FD&C Red No. 2 (Amaranth)


Amaranth is red monoazo dye that serves as a red color in many food systems. Its high water solubility and tinctorial power, and its "true red" hue make it a very useful color for which there is no adequate substitute.



Red No. 2 was on the original list of seven food colors approved for use in the United States by the USDA.


Red No. 2 became part of the USDA voluntary certification program for synthetic color additives.


Red No. 2 became part of the FD&C Act mandatory certification for food, drug, and cosmetic colors.


Having been on the original list of seven food colors permitted by the USDA (1907), it remained on the provisional list, based on toxicological studies before and after adoption of the 1960 Color Additive Amendments.


The FAO/WHO Joint Committee on Food Additives (JEFCA) evaluated amaranth (Red No. 2) and assigned it an ADI of 0-1.5 mg/kg/day.


Amaranth was reported to be embryotoxic, gonadotoxic, and carcinogenic in rats by Russian scientists.


FDA requested teratology and reproduction studies on all FD&C and D&C colors. FDA Commissioner promised to perform new chronic studies on FD&C Red No. 2 and requested no new studies from industry.


Health Research Group petitioned FDA to ban Red No. 2.


While control data in numerous other laboratories showed greater variations and higher control incidences of early resorptions, the FDA took the position that Red No. 2 caused an adverse effect by increasing early resorptions. This effect was not seen in either the industry-supported teratology or the three-generation reproduction studies.


National Academy of Sciences (NAS) originally declined to hold a special review but then convened a committee to review the available toxicity data on Red No. 2. The committee recommended no restrictions but asked for more studies.


Despite the fact that FDA's scientists considered the Russian 1970 study to be questionable on a number of accounts, the FDA undertook a new chronic feeding study as an extension of a three-generation reproduction study.


JEFCA reevaluated amaranth and assigned it a temporary ADI of 0-0.75 mg/kg/day.


Teratology studies were repeated at Industrial Biotest, FDA, and NCTR. Metabolic studies were subsequently performed by General Foods Corporation.


All three of the above collaborative studies showed no difference in the incidence of early resorptions between treated and control rats. By the time these studies were completed, more teratology testing had been done in FDA's laboratories and their control data was similar with those of other laboratories.


Comparative absorption, metabolism, and distribution (AMD) studies between Red No. 2 given via drinking water, diet, or gavage provided dose-response data which demonstrated that blood levels of amaranth and its metabolites were significantly higher in animals fed the high dose of color in the negative three-generation reproduction study

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