A new study published last week in the Journal of the American Medical Association made headlines for its assertion that there’s no “statistically significant” link between genital powder use and ovarian cancer. But a deeper dive into the study reveals how dangerously misleading its conclusions really are.
The study relied on data taken from four US-based cohort studies consisting of 252,745 women who answered questions about whether and how they used powder in the genital area. But while the study was crafted to address shortcomings in several earlier studies—for example, the potential for study participants to over-report their exposure to talc once they know its significance—its design leaves gaping holes in the kinds of conclusions that we can really draw.
First and foremost, women who reported their powder use were not asked to distinguish between talc-based powders and other kinds of powders, even though cornstarch-based baby powders have been marketed for decades as a popular alternative to talc.
Buried near the end of the study, the authors admit that “specific exposure windows could not be examined, nor could type of powder used” (57). But then they glibly imply that the results can nevertheless be extrapolated to talc because “most cosmetic powder products include some quantity of mineral talc” (56). That linguistic sleight of hand caught our attention because “cosmetic powder products” is a category that also includes eye shadow, blush, foundation, beauty cream, and other products not likely to be applied to the genital area.
Digging deeper into the authors’ citation (the World Health Organization International Agency for Research on Cancer monograph on talc) for the claim “most cosmetic powders” we find instead this caution: “The content of body powders used by women varies by product and has changed over time, although data that document this are limited. … Other added ingredients, which depend on the product, could include cornstarch and perfumes.”
The authors of the JAMA study don’t mention the word “cornstarch” once. There’s simply no way of knowing whether study participants used talcum powder alone, cornstarch alone or a combination of both.
That’s a significant omission because asbestos, a known carcinogen sometimes found in talc powders, is one of the possible triggers of ovarian cancer. While cornstarch is unlikely to be tainted with asbestos, veins of asbestos are often found in talc deposits, leading to a risk of cross-contamination. While most people exposed never get cancer, for some, even small amounts are enough to trigger the disease. The exact amount has not been established and there is no known safe level of asbestos exposure.
While it’s potentially helpful to know that some powder use in general may be safe, the study can’t tell us anything about the talc-based powders at the center of the current debate. Essentially, the authors have lumped an unknown number of people exposed to leaded gasoline together with an unknown number of people exposed only to unleaded gasoline into one big group and then concluded based on the group as a whole that leaded gasoline has no dangerous health effects, when we know it does.
Even worse, the study repeatedly and disingenuously implies that asbestos contamination isn’t much of a worry for today’s powder users. In paragraph one, the authors assure us that “talc was first investigated as a carcinogen based on its relationship to asbestos… However, all US-based manufacturers of cosmetic talc agreed to ban asbestos in 1976” (50)—as though that settles it. Six pages later the authors concede that, in fact, “it was recently suggested that some products may have contained asbestos after 1976” (56).
“Recently suggested” is a strange way of communicating that, in fact, an in-depth investigation into the corporate records of talc baby powder maker Johnson & Johnson revealed that the company knew for decades after the ban that its talc could be tainted with asbestos.
A Reuters examination of many of those documents, as well as deposition and trial testimony, shows that from at least 1971 to the early 2000s, the company’s raw talc and finished powders sometimes tested positive for small amounts of asbestos, and that company executives, mine managers, scientists, doctors and lawyers fretted over the problem and how to address it while failing to disclose it to regulators or the public.
In fact, the discovery of asbestos-tainted talcum cosmetics products is not uncommon. In December 2017, independent testing uncovered possible asbestos contamination in talc-based make-up kits sold by Claire’s, a makeup and accessories store for girls. Further, independent testing in 2019 once again found asbestos contamination in certain talc products sold by Claire’s, Justice, and cosmetics maker Beauty Plus Global.
In response to these events, an expert panel formed by the U.S. Food and Drug Administration recently endorsed asbestos testing standards for cosmetics. One important recommendation noted from the panel of government experts is that mineral particles found in talc products small enough to be drawn into the body—even those the industry would not call asbestos—should be counted as potentially harmful.
This is an important conclusion because it contradicts the notion that there is no meaningful association between using talc-based powders and serious health issues.
Finally, the study relies on cohorts that were almost exclusively composed of middle class white women—as much as 98% white in one case. Although rates of feminine hygiene powder use have declined over the last 50 years, it remains a routine practice for many Black women. A 2016 study of African American women who used powder for feminine hygiene had more than a 40 percent increased risk of cancer.
Companies like Johnson & Johnson (J&J) have long capitalized of off these known cultural norms, actively targeting Black and Brown women without disclosing the potential risks associated with use even as internal J&J documents reference the possible carcinogenic effects of its talc-based powders.
By discussing issues that impact vulnerable populations without meaningfully including them, the study does not capture the risk associated for the very population of women who are most effected. The study almost completely erases Black women and other women of color (literally labeled “other” in the analysis (51)) even though toxic personal care products have the potential to harm these women more than any other group.
At the NHWN, we’re committed to ensuring that women have all of the information they need to make good decisions about their health. As consumers read and digest studies like this one, they need to know when bad study design and faulty analysis risk creating a false sense of security about the products they use every day on the most sensitive parts of their bodies. And they need to know when studies ignore women like them.