Colgate Total Ingredient Linked to Hormones, Cancer Spotlights FDA Process
The chemical triclosan has been linked to cancer-cell growth and disrupted development in animals. Regulators are reviewing whether it’s safe to put in soap, cutting boards and toys. Consumer companies are phasing it out. Minnesota voted in May to ban it in many products.
At the same time, millions of Americans are putting it in their mouths every day, by way of a top-selling toothpaste that uses the antibacterial chemical to head off gum disease -- Colgate-Palmolive Co.’s Total.
Total is safe, Colgate says, citing the rigorous Food and Drug Administration process that led to the toothpaste’s 1997 approval as an over-the-counter drug. A closer look at that application process, however, reveals that some of the scientific findings Colgate put forward to establish triclosan’s safety in toothpaste weren’t black and white -- and weren’t, until this year, available to the public.
Colgate’s Total application included 35 pages summarizing toxicology studies on triclosan, which the FDA withheld from view. The agency released the pages earlier this year in response to a lawsuit over a Freedom of Information Act request. Later, following inquiries from Bloomberg News, the FDA put the pages on its website.
The pages show how even with one of the U.S.’s most stringent regulatory processes -- FDA approval of a new drug -- the government relies on company-backed science to show products are safe and effective. The recently released pages, taken alongside new research on triclosan, raise questions about whether the agency did appropriate due diligence in approving Total 17 years ago, and whether its approval should stand in light of new research, said three scientists who reviewed the pages at Bloomberg News’s request.
Rodent Bones
Among the pages were studies showing fetal bone malformations in mice and rats. Colgate said the findings weren’t relevant. Viewed through the prism of today’s science, such malformations look more like a signal that triclosan is disrupting the endocrine system and throwing off hormonal functioning, according to the three scientists.
Colgate’s application materials also show that the FDA asked questions about the thoroughness of cancer studies, which are partly addressed in recently released documents.
Some questions about triclosan’s potential impact on people are, by nature, unanswerable. Humans are exposed to dozens of chemicals that may interact in the body, making it almost impossible to link one substance to one disease, said Thomas Zoeller, a biology professor at the University of Massachusetts Amherst, who specializes in how chemicals affect the endocrine system.
