Green Our Vaccines protests over the perceived connection between heavy metals in vaccines and autism
LEO MILIK is a success story. At age 2 he was diagnosed with autism. After his mother heard the condition could be linked to certain foods, she eliminated wheat and dairy products from his diet. Now six years later, Leo has only a mild form of the condition. He attends a mainstream school and doctors say that in a few years he could lose his diagnosis altogether.
There’s one wrinkle in this tale. The diet that appears to have turned Leo around has recently been tested in a randomised, placebo-controlled trial for the first time. The researchers that it provided no evidence the diet worked.
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The diet is not the only unorthodox treatment around; a range of “biomedical” therapies that purport to treat the root causes of autism have gained popularity in recent years. These range from vitamins and antibiotics through to drugs supposed to remove heavy metals from the body, and even a hormone treatment that can delay puberty.
The autism “biomed” movement is well organised. An organisation called the Autism Research Institute, based in San Diego, California, lists the hundreds of doctors and therapists who provide these treatments. There are countless websites where parents swap advice; some members speak of trying out dozens of treatments, and spending many thousands of dollars over the years.
Some say biomed has helped their child, but others tell heart-rending tales of dashed hopes. None of these therapies has been shown to cure or even alleviate autism in good-quality trials. Some are very expensive, others are difficult and time-consuming. A few are even dangerous. This raises a question: why do so many parents of children with autism opt for unorthodox remedies, some of which are no better than snake oil?
Desperation is part of the answer. Autism is mysterious in origin, variable in manifestation, and lacks any known means of prevention or cure. And it has some unique characteristics that collectively tempt parents down the biomed route. The condition has also become the subject of several myths that encourage parents to throw science out of the window. “The evidence doesn’t come into it most of the time,” says Vanessa Green, a psychologist at Victoria University of Wellington in New Zealand.
Autism is a spectrum of conditions that cause problems with language, social interactions and imagination. Some infants seem to show autistic traits from a few months of age, while about a third develop more typically, but then regress some time between the ages of 1 and 3.
We still do not know what causes autism. The best guess is that most cases are the result of a genetic vulnerability acting in concert with factors in the womb, perhaps maternal infections. As treatment, all mainstream doctors can offer are speech and behavioural therapies. One common approach is a form of rote learning known as applied behavioural analysis, in which children are taught to perform simple actions for small rewards. A number of studies have shown that over several years, ABA improves speech and academic ability.
Out of options
Maria Milik, Leo’s mother, thinks behavioural therapies did help her son, but for her and many other parents, they are not enough. Faced with a paucity of medical help, many families feel they have no choice but to experiment with biomed. Milik started Leo on the diet after a nutritionist said that her son might be allergic to wheat and dairy products. “I thought she was crazy but I had run out of options and was getting nowhere with the mainstream medical community.”
A lack of medical help is not the only factor driving the explosion of biomed. Another is the recent emergence of several myths about the condition. Perhaps the best known centre on the claim that vaccines can trigger autism. In the UK, concern revolves around the triple vaccine for measles, mumps and rubella (MMR). Adherents claim that three vaccines in one shot overloads the immune system. Vaccine fears have a different focus in the US, where some groups claim that the mercury in thimerosal, a preservative in some vaccines, is responsible.
Many large epidemiological studies have shown children who received MMR or thimerosal are no more likely to be autistic than those who didn’t. Yet as with any conspiracy theory, the more evidence that emerges to disprove the idea, the more the goalposts shift and the theories morph into broader, vaguer claims. Some parents now reject the entire childhood immunisation schedule, claiming it is “too much, too young”. In the US there is a prominent anti-vaccine movement that is suspicious of many of the additives in shots; their rallying cry is a call to “green our vaccines”.
Implicitly linked with the vaccine myth in some people’s minds is the belief that autism rates are skyrocketing, and that the cause must therefore be rising levels of some environmental toxin. When the US news programme Today asked readers for their views on autism in an online poll last month, for example, one response option was labelled: “So many more cases, so many more vaccinations – it can’t just be coincidence.”
