Systematic Reviews
Copyright ©The Author(s) 2024.
World J Clin Pediatr. Dec 9, 2024; 13(4): 99649
Published online Dec 9, 2024. doi: 10.5409/wjcp.v13.i4.99649
Table 1 Feeding development in children with normal development vs. those with autism
Age range
Normal feeding development
Feeding development in children with autism
0-6 monthsSuck-swallow reflexes are well-developed; begins to coordinate sucking, swallowing, and breathing during feedingMay exhibit weak suck, poor coordination of sucking and swallowing, or difficulties breastfeeding
6-12 monthsIntroduced to pureed foods; begins to develop pincer grasp for self-feeding; starts to handle a variety of texturesIt may show oral tactile sensitivity or gagging, a preference for smooth, pureed foods, and delays in self-feeding skills
12-18 monthsProgresses to more textured foods; begins to use utensils; starts to drink from a cupPersistent preference for purees; resistance to textured foods; may continue using a bottle; difficulty using utensils
18-24 monthsEats a variety of foods; able to chew a wide range of textures; uses a spoon and fork more efficientlyLimited food variety; preference for specific textures or types of food; may have incomplete mastication and occasional choking
2-3 yearsFurther develops chewing skills; eats most family foods; drinks from an open cup; uses utensils independentlyContinued rigidity with food choices; may insist on specific foods or avoid entire food groups; ongoing issues with chewing and swallowing
3-4 yearsExpands diet to include more complex textures; shows improved self-feeding skills; less picky eatingPersistent selective eating; might insist on using a bottle or refuse sippy cup; difficulty with mixed textures
4-5 yearsEats a wide range of foods; improved social eating behaviors; uses utensils proficientlyOngoing rigidity with food variety and textures; may still prefer smooth or specific-textured foods; potential social eating challenges
5+ yearsGenerally eats a varied diet, participates in family meals, fewer food-related issuesContinues to display selective eating patterns; may require feeding therapy; potential need for specialized diets to meet nutritional needs
Table 2 The differences between the specific carbohydrate diet and the gut and psychology syndrome diet
Aspect
Specific carbohydrate diet
Gut and psychology syndrome diet
Origins and developmentDeveloped by Dr. Sidney V. Haas in the 1920sDeveloped by Dr. Natasha Campbell-McBride in 2004
Original purposeTreatment of celiac disease and gastrointestinal disordersAddressing neurological and psychological conditions
Popularized byElaine Gottschall, through "Breaking the Vicious Cycle"Dr. Campbell-McBride, through "Gut and Psychology Syndrome"
FocusElimination of specific carbohydrates to reduce gut dysbiosisHealing gut lining, restoring healthy gut flora, reducing inflammation
PrinciplesExcludes complex carbohydrates, lactose, and sucroseFocuses on healing the gut lining, restoring gut flora
Includes easily digestible foodsEliminates processed foods, refined sugars, starchy vegetables
Emphasizes nutrient-dense foodsStructured in distinct phases
Main foodsMeat, fish, eggs, vegetables, fruits, nuts, certain dairy productsSimilar to SCD, with greater emphasis on bone broth, fermented foods, healthy fats
Foods excludedAll grains, starchy vegetables, lactose (initially), sucrose, processed foodsAll grains, starchy vegetables, refined sugars, processed foods, certain dairy products
Diet structureMore flexible, with less emphasis on phasesStructured in phases: Introductory phase to full GAPS diet
Emphasis on healingEliminating specific carbohydrates to reduce gut dysbiosisHealing the gut lining and restoring healthy gut flora
Food focusEliminating specific carbohydratesHealing foods like bone broth and fermented foods
Underlying philosophySpecific carbohydrates promote gut dysbiosisGut health linked to psychological and neurological health
Target conditionsCeliac disease, gastrointestinal disorders, IBD, ASDASD, ADHD, depression, psychological and neurological conditions
Overall approachStraightforward food eliminationPhased approach with emphasis on gut healing
Table 3 The dietary interventions, supplements, and their related details for autism spectrum disorder
Intervention/supplement
Description
Functions
Potential links with ASD
Current research findings
Practical considerations
Gluten-free dietEliminates gluten (wheat, barley, rye). Requires careful planning for nutritional adequacyAims to improve gastrointestinal symptoms, behavior, attention, and social interactionsIncreased sensitivity to gluten may affect brain functionMixed evidence; more rigorous trials are needed.Strict adherence is challenging; potential nutritional deficiencies; more expensive and less accessible
Casein-free dietEliminates casein (dairy products). Requires careful planning for nutritional adequacyAims to improve gastrointestinal symptoms, behavior, attention, and social interactionsSensitivity or allergy to casein may exacerbate autism symptomsMixed evidence; more rigorous trials are neededStrict adherence is challenging; potential nutritional deficiencies; more expensive and less accessible
Ketogenic dietHigh-fat, low-carbohydrate, moderate-protein diet. Requires careful planning, medical evaluation, and regular monitoringAims to improve behavior, cognitive function, seizure control, and gastrointestinal symptomsKetones may have neuroprotective properties and improve brain functionLimited data; more rigorous trials are needed.Potential nutritional deficiencies; strict adherence is challenging; potential side effects (GI discomfort, kidney stones, increased cholesterol)
