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."
Here's something to chew on. Can a gulp of water help save the planet? If you're drinking *and* eating your water at the same time, the answer may be yes.
The tasteless packaging is made from brown seaweed that biodegrades naturally in four to six weeks.
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A start-up company called Skipping Rocks Lab has created a "water bubble" encased in an edible sachet that you can pop in your mouth whole. Or if you're not into swallowing it, you can tear off the edge, drink up, and toss the rest in a composter. The tasteless packaging is made from brown seaweed that biodegrades naturally in four to six weeks, whereas plastic water bottles can linger for hundreds of years.
The founders of the London-based company are determined to "make plastic packaging disappear." They had two foodie inspirations: molecular gastronomists and fruit. They tried to emulate the way chefs used edible membranes to encase bubbles of liquid to make things like fake caviar and fake egg yolks; and they also considered the peel of an orange or banana, which protects the tasty insides but can be composted.
The sachets can also contain other liquids that come in single-serve plastic containers -- think packets of condiments with takeout meals, specialty cocktails at parties, and especially single servings of water for sporting events. The London Marathon last month gave out the water bubble pods at a station along the route, using them to replace 200,000 plastic bottles that would have likely ended up first in the street, and ultimately in the ocean.
Next Up
The engineers and chemists at Skipping Rocks intend to lease their machines to others who can then manufacture their own sachets on-site to fill with whatever they desire. The new material, which is dubbed "Notpla" (not plastic), also has other applications beyond holding liquids. It can be used to replace the plastic lining in cardboard takeout boxes, for example. And the startup is working on additional materials to replace other types of ubiquitous plastic packaging, like the netting that encases garlic and onions, and the sachets that hold nails and screws.
Edible water bubbles may be the future of drinks at sporting events and festivals.
Open Questions
One hurdle is that the pods are not very hardy, so while they work fine to hand out along a marathon route, they wouldn't really be viable for a hiker to throw in her backpack. Another issue concerns the retail market: to be stable on a shelf, they'd have to be protected from all that handling, which brings us back to the problem the engineers tried to solve in the first place -- disposable packaging.
So while Skipping Rocks may not achieve their ultimate goal of ridding the world of plastic waste, a little progress can still go a long way. If edible water bubbles are the future of drinks at sporting events and festivals, the environment will certainly benefit from their presence -- and absence.
The Internet has made it easier than ever to misguide people. The anti-vaxx movement, climate change denial, protests against stem cell research, and other movements like these are rooted in the spread of misinformation and a distrust of science.
"I had been taught intelligent design and young-earth creationism instead of evolution, geology, and biology."
Science illiteracy is pervasive in the communities responsible for these movements. For the mainstream, the challenge lies not in sharing the facts, but in combating the spread of misinformation and facilitating an open dialogue between experts and nonexperts.
I grew up in a household that was deeply skeptical of science and medicine. My parents are evangelical Christians who believe the word of the Bible is law. To protect my four siblings and me from secular influence, they homeschooled some of us and put the others in private Christian schools. When my oldest brother left for a Christian college and the tuition began to add up, I was placed in a public charter school to offset the costs.
There, I became acutely aware of my ignorant upbringing. I had been taught intelligent design and young-earth creationism instead of evolution, geology, and biology. My mother skipped over world religions, and much of my history curriculum was more biblical-based than factual. She warned me that stem cell research, vaccines, genetic modification of crops, and other areas of research in biological science were examples of humans trying to be like God. At the time, biologist Richard Dawkins' The God Delusion was a bestseller and science seemed like an excuse to not believe in God, so she and my father discouraged me from studying it.
The gaps in my knowledge left me feeling frustrated and embarrassed. The solution was to learn about the things that had been censored from my education, but several obstacles stood in the way.
"When I first learned about fundamentalism, my parents' behavior finally made sense."
I lacked a good foundation in basic mathematics after being taught by my mother, who never graduated college. My father, who holds a graduate degree in computer science, repeatedly told me that I inherited my mother's "bad math genes" and was therefore ill-equipped for science. While my brothers excelled at math under his supervision and were even encouraged toward careers in engineering and psychology, I was expected to do well in other subjects, such as literature. When I tried to change this by enrolling in honors math and science classes, they scolded me -- so reluctantly, I dropped math. By the time I graduated high school, I was convinced that math and science were beyond me.
When I look back at my high school transcripts, that sense of failure was unfounded: my grades were mostly A's and B's, and I excelled in honors biology. Even my elementary standardized test scores don't reflect a student disinclined toward STEM, because I consistently scored in the top percentile for sciences. Teachers often encouraged me to consider studying science in college. Why then, I wondered, did my parents reject that idea? Why did they work so hard to sway me from that path? It wasn't until I moved away from my parents' home and started working to put myself through community college that I discovered my passion for both biology and science writing.
As a young adult venturing into the field of science communication, I've become fascinated with understanding communities that foster antagonistic views toward science. When I first learned about fundamentalism, my parents' behavior finally made sense. It is the foundation of the Religious Right, a right-wing Christian group which heavily influences the Republican party in the United States. The Religious Right crusades against secular education, stem cell research, abortion, evolution, and other controversial issues in science and medicine on the basis that they contradict Christian beliefs. They are quietly overturning the separation of church and state in order to enforce their religion as policy -- at the expense of science and progress.
Growing up in this community, I learned that strong feelings about these issues arise from both a lack of science literacy and a distrust of experts. Those who are against genetic modification of crops don't understand that GMO research aims to produce more, and longer-lasting, food for a growing planet. The anti-vaxx movement is still relying on a deeply flawed study that was ultimately retracted. Those who are against stem cell research don't understand how it works or the important benefits it provides the field of medicine, such as discovering new treatment methods.
In fact, at one point the famous Christian radio show Focus on the Family spread anti-vaxx mentality when they discussed vaccines that, long ago, were derived from aborted fetal cells. Although Focus on the Family now endorses vaccines, at the time it was enough to convince my own mother, who listened to the show every morning, not to vaccinate us unless the law required it.
"In everyday interactions with skeptics, science communicators need to shift their focus from convincing to discussing."
We can help clear up misunderstandings by sharing the facts, but the real challenge lies in willful ignorance. It was hard for me to accept, but I've come to understand that I'm not going to change anyone's mind. It's up to an individual to evaluate the facts, consider the arguments for and against, and make his or her own decision.
As my parents grew older and my siblings and I introduced them to basic concepts in science, they came around to trusting the experts a little more. They now see real doctors instead of homeopathic practitioners. They acknowledge our world's changing climate instead of denying it. And they even applaud two of their children for pursuing careers in science. Although they have held on to their fundamentalism and we still disagree on many issues, these basic changes give me hope that people in deeply skeptical communities are not entirely out of reach.
In everyday interactions with skeptics, science communicators need to shift their focus from convincing to discussing. This means creating an open dialogue with the intention of being understanding and helpful, not persuasive. This approach can be beneficial in both personal and online interactions. There are people within these movements who have doubts, and their doubts will grow as we continue to feed them through discussion.
People will only change their minds when it is the right time for them to do so. We need to be there ready to hold their hand and lead them toward truth when they reach out. Until then, all we can do is keep the channels of communication open, keep sharing the facts, and fight the spread of misinformation. Science is the pursuit of truth, and as scientists and science communicators, sometimes we need to let the truth speak for itself. We're just there to hold the megaphone.