Food Allergy Assessment in Children in the Autism Spectrum.
Sidney MacDonald Baker, MD
(EDITOR’S NOTE: Society’s image of autism is shifting and early intervention is the key to success. A recent Newsweek article reported that of the million-plus Americans with autistic disorders, more than 80 percent are males.)
Children with a whole range of problems from typical forms of autism to attention deficits frequently have been observed by their parents to have sensitivities to certain foods. The sensitivities are usually not immediate hypersensitivity reactions involving hives, or sudden respiratory or intestinal reactions, but reactions that occur hours to days after exposure, or cumulative exposure, to foods.
A key link between the immune system and central nervous system
It is helpful to keep in mind that the immune system has the same functions as the central nervous system: to perceive and remember the environment. The differences are only in the locations of the tissues involved and the scale of the perception. The brain perceives and remembers the big world of the senses and the immune system perceives and remembers antigens and molecules. The outcome of both brain and immune system processing embraces the resulting function of recognition. From this perspective, it does not seem surprising that children with difficulties in perception and processing at the cognitive level may have parallel difficulties at the immune level. Similarly, just as therapies may be usefully directed at simplifying and integrating a child’s sensory experience, the diet and general antigenic environment may require simplification to suit a child’s particular sensitivities. Desensitization is a word we use with equal comfort in both domains.
Which foods are the right, healthy foods?
Many children have already simplified their diets by refusing a wide variety of healthy foods. The restricted intake of sick children may be limited to foods for which they have an allergic craving or which are not very nourishing, such as potato chips. It is helpful, therefore, to have a test that gives reliable information concerning safe, healthy foods, as well as potentially reactive foods.
IgG ELISA food testing controversy and proven benefits…
Food allergy testing is controversial. Many allergist/immunologists believe that IgE testing for immediate food hypersensitivity and limited use of skin testing and elimination diets is all that can be done to evaluate food sensitivities. I have found IgG ELISA to be a very useful tool for screening for safe foods, evaluating the overall state of immune activation against foods as reflected in the total number of reactive foods in the panel, and spotting reactive foods. I have conducted two double blind, placebo diet controlled studies validating IgG ELISA by showing a significant difference in symptom reduction in subjects avoiding IgG reactive foods as compared with IgG non-reactive foods. I recommend such testing and, at least, a trial of avoidance of IgG reactive foods for children in guidelines in food elimination. Such tests are not absolute arbiters of every food that may be safe or unsafe. This is particularly true for foods for which the mechanism of sensitivity is not immunologic (because they interfere with phenosulfotransferase – chocolate, cheese, banana, citrus, contain fungal antigens and toxins, are a source of peptides, or contain sugar or additives).
McDonald Baker MD, Sidney. “Food Allergy Assessment in Children in the Autism Spectrum.” BasicHealthUSA. 2010. Immuno Labs, Web. 9/2/11.