It’s true that the number of diagnoses of autism has increased dramatically in many western countries. Before the 1980s, autism was thought to affect around 1 in 2000 children in the US; now almost 1 in 100 children has a diagnosis of an autistic spectrum disorder.
But is this increase real? Perhaps not, because the range of conditions labelled as autism has broadened over the last 20 years. Doctors have also become much more aware of the condition. Many children once diagnosed with learning difficulties, say, are now considered to be on the autistic spectrum. Researchers say these factors have caused much of the increase. Although it cannot be ruled out that there has also been a rise in the underlying rate, the picture is murkier than suggested by headlines about an autism “epidemic”.
Still, these myths have an intuitive appeal, especially for one group in particular: families of children who have the regressive form of autism. As regression often occurs around the time of childhood vaccination, parents blame the shots, says Paul Law, a paediatrician at the Kennedy Krieger Institute in Baltimore, Maryland. “It’s a very frightening experience to go through,” he says. “It’s an experience that demands an explanation.”
Yet cases of regressive autism have been documented for about as long as autism has been recognised as a clinical entity. Anyway, just because an illness arises in childhood as opposed to being present from birth does not mean the cause must be something in their environment. Law points out that there are other genetic conditions whose symptoms arise only later in life – sometimes even in adulthood, such as Huntington’s disease. “Most genetic disorders are characterised by a period of normal development and then loss of function,” says Law.
Opioids on the brain
Law, who has a son with autism, is concerned about the growing use of untested therapies. Four years ago he set up the , an online database of information from parents about their children’s diagnosis, behaviour, family, environment, and the therapies they receive, including biomed.
The network’s preliminary figures show that the wheat-free and dairy-free diet is one of the most common biomed options. Of the 7021 families who have entered information about treatments, about 1 in 6 is now using some form of it. That’s a staggering proportion considering controlled trials have failed to find any benefit.
“One in six US families with autistic children said they used some form of the wheat-and-dairy-free diet”
Editorial: Stop uncontrolled experiments on autistic children
The diet stems from the work of the late Robert Cade, who was a kidney specialist at the University of Florida. Cade is chiefly known for inventing the sports drink Gatorade, but he became interested in studies showing that South Pacific islanders, whose diets used to be free of wheat, had fewer psychiatric problems. It is known that if gluten, a compound in wheat, is improperly metabolised, proteins known as gliadinomorphins can build up in the body and can activate the brain’s opioid receptors. Casomorphins, metabolites of the casein in dairy products, have a similar effect. Cade speculated that some children with autism have problems metabolising gluten and casein, and that raised levels of opioid-like substances in their blood could be interfering with brain development.
The gluten-free casein-free (GFCF) diet is far from an easy option for parents or their children. In many cases, a child will find their favourite foods off the menu. Bread, milk and normal cookies are out. Since dairy products are usually children’s main source of calcium, parents need to find alternative sources or use supplements. Parents say they spend hours studying food packaging. “You have to be a food chemist to understand the labels,” says Susan Hyman, a paediatrician at the University of Rochester in New York.
The biomed movement bombards parents with dubious claims about the GFCF diet. One popular website, , compares giving wheat to a susceptible infant to “feeding your child poison”. It is rarely acknowledged that children with autism have never been shown to have high levels of opioid-like substances in their blood.
Some trials have hinted at benefits from the diet, but none used the proper controls. Hyman presented results from the first rigorous trial at the International Meeting for Autism Research, held last month in Philadelphia. While the study was small, involving just 14 children, it failed to show a benefit.
The GFCF diet appears positively benign, however, beside some of the other biomed options on offer. Perhaps the most infamous is chelation therapy, promoted by those who say autism is caused by mercury from vaccines, or sometimes other heavy metals, such as lead from the environment. Chelation involves injecting a drug such as dimercaptosuccinic acid, or DMSA, which flushes heavy metals from the body – it is usually used only to treat heavy metal poisoning. Side effects can include temporary damage to the liver and bone marrow.
