Beauty products companies have long used dermatologists to give a sheen of scientific credibility to their cosmetics products–a tradition whose troubling implications have been amply explored by major media outlets in the past. (See here and here for examples). Given this checkered history, we think journalists bear a special responsibility to closely examine scientific claims related to cosmetics products. Unfortunately, this story from WebMD mostly gave a pass to a weak study about a new moisturizing cream that purports to treat stretch marks. There was little exploration of the quality of the evidence, no quantification of benefits, and no discussion of the myriad other creams on the market that offer similar flimsy proof of effectiveness.
Quality health journalism can help consumers determine whether this "proof" of reducing stretch marks holds up to careful scrutiny. Or, quality health care journalism could spend its time exploring other, more important topics.
The story notes that a 5.29-ounce tube of the product retails for $39.99 at drugstores.
Women reported that the treated stretch mark "looked better, was less red, and was softer and smoother," according to the story, but no statistics are provided. There is no way for the reader to judge the frequency or magnitude of the benefits reported.
The story reports that women experienced no side effects from the cream.
The design of this study was such that the onion cream treatment was almost guaranteed to come out ahead, but the story offers no cautionary notes regarding the generally poor quality of the evidence. It is a well-established fact that patients often will perceive benefits from a treatment regardless of whether the therapy is objectively effective (the placebo effect). So one has to question why this study didn’t use blinded observers to grade the effects of the cream instead of relying on the unblinded participant reports. Moreover, instead of comparing the onion cream to no treatment, why not compare it with one of the many other moisturizing creams that claim to reduce stretch marks? This would have provided a more useful test of the onion extract’s "anti-inflammatory" properties. The story just didn’t pose any questions about the evidence.
The entire concept behind this story is a subtle form of disease-mongering. Stretch marks are a ubiquitous part of the human experience, and the notion that we need to "treat" them is a medicalization of a normal state.
The story does earn credit for pointing out that stretch marks "are not harmful to your health," but it wanders into unsatisfactory territory when it characterizes stretch marks as "a problem that currently has no cure." Stretch marks are not a disease, but this description makes them sound like one.
The story quotes one independent source and identifies Dr. Draelos, the lead researcher on the study, as a consultant to Merz Pharmaceuticals, which funded the research.
This story fails to mention the existence of the many other moisturizing creams that purport to treat stretch marks. It also did not mention that plastic surgery is sometimes used to treat stretch marks.
The story states that the product is available in drug stores.
There are many creams that combine moisturizers and plant extracts and claim to treat skin problems. This story should have challenged the notion that adding onion extract to a skin cream makes it in any way "new."
It doesn’t appear that the story relied solely on a news release.