Front Burner - Autism and Tylenol: what the science says

Episode Date: September 24, 2025

Health professionals around the world are disputing  the Trump administration’s claims about autism and its potential causes. U.S. Secretary of Health Robert F. Kennedy Jr., along with President Donald Trump himself, said this week that taking Tylenol while pregnant may cause autism in babies, and the U.S. FDA said it would reclassify the drug leucovorin — primarily used to mitigate chemotherapy side effects — to treat autism symptoms in children.But the established, peer-reviewed research on autism and its causes does not support either of these claims — or a number of other statements made in that announcement. Health experts have called the claims premature, misleading, and even dangerous.Deepa Singal, the scientific director of the Autism Alliance of Canada, explains what the science actually says about autism, why health professionals aren't changing their recommendations, and why autism is so hard to get definitive answers about in the first place.For transcripts of Front Burner, please visit: https://www.cbc.ca/radio/frontburner/transcripts

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not good. I'll say it. It's not good. On Monday, Donald Trump held a press conference at the White House, along with his health secretary Robert F. Kennedy Jr., his head of Medicare and Medicaid, Dr. Mehmet Oz, and several others. Trump billed it as a major breakthrough in understanding autism. This, of course, is an RFK Jr. crusade that began long before his time in the Trump administration. But what followed has been described by doctors, researchers, and other health experts around the world as misrepresentations, over-generalizations, and even outright lies. Trump repeatedly claimed that taking Tylenol while pregnant could cause autism in the baby.

He claimed a drug called Lecovorin could be an effective treatment for autism. It's a drug most commonly used to treat the side effects of chemotherapy, but the research around using it to treat autism symptoms is very preliminary. He said babies get too many vaccinations. Trump, in particular, did not back up almost anything. he said with scientific evidence. And by the way, I think I can say that there are certain groups of people that don't take vaccines and don't take any pills that have no autism, that have no autism.

Does that tell you something? That's currently, is that a correct statement, by the way? So today on the show, we wanted to take a closer look at autism itself. What we know about it and maybe more importantly, what we don't. Whether there's any science at all to support the claims made by the Trump administration, and what all of this means for the people directly affected by autism, either themselves or their families. With me today is Deepa Single. She is a scientific director of the Autism Alliance of Canada.

She's also an adjunct assistant professor in the Department of Pediatrics of the University of Alberta, and a researcher who has worked directly on studies about autism prevalence and prenatal medical exposure. Deepa, thank you so much for coming on to. to Frontburner. Thank you so much for having me, Jamie. Well, I'm really glad to be speaking with someone like you today. So we'll talk more about these claims that the American government has made this week in a few minutes, but I wanted to start by talking a bit more about autism itself. What exactly is autism? Okay, so autism is a lifelong neurodevelopmental condition and it affects how a person experiences the world, how they communicate, how they interact, how they

interact with one another, how they process information. And so it's called a spectrum because every artistic person is different. There's a lot of heterogeneity there. They've got their own strengths, their own challenges, their own ways of learning and engaging with society and with people. And tell me how it's diagnosed. What are the criteria? So it's diagnosed based on largely behavioral criteria, typically by a team of specialists such as pediatrician, psychologists, or developmental clinicians. And the main diagnostic criteria looks at challenges in social behavior, patterns of repetitive behavior, and sensory needs or sensory differences. And what would a person normally be diagnosed with autism? What age, typically? Autism is usually diagnosed earlier in the

lifespan, so during early childhood. But what we're seeing in a lot of the research is showing the prevalence research is that autism can be diagnosed throughout the lifespan. And particularly right now, we're diagnosing adults who've been previously misdiagnosed or missed because the awareness of autism and the medical community's ability to diagnose has changed and increased over time. So really what we're seeing is an increase in diagnoses across the lifespan, but primarily in the younger ages. And I know this is going to get into my next question, which is what does the science show about what might cause it? But is autism something that you are born with? Or is it something that develops after you're born? What do we know about that? Yeah, it is something that you're

born with. And it's lifelong. And there's no evidence that it can be, quote unquote, prevented. And multiple lines of evidence point to genetics that are playing a major role in autism. And so we see siblings, quite often if one sibling has autism, another can. You know, parents of autistic kids are often autistic themselves. You know, and I want to take this moment to say that framing autism as an epidemic or as a disease or something that's preventable is really inaccurate according to the science, and it's very stigmatizing for the population. When we're talking about what might cause it, I hear a lot of talk about. pollutants, genetics, screens, people having children later in life. And just what does the

research say about some of these popular explanations? So the research, there is research that shows links to all of the things that you're talking about. But when you're looking and thinking about the research, you're thinking about the quality of that research and the ability of that research to prove causation, which none of these observational studies can do. And so there's they're looking at sort of what research is called association versus causation. And right now, the totality of the body of research evidence is saying there's these multiple, multiple causes. Right, right. There's still a lot of uncertainty, right? Like, we have no smoking gun. Absolutely. There's no smoking gun and more research is being done in this area. You know,

