Ethoxyquin in the Rat Diet
From the RMCA web site, April 2003
Ethoxyquin is an antioxidant. Antioxidants interfere with the process known as "spoilage." Antioxidants also interfere with the process known as "mutation," as used when speaking of cancer.
Ethoxyquin is used as a preservative in both human- and animal-grade foods. The FDA allows ethoxyquin levels of up to 100ppm in human-grade foods and up to 150ppm in animal-grade foods. In human foods, ethoxyquin is most often found on fresh fruits, in spices, and in eggs and meat.
Ethoxyquin is currently being investigated for its cancer fighting properties. In particular, ethoxyquin in the rat diet has been found to prevent liver cancer caused by aflatoxin. Aflatoxin is a common, naturally occurring carcinogen found in foods, most notably in corn, but also in many other grains, nuts, and seeds. Rats are the species most vulnerable to the cancer causing effects of aflatoxin. Ethoxyquin in the rat diet also prevents chemically initiated mammary tumors.
At FDA-allowable levels of 150ppm, ethoxyquin in the rat diet does not cause disease, cancers, or tumors. These results, originally published in a study done in 1955, have been repeatedly verified in many subsequent studies. Ethoxyquin at FDA-allowable levels of 150ppm does not cause disease, cancers or tumors in rats.
At experimental levels of 5000ppm, ethoxyquin in the rat diet prevents liver cancer caused by aflatoxin and mammary tumors caused by chemicals. At levels of 5000ppm, ethoxyquin in the rat diet also causes kidney damage in males, but not in females. Below levels of 5000ppm, ethoxyquin in the rat diet does not induce any change in histopathology and does not cause cancers or tumors. Ethoxyquin at FDA-allowable levels of 150ppm does not cause disease, cancers, or tumors in rats.
At low levels, alcohol in the human diet may protect against heart disease and cancer. At high levels, alcohol in the human diet may result in pancreatitis, cardiomyopathy, neuropathy, bleeding esophageal varices, cerebellar degeneration, and cirrhosis. One man has never had a drop of alcohol in his life, while another man of the same age, ever since he was young, has had one glass of red wine with dinner every night of his life. So who is healthier?
Lab blocks remain, far and away, the best staple diet for rats because they are nutritionally complete and rats cannot pick out only what they like. Not all rat caretakers, however, have access to lab blocks, and they use pet store rat foods, many of which do contain ethoxyquin. Ethoxyquin at FDA-allowable levels of 150ppm does not cause disease, cancers or tumors in rats. Rat caretakers should not feel they are negligent if they choose commercially packaged rat mixes or use foods which contain ethoxyquin.
REFERENCES:"Food Additives Permitted for Direct Addition to Food for Human Consumption," Code of Federal Regulations. Title 21, Part 172. (rev. 1 Apr. 2002).
"Food Additives Permitted in Feed and Drinking Water of Animals," Code of Federal Regulations. Title 21, Sec. 573.380. (rev. 1 Apr. 2002).
Lee, Theresa. "Corn in the Rat Diet," Rat & Mouse Club of America Articles Online. (Aug. 2002).
Cabral JR and Neal GE, "The inhibitory effects of ethoxyquin on the carcinogenic action of aflatoxin B1 in rats," Cancer Lett. 19, 125 (1983).
Hard GC and Neal GE, "Sequential study of the chronic nephrotoxicity induced by dietary administration of ethoxyquin in Fischer 344 rats," Fundam Appl Toxicol. 18, 278 (1992).
Ito N, Hirose M, Fukushima S, Tsuda H, Tatematsu M, and Asamoto M, "Modifying effects of antioxidants on chemical carcinogenesis," Toxicol Pathol. 14, 315 (1986).
Western Utilization Research Branch, Albany CA, Agricultural Research Branch, "Supplementary Report of Data on Santoquin Feeding to Rats for 700 days," (1955).