The emails came to light in litigation against Johnson & Johnson.
The manufacturer of Tylenol was keeping tabs on research into the drug and neurodevelopmental issues such as autism, and concluded in 2018 that evidence of a link between them was becoming significant, according to newly disclosed documents.
In a Feb. 8, 2018, email obtained by The Epoch Times, Rachel Weinstein, director of epidemiology at Johnson & Johnson subsidiary Janssen, wrote, “The weight of evidence is starting to feel heavy to me.”
Weinstein was emailing Jesse Berlin, Johnson & Johnson’s global head of epidemiology, about a review that concluded that nine studies suggested that use of acetaminophen—the active ingredient in Tylenol—by pregnant women was linked to autism and other neurodevelopmental issues in the women’s children.
Weinstein said that Janssen had been discussing with a neurologist about how acetaminophen could be beneficial.
“But now we’ve added the studies in prenatal exposure and neurodev [sic] outcome,” she said.
Berlin wrote that he read the review and that “there appears to be some specificity of the association.” While he took issue with how some papers did not analyze other drugs, “at least one study looked separately at specific indications and the association didn’t go away,” he said.
Johnson & Johnson was the maker of Tylenol for years. In 2023, a newly created company called Kenvue took over the Tylenol brand and other consumer brands.
“These documents show we were doing exactly the right thing,” a spokesperson for Kenvue told The Epoch Times in an email. “We have continuously evaluated the science, and there is no credible evidence that taking acetaminophen causes autism.”
‘Difficult Options’
Dr. Jørn Olsen of Aarhus University in Denmark and other researchers in 2014 released an observational study that determined maternal acetaminophen use during pregnancy was linked to a higher risk of attention-deficit/hyperactivity disorder-like behavioral problems or hyperkinetic disorders in their children.
Weinstein, in an email, told Olsen that the study had strengths but wondered whether the researchers had tried assessing any association between other drugs pregnant women take, such as aspirin, and the disorders. Olsen, in a brief reply, said the researchers planned to look at those drugs in future studies.
Weinstein forwarded the email to the company’s consumer medical safety division.
“Recall that we have ruled out the possibility of conducting a database study of our own because other existing databases would be underpowered to detect the same effect that the Danish study found, due to the lack of a large enough database,” she wrote in her email.
She asked whether the question for the company was whether there was a willingness to support Olsen “up to a reasonable amount with the provision that the investigator has final say on publication but the sponsor can review and comment on the manuscript prior to publication.”