and for those studies that are showing environmental causes, pollutants, etc., most of those studies are observational right so again can't show causation and just we've more investment needs to be done more research needs to be done in this area using high quality methodology deep but like considering this is something that's gotten millions of dollars in research funding there's so much motivation behind trying to understand it and develop treatments why do you think it's been so hard to find that smoking gun or these conclusive answers here yeah that that is really the billion dollar question, Jamie, that scientists are pondering around the world right now, you know, research in autism is really challenging. It's heterogeneous. No two autistic people are the same.

There's a wide variety of behaviors, of symptoms, of co-occurring conditions as well that add to the complexity of studying this. So then now let's go through some of what President Trump and his health official said on Monday and break down some of the claims that they were making. And the one that I want to start with is Tylenol. So most people probably have a bottle at home right now. I do. It's also called acetaminopin or paracetamol.

And Trump claimed that taking it while pregnant could give your baby autism. Effective immediately, the FDA will be notifying physicians at the use of acetya... Well, let's see how we say that. Acetaminophen. Acetaminophen. Is that okay? Which is basically commonly known as Tylenol during pregnancy can be associated with a very increased risk of autism. He said that pregnant mothers should avoid taking it.

They are strongly recommending that women limit Tylenol use during pregnancy unless medically necessary. That's, for instance, in cases of extremely high fever, that you feel you can't tough it out, you can't do it. I guess there's that. It's a small number of cases, I think. He said parents shouldn't give it to their young children. What does the science say about any possible link between Tylenol and autism? So unequivocally, the body of evidence shows that Tylenol does not cause autism. So Tylenol during pregnancy, prenal exposure to Tylenol does not cause autism in children.

The biggest study out there, the largest study that he might have Sweden, that used a sibling design to sort of tease apart whether Tylenol causes autism, they're looking at it. at siblings that were, one of them was exposed to Tylenol in the prenatal period. One of them wasn't. And then they're looking to see the relationship between those sibling pairs if they've got autism or not in childhood. And what the study is showing, and they followed 2.48 million children, I believe, over time. And the study is showing that when they use this sibling design, and the sibling design is what accounts for things like family genetics and prenatal health and socioeconomic factors that can't be used in observational studies, that there is no association.

Numerous medical societies, including the Canadian Society of Obstetricians and Gynaecologists in Canada, the American College of Obstitutions and Gynaecologists have reviewed this issue, and they continue to recommend Tylenol is safe during pregnancy when medically indicated. This morning, World Health Organization also issued a statement confirming globally that the totality of evidence demonstrates that there is no causal link between prenatal Tylenol exposure and autism in the developing child. Yeah, I believe Health Canada just released a statement as well along similar lines. Other medications that are commonly used to control fever and pain like ibuprofen or neproxin, those have been shown pretty conclusively to have

negative outcomes on your unborn baby, right? Like that is why health professionals have said that acetaminophen is the safe option, right? Absolutely. And so that's the other really important thing to consider here is that Tylenol is the safe option to treat fever during pregnancy. And that fever during pregnancy can also have harmful consequences towards both mom and baby. And so these risks need to be considered really carefully when pregnant women are looking at this rhetoric in the media at the moment.

and they need to consult their health care providers. But unequivocally, scientific bodies are coming out across the world right now to say that this is unsubstantiated. And I want to ask you specifically about Trump's claim that he does not think you should give young children Tylenol at all. If you're pregnant, don't take Tylenol. When you have your baby, don't give your baby Tylenol at all, unless it's absolutely necessary. Don't do it.

Which was a pretty jaw-dropping moment for me. What do we know about that? You know, once again, no medical bodies are coming out to change their guidance and change medical treatment, right? There's not a body of evidence that is strong enough for both of these claims to change the medical advice that clinicians are giving. their patients across the world. Trump and his team, they did seem to be drawing on some studies that did seem to find some connection between Tylenol and autism. And can you tell me more about those studies that have actually looked at this and what they

found and what you think of them? So this is really important because the nuances of the scientific process and the nuances of scientific design are really important to take into account. So the studies that Trump and his team are talking about are largely observational studies. And observational studies are designed to look at association and not causation. And so the gold standard of causation are randomized control trials. And ethically, pregnant women don't participate in randomized control trials. Like we can't say, okay, we're going to randomize a group of pregnant women to Tylenol and one group not to Tylenol if there's perceived harm.

