The unprecedented occurrence of autism has fueled concerns that we are experiencing an apparent “epidemic” of ASD.
Nutrition for Optimal Wellness | Marcia Zimmerman, CN | Autism spectrum disorders (ASD) is a devastating childhood developmental disorder that features language impairment, dysfunctional social interactions, and repetitive behavior patterns.1 The disorder affects 4 times more males than females and is generally discovered by the age of 36 months. A regression of developmental skills is found in approximately 30 percent of children.2 The disorder wasn’t even named until mid 20th century, although it had been described by doctors Kenner and Asperger in the 1940s.3
Today ASD affects an estimated 1 in 110 children in the United States.4 Adding to this are thousands of adults who may not have been previously diagnosed. Roughly translated, this means as many as 1.5 million Americans today are believed to have some form of autism.5 It is a lifelong condition that impacts families and is a huge societal cost, not only for children,6 but in adult disability and health care costs.7
An Autism Epidemic?
The unprecedented occurrence of autism has fueled concerns that we are experiencing an apparent “epidemic” of ASD.8 According to the Centers for Disease Control, the average prevalence of diagnosed ASD among children 8 years old, increased 57% between 2002 and 2006, in the 10 states that had been randomly selected.9 It’s not clear if this increase is due to better diagnosis and identification of ASD at an earlier age, and/or a greater public awareness.10 However, there have been other reasons proposed that explain how this condition is increasing at such a rapid rate. One of these is repeated exposure to some food additives.11 Another is exposure to environmental contamination – possibly while the child is in utero.12 In this month’s Zimmerman File, we will explore dietary considerations. Next month, we will delve into environmental exposure.
Dietary Treatment for ASD
Dietary treatment of children with “behavioral problems” is not new. Beginning in the 1920s, dietary restriction was used to improve behavior.13 In the 1970s Dr. Benjamin Feingold reported that 50 percent of hyperactive and learning disabled children improved when placed on diets free of salicylates, preservatives, sugars, and additives.14 Over the years, Feingold’s diet was modified and salicylates occupied a less prominent position in dietary regimens. There is more evidence in the scientific literature on the effect of food additives in hyperactive behavior, which can be a component of ASD which is a very complex disorder. Consequently, elimination diets for ASD typically restrict all food additives and colors, plus glutamate (MSG), and aspartate (Equal, Nutrisweet), because they have been shown to be neurotoxic to some children.15 Typical diets emphasize fresh organic fruit and vegetables, organic non-genetically modified (GMO) whole grain cereals (except wheat, rye, barley), range fed meat, and wild caught fish, and natural sweeteners such as stevia, honey and agave.16
In addition to the contribution food additives may make in ASD, attention has also focused on immune dysregulation that occurs from ingestion of dietary proteins, specifically those found in wheat, rye, barley, and oats (gluten, gliadin) and dairy products (casein).17 For parents seeking dietary intervention for their children, a gluten-free and casein-free (GFCF) diet, which also bans artificial colors, flavors, high fructose corn syrup, corn syrup, and preservatives, has become the norm.
Good controlled scientific studies on the treatment of ASD with such diets are scarce. Two placebo, controlled studies that are particularly noteworthy. The number of children tested is small, 15 in one 18 and 20 in the other.19 Results reported in the larger study showed improvement in autistic traits among the group of children on the GFCF diet as compared to controls. The smaller study found no difference between the two groups of children tested. However the study authors noted that theirs was a pilot study and a larger well controlled study might well show significant improvement on the diet. A 2009 Cochran review of GFCD diet studies found no new information in the current state of dietary intervention studies for ASD as compared to the first review published in 2002. They expressed disappointment that there haven’t been studies that indicated a positive response to restriction of gluten and casein containing foods, given the popularity of these diets among parents of autistic children.20
A brand-new study of 72 Danish children studied over a 2-year period found that the GFCF diet had a significant beneficial effect on core autistic and related behaviors in ASD children who had pathological urinary results. This means that initial urinary testing found certain gluten and casein metabolites in a subset of ASD children and this indicated intolerance to these proteins. The study authors conclude that for some ASD children, eliminating these proteins may improve symptoms.21
Based on the paucity of evidence that the GFCF diet may not lessen ASD behaviors, the media jumped on the news that such diets don’t work. Susan Hyman M.D. associate professor of Pediatrics at Golisano Children’s hospital at the University of Rochester Medical Center (URMC) is scheduled to present the latest findings on the GFCF diet at the International Meeting of Autism Research in May, 2010. Dr Hyman is coauthor of a paper that discusses complementary and alternative medicine (CAM) treatments for Autism. In this paper, she supports the view that for some children, the GFCF diet seems to be very effective.22 Yet a positive response among all ASD children has been lacking.
