Viadent, Sanguinaria and Bloodroot
I was browsing the other day and remembered Viadent toothpaste. I used it in the 1990s. My mouth always felt squeaky clean after brushing with Viadent, though it wasn’t abrasive at all, but not many stores carried it on their shelves. In 1985, the NY Times described Viadent as a potentially revolutionary product from a small company – a product that Colgate-Palmolive and Procter & Gamble couldn’t match:
Viadent, consisting of a toothpaste and a mouth wash, … produced by Vipont Laboratories, Fort Collins, Colo. Its active ingredient … is sanguinarine, an extract from the bloodroot plant that attacks and destroys bacteria in dark, wet places like the mouth, in which it allegedly destroys bacteria.
After moving to a new area I had given up looking for it, but I decided to see whether Amazon had it. They listed it as discontinued, and google revealed a number of disturbing posts about a key ingredient. An Ohio State paper claimed :
Sanguinarine, a natural anti-bacterial agent, was once a key ingredient in the Viadent line of toothpastes and mouth rinses. Researchers suspect that sanguinarine causes the formation of white lesions, called oral leukoplakia.
“Patients who had used Viadent products were 9.7 times more likely to have developed the white lesions.”
While leukoplakia often causes no symptoms and may disappear, it can also sometimes lead to oral cancer, said Carl Allen, a study co-author and a professor of oral pathology and dentistry at Ohio State University.
“We’re seeing patients who used the old formulation of Viadent develop lesions two, three, four, even five years after they stopped using the product,” he said.
Ok, I thought, I never had any symptoms, but I guess it’s a good thing I stopped using it. Then I found this 1999 NIH abstract, Viadent usage and oral leukoplakia: a spurious association, by Munro IC, Delzell ES, Nestmann ER, & Lynch BS:
… In 1990 and 1993, an Expert Panel reported on reviews of these data and concluded that Viadent products are safe for their intended use. Despite the large database of information to support the safety of Viadent products, Damm et al. (1999) recently raised the possibility that their usage may be causally associated with development of oral leukoplakia. However, a critique of this recent report shows that it does not fulfil criteria for establishing causation. In particular, the study does not show that exposure to Viadent preceded the onset of leukoplakia, it does not demonstrate dose-response or biological plausibility, and it suffers from selection and information bias and from potential confounding. Furthermore, upon critical evaluation, the Damm et al. (1999) report on a case-series is inconsistent with the weight of available clinical evidence showing that Sanguinaria extract-containing oral health care products cause no cytotoxic or significant irritant effects in the oral mucosa in human studies of up to 6 months duration. The animal data similarly do not support a causal association between Viadent usage and oral leukoplakia in humans. These data demonstrate that Sanguinaria extract and whole Viadent formulations are without significant irritation potential and have no effects on the oral mucosa, even in studies with life-long dietary exposure to Sanguinaria extract. The mutagenicity and genotoxicity data do not indicate that Sanguinaria extract or its components are genotoxic in vivo. The results of 2 GLP-compliant rat oncogenicity studies provide no evidence of any carcinogenic effect of Sanguinaria extract. In conclusion, the available clinical and animal data provide no support for and in fact argue strongly against the hypothesis that the use of Viadent toothpaste and/or oral rinse products may be causally associated with the development of leukoplakia in humans.
However by 2002, there were several more studies linking Viadent with leukoplakia, and it disappeared from the market. In 2012, Vlachojannis C, Magora F, Chrubasik S. published, Rise and fall of oral health products with Canadian bloodroot extract:
The rhizome of Sanguinaria canadensis (SC, bloodroot) contains an active principle with antimicrobial, antiinflammatory, antioxidative and immunomodulatory effects. For this reason SC extract has been added to toothpastes and mouthwashes in various concentrations. When tested separately, neither the toothpastes nor the mouthwashes with SC extract had any demonstrable clinical effectiveness against dental plaque and gingivitis. Although using them together twice a day seemed more effective than using placebo, more recent studies have shown conflicting results. Preclinical safety studies up to 2000, which did not include studies longer than 6 months, were thought not to indicate any appreciable potential for harm – to the oral mucosa in particular. In 2003, the FDA Subcommittee on Oral Health Care Drug Products for Over-the-Counter Human Use concluded from a review that using SC-containing products is safe. However, for reasons unknown, the review failed to consider publications between 1999 and 2001 that suggested a possible link between the use of SC-containing products and the pre-neoplastic lesion, leukoplakia. As it happened, bloodroot had already been removed (in 2001) from the formula of one of the most widely used products in question and the brand has since then disappeared altogether from the worldwide market.
BTW, bloodroot, or bloodwort, is an old homeopathic remedy for a variety of respiratory and rheumatic ailments. So I wonder, why the dueling papers? Was Viadent indeed a dangerous product? Or was it torpedoed with studies funded by larger firms? And how would we ever know the truth?