Wednesday, January 03, 2007
Autism linked to cow’s milk protein when GI symptoms present: More thoughts on the brain gut connection.
Though most doctors have been and remain skeptical of a link between autistic behavior and diet many people report improvement of their children’s behavior when wheat and cow’s milk or dairy are avoided. There are quite a number of lay organizations, websites, and articles that advocate a gluten-free and casein-free diet for autism spectrum disorder. Scientific studies that satisfy evidence-based standards of medical experts are very rare. However, studies proving dietary interventions result in a favorable outcome in health and disease are very difficult to design and carry out. An article in 2005 examined the association of immune response to common food proteins in a group of autistic children and found there was a link between cow’s milk protein and autistic behavior when gastrointestinal (GI) symptoms were also present.
Innate immune response was evaluated by measuring the levels of proinflammatory cytokines, chemicals released by white blood cells (WBC) of the body. Both autistic children and children with “non-allergic food hypersensitivity” (NFH) produced higher levels of these chemicals. Only in WBC’s from autistic children with GI symptoms did they find a positive association of these proinflammatory chemicals and cow’s milk protein (CMP).
Casein is the major cow’s milk protein. Besides milk and dairy products it is in many processed foods, medications, cosmetics, margarine, puddings, soups, artificial flavors, protein powders, and canned fish. Casein is also used to manufacture plastics, fabrics, glues and adhesives.
Many parents report a casein-free gluten-free diet increases eye contact, attention, and mood while decreasing aggressive or oppositional behavior, tantrums, and poor attention. Theories for improvement of casein-free diet include improved brain function due to removal of cow’s milk protein by-products that have opiate like effects. Casomorphin is protein fragment or peptide sequence derived from casein that is considered to have an opiate like effect. There are several casomorphins produced by digestion of casein from cow’s milk. People who stop eating wheat and dairy containing foods commonly report withdrawal symptoms. Such effects give new meaning to the term comfort foods and should cause us to pause before offering milk and cookies young children with developing brains and people with neurological or behavioral problems.
The findings of elevated proinflammatory chemicals in autistic children with GI symptoms suggests there is a link between the gut and behavioral symptoms that is immune mediated and related to leaky gut. It has been theorized that milk proteins get into the blood stream through a leaky gut allowing them to reach the rest of the body resulting in skin rashes, bone and joint inflammation of pain, and disturbed brain function. More research is needed in this area but trials of dairy free diet (and gluten-free diet) have been received with great support from many individuals who note improvements in their symptoms and overall health.
Dysregulated innate immune responses in young children with autism spectrum disorders. Their relationship to gastrointestinal symptoms and dietary interventions. H. Jyonouchi, Lee Geng, Agnes Ruby, Barbie Zimmerman-Bier. Neuropsychobiology. 2005;51:77-55.
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