Science Update

A new review evaluates the efficacy of dietary supplements on clinical aspects of autism

 

Autism spectrum disorder (ASD) has an unclear cause but is associated with various genetic neurologic metabolic and immunologic factors. Although there is no definitive treatment there has been an increase in the use of dietary interventions and nutritional support in these patients.

Pharmaceutical and behavioral therapies are often used but their success is limited. This can be due to the high variability of autism as well as adverse reactions to medications.

According to a review published two weeks ago in the European Journal of Nutrition researchers evaluated the clinical efficacy and safety of dietary supplements in children with autism.

This review of 18 studies looked at five supplements: B6/magnesium methylcobalamin vitamin D omega-3 fatty acids and folinic acid. The study sizes ranged from 13 to 109 participants and the supplement duration ranged from 2 to 35 weeks. 

Previous research demonstrated that vitamin B6 and magnesium have been shown to be involved in serotonin dopamine and norepinephrine synthesis and a B12 deficiency has been associated with defects in myelin synthesis and neurotransmitter imbalances.

As a result of this review vitamin B6 and magnesium were not recommended while vitamin B12 vitamin D and essential fatty acids were recommended to address a deficiency but further research is needed for their effectiveness on ASD. One of the two studies on vitamin D did suggest it could significantly improve the core symptoms of ASD. Folinic acid was shown to be effective and did improve the symptoms of ASD. 

Several abnormalities in the metabolism of folic acid have been associated with ASD. In addition other studies have demonstrated a cerebral folate deficiency in autism. Folate cannot be synthesized by the body and is dependent upon dietary or supplemental sources.

In one of the recent studies reviewed folinic acid was dosed at 2 mg/kg/day. After 12 weeks of supplementation of folinic acid or placebo significant improvements were seen in verbal communication and core symptoms of ASD.

Children with ASD may obtain most of their required nutrients from their diet; however it is essential to determine the specific nutrient need of each child. The level of nutrient intake that maintains the best possible health is highly variable from person to person. Lifestyle choices and environmental exposures filtered through genetic predisposition are fundamental factors in ASD and a successful treatment approach must include investigation into these factors. It is important to assess the nutrient status of the child such as the antioxidant status vitamins essential fatty acids vitamin D magnesium and more. Also it is critical to assess gut health including leaky gut and dysbiosis since many of these children have a dysbiosis and opportunistic infections.

Children with ASD have significantly different concentrations of certain bacteria in their stool compared to children without ASD. Increasing evidence suggests that these children have altered gut bacteria. It is suspected that gut microbes can alter the levels of neurotransmitter-related metabolites affecting the gut-to-brain communication and thus alter brain function. 

By Michael Jurgelewicz DC DACBN DCBCN CNS 

Source: Li YJ Li YM and Xiang DX. Supplement intervention associated with nutritional deficiencies in autism spectrum disorders: a systemic review. European Journal of Nutrition. 2017 September 7. doi: 10.1007/s00394-017-1528-6.