Specific carbohydrate dietEliminates complex carbohydrates, disaccharides, and polysaccharides. Includes meats, certain vegetables, fruits, nuts, and seedsAims to improve gastrointestinal symptoms, behavior, and cognitive functionAddresses gut dysbiosis and gastrointestinal inflammationMixed results; more rigorous trials are neededRestrictive; potential nutritional deficiencies; strict adherence is challenging; more expensive and less accessible
Gut and psychology syndrome dietStructured in phases, includes bone broths, fermented foods, and healthy fatsAims to improve gut health, behavior, cognitive function, and overall well-beingFocuses on healing the gut lining and restoring healthy gut floraLimited peer-reviewed research; indirect support from studies on gut microbiota.Restrictive; potential nutritional deficiencies; challenging to implement; anecdotal evidence
Camel milkRich in vitamins, minerals, and unique proteinsAnti-inflammatory, antioxidant, immune modulation, gut health promotionEmerging research suggests behavioral improvements, cognitive functions, and GI symptom reliefEmerging research and anecdotal reports suggest significant benefitsObtain from reputable sources, gradually introduce, consult healthcare provider for dosage, monitor response and allergic reactions
ProbioticsRestores healthy gut bacteria balance, reduces gut inflammation, strengthens gut barrierImproves GI function, potential behavioral improvementsMay improve gut health and behavior by restoring healthy gut bacteriaMixed results; some studies show improved GI and behavioral symptomsChoose effective strains, determine optimal dosage with clinical guidance, monitor and adjust based on individual response
PrebioticsPromotes growth of beneficial gut bacteria, reduces inflammation, supports neurotransmitter synthesisImproves gut health, potential behavioral and cognitive benefitsMay improve gut health and behavior by promoting beneficial gut bacteria growthLimited human trials but promising; animal models support positive effectsStart with low dose, include prebiotic-rich foods, use supplements under healthcare guidance, consider combining with probiotics, monitor for adverse reactions
High-dose methylcobalaminSupports methylation cycle, boosts glutathione synthesis, neuroprotective propertiesEnhances cognitive functions, reduces oxidative stress, improves detoxificationMay improve behavioral and cognitive functions, reduce oxidative stressPromising results; improved methylation capacity and reduced oxidative stress markersAdminister via injections, determine dosage with healthcare provider, regular monitoring of vitamin B12 Levels, consider combined treatment with folinic acid
Folic acidSupports DNA methylation, reduces homocysteine levels, involved in neurotransmitter synthesisPotential reduction in ASD risk, improved neurodevelopment, reduced oxidative stressPrenatal supplementation may reduce ASD risk.Prenatal doses support reduced ASD risk; large epidemiological studies support benefitsRecommend 400-800 mcg/day prenatal doses, consider genetic variations, ensure balanced diet, consult healthcare provider for high doses
Vitamin B6Synthesizes neurotransmitters, reduces homocysteine levels, converts glutamate to GABAPotential improvements in behavior, language development, cognitive functionMay improve behavior, language, and cognitive functionsMixed results; some studies show improvements; variability in outcomesDetermine dosage with healthcare provider, monitor for side effects (peripheral neuropathy), consider combination with magnesium.
Vitamin DFat-soluble vitamin; exists as vitamin D2 and D3; synthesized in skin or obtained from food sourcesFacilitates calcium and phosphorus absorption, modulates immune system, reduces inflammation, supports brain developmentLow vitamin D levels linked with ASD risk; deficiency associated with immune dysregulation and neurotransmitter imbalancesBenefits of vitamin D3 supplementation include improved autism severity scores and social behaviorsDosage varies; general recommendation 600-800 IU daily; excessive intake can lead to toxicity; regular monitoring essential
L-CarnitineNaturally occurring amino acid derivative; involved in energy metabolism and mitochondrial healthFacilitates fatty acid transport into mitochondria, supports mitochondrial health, and has antioxidant propertiesMitochondrial dysfunction and oxidative stress observed in autism; L-carnitine may improve mitochondrial function and reduce oxidative stressLower L-carnitine levels in autism; improvements in behavior and communication with supplementation.Dosage ranges from 50 to 100 mg/kg/day; consult healthcare providers; generally safe but may cause gastrointestinal discomfort or fishy odor
Omega-3 and Omega-6Essential polyunsaturated fatty acids; Omega-3 (ALA, EPA, DHA) and Omega-6 (LA, AA)Vital for brain function, anti-inflammatory effects, and overall neural healthOmega-3 deficiencies may impair neurodevelopment; Omega-3s may improve behavior; Omega-6 imbalance can promote inflammationMixed results; some studies show improvements in behavior, cognitive development, and social skillsNo standardized dosage; consult healthcare providers; high doses may cause GI issues and increased bleeding risk; balance omega-3 and omega-6 intake