How the White House used studies with ‘weak’ evidence to tie Tylenol to autism | Donald Trump

The White House recently published a press release with links to scientific studies to support Trump’s claim according to which the use of acetaminophen, commonly known as tylenol, during pregnancy causes autism, but these studies only provided “weak” and “not conclusive”, according to evidence, according to doctors an expertise in the revision of medical research that spoke to the goalkeeper.

Jeffrey Singer, surgeon and principal researcher at the Cato Institute who wrote on the claims of Tylenol / Autism, said that the bonds of the press release from the White House showed that the affirmations contained a political rotation.

The exit creates the appearance of additional evidence by linking several times to the same studies, said Singer. The most recent study cited – an article of review published in August by authors affiliated with Mount Sinai and Harvard – is designed to resemble two distinct studies, one from Harvard and one from Mount Sinai. A Boston birth cohort study written by Johns Hopkins Researchers is also linked twice in the press release, as if they were two distinct studies.

“So you say that a Harvard study found the same thing as the study by Hopkins and the study of Mount Sinai. He can give the appearance that [the same results have] Was carried out in one study after another, all of very prestigious centers, “said Singer.

Jake Scott, doctor and member of the Stanford vaccine clinical advisory committee, said the press release “makes me sick in my stomach, to be honest”, because “they present the association as a causality, for a thing”.

There is a much higher bar to prove causality than the association. In this case, proving causality would mean showing that the elimination of exposure to Tylenol would in fact reduce the number of cases of autism.

For example, the rise in ice cream sales can be associated with a heat stroke, simply because the two are things that happen in summer, but the ban on the sale of ice would not reduce the number of heat strokes. To prove causality, it is not enough to show that an occurrence follows another – these results must appear again and again in a variety of study conceptions, and scientists must also find a plausible explanation on how the two factors are linked.

None of the studies related in the press release pretends to have proven causality.

In fact, everyone recognizes that they cannot definitively establish causality, although some use a more prudent label than others. One way to quickly find the scope of the allegations of a study is to seek key terms such as “causal”, “causality”, “association”, “limitations”, “prudence” and “more in -depth investigation”, according to experts.

Once you have started to read studies, more statements in the press release are starting to collapse, experts said. For example, the release indicates: “Scientists have proposed biological mechanisms connecting prenatal exposure to acetaminophen to the development of the altered brain and the results of the unfavorable birth.” The biological mechanisms explaining how exposure leads to a result is an important means of establishing causality. It took decades to scientists to establish that cigarettes cause cancer by the biological mechanism of the introduction of carcinogens into the lungs, which create cancer mutations in cells, for example.

But the study linked in the version to illustrate a biological mechanism does not really include a biological mechanism, but the opposite. The authors write: “The mechanisms underlying associations from prenatal exposure to acetaminophen with unfavorable birth results remain unknown.” In addition, the study has not at all studied “modified brain development”, as the press release said, but has only examined only the results of birth weight and gestational age.

The singer and Scott agree that another way of verifying the scientific claims of the Trump administration is to look at the research left aside.

For example, the press release left aside a Swedish study published in 2024. “This is a study in which they followed nearly two and a half million births … They used brothers witnesses,” said the singer, “so what they have noted is that the acetaminopène [the generic name for Tylenol] Use during pregnancy has shown a slight association [with autism]. “But this association disappears when you compare the brothers and sisters, who have many more genetic and environmental similarities than comparison groups in other studies, said Singer.

The authors of the Swedish study wrote: “This suggests that the associations observed in other models can be attributable to confusion”, which means that it was probably not Tylenol itself, but other factors related to the use of Tylenol (which could include, for example, more fever during pregnancy) which created the risk.

“This is a fairly impressive study,” said Singer. “I’m not saying that they didn’t say. What I say as a doctor who reads research literature, this question has not yet been answered. ”

The singer says that there is probably a reason why the White House included some studies and no others: “Kennedy secretary, I think he is under pressure, because you would remember, he was going to tell us the cause of autism by September.”

Tylenol’s complaints recall the arguments against vaccines, according to Scott, which recently testified before the Congress to compete for allegations according to which vaccines cause chronic diseases – complaints based on a study that has never been submitted for publication due to defects in its design.

“All of this is part of a truly weak evidence operating scheme that is based on very poor quality studies,” said Scott.