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."
The Real Science Behind “Anti-Aging” Beauty Products
The beauty industry heavily hypes the nascent promise of stem cells for rejuvenation.
The beauty market abounds with high-end creams and serums that claim the use of stem cells to rejuvenate aging skin.
Selling on the internet and at department stores like Nordstrom, these products promise "breakthrough" applications to plump, smooth, and "reverse visible signs of aging," and at least one product offers to create a "regenerative firming serum, moisturizer, and eye cream" from customers' own stem cells – for a whopping $1200.
The beauty industry is heavily hyping glimmers of the nascent field of stem cell therapy.
Steeped in clinical-sounding terms like "proteins and peptides from pluripotent stem cells," the marketing of these products evokes a dramatic restoration of youthfulness based on cutting-edge science. But the beauty industry is heavily hyping glimmers of the nascent field of stem cell therapy. So what is real and what's not? And is there in fact a way to harness the potential of stem cells in the service of beauty?
Plant vs. Human Stem Cells
Stem cells do indeed have tremendous promise for treating a wide range of diseases and conditions. The cells come from early-stage embryos or, more commonly, from umbilical cord blood or our own bodies. Embryonic stem cells are considered the body's "master" cells because they can develop into any of our several hundred cell types. Adult stem cells, on the other hand, reside in mature tissues and organs like the brain, bone marrow, and skin, and their versatility is more limited. As an internal repair system for many tissue types, they replenish sick, injured, and worn-out cells.
Nowadays, with some sophisticated chemical coaxing, adult stem cells can be returned to an embryonic-like blank state, with the ability to become any cell type that the body might need.
Beauty product manufacturers convey in their advertising that the rejuvenating power of these cells could hold the key to the fountain of youth. But there's something the manufacturers don't always tell you: their products do not typically use human stem cells.
"The whole concept of stem cells is intriguing to the public," says Tamara Griffiths, a consultant dermatologist for the British Skin Foundation. "But what these products contain is plant stem cells and, more commonly, chemicals that have been derived from plant stem cells."
The plant stem cells are cultured in the lab with special media to get them to produce signaling proteins and peptides, like cytokines and chemokines. These have been shown to be good for reducing inflammation and promoting healthy cell functioning, even if derived from plants. However, according to Griffiths, there are so many active ingredients in these products that it's hard to say just what role each one of them plays. We do know that their ability to replenish human stem cells is extremely limited, and the effects of plant stem cells on human cells are unproven.
"...any cosmetic that is advertised to be anti-aging due to plant stem cells at this time is about as effective as all the skin creams without stem cells."
Whether products containing plant cell-derived ingredients work better than conventional skin products is unknown because these products are not regulated by the U.S. Food and Drug Administration and may rest on dubious, even more or less nonexistent, research. Cosmetics companies have conducted most of the research and the exact formulas they devise are considered proprietary information. They have no incentive to publish their research findings, and they don't have to meet standards imposed by the FDA unless they start using human cells in their products.
"There are biological limits to what you can do with plant cells in the first place," says Griffiths. "No plant stem cell is going to morph into a human skin cell no matter what magic medium you immerse it in. Nor is a plant cell likely to stimulate the production of human stem cells if applied to the skin."
According to Sarah Baucus, a cell biologist, for any type of stem cell to be of any use whatsoever, the cells must be alive. The processing needed to incorporate living cells into any type of cream or serum would inevitably kill them, rendering them useless. The splashy marketing of these products suggests that results may be drastic, but none of these creams is likely to produce the kind of rejuvenating effect that would be on par with a facelift or several other surgical or dermatological procedures.
"Plant stem cell therapy needs to move in the right direction to implement its inherent potential in skin care," researchers wrote in a 2017 paper in the journal Future Science OA. "This might happen in the next 20 years but any cosmetic that is advertised to be anti-aging due to plant stem cells at this time is about as effective as all the skin creams without stem cells."
From Beauty Counter to Doctor's Clinic
Where do you turn if you still want to harness the power of stem cells to reinvigorate the skin? Is there a legitimate treatment using human cells? The answer is possibly, but for that you have to switch from the Nordstrom cosmetics counter to a clinic with a lab, where plastic surgeons work with specialists who culture and manipulate living cells.
Plastic surgeons are experts in wound healing, a process in which stem cells play a prominent role. Doctors have long used the technique of taking fat from the body and injecting it into hollowed-out or depressed areas of the face to fill in injuries, correct wrinkles, and improve the face's curvature. Lipotransfer, or the harvesting of body fat and injecting it into the face, has been around for many years in traditional plastic surgery clinics. In recent years, some plastic surgeons have started to cull stem cells from fat. One procedure that does just that is called cell-assisted lipotransfer, or CAL.
