By Dr. Mercola
About 1 in 68 U.S. children has been diagnosed with autism spectrum disorder (ASD), up from 1 in 150 in 2000.1 This rising trend isn't only occurring in the U.S., however, as autism rates have increased rapidly worldwide, taking a heavy toll on families and economies alike. While certain genetic mutations have been linked to autism, they're thought to be involved in less than one-third of cases.2
The other major cause of autism is thought to be environmental in nature, with exposure to toxins and nutrient deficiencies among the possible culprits. "The rapid increase in numbers during [the] last few decades supports a major role in environmental factors over genetic causes alone. The other possibility is that the environmental factors may be contributing to activate the genetic or epigenetic mechanisms of development of autism," researchers wrote in the Journal of Heavy Metal Toxicity and Diseases.3
Some experts believe autism development starts in the womb, with environmental exposures during this time playing a crucial role. However, children are typically diagnosed with autism around the age of 3 or 4, which is often too late to link the condition back to a certain in-womb exposure.
Recently, however, a study funded by the National Institutes of Health's (NIH) National Institute of Environmental Health Sciences found that baby teeth could be used to measure exposure to heavy metals in early life, including in the womb, shedding light on another possible cause of autism.4
Baby Teeth Reveal Heavy Metals' Link to Autism
Researchers used baby teeth from 32 pairs of twins and 12 individual twins for the study. They were able to use lasers to analyze growth rings in the teeth, which begin to form during the second trimester of pregnancy.5 The rings revealed exposures to heavy metals as well as certain mineral levels, linking the exposures and nutrient levels with key periods of development (even prior to birth), much like rings on a tree.
Teeth from children with autism were found to have more lead and less of the nutrients zinc and manganese than teeth from children without autism. The differences in metal uptake were greatest in the months just before and after birth, and several other notable differences were also revealed, according to an NIH press release:6
"The researchers observed higher levels of lead in children with autism throughout development, with the greatest disparity observed during the period following birth. They also observed lower uptake of manganese in children with autism, both before and after birth. The pattern was more complex for zinc. Children with autism had lower zinc levels earlier in the womb, but these levels then increased after birth, compared to children without autism."
Among twin pairs in which both children had autism, smaller differences in metal patterns in their baby teeth were observed while larger differences were found in teeth from twin pairs where only one had autism. The findings add more support that exposure to environmental stressors, particularly at key periods of development and possibly in combination with certain nutrient deficiencies, may be harmful to brain development. The researchers concluded:7
"Our study suggests that metal toxicant uptake and essential element deficiency during specific developmental windows increases ASD risk and severity, supporting the hypothesis of systemic elemental dysregulation in ASD."
Environmental Exposures Causing Autism — Known for a Decade
It was nearly a decade ago in 2009 when researchers from the University of California, Davis, reported a seven-fold increase in autism diagnoses in the state — a rise they said could not be explained away by changes in doctors' diagnoses, migration to the state or genetics. Instead, they suggested environmental exposures as the most likely explanation.8,9 Exposure to pesticides, including pet flea shampoos, phthalates, PCBs, flame retardants, antibacterial soaps and other chemicals were suggested as potential culprits.
Despite the urgent need to conduct more research to uncover the environmental factors leading to autism, funding for studies looking at the genetic causes of autism was up to 20 times higher than funding for studies of environmental causes.10
When I spoke with Dr. Suruchi Chandra, a Harvard-trained, board-certified psychiatrist who has focused her career on using a holistic and integrative approach to help children and adults with challenging emotional and behavioral issues, including autism and other developmental delays, she, too, indicated that environmental exposures are a significant factor.
As noted by Chandra, "There is no such thing as a genetic epidemic. Genes don't change that fast." She believes looking at everything surrounding a child during development is crucial, and this includes not only environmental toxins but also the child's microbiome, diet, exposure to electromagnetic fields (EMF) and antibiotics, vitamin D levels and more.
"We need to take a really broad view. It's unlikely that autism is going to be caused by one or two factors. It's likely to be caused by this combination of many factors, and it's going to be unique for each child. It's really challenging when you have this very individualized complex system, as studies aren't going to figure this out easily. If we just wait for studies, we may be waiting a long, long time to act," she said.
Overall, the approach Chandra uses is precautionary, beginning with identifying and reducing toxic exposures in your home. She has a handout she gives to parents, which you can download from her website, chandramd.com. It's four pages long, covering aspects like air and water quality, pesticides, flame retardants and volatile organic compounds (VOCs) found in a range of products, including furniture.
