Why Are Autism Rates Steadily Rising?
Stefania Sterling was just 21 when she had her son, Charlie. She was young and healthy, with no genetic issues apparent in either her or her husband's family, so she expected Charlie to be typical.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period."
It wasn't until she went to a Mommy and Me music class when he was one, and she saw all the other one-year-olds walking, that she realized how different her son was. He could barely crawl, didn't speak, and made no eye contact. By the time he was three, he was diagnosed as being on the lower functioning end of the autism spectrum.
She isn't sure why it happened – and researchers, too, are still trying to understand the basis of the complex condition. Studies suggest that genes can act together with influences from the environment to affect development in ways that lead to Autism Spectrum Disorder (ASD). But rates of ASD are rising dramatically, making the need to figure out why it's happening all the more urgent.
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Indeed, the CDC's latest autism report, released last week, which uses 2016 data, found that the prevalence of ASD in four-year-old children was one in 64 children, or 15.6 affected children per 1,000. That's more than the 14.1 rate they found in 2014, for the 11 states included in the study. New Jersey, as in years past, was the highest, with 25.3 per 1,000, compared to Missouri, which had just 8.8 per 1,000.
The rate for eight-year-olds had risen as well. Researchers found the ASD prevalence nationwide was 18.5 per 1,000, or one in 54, about 10 percent higher than the 16.8 rate found in 2014. New Jersey, again, was the highest, at one in 32 kids, compared to Colorado, which had the lowest rate, at one in 76 kids. For New Jersey, that's a 175 percent rise from the baseline number taken in 2000, when the state had just one in 101 kids.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period," said Walter Zahorodny, an associate professor of pediatrics at Rutgers New Jersey Medical School, who was involved in collecting the data.
The study echoed the findings of a surprising 2011 study in South Korea that found 1 in every 38 students had ASD. That was the the first comprehensive study of autism prevalence using a total population sample: A team of investigators from the U.S., South Korea, and Canada looked at 55,000 children ages 7 to 12 living in a community in South Korea and found that 2.64 percent of them had some level of autism.
Searching for Answers
Scientists can't put their finger on why rates are rising. Some say it's better diagnosis. That is, it's not that more people have autism. It's that we're better at detecting it. Others attribute it to changes in the diagnostic criteria. Specifically, the May 2013 update of the Diagnostic and Statistical Manual of Mental Disorders-5 -- the standard classification of mental disorders -- removed the communication deficit from the autism definition, which made more children fall under that category. Cynical observers believe physicians and therapists are handing out the diagnosis more freely to allow access to services available only to children with autism, but that are also effective for other children.
Alycia Halladay, chief science officer for the Autism Science Foundation in New York, said she wishes there were just one answer, but there's not. While she believes the rising ASD numbers are due in part to factors like better diagnosis and a change in the definition, she does not believe that accounts for the entire rise in prevalence. As for the high numbers in New Jersey, she said the state has always had a higher prevalence of autism compared to other states. It is also one of the few states that does a good job at recording cases of autism in its educational records, meaning that children in New Jersey are more likely to be counted compared to kids in other states.
"Not every state is as good as New Jersey," she said. "That accounts for some of the difference compared to elsewhere, but we don't know if it's all of the difference in prevalence, or most of it, or what."
"What we do know is that vaccinations do not cause autism."
There is simply no defined proven reason for these increases, said Scott Badesch, outgoing president and CEO of the Autism Society of America.
"There are suggestions that it is based on better diagnosis, but there are also suggestions that the incidence of autism is in fact increasing due to reasons that have yet been determined," he said, adding, "What we do know is that vaccinations do not cause autism."
Zahorodny, the pediatrics professor, believes something is going on beyond better detection or evolving definitions.
"Changes in awareness and shifts in how children are identified or diagnosed are relevant, but they only take you so far in accounting for an increase of this magnitude," he said. "We don't know what is driving the surge in autism recorded by the ADDM Network and others."
He suggested that the increase in prevalence could be due to non-genetic environmental triggers or risk factors we do not yet know about, citing possibilities including parental age, prematurity, low birth rate, multiplicity, breech presentation, or C-section delivery. It may not be one, but rather several factors combined, he said.
