For their research, Kyung-Chul Choi and colleagues from Chungbuk National University and the Korea Research Institute of Bioscience and Biotechnology looked at triclosan in the context of how it affects the hormonal system. A known hormone-disruptor, triclosan has been shown in previous research to mimic the feminizing hormone estrogen, which in turn alters the normal production and expression of other hormones like testosterone.
As a result, triclosan appears to throw the endocrine system out of balance, leading to abnormal cellular growths. Particularly in women, triclosan appears to trigger the growth of breast cancer cells, leading to the formation of malignant tumors. This was demonstrated both in cell samples and in live mice, as breast cancer cells were shown to thrive in the presence of triclosan.
After comparing the frequency and progression patterns of breast cancer growth in both the cell samples and the mice, some of which were exposed to triclosan and some of which were not, it became clear that the chemical spurs abnormal cell proliferation. And the fact that triclosan bioaccumulates in the body over time makes the threat of it even more pronounced.
"Although the doses of EDCs were somewhat high, we did this to simulate the effects of daily exposure, as well as body accumulation due to long-term exposure, simultaneously in animal experiments," stated Choi. "Thus, exposure to EDCs may significantly increase the risk of breast cancer development and adversely affect human health," wrote he and the others in their paper.
Octylphenol amplifies cancer-causing effects of triclosan
The team also identified another antibacterial chemical, octylphenol, which exhibits similar cancer-promoting effects. Though lesser known than triclosan, octylphenol was shown to work in conjunction with triclosan to amplify the growth and spread of cancer cells, illustrating the immense dangers associated with these ubiquitous chemicals.
"Research has found that two EDCs -- triclosan, an antimicrobial ingredient in many products, including soaps, cosmetics and cutting boards; and octylphenol, which is in some paints, pesticides and plastics -- have accumulated in the environment," explains ScienceDaily.com. "Additionally, triclosan is reportedly in the urine of an estimated 75 percent of Americans."
Consumer groups like Beyond Pesticides and the Environmental Working Group (EWG) have been raising awareness about the dangers of triclosan for years, highlighting its status as a known endocrine-disrupting chemical (EDC) and pushing for its removal from personal care products. But many commercial products still contain it, which is why consumers need to beware.
"Studies have increasingly linked triclosan and its chemical cousin triclocarban, to a range of adverse health and environmental effects, from skin irritation, endocrine disruption, bacterial and compounded antibiotic resistance, to the contamination of water and its negative impact on fragile aquatic ecosystems," explains Beyond Pesticides.
For an abstract on this latest study linking triclosan and octylphenol to breast cancer, visit:
http://pubs.acs.org/doi/abs/10.1021/tx5000156