And so when you look at the observational studies, there's sort of a host of limitations within their study design that prevent such a strong association from being determined. Listening to all of this, I couldn't help, but think about what this puts on mothers and parents, more generally, mothers who maybe have a child with an autism diagnosis who are now feeling, God, I don't know, guilty about taking Tylenol, parents, one of them. if they should have given their young children the medication to calm a raging fever. And I just, I wonder if you could speak directly to those mothers, those parents right now. I know you have children of your own. I do. I do. I'm really glad you asked me this question. The fear is real and the guilt that moms carry all the time for so many different reasons is so very real. but fear and guilt over Tylenol is not what we want Canadians and pregnant women and families to feel because there's no scientific evidence that shows that this could have been a possibility.

the totality of the evidence does not show this. These are inconclusive claims. They're extrapolated. It's not a measured approach that's being taken when you look at the science, when you analyze science. And so I think what families and women in particular need to know right now is that the evidence that is being cited or is being spoken about is not strong enough to change any medical guidance at this moment by any credible medical body globally. You know, shopping for a car should be exciting, not exhausting, and that's where Car Gurus comes in. They have advanced search tools, unbiased deal ratings, and price history, so you know a great deal when you see one. It's no wonder Car Gurus is the number one rated car shopping app in Canada on the Apple app and Google Play, according to AppFollow. Buy your next car today with Car Gurus and make sure your big deal is the best deal at Cargooros.ca. That's C-A-R-G-U-R-U-S dot CA. Car gurus.com. Hey, how's it going?

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When Debt's got you, you've got us. Give Credit Counseling Society a call today. Visit no more debts.org. Another drug that was talked about at length on Monday was Lukeoverin. The commissioner of the FDA, Dr. Marty McRey, said that his agency would relabel the drug for treatment of autism symptoms. It's a fairly established, mature pathway. Again, we have a duty to let doctors and the public know. We are going to change the label to make it available.

Hundreds of thousands of kids, in my opinion, will benefit. One study found that we... What is Lecoverin? What does the research show about any possible clinical role it might play in treating autism? You know, it's a prescription form of folate, and it's primarily using cancer care. Right now, there's emerging studies, right? So these are emerging studies using really small sample sizes, which is really important. So, you know, I think the largest sample size was 48 or 80.

It was under 100 kids that were these randomized control trials. And the take-home message is at this moment, once again, no medical body is saying that this is a standard of care for autism. It's not a cure. And much, much more research needs to be done before those claims can be made. So we need randomized control trials with big populations. We need reproducible evidence for the totality of evidence to show that it's a standard of care. Right. Am I right to say that there were some studies?

I mean, I know these are very, very small studies, but do you think it's fair to say that there was some promise? Yeah. Just that promise didn't meet, you know, the level of confidence that we heard yesterday. Would that be a fair summary? That's absolutely a fair. summary. So what those smaller studies are showing is that it might help communication. It may help social interaction. It might help some irritability in some children as small subsets. It's likely not going to help everybody who's autistic and it's an emerging field. And so much, much more

study has to be done. The scientific process takes time. It needs to be respected for this very reason, right, so that we don't draw harmful claims or we don't draw incorrect claims. And so, yes, while these smaller studies do show some promising results, it isn't enough to change medical guidance at this moment in time. So, as you mentioned, the chemical name for it is folinic acid. You can buy, as I understand, non-prescription forms of it, often billed as like a health supplement. I'm just going to note here, one of the main suppliers of this form of it in the United States is a company called iHerb, which Dr. Mehmet Oz at one point held a substantial stake in. reportedly said he planned to divest, but it's not clear whether he's actually done that yet. But what do we know about any potential negative effects from taking leukovrin or falinic acid

when not prescribed by a doctor? So the studies have shown relatively mild side effects, like sleep changes, agitation, but what people should know is that this is still being studied, right? And so until there are studies that are looking at, you know, drug interactions, right? So if your child is also taking other medications, that has been. been studied, right? And so is taking this drug going to affect the effectiveness of another drug that they're taking? Are there longer-term side effects that hasn't been studied? And so this is very much an emerging field. Right now, it's mild side effects, but there could be more serious

side effects, but it just hasn't been studied yet, right? And best advice to families is to talk to your health care provider, who knows the fulsomeness of your medical history, who knows what medications your children are on and who can give you that case-by-case advice. Trump also talked at length about concerns that he has about vaccines. Most of this seem to be based on his personal feelings rather than any hard science. The MMR, I think, should be taken separately. This is based on what I feel, the mumps, measles, and the three should be taken separately.