"Increases in ASD prevalence have affected the whole population, so the triggers or risks must be very widely dispersed across all strata," he added.
There are studies that find new risk factors for ASD almost on a daily basis, said Idan Menashe, assistant professor in the Department of Health at Ben-Gurion University of the Negev, the fastest growing research university in Israel.
"There are plenty of studies that find new genetic variants (and new genes)," he said. In addition, various prenatal and perinatal risk factors are associated with a risk of ASD. He cited a study his university conducted last year on the relationship between C-section births and ASD, which found that exposure to general anesthesia may explain the association.
Whatever the cause, health practitioners are seeing the consequences in real time.
"People say rates are higher because of the changes in the diagnostic criteria," said Dr. Roseann Capanna-Hodge, a psychologist in Ridgefield, CT. "And they say it's easier for children to get identified. I say that's not the truth and that I've been doing this for 30 years, and that even 10 years ago, I did not see the level of autism that I do see today."
Sure, we're better at detecting autism, she added, but the detection improvements have largely occurred at the low- to mid- level part of the spectrum. The higher rates of autism are occurring at the more severe end, in her experience.
A Polarizing Theory
Among the more controversial risk factors scientists are exploring is the role environmental toxins may play in the development of autism. Some scientists, doctors and mental health experts suspect that toxins like heavy metals, pesticides, chemicals, or pollution may interrupt the way genes are expressed or the way endocrine systems function, manifesting in symptoms of autism. But others firmly resist such claims, at least until more evidence comes forth. To date, studies have been mixed and many have been more associative than causative.
"Today, scientists are still trying to figure out whether there are other environmental changes that can explain this rise, but studies of this question didn't provide any conclusive answer," said Menashe, who also serves as the scientific director of the National Autism Research Center at BGU.
"It's not everything that makes Charlie. He's just like any other kid."
That inconclusiveness has not dissuaded some doctors from taking the perspective that toxins do play a role. "Autism rates are rising because there is a mismatch between our genes and our environment," said Julia Getzelman, a pediatrician in San Francisco. "The majority of our evolution didn't include the kinds of toxic hits we are experiencing. The planet has changed drastically in just the last 75 years –- it has become more and more polluted with tens of thousands of unregulated chemicals being used by industry that are having effects on our most vulnerable."
She cites BPA, an industrial chemical that has been used since the 1960s to make certain plastics and resins. A large body of research, she says, has shown its impact on human health and the endocrine system. BPA binds to our own hormone receptors, so it may negatively impact the thyroid and brain. A study in 2015 was the first to identify a link between BPA and some children with autism, but the relationship was associative, not causative. Meanwhile, the Food and Drug Administration maintains that BPA is safe at the current levels occurring in food, based on its ongoing review of the available scientific evidence.
Michael Mooney, President of St. Louis-based Delta Genesis, a non-profit organization that treats children struggling with neurodevelopmental delays like autism, suspects a strong role for epigenetics, which refers to changes in how genes are expressed as a result of environmental influences, lifestyle behaviors, age, or disease states.
He believes some children are genetically predisposed to the disorder, and some unknown influence or combination of influences pushes them over the edge, triggering epigenetic changes that result in symptoms of autism.
For Stefania Sterling, it doesn't really matter how or why she had an autistic child. That's only one part of Charlie.
"It's not everything that makes Charlie," she said. "He's just like any other kid. He comes with happy moments. He comes with sad moments. Just like my other three kids."
Forget Farm-to-Table: Lab-to-Table Fresh Fish Is Making Waves
Ever wonder why you've never heard of wild-caught organic fish? It's because there's no way to certify a food that has a mysterious history. Mike Selden, a 26-year-old biochemist with an animal lover's heart and an entrepreneur's mind, decided there must be better way to consume one of our planet's primary sources of animal protein. A way that would eliminate the need to kill billions of fish per year while also producing toxin-free, cheap, delicious fish meat for your dinner table. Enter Finless Foods, a young startup with a bold vision. Selden took time out of chauffeuring fish carcasses around San Francisco (no joke!) to share his journey with LeapsMag.
What is the biggest problem with the way fish is consumed today?
