Autism and the Gastrointestinal Tract
Many studies have suggested a link between autistic symptoms and gastrointestinal defects. Clinical assessments of gastrointestinal symptoms have suggested that up to half of autistic children have gastrointestinal abnormalities. In one study, 76% of autistic patients had at least one gastrointestinal symptom (compared to 30% of their non-autistic siblings) and 64% had two or more symptoms, including diarrhea, constipation, abdominal bloating or discomfort. These problems are likely mediated by abnormalities in the regulation of the immune system. Alterations in the immune system lead to a disturbance of the microflora (healthy bacteria) in the stomach, duodenum and colon, which is highly prevalent in autistic disorder. Many autistic children have chronic gastrointestinal inflammation and compromised structure in the digestive tract, both of which may reduce the absorption of essential nutrients. The lack of nutrients may in turn disrupt important areas of metabolism.
Autism and Seizures
Autistic disorders are also associated with seizures. One third of autistic children suffer one or more seizure by the time they reach adolescence, and an association has been suggested between subclinical epilepsy and the regression of autism.
Autism and Oxidative Stress
Increasing evidence suggests a link between autistic disorder and oxidative stress, which occurs when cells are damaged by free radicals. It has been suggested that autism results from interactions between genetic, environmental, and immunological factors, and that oxidative stress is the link between these risk factors. The brain is particularly vulnerable to oxidative stress because it has a higher energy requirement, lower levels of antioxidants, and higher levels of lipids and iron, which are sensitive to oxidation. An increase in oxidative stress can lead to damaged membrane lipids, mitochondrial dysfunction, and abnormalities in the immune and inflammatory systems, which could in turn contribute to the behavioral problems, sleep disorders and gastrointestinal abnormalities commonly found in autism.
Carnosine
Carnosine is a simple nutrient made of two amino acids that is produced by cells in the muscle, heart, and brain. It is renowned for its antioxidant and anti-aging effects, and studies indicate that it may also have protective roles in the gastrointestinal system and in the nervous system. Carnosine appears to indirectly affect electrochemical processes in the brain. It has been suggested to enhance the function of the frontal lobe of the brain, and may have anticonvulsive effects.
Levels of homocarnosine (a carnosine metabolite bound to the neurotransmitter GABA) in the brain appear to be associated with the control of seizures. One study tested the effects of dietary carnosine on seizure control, observing both overt seizures and the findings of electroencephalograms (EEGs). Seven children affected by seizures were given 400 mg of L-carnosine per day for 10 weeks. At the end of the study, 5 of the 7 children had improved EEG findings, and all 7 exhibited improvement in seizure frequency. Still more, the children were found to have improvements in overall cognition, behavior, and language function, although these effects were not formally evaluated since they had not been predicted to be affected by carnosine. While the exact mechanism of carnosine in seizure control is not understood, it may be due to homocarnosine's ability to regulate the influx of copper and zinc into neurons, which appear to have antiepileptic effects in the brain, and to decrease abnormal EEG wave patterns which are associated with seizures. Carnosine may therefore be helpful in decreasing the frequency of seizures and improving EEG patterns.
A double-blind study evaluated the effects of supplemental carnosine in autism. 31 children (aged 3 to 12 years) with autistic spectrum disorder were given 400 mg of carnosine twice daily for 8 weeks. At the end of the study, the supplementation group showed significant improvements in receptive speech, socialization and behavior as assessed by the Gilliam Autism Rating Scale and the Receptive One-Word Picture Vocabulary test. The supplement was well-tolerated, and none of the children had to discontinue the study because of side effects.
Zinc
Zinc is an important nutrient in the development of the brain because of its roles in gene expression. Zinc deficiency during pregnancy has been proposed as a contributing factor to developmental diseases, including autism. Preliminary studies have found altered serum copper/zinc ratios in people with autistic disorders. Zinc may be beneficial in helping with the gastrointestinal defects associated with autistic disorder. Zinc compounds have been found to prevent lesions in the gastric mucosa in a wide range of animal models. The mineral helps to maintain the gastric mucosal barrier and to stimulate mucus production.
A Protective Combination
The combination of zinc and carnosine has been tested in several models and found to be effective for protecting the gastrointestinal tract. In animal models, zinc and carnosine dose-dependently and potently inhibit gastric damage, prevent gastric lesions, reduce the amount of gastric injury, and prevent structural changes with no significant change in gastric pH. In a study of 10 volunteers aged 24-40, zinc carnosine prevented increases in gut permeability (an indication of intestinal damage) after participants took indomethacin, a non-steroidal anti-inflammatory drug known to cause gastrointestinal damage. Indomethacine caused a threefold increase in gut permeability in the control group, but there was no significant change in permeability when zinc carnosine was also administered. These effects may be due to the nutrients' ability to protect against oxidative damage, and to stabilize mast cells, which are a type of immune cell that releases inflammatory mediators.
Vitamin E
Studies have found that oxidative stress is generally significantly increased in autism, with elevated markers of lipid peroxidation and decreased levels of major antioxidants. Preliminary trials have found that behavior improves in autistic individuals who are supplemented with antioxidants. The vitamin E complex is one of the most powerful antioxidant groups. It may also enhance the antioxidant effects of carnosine. Vitamin E also has protective effects in the gastrointestinal tract. Alpha-tocopherol has been found to dose-dependently suppress the formation of gastric ulcers and the activation of certain immune cells, which may help decrease inappropriate inflammation.
AutiFocus contains a combination of ingredients that have shown potential in reducing the symptoms and related problems of autistic disorder.
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