And it seems to be that when you mix them, there could be a problem. But the supposed connection between vaccines and autism is, of course, not new. It's something RFC Jr. has talked a lot about, too, but the science has really been clear on this, that vaccines cause autism have been disproven again and again and again. I want to say that again, disproven, not unproven because there's a difference between those two things. And why do you think this supposed connection has been so hard to debunk? So the evidence here is unequivocal. There's decades of research across millions of children worldwide to show the vaccines are safe. They're

safe and they're essential and bringing this conversation back into the global discourse is dangerous and harmful. And we are saying that in pockets across the world where we're seeing a resurgence of measles because parents are not getting their kids vaccinated. Vaccines don't cause autism. Why this keeps coming up, I think it is sensational. I think media is speaking up on sensationalism and we're revisiting this again and again and again. And to be honest, I just think instead of debating these inconclusive claims, we just really need to bring it back and focus on what is going to help autistic Canadians

and their families. Think about the challenges they're facing within our systems here in Canada. Think about how we can better include them, how we can support employment, how we can ensure that autistic kids are supported within our education system so that they thrive and contribute to society.

Instead of focusing on these inconclusive claims that are just decades-old, debunked, fraudulent science. Yeah. Another thing that Trump and RFK talked about was the increasing rates of autism. It used to be one in 20,000, then one in 10,000. And I would say that's probably 18 years ago. And now it's one in 31, but in some areas it's much worse than that, if you can believe it.

This is also something RFK has talked about a lot before he's called it an epidemic. And it certainly does seem to be the case that there are many, many more cases of autism diagnosed now than even a few decades ago, right? But can you put some numbers on that for me in terms of the rates that we're seeing now? So we're seeing rates of anywhere from 1 to 27, 1 in 31 kids up to 1 in 50 kids. And we're definitely seeing an increase in rates. But the increase in rates is really due to broader. diagnostic criteria, better awareness, better recognition and screening. We're identifying people who are long overlooked, including girls, gender diverse people, racialized communities,

there's less stigma, better understanding of what being autistic means. You know, those are the reasons that the rates are primarily increasing. And so, you know, these figures are really reflecting inclusion and understanding and not this emergency, not this epidemic of how it's being framed. Yeah, I've, I've heard R of K respond to what you just said, essentially, you know, and say that it's not just broader diagnostic definitions. Oh, doctors and therapists in the past were not stupid. They weren't missing all these cases. The epidemic is real. He's claimed that the rates of more severe cases of autism are going up to. And all the core states, the trend is consistently upward.

And most cases now are severe. And how much truth is there to that? Rates are going up across the spectrum, right? So for lower needs, individuals, higher need individuals, for the reasons that I just stated, that is what the scientific community is reporting. He has also been a major proponent of the idea, the idea of causes of autism aren't genetic

that is caused by things that happen to the baby as it's growing and developing, right? things like environmental pollution, vaccines, or other drugs. We know it's an environmental exposure. It has to be genes do not cause epidemics. They can provide a vulnerability. You need an environmental toxin. So he has talked a lot about specific populations that have lower rates of autism than we'd expect from the general public,

specifically mentioned on Monday was the Amish. There are some studies that suggest that, yeah, with the Amish, for example. The Amish, yeah, virtually. I heard none. See, Bobby wants to be very careful with what he says, and he should, but I'm not so careful with what I say. But you have certain groups. The Amish, as an example, they have essentially no autism.

Are there specific populations that do not, in fact, have higher or lower autism rates? And do we know why? That is a very interesting line of inquiry. I'm not, you know, completely familiar with the Amish population that was being referred to. But let's unpack that a little bit of what we see here at home. And so we do see that there is, you know, different cultures have stigma around autism, that, you know, members of the Autism Alliance of Canada, which is the organization that I lead, are working really, really hard at alleviating.

And so often what we can see with different cultural norms or different populations, is that stigma is what is preventing, you know, parents from communicating with their physicians or getting that diagnosis or from autistic people themselves, from sort of understanding their autistic traits or symptoms. And so I think that probably is a reasonable explanation for some of what is happening and why we're seeing lower rates in some populations than others. Deepa, we've heard a lot of reaction since that press conference on Monday, health professionals have called it irresponsible and dangerous, as I mentioned. But one thing I am wondering about in all of this is autistic people themselves, you know, who you've mentioned a couple times during this interview and their families, of course. This is a community that your organization works directly with here in Canada.

And I know it's not a monolith. But when claims like this are made at this level, how does this affect all this? the people that you're working with. What are you hearing from them right now? Yeah, thanks so much for bringing that human element into this, Jamie, because I think that so often experts forget that they're talking about real human beings with emotions, feelings, dignity. And so, you know, framing autism in this, in this epidemic way, this emergency way, this burden, it really, really disrespects the life experience and the contributions and the dignity of of autistic people and their families.

We're hearing from our members from coast to coast to coast about, you know, this really sad, tragic moment where the global discourse has shifted from awareness, from acceptance, from supports, from services, from dignity to fear dehumanizing language. And it's really quite unfortunate and dangerous. Okay, Deepa, thank you so much for this. Thank you so much for having me.

That is all for today. I'm J.B. Plesson. Thank you so much for listening. Talk to you tomorrow. Go to cBC.ca slash podcasts.