There are a lot of problems ranging from metals to animal welfare to human health. Technology is solving those problems at the same time. You've got extreme over fishing, which is collapsing ocean ecosystems and removing populations of fish that are traditionally used as food sources in developing nations.
In terms of animal welfare, fish are killed in massive numbers, billions a year. Even if people don't care too much about that, we want to give them another option.
In terms of health, which I think for most people is the most convincing argument, current fish have mercury and plastic in them. And if you're getting that fish from a farm, you will also have high levels of antibiotics and growth hormones if you're getting it from outside the U.S. What we're doing is producing fish that doesn't have any of those contaminants.
What gave you the idea to start a company around lab-grown fish?
I studied biochemistry and molecular biology at UMass Amherst, traditionally an agricultural school out in the woods of Massachusetts. I have always been an environmental activist and cared about animals. I thought, animal agriculture is so incredibly inefficient, what could be done to change it?
"The worst way you can possibly make a hamburger is with a cow."
Agriculture is a system of inputs and outputs, the inputs being feed and the outputs being meat – so why are we wasting all of this input on outputs we don't care about? Why are we creating these animals that waste all this energy through sitting around, moving around, having a heartbeat, blinking? All of this uses energy and that's valuable input.
The worst way you can possibly make a hamburger is with a cow. It's an awful transfer of energy: you have to feed it many times its own weight in food that could have fed other people or other things.
In February, I got funding from Indie Bio, a startup accelerator for synthetic biology, and moved out to San Francisco with my co-founder Brian Wyrwas. We started working in our lab in March. We're the newest company in the space.
Walk me through the process of creating edible fish in the lab. Do you have to catch a real live fish first and get their cells?
We have a deal with the Aquarium of the Bay, and whenever a fish dies, they call me, I get in a zip car, drive over, and bring the fish back to the lab, where Brian cultures it up into a cell culture. We do use real, high-quality fish stock. From there, we get the cells going in a bioreactor in a suspension culture, grow them into large quantities, and then bring them out to differentiate them into the cells people want to eat—the muscle and fat tissue. Then we formulate it and bring it to people's tables.
How long does the whole process take from the phone call about the fish dying to the food on the table?
There are two different processes: One is a research process, getting the initial cells and engineering them to be what we're looking for.
The other is a production process – we have a cell line ready and need to grow it out. That timing depends on how big of a facility we have. Since we're working with cell division: If you have 1 cell, in 24 hours, you'll have two cells. Let's say you have 1 ton of cells, in 24 hours you'll have two tons of cells.
"We want to give people the wholesome food they are used to in a healthier setting."
How are you looking to scale this process?
We're trying to find a middle ground between efficiency and local distribution. Organic farming is hilariously bad for the environment and horrifyingly inefficient, but on the other hand, industrial agriculture requires lots of transport, which is also bad for the environment. We're looking to create regionally distributed facilities which don't require a lot of transit, so people can have fresh fish even extremely far inland.
What kinds of fish are you "cooking"?
Our first product will be Bluefin tuna. It's a high-quality fish with high demand and it's also a conservation issue. We also currently have a culture going with Branzino, European sea bass, that we're really happy with.
There's a concept in science called a model organism – one that is extremely well studied and understood. Like the fruit fly, for example. For fish, it's the zebra fish, which is used for genetic research, but no one eats it. It's tiny, so we started by thinking: what fish do people eat that is also close evolutionarily to the zebra fish? We came up with carp, even though it's not too widely eaten.
But our process is very species agnostic. We've done work in trout, salmon, goldfish. Any fish with a dorsal fin works with our process. We tried a wolf eel but it didn't work. Eels are pretty far evolutionarily from fish, so we dropped that one.
From left to right, Ron Shigeta (IndieBio), Brian Wyrwas (Finless Foods), Amy Fleming (The Guardian), and Jihyun Kim (Finless Foods) tasting the first ever clean carp croquettes.
(Courtesy Mike Selden)
Why fish as opposed to, say, a cow?
Scientifically, there are a lot of advantages. Fish have a simpler structure than land animals. A fillet from a cow has complex marbling going on between the fat and muscle. When it's fish, like sashimi, it's in layers of muscle and fat. So it's simpler to build, plus fish are cold-blooded, so because they breathe underwater, our equipment needs less complexity. We don't need a CO2 line and we don't need to culture our cells at 37 degrees Celsius. We culture them at room temperature.
