephant. The ban is not the result of some new research that implicates this dye as a felon lurking in the food supply. It is the result of years of legal wrangling about the application of an amendment to the 1938 Food, Drugs and Cosmetic Act known as the “Delaney Clause”. Sponsored by Congressman James Delaney of New York, the amendment states “that the Food and Drug Administration shall not approve for use in food any chemical additive found to induce cancer in man, or, after tests, found to induce cancer in animals.” That sounds like motherhood and apple pie, since it seems obvious that a carcinogen should not be purposefully added to the food supply. The Delaney Clause presents carcinogenesis as a white or black issue, however, science is hardly ever white or black, it is shades of gray. The Delaney Clause ignores the cornerstone of toxicology first voiced by the sage Paracelsus in the 16th century that only the dose makes the poison.
So, how poisonous is erythrosine, commonly known as Red Dye #3? Somewhat, if you are a male rat. The controversy over this food colourant began with a 1990 study in which rats were fed a daily dose of erythrosine amounting to 4% of their diet. That is a staggeringly large amount, hundreds of times greater than to what a human would be exposed. This resulted in an increase in thyroid cancer in the animals. There seemed to be some theoretical justification for this since erythrosine was found to increase levels of thyroid stimulating hormone (TSH) that is released by the pituitary gland and signals the thyroid gland to release hormones that regulate numerous body functions ranging from metabolism to heart rate and temperature. It is known that increased activity in the thyroid gland can also trigger cancer, but there is controversy about whether the mechanism by which thyroid activity is increased in a rat is also operative in humans. Furthermore, there was no increased risk of cancer in female rats or in other animals exposed to the dye. And there is absolutely no evidence of the dye causing cancer in people.
There have also been some studies implicating certain food dyes in behavioural problems in children with reference often being made to a 2008 study carried out at Southampton University in England that tested the effects of food additives including some dyes and preservatives on the behaviour of children but Red Dye #3 was not fingered. In any case, the food industry has been aware of the impending ban on erythrosine and has been replacing it in the food supply mostly with Red #40 (allura red), so contrary to claims, it is not found in thousands of foods. And wherever it does appear, it is in foods that fall into the highly-processed category, foods that we should not be encouraging the consumption of. Yet that is exactly what food dyes do. They serve only a cosmetic purpose without any nutritional value and generally attract consumers to highly processed foods that should be limited, not because of any perceived toxicity of food dyes, but because numerous studies have shown such ultra-processed foods to be detrimental to health.
For that reason, I do not favour the use of food dyes. I think the toxicity issue has no practical relevance, and replacing synthetic dyes with natural ones extracted from beets or berries does not make “junk” foods “safer.” Red dye #3 being synthesized from petroleum, as reported by fear-mongering bloggers, is a totally moot point. But I think that eating fewer foods that contain dyes signals an improvement in the overall diet.
