Why Are Autism Rates Steadily Rising?
Stefania Sterling with her son Charlie, who was diagnosed at age 3 with autism.
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."
We Pioneered a Technology to Save Millions of Poor Children, But a Worldwide Smear Campaign Has Blocked It
On left, a picture of white rice next to Golden Rice, and on right, a girl who lost one eye due to vitamin A deficiency.
In a few weeks it will be 20 years that we three have been working together. Our project has been independently praised as one of the most influential of all projects of the last 50 years.
Two of us figured out how to make rice produce a source of vitamin A, and the rice becomes a golden color instead of white.
The project's objectives have been admired by some and vilified by others. It has directly involved teams of highly motivated people from a handful of nations, from both the private and public sector. A book, dedicated to the three of us, has been written about our work. Nevertheless, success has, so far, eluded us all. The story of our thwarted efforts is a tragedy that we hope will soon – finally – reach a milestone of potentially profound significance for humanity.
So, what have we been working on, and why haven't we succeeded yet?
Food: everybody needs it, and many are fortunate enough to have enough, even too much of it. Food is a highly emotional subject on every continent and in every culture. For a healthy life our food has to provide energy, as well as, in very small amounts, minerals and vitamins. A varied diet, easily achieved and common in industrialised countries, provides everything.
But poor people in countries where rice is grown often eat little else. White rice only provides energy: no minerals or vitamins. And the lack of one of the vitamins, vitamin A, is responsible for killing around 4,500 poor children every day. Lack of vitamin A is the biggest killer of children, and also the main cause of irreversible childhood blindness.
Our project is about fixing this one dietary deficiency – vitamin A – in this one crop – rice – for this one group of people. It is a huge group though: half of the world's population live by eating a lot of rice every day. Two of us (PB & IP) figured out how to make rice produce a source of vitamin A, and the rice becomes a golden color instead of white. The source is beta-carotene, which the human body converts to vitamin A. Beta-carotene is what makes carrots orange. Our rice is called "Golden Rice."
The technology has been donated to assist those rice eaters who suffer from vitamin A deficiency ('VAD') so that Golden Rice will cost no more than white rice, there will be no restrictions on the small farmers who grow it, and nothing extra to pay for the additional nutrition. Very small amounts of beta-carotene will contribute to alleviation of VAD, and even the earliest version of Golden Rice – which had smaller amounts than today's Golden Rice - would have helped. So far, though, no small farmer has been allowed to grow it. What happened?
To create Golden Rice, it was necessary to precisely add two genes to the 30,000 genes normally present in rice plants. One of the genes is from maize, also known as corn, and the other from a commonly eaten soil bacterium. The only difference from white rice is that Golden Rice contains beta-carotene.
It has been proven to be safe to man and the environment, and consumption of only small quantities of Golden Rice will combat VAD, with no chance of overdosing. All current Golden Rice results from one introduction of these two genes in 2004. But the use of that method – once, 15 years ago - means that Golden Rice is a 'GMO' ('genetically modified organism'). The enzymes used in the manufacture of bread, cheese, beer and wine, and the insulin which diabetics take to keep them alive, are all made from GMOs too.
The first GMO crops were created by agri-business companies. Suspicion of the technology and suspicion of commercial motivations merged, only for crop (but not enzymes or pharmaceutical) applications of GMO technology. Activists motivated by these suspicions were successful in getting the 'precautionary principle' incorporated in an international treaty which has been ratified by 166 countries and the European Union – The Cartagena Protocol.
The equivalent of 13 jumbo jets full of children crashes into the ground every day and kills them all, because of vitamin A deficiency.
This protocol is the basis of national rules governing the introduction of GMO crops in every signatory country. Government regulators in, and for, each country must agree before a GMO crop can be 'registered' to be allowed to be used by the public in that country. Currently regulatory decisions to allow Golden Rice release are being considered in Bangladesh and the Philippines.
The Cartagena Protocol obliges the regulators in each country to consider all possible risks, and to take no account of any possible benefits. Because the anti-gmo-activists' initial concerns were principally about the environment, the responsibility for governments' regulation for GMO crops – even for Golden Rice, a public health project delivered through agriculture – usually rests with the Ministry of the Environment, not the Ministry of Health or the Ministry of Agriculture.
Activists discovered, before Golden Rice was created, that inducing fear of GMO food crops from 'multinational agribusinesses' was very good for generating donations from a public that was largely illiterate about food technology and production. And this source of emotionally charged donations would cease if Golden Rice was proven to save sight and lives, because Golden Rice represented the opposite of all the tropes used in anti-GMO campaigns.
Golden Rice is created to deliver a consumer benefit, it is not for profit – to multinational agribusiness or anyone else; the technology originated in the public sector and is being delivered through the public sector. It is entirely altruistic in its motivations; which activists find impossible to accept. So, the activists believed, suspicion against Golden Rice had to be amplified, Golden Rice had to be stopped: "If we lose the Golden Rice battle, we lose the GMO war."
Activism continues to this day. And any Environment Ministry, with no responsibility for public health or agriculture, and of course an interest in avoiding controversy about its regulatory decisions, is vulnerable to such activism.
The anti-GMO crop campaigns, and especially anti-Golden Rice campaigns, have been extraordinarily effective. If so much regulation by governments is required, surely there must be something to be suspicious about: 'There is no smoke without fire'. The suspicion pervades research institutions and universities, the publishers of scientific journals and The World Health Organisation, and UNICEF: even the most scientifically literate are fearful of entanglement in activist-stoked public controversy.
The equivalent of 13 jumbo jets full of children crashes into the ground every day and kills them all, because of VAD. Yet the solution of Golden Rice, developed by national scientists in the counties where VAD is endemic, is ignored because of fear of controversy, and because poor children's deaths can be ignored without controversy.
Perhaps more controversy lies in not taking scientifically based regulatory decisions than in taking them.
The tide is turning, however. 151 Nobel Laureates, a very significant proportion of all Nobel Laureates, have called on the UN, governments of the world, and Greenpeace to cease their unfounded vilification of GMO crops in general and Golden Rice in particular. A recent Golden Rice article commented, "What shocks me is that some activists continue to misrepresent the truth about the rice. The cynic in me expects profit-driven multinationals to behave unethically, but I want to think that those voluntarily campaigning on issues they care about have higher standards."
The recently published book has exposed the frustrating saga in simple detail. And the publicity from all the above is perhaps starting to change the balance of where controversy lies. Perhaps more controversy lies in not taking scientifically based regulatory decisions than in taking them.
But until they are taken, while there continues a chance of frustrating the objectives of the Golden Rice project, the antagonism will continue. And despite a solution so close at hand, VAD-induced death and blindness, and the misery of affected families, will continue also.
© The Authors 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver applies to the data made available in this article, unless otherwise stated.
An emerging technology called in vitro gametogenesis would allow babies to be made from skin cells.
[Ed. Note: This is the third episode in our Moonshot series, which will explore four cutting-edge scientific developments that stand to fundamentally transform our world.]
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.