Zeranol: Carcinogen and synthetic Toxic Chemical that causes Breast Cancer, found in beef cattle

Zeranol is a mycotoxin derived from a fungus in the Fusarium family where it is found as a contaminant in fungus-infected crops. Natural sources of zeranol comes from contamination of feed sources, corn silages and hay by the fungus, Fusarium, which is an active producer of this toxic chemical and carcinogen that
have been found to cause breast cancer.

Zeranol (synthetic form of zearalenone) is also an estrogenic compound to which cattle and swine in the United States’ meat industry are extensively exposed to because it promotes rapid and more efficient growth rates in animals used as meat sources. This carcinogen called zeranol is used as a growth promoter for livestock in the United States, approved for use in beef only in Canada, but not approved for use at all for any livestock in the European Union-a testimony to its carcinogenicity.

Studies into zeranol have discovered that food products which have been contaminated by this toxic chemical are largely responsible for the development of precocious puberty in young girls. This precocious puberty is a well known risk factor for breast cancer development. Also, research studies on the effect of this carcinogen on human health showed that serum from zeranol-treated cattle can stimulate normal breast epithelial cells and convert them to breast tumor cells in vitro. Another separate study showed that the toxic chemical, zeranol, can enhance the action of obese (ob) gene, which plays an important role in breast cancer development. It has also been proven that this toxic chemical/carcinogen stimulates the activity of a protein disulfide isomerase, an enzyme whose activity is often increased in cancer tissues.

As a carcinogen,this toxic chemical has been shown to enhance the proliferation of human breast cancer cells. It does this by using the same way that natural estrogen (estradiol) uses to cause cancer. It is believed that the pathways that zeranol uses to promote cancer formation is similar to those activated by the natural estradiol. This was proven when young adult female mice, treated with zeranol, led to the increased growth and branching of mammary glands, an action similar to what is found in natural estrogen. 

Furthermore, as a powerful estrogenic compound, zeranol has demonstrated, by its ability to the growth and proliferation of human breast cancer in vitro, that it is as potent in causing breast cancer just like the natural hormone, estrogen, and another known carcinogen, Diethylstilbestrol or DES. In fact, a separate study showed a similarity between this toxic chemical (zeranol), the carcinogen (DES) and natural estrogen in the trios’ ability to transform MCF-10A human breast epithelial cells to breast cancer cells in vitro. The only difference between these three carcinogens and toxic chemicals is that, according to one study, normal breast epithelial cells treated with zeranol, even at levels that were 30 xs lower that the FDA established limit in beef, showed abnormal cancer cell growth.