Comprehensive Nutritional and Dietary Intervention for Autism Spectrum Disorder-A Randomized, Controlled 12-Month Trial
Authors:
Adams, J.B., Audhya, T., Geis, E., Gehn, E., Fimbres, V., Pollard, E.L., Mitchell, J., Ingram, J., Hellmers, R., Laake, D. and Matthews, J.S.
Key Findings of the Study
The treatment group received a series of interventions introduced sequentially over 12 months, including:
A special vitamin/mineral supplement (started at Day 0)
Essential fatty acids (Day 30)
Epsom salt baths (Day 60)
Carnitine (Day 90)
Digestive enzymes (Day 180)
A healthy gluten-free, casein-free, soy-free (HGCSF) diet (Day 210)
The final assessment occurred at Day 365 (12 months). The study measured outcomes such as nonverbal IQ, autism symptoms, developmental abilities, and nutrient levels in the blood. Here are the primary findings:
Nonverbal IQ Improvement: The treatment group showed a significant increase in nonverbal IQ, gaining an average of 6.7 IQ points (±11), compared to a slight decrease of 0.6 IQ points (±11) in the non-treatment group (p = 0.009). This was assessed using the Reynolds Intellectual Assessment Scales (RIAS) in a blinded manner.
Autism Symptoms: Based on semi-blinded assessments with the Childhood Autism Rating Scale 2 (CARS-2) and Autism Treatment Evaluation Checklist (ATEC), the treatment group exhibited significant reductions in autism symptoms compared to the non-treatment group.
Developmental Abilities: The treatment group experienced an average increase of 18 months in developmental age over the 12 months, as measured by the Vineland Adaptive Behavior Scale II (VABS-II), indicating improvements in communication, daily living skills, and social skills.
Nutritional Improvements: The treatment group had significant increases in key nutrients, including:
EPA and DHA (omega-3 fatty acids, with DHA increasing by 83%)
Carnitine
Vitamins A, B2, B5, B6, B12, folic acid, and Coenzyme Q10
Gastrointestinal Symptoms: Improvements were noted in gastrointestinal (GI) symptoms, assessed via the 6-Item Gastrointestinal Severity Index (6-GSI) and Parent Global Impressions-2 (PGI-2).
Parent Perceptions: Parents reported that the vitamin/mineral supplement, essential fatty acids, and HGCSF diet were the most beneficial interventions, based on a Treatment Effectiveness Survey rated on a scale from -3 (much worse) to +3 (much better).
The study concluded that this comprehensive approach was safe and effective, improving nutritional status, nonverbal IQ, autism symptoms, and overall functioning, with minimal adverse effects.
Which Diet Helped Autism Symptoms?
The diet implemented in the study was the healthy gluten-free, casein-free, soy-free (HGCSF) diet. This diet eliminates:
Gluten (found in wheat, barley, rye)
Casein (found in dairy products)
Soy while emphasizing nutrient-rich, healthy foods. It was introduced as the final intervention at Day 210 (approximately 7 months into the study) and continued until the end at Day 365.
Although the study included multiple interventions, the HGCSF diet was highlighted by parents as one of the three most beneficial components (alongside the vitamin/mineral supplement and essential fatty acids). The diet aligns with previous research suggesting that gluten-free, casein-free diets can benefit some individuals with ASD, possibly by reducing food sensitivities and improving nutritional intake.
How Much Did the Diet Help?
The study did not isolate the specific effects of the HGCSF diet due to the sequential and cumulative nature of the interventions. Instead, the reported improvements reflect the combined impact of all treatments, including the diet. Key metrics of overall improvement include:
Nonverbal IQ: An average increase of 6.7 IQ points in the treatment group, compared to a 0.6-point decrease in the non-treatment group.
Autism Symptoms: Significant reductions in CARS-2 and ATEC scores, indicating lessened symptom severity.
Developmental Age: An average gain of 18 months in developmental abilities over 12 months.
Parent Ratings: On the Treatment Effectiveness Survey, the HGCSF diet received an average rating of 1.5 on a scale of -3 to +3, interpreted as "better." For comparison:
Vitamin/mineral supplement: 1.9
Essential fatty acids: 1.7
Carnitine: 1.2
Digestive enzymes: 1.1
Epsom salt baths: 0.9
While the exact contribution of the diet alone cannot be quantified, its high parent rating and the study's discussion of its potential role in reducing GI symptoms and food sensitivities suggest it was a meaningful contributor to the overall benefits. For instance, improvements in GI symptoms (via 6-GSI and PGI-2) may be partly attributable to the diet, given its focus on eliminating common allergens.
A specific case study further supports the diet’s impact: a 10-year-old boy with severe autism and pica (eating non-food items) ceased this behavior within a week of starting the HGCSF diet, with continued improvements in behavior and cognition over subsequent months. This anecdotal evidence indicates that the diet may have substantial effects for some individuals, though it’s not representative of the entire group.
How Long Did It Take for the Diet to Help?
The HGCSF diet was introduced at Day 210 (around 7 months) and continued for approximately 5 months until the final assessment at Day 365 (12 months). The timeline of its effects is challenging to pinpoint precisely because:
The study assessed outcomes primarily at the beginning and end (Day 0 and Day 365), with limited intermediate data.
The PGI-2 (Parent Global Impressions-2) was measured at months 3, 6, 9, and 12 for the treatment group, showing steady improvement over time:
Month 3: ~0.5 (after vitamin/mineral and fatty acids)
Month 6: ~1.0 (after adding Epsom salts and carnitine)
Month 9: ~1.5 (after adding digestive enzymes at Month 6 and diet at Month 7)
Month 12: ~1.7
The diet began between the Month 6 and Month 9 assessments, and no significant "jump" in PGI-2 scores occurred immediately after its introduction, suggesting its effects may have been gradual and cumulative.
However, the case study of the boy with pica indicates that for some individuals, the diet’s effects could be rapid—within 1 week for specific symptoms like pica, with broader improvements unfolding over months. For the group as a whole, the full extent of the diet’s contribution was observed at the 12-month mark, after 5 months of adherence, as part of the comprehensive treatment.
Conclusion of study:
The healthy gluten-free, casein-free, soy-free (HGCSF) diet was a key component of a successful comprehensive intervention for individuals with ASD. While its isolated effect wasn’t measured, it contributed to significant improvements over 12 months, including a 6.7-point increase in nonverbal IQ, reduced autism symptoms, and an 18-month gain in developmental age. Parents rated it highly (1.5/3), and it was followed for 5 months, with potential effects ranging from rapid (within a week, per case studies) to gradual (over 5 months, per group data). This suggests the HGCSF diet is a promising intervention for managing autism symptoms, particularly when combined with nutritional supplements.
https://pubmed.ncbi.nlm.nih.gov/29562612/
doi: 10.3390/nu10030369
