The debate over talc began decades ago. In the early 1970s, scientists discovered talc particles in ovarian tumors. In 1982, Harvard researcher Daniel Cramer reported a link between talcum powder and ovarian cancer. His study was followed by several more finding an increased risk of ovarian cancer among regular users of talcum powder. Cramer, who at one point advised J&J to put a warning on its products, has become a frequent expert witness for women suing the company.His studies and the many others that found a relationship used a case-control approach: A group of women diagnosed with ovarian cancer and a group without it were asked to recall their past diet and activities, and the results were then compared.Critics say these kinds of studies have serious drawbacks, particularly “recall bias.” Women may forget what they did or, if diagnosed with cancer, might inadvertently overestimate their use of a suspect substance. People without a serious disease may be less motivated to remember details.Three other studies — considered cohort studies — did not find any overall link. Unlike the case-control studies, these efforts began with a large group of women who did not have cancer and followed the progress of their health, with participants recording what they were doing in real time. The results of this approach, most scientists say, are stronger because they aren’t subject to the vagaries of memory.
July 13, 2018 at 12:20 PM EDT