President Trump blamed the over-the-counter drug acetaminophen, commonly known by the brand name Tylenol, as a significant factor in the rise of U.S. autism diagnoses on Monday, at a news conference in which he offered often inaccurate medical advice for the nation’s children and pregnant women.
“Taking Tylenol is not good. I’ll say it. It’s not good,” Trump said, flanked by Health and Human Services Secretary Robert F. Kennedy Jr. and Centers for Medicare & Medicaid Services Administrator Dr. Mehmet Oz.
In a series of rambling, error-filled remarks that touched upon pain relievers, pregnancy, vaccines and the Amish — who he inaccurately said have no autism prevalence in their communities — Trump also said that the mumps, measles and rubella vaccine should be broken up into multiple shots and that children defer until age 12 the hepatitis B vaccine series now started at birth.
“I’m just making these statements from me, I’m not making them from these doctors,” he said. “It’s too much liquid. Too many different things are going into that baby.”
The announcement was met with dismay from autism researchers and advocates who said that research thus far into causal links between acetaminophen and autism has turned up minimal evidence.
“Researchers have been studying the possible connections between acetaminophen and autism for more than a decade,” said Dr. David Mandell, a professor of psychiatry at the University of Pennsylvania Perelman School of Medicine. The Trump administration, he said, “has cherry-picked findings that are not in line with most of the research.”
Physicians and researchers also took issue with Trump’s insistence that there was “no downside” to women avoiding fever-reducing drugs in pregnancy. In fact, studies show that untreated fever in pregnancy is associated with higher risk of heart and facial birth defects, miscarriage and neurodevelopmental disorders — including autism.
The U.S. Food and Drug Administration will initiate a safety-label update for Tylenol and other acetaminophen products and send a letter to physicians about potential links between the drug’s use and autism, Kennedy said.
The actual text of the letter is much milder than Trump’s impassioned critique.
“In the spirit of patient safety and prudent medicine, clinicians should consider minimizing the use of acetaminophen during pregnancy for routine low-grade fevers. This consideration should also be balanced with the fact that acetaminophen is the safest over-the-counter alternative in pregnancy among all analgesics and antipyretics,” states the letter, signed by FDA Commissioner Dr. Marty Makary.
Monday’s announcement followed weeks of speculation that Kennedy planned to publicly link Tylenol usage to autism, which prompted multiple medical associations to release statements clarifying that any evidence of a causal relationship between the two is limited, and that the drug is safe to take during pregnancy with medical advice.
“All of us in the advocacy community, and all of us who have children with autism, had very high hopes that RFK and the President were serious when they said they wanted to find the causes of autism,” said Alison Singer, co-founder and president of the Autism Science Foundation. “The problem is that so far, what we’ve heard has not been gold-standard science.”
The administration also said it would fast-track the labeling of leucovorin, a generic drug currently used to reduce side effects of chemotherapy, as a treatment for autism-related speech deficits. Also known as folinic acid, leucovorin is a form of the B vitamin folate. Research into its effect on autistic children is still in its early stages, researchers said. The few studies that have been published had small sample sizes and found only minimal improvements in symptoms of concern, Mandell said.
“I want to see a large, rigorous, independent trial. In the absence of that, to tout this as a cure is reckless,” he said. “Families deserve better.”
Autism spectrum disorder is a complex neurological and developmental condition. Symptoms cluster around difficulties in communication, social interaction and sensory processing, and the condition can manifest in many different ways based on co-occurring disabilities and other factors.
Diagnoses in the U.S. have risen steadily since the Centers for Disease Control and Prevention began tracking data in 2000, thanks in large part to a broadening definition of the disorder and increased efforts to identify children with ASD.
Today one in 31 U.S. 8-year-olds has been identified as having autism spectrum disorder, according to the most recent CDC data, up from one in 150 in 2000.
Kennedy has long asserted that’s due to an external environmental cause, often using inaccurate statements to describe both the condition and the research around it.
Most experts believe genetic links and changing diagnostic criteria play a significant role in the trend. In April, Kennedy dismissed such research and arguments as “epidemic denial.” He said he was certain an external factor was to blame.
“We know it’s an environmental exposure. It has to be,” Kennedy said. “Genes do not cause epidemics.” He said at the time that the administration would find an environmental cause by September.
Research into causal links between acetaminophen and autism have not found strong evidence.
Last year, a team of researchers from the U.S. and Europe reviewed records of 2.5 million babies born in Sweden between 1995 and 2019. At first glance, it did seem like children exposed to acetaminophen in the womb were 5% to 7% more likely to be diagnosed with autism than those who weren’t. But when the researchers compared those children to their siblings, they found that kids from the same parents were equally likely to be diagnosed with autism, whether their mother took acetaminophen during pregnancy or not.
“If you actually do an apples to apples comparison, you see absolutely zero effect. The association flatlines. In other words, there’s no real risk that’s attributable to acetaminophen,” said Brian K. Lee, a professor of epidemiology and biostatistics at Drexel University who was on the study team. “A large elephant in the room is being ignored, and that’s genetics.” Hundreds of studies over the years have explored the complex genetics of autism, with both inherited and spontaneous genes contributing to the condition.
The paper also noted that women who took acetaminophen while pregnant were, unsurprisingly, more likely to suffer from the kinds of ailments for which the medication is indicated, like fevers or chronic pain.
They were also more likely to have diagnoses of autism or other neurodevelopmental disorders, to have pre-existing mental health conditions or to be taking other prescribed medications, the team found. Their results were published in the Journal of the American Medical Association.
“People don’t take acetaminophen for fun. They are taking it for a health condition,” Lee said.
He compared the correlation between Tylenol exposure and autism to the correlation between ice cream sales and drownings. Both of those things tend to increase at the same time each year, he said, not because ice cream is deadly but because both rise during hot summer months. In other words, the underlying health causes that women are taking acetaminophen to treat could be more likely linked to autism than the pain reliever itself.
“This is just such a shame when there are so many things we could do to help autistic children and adults, and the negative consequences — making parents feel guilty about taking Tylenol during pregnancy and newly pregnant women afraid — are real,” said Catherine Lord, a clinical psychologist and autism researcher at UCLA. “Just sad all around.”
This story originally appeared in Los Angeles Times.