A parent wondering whether to try this drastic treatment may struggle to separate fact from fiction. Doctor’s Data, a private lab based in St. Charles, Illinois, sells a test that parents can use to measure the levels of heavy metals in their child’s urine. But an by the medical website Quackwatch found that the Doctor’s Data test gave results that were misleadingly high. Doctor’s Data did not reply to a request from żěè¶ĚĘÓƵ for comment.
Another risky therapy is Lupron, a drug that lowers testosterone levels in men and oestrogen in women, and is sometimes used to delay puberty in children if it starts very early. The use of Lupron in autism is promoted by Mark Geier and David Geier, a father-and-son doctor team based in Rockville, Maryland, who say that the hormonal changes induced by the drug help protect the body against the toxic effects of mercury. Most doctors say there is no science to back up this claim, and that in older children the treatment may undesirably delay the onset of puberty.
There are many other kinds of biomed – too many to count – ranging from vitamins to antibiotics and even oxygen chambers. A host of websites exist where parents swap tips and tell stories. The Yahoo discussion group “Autism-Mercury”, for example, has nearly 9000 members and gets hundreds of posts a week. One member estimated she had given 50 different treatments to her child.
Oprah appearance
Some parents are convinced that biomed works. They include the former model and actress Jenny McCarthy, who became the de facto spokeswoman for the idea that autism can be cured after telling her story to Oprah Winfrey. McCarthy’s son was diagnosed with autism in 2005. After a barrage of biomed, she says he is now “recovered” from the most severe features of the condition.
“In 30 years of working with children with autism I have yet to see one cured,” says Jennifer Elder at the University of Florida in Gainesville. Of the internet tales of cures, Elder says: “I don’t disregard what they’re saying, but they rely heavily on anecdotal reports.”
How, then, to explain the apparent success stories? As with treatments for any condition, the placebo effect may be playing a role. “When you try a new intervention you focus time and energy on them,” says Alison Singer, president of research charity the Autism Science Foundation. “You have this natural tendency to ascribe causality.”
Singer, whose daughter has autism, tried the GFCF diet and vitamins but she has now turned her back on biomed. “You’re exposing your child to risk with no evidence it will help,” she says. “I have a daughter, not a guinea pig. She deserves better.”
But the cure myth is also being fuelled by some of autism’s unique characteristics. The condition can be tricky to diagnose, so some children may have been wrongly labelled autistic in the first place. A study published in the found that 20 per cent of children diagnosed with autism at 2 were given the all-clear, or diagnosed with a different disorder, two years later.
Even if the original diagnosis was correct, another factor to bear in mind is that autism delays development, so a child who was non-verbal at 3 could have good speech by the age of 5 without any intervention. A parent could easily assume it was all thanks to the biomed at age 4, say, but perhaps the child would have improved anyway. Autism is so variable that it is impossible to predict an individual’s outcome with any accuracy.
And yet the tantalising possibility remains that something, somewhere out there, really does work, but that trials so far have lacked the sophistication to separate effective treatments from the duds. Autism is thought to encompass a range of conditions that cannot yet be differentiated. If a treatment helped only one subtype of autism, within a trial, the benefits would be hidden when the results were averaged across all subjects. “The fear is that we generalise,” says Clara Lajonchere at the University of Southern California, Los Angeles.
Lajonchere, who helps manage the research funded by the US charity Autism Speaks, says that genetic tests and MRI scans might show that a subset of children benefit from a particular therapy. These “stratification” techniques are not yet in use, but discussions are under way to include them in future trials.
In the meantime, parents will continue to take whatever steps they feel are necessary. “I didn’t have any knowledge of scientific research at the time I put my son on the diet,” says Milik. “I just felt I needed to try it.”
Editorial: Stop uncontrolled experiments on autistic children