In CAL, adipose tissue, or fat, is harvested by liposuction, usually from the lower abdomen. Fat contains stem cells that can differentiate into several cell types, including skin, muscle, cartilage, and bone. Fat tissue has an especially stem cell-rich layer. These cells are then mixed with some regular fat, making in effect a very stem cell-rich fat solution, right in the doctor's office. The process of manipulating the fat cells takes about 90 to 110 minutes, and then the solution is ready to be injected into the skin, to fill in the lips, the cheeks, and the nasolabial folds, or the deep folds around the nose and mouth.
Unlike regular fat, which is often injected into the face, some experts claim that the cell-enriched fat has better, longer-lasting results. The tissue graft grows its own blood vessels, an advantage that may lead to a more long-lasting graft – though the research is mixed, with some studies showing they do and other studies showing the complete opposite.
For almost all stem cell products on the market today in the U.S., it is not yet known whether they are safe or effective, despite how they are marketed.
One of the pioneers in CAL, a plastic surgeon in Brazil named Dr. Aris Sterodimas, says that the stem cells secrete growth factors that rejuvenate the skin -- like the plant stem cells that are used in topical creams and serums. Except that these cells are human stem cells and hence have inherently more potential in the human body.
Note that CAL doesn't actually result in large numbers of fresh, new replacement cells, as might be imagined. It's simply fat tissue treated to make it richer in stem cells, to have more of the growth-inducing proteins and peptides delivered to the dermis layer of the skin.
Sterodimas works alongside a tissue engineer to provide CAL in his clinic. He uses it as a way to rebuild soft tissues in people disfigured by accidents or diseases, or who are suffering the after-effects of radiation treatments for cancer.
Plastic surgeons get plenty of these patients. But how widespread is CAL for beauty purposes? Sterodimas says that he regularly performs the procedure for Brazilians, and it's widely available in Europe and Japan. In the U.S., the procedure hasn't taken off because there is no FDA approval for the various methods used by different doctors and clinics. A few major academic centers in the U.S. offer the treatment on a clinical trials basis and there are several trials ongoing.
But there is a downside to all lipotransfers: the transplanted fat will eventually be absorbed by the body. Even the cell-enriched fat has a limited lifespan before reabsorption. That means if you like the cosmetic results of CAL, you'll have to repeat the treatment about every two years to maintain the plumping, firming, and smoothing effects on the skin. The results of CAL are "superior to the results of laser treatments and other plastic surgery interventions, though the effect is not as dramatic as a facelift," says Sterodimas.
Buyer Beware
For almost all stem cell products on the market today in the U.S., it is not yet known whether they are safe or effective, despite how they are marketed. There are around 700 clinics in the U.S. offering stem cell treatments and up to 20,000 people have received these therapies. However, the only FDA-approved stem cell treatments use cells from bone marrow or cord blood to treat cancers of the blood and bone marrow. Safety concerns have prompted the FDA to announce increased oversight of stem cell clinics.
As for CAL, most of the clinical trials so far have been focused on using it for breast reconstruction after mastectomy, and results are mixed. Experts warn that the procedure has yet to be proven safe as well as effective. It's important to remember that this newborn science is in the early stages of research.
One question that has also not been definitively settled is whether the transplanted stem cells may give rise to tumors — a risk that is ever-present any time stem cells are used. More research is required to assess the long-term safety and effectiveness of these treatments.
Given the lack of uniform industry standards, one can easily end up at a clinic that overpromises what it can deliver.
In the journal Plastic Reconstruction Surgery in 2014, Adrian McArdle and a team of Stanford University plastic surgeons examined the common claims of CAL's "stem cell facelifts" being offered by clinics across the world. McArdle and his team write: "…the marketplace is characterized by direct-to-consumer corporate medicine strategies that are characterized by unsubstantiated, and sometimes fraudulent claims, that put our patients at risk." Given the lack of uniform industry standards, one can easily end up at a clinic that overpromises what it can deliver.
But according to McArdle, further research on CAL, including clinical trials, is proceeding apace. It's possible that as more research on the potential of stem cells accrues, many of the technical hurdles will be crossed.
If you decide to try CAL in a research or clinical setting, be forewarned. You will be taking part in a young science, with many unknown questions. However, the next time someone offers to sell you stem cells in a jar, you'll know what you're paying for.
