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 lost productivity. Added to this are the attendant 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 still in the uterus – contaminated by its mother’s toxic burden. (12) In this article, part one of a series on ASD, I will explore dietary considerations. In part two, we will delve into environmental exposure and its effects on ASD. Finally we will present complementary and alternative (CAM) therapies.
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, which are found in many fruits and vegetables. Some examples are apples, peaches, grapes, berries, broccoli, cauliflower, cucumbers, and hot peppers. He also eliminated all food preservatives, sugars, and color additives. (14) Over the years, Feingold’s diet was modified and eliminating 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 one of the components in this very complex disorder.
Most importantly, elimination diets for ASD typically restrict all food additives and colors, plus glutamate (MSG), and the sweetener aspartame (Equal, NutraSweet). These items have been shown to be brain and nervous system toxins in some children. (15) Typical diets used for ASD emphasize fresh organic fruit and vegetables, organic non-genetically modified (GMO) whole grain cereals (except wheat, rye, barley, if gluten sensitivity is a factor), and organic rice. Meats and poultry should be from range-fed or free-range animals. Wild caught fish are better choices than those that are farm raised. That’s because the farmed fish have been fed additives. Natural sweeteners such as Stevia, honey and agave are becoming more popular and easy to find in products. (16)
Diet and the Immune System in ASD
In addition to the contribution food additives may make in ASD, attention has also focused on the impact of dietary components on the immune system. Certain foods contain proteins that ASD children and adults may not be able to process. These are “gluten” and “gliadin” containing foods; wheat, rye, barley, and oats. Additionally some children are allergic to dairy products and any foods that contain casein, a milk protein. (17) For parents seeking dietary intervention for their children, a gluten-free and casein-free (GFCF) diet can alleviate many symptoms. The GFCF diet of course, also bans artificial colors, flavors, high fructose corn syrup, corn syrup, and preservatives.
Scientific Validation for Dietary Intervention in ASD
Good controlled scientific studies on the treatment of ASD with such diets are scarce. Two placebo, controlled studies are particularly noteworthy. The number of children tested was 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. Given the popularity of the GFCF diet among parents of ASD children, it seems odd that more attention has not been paid to dietary intervention for the disorder. In fact, a 2009 Cochran Review compared the most recent scientific studies to those reviewed in 2002. The reviewers expressed disappointment that there was little new information that showed a positive response to restriction of gluten and casein containing foods.(20)
Since the 2009 Cochran Review, a study of 72 Danish children found that over a 2-year period the GFCF diet had a significant beneficial effect on core autistic and related behaviors in some of the children. This group of children had gluten and casein metabolites in their urine at the beginning of the study that other children did not have. This was interpreted to mean that having these particular metabolites indicated intolerance to these proteins. These children would be expected to benefit most from the GFCF diet. The study authors conclude that for some ASD children, eliminating these proteins may improve symptoms. (21) These findings echo what Susan Hyman M.D. associate professor of Pediatrics at Golisano Children’s hospital at the University of Rochester Medical Center (URMC), and colleagues have found. 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. If children are screened for gluten and casein metabolites in their urine, it could be anticipated that the GFCF diet would produce positive results.
Even more benefit might be derived from the GFCF diet if the gluten and casein intolerant children were treated with 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 approaching this very complex disorder, a one-size-fits-all approach is not likely to produce the hoped for results. An important consideration is that restrictive diets might actually impair the health of children because important food sources of nutrients might be eliminated from the diet. Consequently, some children will need to be supplemented with nutrients such as calcium, magnesium, iron and B vitamins.
References:
1) http://www.nimh.nih.gov/health/publications/autism/complete-index.shtml
2) Blaylock, RL; “A Possible Central Mechansm in Autism
3) Ibid.
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” www.dr.rapp.com.
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.