Mineral Deficiencies May Also Play a Role
The featured study found children with autism had lower levels of manganese and zinc than children without autism, at varying times during development. Previous research has also suggested nutrient deficiencies, as well as excess levels and exposure to heavy metals, may play a role, even when they occur in the mother during pregnancy. According to the Journal of Heavy Metal Toxicity and Diseases:11
"The deficiency of some trace elements like zinc (Zn), manganese (Mn), molybdenum (Mo), Aluminium (Al) and selenium (Se) were found to be deficient in children with ASD. Iron (Fe) deficiency and vitamin (eg: B9-folate) deficiency has also shown associations with ASD.
The excess of some elements like copper (Cu), lead (Pb), mercury (Hg) and cadmium (Cd) has also shown significant associations. Maternal micronutrient deficiency and toxin exposure can lead to defective fetal brain development."
It's interesting to note that glyphosate, the active ingredient in Roundup and the most widely used herbicide in the world, is a manganese chelator,12 which may explain why children are deficient. The rise in glyphosate usage correlates closely with the incidence of autism, and there may be multiple mechanisms of harm at play. Stephanie Seneff, a senior research scientist at Massachusetts Institute of Technology, has been instrumental in educating people about the hazards of glyphosate.
She has found that aluminum and glyphosate act together as synergistic poisons that promote autism. Based on the current trend, Seneff predicts that by 2025, half of all children born will be diagnosed with autism. Clearly, we must identify the leading environmental factors contributing to this alarming trend. Glyphosate also negatively impacts your gut microbiome and your mitochondria, so it really delivers a double whammy.
Treating Mental Disorders With Nutrition
In the lecture featured above, Chandra discusses research findings showing how environmental toxins can influence ASD and other developmental delays, and reviews a number of safe, gentle natural treatment options that can be quite helpful. Chandra also believes that the microbiome is likely key in understanding ASD, similar to the views of Dr. Natasha Campbell-McBride, whom I've interviewed in the past about her Gut and Psychology Syndrome (GAPS) Diet.
Campbell-McBride's basic thesis is that the autistic child's microbiome was disrupted by the mother's poor diet and use of antibiotics or birth control pills. The mother then transfers that poor microbiome to the child. This early disruption in the microflora, combined with other environmental variables, ends up wreaking both physical and neurological havoc. Chandra, like Campbell-McBride, finds the greatest improvements are typically seen once strategies that help heal the microbiome are implemented.
When I was treating autistic patients, I typically saw enormous improvements when we restricted sugars, grains, fruit juices and fruits — all sources of net carbs (total carbohydrates minus fiber) that disturb the gut microbiome, increase pathogenic yeast, fungi and viruses, and wreak havoc with the mitochondrial fuel structure. Increasing intake of healthy fats is also important.
Chandra relies on a wide variety of diagnostic tools that most conventional psychiatrists would never think to use. If you have a child with autism or suspect any type of neurological condition, don't wait to start treatment, as early intervention is important. Seek the guidance of a knowledgeable integrative physician and/or psychiatrist who can address the following variables and any others that need attention. For example, Chandra's protocol includes the following:
• GI function: To assess the child's GI tract, she begins by taking a family history and doing a physical examination. She also performs tests to assess the child's gut bacteria, level of inflammation and digestive function. If it's determined that the child cannot digest carbs, for example, she will recommend reducing or avoiding grains and using a digestive enzyme.
• Immune function and chronic infections: Many autistic children have evidence of immune dysfunction, such as autoimmune problems and/or excess inflammation, so she will also assess and prescribe support for the child's immune function. Diagnosing and treating chronic infections is a related component.
• Mitochondrial health: Mitochondria are organelles inside nearly every one of your cells. "They are, we now know, kind of the canaries in the coal mine. When there's some danger or stress, they're the first things that respond to the damage," Chandra says. Studies suggest 60 percent of children with autism have mitochondrial dysfunction, so this is a significant factor.
There are tests that can indicate whether your child's mitochondria are affected. For example, low carnitine, coenzyme Q10 and certain amino acid ratios can signify mitochondrial dysfunction. If mitochondrial dysfunction is found to be part of the problem, adding more healthy fats to the diet, "healing and sealing" the gut and addressing any infections may help.