Growing Human Organs Inside Pigs Could Save Lives, But the U.S. Won't Fund the Research
Pigs in a barn.
The shortage of organs is a public health menace. Approximately 120,000 people in the U.S. need a lifesaving organ transplant. Of those, approximately 75,000 patients are on the active waiting list. Every day, nearly 20 individuals die from the shortage of organs in the United States.
Ethical concerns about human-animal chimera research might be dramatically overblown.
Scientists worldwide are developing new methods with potential to save countless patients in need of organs. Such approaches have tremendous potential, if only ethical and regulatory challenges could be overcome first.
One way that scientists are proposing to increase the number of transplantable organs is to produce organs from patient stem cells. Owed to their ability to grow limitlessly in the lab and form all tissue types, pluripotent stem cells from patients, in principle, could supply an infinite amount of cells that could potentially be transplanted back into patients. Unfortunately, all efforts to generate organs that can be transplanted into patients from stem cells to date have been unsuccessful.
A different encouraging approach is to generate patient organs inside livestock species, such as pigs. In the latest methods, interspecies chimeras – animals containing cells from both humans and animals – are generated by introducing human stem cells into early-stage animal embryos. Key genes essential for organ formation are disabled, allowing the introduced human stem cells to fill the empty space. In theory, this strategy will produce a human organ inside pigs or sheep.
Creating chimeras is not new in biology. Chimeras, or animals comprised of tissues from two different individuals, have already been deployed in research. Mouse chimeras are routinely used to create genetically engineered mice to study genes. The concept of generating human organs inside pigs or sheep comes from previous studies involving interspecies chimeras generated between mice and rats. Past experiments have demonstrated that it is possible to generate a rat pancreas inside a mouse.
Scientific and Ethical Obstacles
Unfortunately, chimera research has faced hurdles that have impeded progress. Of note, attempts to generate interspecies chimeras by several groups have failed. The results of these studies indicate that human cells appear unable to grow inside mouse embryos. The levels of human chimerism – the number of human cells inside the host animal embryo – appear too low to support any human organ generation.
Another obstacle is that chimera generation is ethically controversial. Some question the moral status of an animal that is comprised of human and animal cells. The most concerning question is whether human cells will contribute to the host animal's brain, potentially altering the cognition of the animal. These issues have prompted scientists to proceed very cautiously with chimera experiments. However, such concerns might be dramatically overblown. This is because the levels of human chimerism are too low to cause any significant change in animal brain function.
The ethical controversy has affected research policy in the United States. In the United States, the National Institutes of Health (NIH), the major funding body of biomedical research, blocked funding for chimera research while ethical questions were considered. Later, it was proposed that a new review process would be instated for chimera research. However, no change in policy has actually happened. The restrictive NIH policy is a major barrier to chimera research progress because laboratories around the United States cannot obtain funding for it. Lifting the restrictions on NIH funding for chimera research would dramatically accelerate chimera research.
Nonetheless, despite the past and current hurdles that chimera research has faced, new advances are changing the landscape of chimera research.
It is time to lift restrictions on chimera research so that its promise can be fully realized.
Progress on the Horizon
Scientists are developing improved strategies to increase the numbers of cells in animal embryos to the point where it might be possible to generate a human organ in an animal. For example, it has been suggested that the human stem cells researchers have been using cannot grow in animals. Scientists have made advances in generating new types of human stem cells that might have an improved ability to form chimeras.
Additionally, scientists have identified some barriers responsible for the failure to generate chimeras. For example, preventing cell death and enhancing the ability of stem cells to compete with host animal tissues also improves the numbers of human cells to the point where human organs can be generated inside an animal.
Finally, a relaxation of regulatory hurdles in other countries has created a more permissive environment for human-animal interspecies chimera research. In March, the Japanese government approved the first such experiments that could comprise a new way of generating organs from patients for transplantation.
Additionally, in spite of the somewhat negative attention that chimera generation has received, the International Society for Stem Cell Research (ISSCR) supports the new Japanese policies allowing chimera experiments. The ISSCR maintains that research involving the generation of chimeras should be permitted, as long as rigorous oversight and ethics review occur.
Chimera research has the potential to transform medicine. Of all the impediments, the NIH restrictions on funding remain the single most significant barrier. It is time to lift restrictions on chimera research so that its promise can be fully realized. One day, it might be possible to grow patient-specific organs inside of livestock animals such as pigs and sheep, saving thousands of human lives. But to change our current policy, the public, scientists, and bioethicists must first agree that this critical cause is worth fighting for.