A day after saying his administration had “found the answer to autism,” President Trump announced Monday new efforts to warn Americans that taking Tylenol and other acetaminophen-based painkillers during pregnancy may be linked to a neurological disease and to encourage the use of leucovorin, a lesser-known cancer and anemia drug, to treat it.
But both theories are unproven, and Trump has not provided any new evidence to support his administration's new recommendations.
“I've always had very strong feelings about autism, how it came about and where it came from,” the president insisted. “We understood a lot more than a lot of the people who studied it.”
Since returning to the Oval Office in January, Trump has repeatedly promised to solve America's problem. rising rates of autism. In April, the Secretary of Health and Human Services Robert F. Kennedy Jr.who has has long promoted debunked theories about the disordersaid the administration has “begun a massive testing and research effort that will involve hundreds of scientists from around the world,” promising that “by September, we will know what is causing the autism epidemic and will be able to reverse those impacts.”
Kennedy did not follow through on that promise on Monday. Instead, he said the National Institutes of Health will continue to explore “multiple” hypotheses about potential causes and will begin awarding 13 research grants this month, with updates likely coming next year.
But Trump and Kennedy and other administration officials have said that prenatal exposure to acetaminophen, the active ingredient in Tylenol and one of the most widely used drugs in the world, may increase the risk of autism spectrum disorder (ASD)—and as a result, the Food and Drug Administration issued a new recommendation that pregnant women should take it only when they have a fever.
Officials also highlighted research showing that folinic acid (a form of vitamin B9), also called leucovorin, a decades-old drug that is often prescribed to counteract the toxic effects of a certain cancer drug, may help improve communication and cognition in at least some people with autism.
During Monday's announcement, Kennedy continued his efforts to link childhood vaccines to autism. a claim that has been completely debunked. Calling ASD a “complex disorder,” he insisted that future research “will not be taboo.” “One of the areas we are looking closely at is vaccines,” Kennedy said. “It will take time for scientists to take an honest look at this topic. We will be uncompromising and tireless in our search for answers.”
The rest of Monday's statement was not based on equally discredited science. But experts also don't consider it the “answer to autism.”
What We Know About Tylenol and Autism
Recent studies have reached conflicting conclusions regarding acetaminophen. In August, BMC Environmental Health magazine published review of existing studies — including six studies of the link between prenatal acetaminophen use and the risk of ASD in children — that aimed to find “strong evidence of an association” between the drug and the disorder.
The article was co-authored by Dr. Andrea Baccarelli, dean of the Harvard T.H. School of Public Health. T.Ch. Chan, and ultimately recommended “judicious use of acetaminophen—lowest effective dose, shortest duration—under medical guidance, based on individual assessment of risk and benefit.”
More big study 2024The study, which looked at almost 2.5 million people born in Sweden between 1995 and 2019, concluded that “acetaminophen use during pregnancy is not associated with the risk of autism in children.”
Why is there such a difference? Like other researchers, the Swedish team found an increased prevalence of autism among the offspring of people who took acetaminophen during pregnancy. But according to their study, the risk was only slightly higher—0.09 percentage points to be exact—and it disappeared when they focused on cases where a parent took acetaminophen during one pregnancy rather than another.
“This suggests that what initially appeared to be an increased risk of autism from acetaminophen during pregnancy may have been the result of other risk factors,” Scientific American says. recently explained — specifically, “fever or underlying infections for which Tylenol has been used.” (A 2014 study of more than 2 million people found that if a pregnant woman is hospitalized with an infection, their child is about 30% more likely to develop autism.)
“The conditions that people use acetaminophen to treat during pregnancy are far more dangerous than any theoretical risks and can result in serious morbidity and mortality for the pregnant woman and the fetus,” American College of Obstetricians and Gynecologists. says the statement.
What do we know about leucovorin and autism?
Meanwhile, leucovorin has shown promise as a possible treatment for autism, but it is too early to draw any definitive conclusions about its effectiveness.
Scientists have long known that folic acid deficiency during pregnancy can increase the risk of neural tube defects. (The neural tube eventually develops into the brain and spinal cord.) In 2004 study found that in some children with autism-like symptoms, the body has a harder time transporting folic acid to the brain. As a result, researchers in Arizona, France, China, India And Iran conducted small randomized controlled trials of folinic acid for the treatment of autism, that is, as a way to deliver folic acid more effectively, and all found modest improvements in receptive and expressive language.
However, each of these studies included only a few dozen children, and larger trials of leucovorin were slow to start as its original patents expired (leaving drug companies with little incentive to fund further research).
Controversial statements
Monday's announcement is likely to spark controversy in the autism community. ASD diagnoses have increased by about 300% over the past 20 years, a shift Trump attributed largely to environmental factors.
“It’s something artificial,” he said Monday. “They're taking something.”
On the contrary, half a century of research shows that ASD is “a complex disorder of the nervous system that results from a combination of genetic and environmental influences.” Scientific American magazine expressed thisMost public health officials attribute the rising rates to a broader definition of the disease and increased screening and awareness, rather than to any toxin.
So while promises of special causes and silver treatments may attract attention, experts warn that getting ahead of the existing science could backfire on families.
“A press statement suggesting a potential link would create great fear,” Dr. Debra Khoury, former chief medical officer of the Centers for Disease Control and Prevention, told reporters Monday morning. “Unless there is scientific evidence to back it up, we'll see changes in practice, worried moms and more, and that's not appropriate.”