It's also easier to get to market since there's much higher value. Chicken in the last year was $3.84 per pound in America, whereas Bluefin tuna is between $100 and $1200 a pound. Because this is about dropping cost, we can get to market faster and give investors a better value proposition.
What's also cool is that something like Bluefin tuna is something many people haven't had the opportunity to eat. We can get these down in cost until there is price parity with any cheap conventional fish. We want to give people a choice between buying something like albacore tuna in a can –with mercury and plastic– or high-quality tuna without any contaminants for the same price.
Do you shape them like fish fillets to help the consumer overcome whatever discomfort they might feel about eating a bunch of lab-grown cells?
Yeah, people want to continue eating food they are eating, and that's fine. We want to give people a better option. We don't want to give them something weird and out there. We want to give them the wholesome food they are used to in a healthier setting that also solves some environmental issues.
How about the taste? Have you done any blind side-by-side tests with the real thing and your version?
Not blind taste tests. But we have been tasting it, and it is firmly fish. I even tried leaving it outside of the fridge – and man, that tasted like spoiled fish.
We want it to have the exact same properties as real fish. We don't want people to have to learn how to cook with it. We want them to just bring it into their homes and eat it exactly like they were doing before, but better.
What you're growing isn't the whole fish, right? It is not an actual organism?
Right, we're only growing muscle cells. It doesn't know where it is. There is no brain, nervous system, or pain receptors.
Are you the only people in this lab-grown food space working on fish?
We're the only ones doing fish so far. Other companies are doing chicken, duck, egg white, milk, gelatin, leather, and beef.
Are people generally weirded out by sci-fi lab food, or intrigued?
It's been very positive. When people sit down and talk to us, they realize it's not some crazed money grab or some weird Ted talk, it's real activists using real science trying to solve real problems. Sure, there will be some pushback from people who don't understand it, and that's fine.
When can I expect to see Finless Food at my local Whole Foods?
We plan on being in restaurants in two years, and grocery stores in four years.
What about people who aren't big fans of fish in the first place? Like those who don't eat sushi, because consuming something raw with an unknown history isn't very appetizing.
There are too many examples of food poisoning because fish are in a less clean environment than they should be, swimming around in their own fecal matter, and being doused in antibiotics so their diseases don't transmit. It's a bit of a mess. That's why as an industry, we're calling this clean meat. Fish is a healthy thing, or at least it should be, with Omega 3 and 6, and DHA. This is a way for people to continue getting those nutrients without any of the questions of where it came from. For people who are skeptical of fish, we invite you to dive in.
Brian Wyrwas, Co-Founder & CSO, and Mike Selden, Co-Founder & CEO
(Courtesy Mike Selden)
Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.
Why the Panic Over "Designer Babies" Is the Wrong Worry
BIG QUESTION OF THE MONTH: Should we use CRISPR, the new technique that enables precise DNA editing, to change the genes of human embryos to eradicate disease--or even to enhance desirable traits? LeapsMag invited three leading experts to weigh in.
CRISPR is producing an important revolution in the biosciences, a revolution that will change our world in fundamental ways. Its implications need to be discussed and debated, and not just by scientists and ethicists. Unfortunately, so far we are debating the wrong issues.
Controversy has raged about editing human genes, particularly the DNA of embryos that could pass the changes down to their descendants. This technology, human germline editing, seems highly unlikely to be broadly available for at least the next few decades; if and when it is, it may well be unimportant.
Human germline editing is unlikely to happen soon because it has important safety risks but almost no significant benefits.
Human germline editing is unlikely to happen soon because it has important safety risks but almost no significant benefits. The risks – harm to babies – are compelling. We care a lot about babies. A technology that worked 95 percent of the time (and produced disabled or dying infants "only" five percent of the time) would be a disaster. Our concern for babies will lead, at the least, to rigorous legal requirements for preapproval safety testing. Many countries will just impose flat bans.
But these risks also have implications beyond safety regulation. For this technology to take off, physicians, assisted reproduction clinics, and geneticists will have to be willing to put their reputations – and their malpractice liability – on the line. And prospective mothers will have to be willing to take unknown risks with their children.