The Danish study may reveal why. Children were selected based on laboratory findings that they were gluten and casein sensitive. It would naturally be expected that they would respond favorably. Another possibility is that none of these studies undertook the complete elimination diet that has become the benchmark for treating ASD behaviors. It may be that eliminating a combination of dietary ingredients will target more children’s sensitivities. This type of trial would better validate what so many parents and teachers have found in alleviation of some aspects of ASD. In approaching this very complex disorder, a one-size-fits-all approach is not likely to produce the hoped for results. Additionally, restrictive diets might actually impair the health of children who need to be supplemented when significant nutrients such as calcium, magnesium, iron and B vitamins are removed from their diet.
There is so much more to the story and dietary change is an important part of CAM treatment for ASD. Stay tuned for next month’s Zimmerman File, the second in this important series on autism. We will be discussing the role of diet, immunity, and environmental factors in autism during our July and August monthly webinars. Go to www.now-university.com to register.
2 Blaylock, RL; “A Possible Central Mechansm in Autism
4 Morbidity and Mortality Weekly Report (MMWR) December 31, 2009; Centers for Disease Control and Prevention http://www.cdc.gov/ncbddd/autism/data.html
5 Autism Society June 5, 2009 http://www.autism-society.org
6 Kogan, MD; “A National Profile of the Health Care Experiences and Family Impact of Autism Spectrum Disorder Among Children in the United States, 2006-2006. Pediatrics 2008;122:e1149-e1158.
7 Ganz, ML; “The Lifetime Distribution of the Incremental Societal Costs of Autism” Arch Pediatr Adolesc Med 2007;161:343-349.
8 Leslie, DL; “Health Care Expenditures Associated With Autism Spectrum Disorders” Arch Pediatr Adolesc Med 2007;161:350-355.
9 Op Cit. MMWR.
10 Op Cit. Leslie, DL.
11 McCann, D.; et. al.; “Food Additives and Hyperactive Behavior in 3-Year-Old an 8/9-Year-Old Children in the Community: a Randomised, Double-Blinded,Placebo-Controlled Trial.” Lancet 2007;370:
12 Dietert, RR; Dietert, JM.; ”Potential for Early-Life Immune Insult Including Developmental Immunotoxicity in Autism and Autism Spectrum Disorders: Focus on Critical Windows of Immune Vulnerability” J Toxicol Environm Health Part B 2008;11:660-680.
13 Elder, JH; “The Gluten-Free, Casein-Free Diet in Autism: Results of A Preliminary Double Blind Clinical Trail” J Autism Developmental Disorders 2006;36:413-420.
14 Thorley, J “Childhood Hyperactivity and Food Additives” Developmental Med Child Neurol 1983;25:531-532.
15 Blaylock, RL; “A Possible Central Mechanism in Autism Spectrum Disorders, Part 3: The Role of Excitotoxin Food Additives and The Synergistic Effects of Other Environmental Toxins” Altern. Ther. 2009;15:56-80.
16 Rapp, DJ “A Fast, Easy Allergy Diet for Behavior and Activity Problems”.
17 Vojdani, A; “Immune Response to Dietary Proteins, Gliadin and Cerebellar Peptides in Children with Autism” Nutritional Neuroscience 2004;7:151-161.
18 Elder, JH; “The Gluten-Free, Casein-Free Diet in Autism: Results of A Preliminary Double Blind Clinical Trail” J Autism Developmental Disorders 2006;36:413-420
19 Knivsberg, AM “A Randomized, Controlled Study of Dietary Intervention in Autistic Syndromes” Nutritional Neuroscience 2002;5:251-261.
20 Millward, C. et al.; “Glute-Free and Casein-Free Diets for Autistic Spectrum Disorder (Review) The Cochrane Collaboration 2009;Issue 1. John Wiley & Sons, Ltd. New York
21 Whiteley, P.; et. al.; “The ScanBrit Randomised, Controlled, Single-Blind Study of a Gluten-and Casein-free dietary intervention for Children with Autism Spectrum Disorders Nutritional Neuroscience 2010; 13:87-100.
22 Levy, S.; Hyman, S.; “Complementary and Alternative Medicine Treatments for Children with Autism Spectrum Disorders” Child Adolesc Psychiatr Clin Nut. Am 2008; NIH public access.
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