Sometimes, large and unknown risks are worth taking, but not here. For the next few decades, human germline editing offers almost no substantial benefits, for health or for enhancement.
Prospective parents already have a tried and true alternative to avoid having children with genetic diseases: preimplantation genetic diagnosis (PGD). In PGD, clinicians remove cells from three- to five-day-old embryos. Those cells are then tested to see which embryos would inherit the disease and which would not. This technology has been in use for over 27 years and is safe and effective. Rather than engaging in editing an embryo's disease-causing DNA, parents can just select embryos without those DNA variations. For so-called autosomal recessive diseases, three out of four embryos, on average, will be disease free; for autosomal dominant diseases, half will be.
Only a handful of prospective parents would need to use gene editing to avoid genetic disease.
Couples where each has the same recessive condition (cystic fibrosis) or where one of them has the terrible luck to have two copies of the DNA variant for a dominant disease (Huntington's disease). In those cases, the prospective parents would need to stay alive long enough to be able, and be sufficiently healthy to want, to have children. In a world of 7.3 billion humans, there will be some such cases, but they will probably be no more than a few thousand – or hundred.
People are also concerned about germline editing for genetic enhancement. But this is also unlikely anytime soon. We know basically nothing about genetic variations that enhance people beyond normal. For example, we know hundreds of genes that, when damaged, affect intelligence – but these all cause very low intelligence. We know of no variations that non-trivially increase it.
Over the next few decades, we might (or might not) learn about complex diseases where several genes are involved, making embryo selection less useful. And we might (or might not) learn about genetic enhancements involving DNA sequences not typically found in prospective parents and so not available to embryo selection. By that time, the safety issues could be resolved.
And, even then, how worried should we be – and about what? A bit, but not very and not about much.
"The human germline genome is not the holy essence of humanity."
The human germline genome is not the holy essence of humanity. For one thing, it doesn't really exist. There are 7.3 billion human germline genomes; each of us has a different one. And those genomes change every generation. I do not have exactly the same genetic variations my parents received from my grandparents; my children do not have exactly the ones I received from my parents. The DNA changed, through mutation, during each generation.
And our editing will usually be insignificant in the context of the whole human genome. For medical purposes, we will change some rare DNA variations that cause disease into the much more common DNA variations that do not cause disease. Rare, nasty variants will become rarer, but civilization changes these frequencies all the time. For instance, the use of insulin has increased the number of people with DNA variations that predispose people to type 1 ("juvenile") diabetes – because now those people live long enough to reproduce. Even agriculture changed our DNA, leading, for example, to more copies of starch-digesting genes. And, in any event, what is the meaningful difference between "fixing" a disease gene in an embryo or waiting to fix it with gene therapy in a born baby . . . other than avoiding the need to repeat the gene therapy in the next generation?
If genetic enhancement ever becomes possible in a non-trivial way, it would raise important questions, but questions about enhancement generally and not fundamentally about genetics. Enhancement through drugs, prosthetics, brain-computer interfaces, genes, or tools (like the laptop I wrote this on) all raise similar ethical issues. We can use the decades we will have to try to think more systematically about the ethical and policy issues for all enhancements. We should not panic about germline genetic enhancement.
One superficially appealing argument is that we are not wise enough to change our own genomes. This ignores the fact that we have been changing our genomes, inadvertently, since at least the dawn of civilization. We do not have to be wise enough to change our genome perfectly; we just need to be wise enough to change it better than the random and unforeseen ways we change it now. That should not be beyond our power.
Human germline editing will not be a concern for several decades and it may never be an important concern. What should we be paying attention to?
Non-human genome editing. Governments, researchers, and even do-it-yourself hobbyists can use CRISPR, especially when coupled with a technique called "gene drive," to change the genomes of whole species of living things – domestic or wild; animal, vegetable, or microbial – cheaply, easily, and before we even know it is happening. We care much less about mosquito babies than human ones and our legal structures are not built for wise and nuanced regulation of this kind of genome editing. Those issues demand our urgent attention – if we can tear ourselves away from dramatic but less important visions of "designer babies."
Editor's Note: Check out the viewpoints expressing condemnation and enthusiastic support.