Systematic review of prenatal exposure to endocrine disrupting chemicals and autism spectrum disorder in offspring.

LAY ABSTRACT: Autism spectrum disorders comprise a complex group with many subtypes of behaviorally defined neurodevelopmental abnormalities in two core areas: deficits in social communication and fixated, restricted, repetitive, or stereotyped behaviors and interests each with potential unique risk factors and characteristics. The underlying mechanisms and the possible causes of autism spectrum disorder remain elusive and while increased prevalence is undoubtable, it is unclear if it is a reflection of diagnostic improvement or emerging risk factors such as endocrine disrupting chemicals. Epidemiological studies, which are used to study the relation between endocrine disrupting chemicals and autism spectrum disorder, can have inherent methodological challenges that limit the quality and strength of their findings. The objective of this work is to systematically review the treatment of these challenges and assess the quality and strength of the findings in the currently available literature. The overall quality and strength were "moderate" and "limited," respectively. Risk of bias due to the exclusion of potential confounding factors and the lack of accuracy of exposure assessment methods were the most prevalent. The omnipresence of endocrine disrupting chemicals and the biological plausibility of the association between prenatal exposure and later development of autism spectrum disorder highlight the need to carry out well-designed epidemiological studies that overcome the methodological challenges observed in the currently available literature in order to be able to inform public policy to prevent exposure to these potentially harmful chemicals and aid in the establishment of predictor variables to facilitate early diagnosis of autism spectrum disorder and improve long-term outcomes.

Perinatal and Obstetric Predictors for Autism Spectrum Disorder.

The objective is to identify obstetric and perinatal factors that could be significant predictors of ASD and may lead to early detection and intervention. A population-based case-control study including 128 children diagnosed with ASD and 311 controls was conducted. Information was collected through self-reported questionnaires. The factors retained as significant predictors for ASD in the final adjusted hierarchical logistic regression model were cesarean section and male gender. The study revealed a higher incidence of cesarean sections and male gender in children with ASD in comparison to unaffected children confirming the results of previous studies. Children born by cesarean section, especially males, should be more closely monitored for the presence of ASD traits for early diagnosis and intervention.

Burnout Syndrome Risk in Child and Adolescent Tennis Players and The Role of Adherence to the Mediterranean Diet.

This cross-sectional study examined the impact of adherence to Mediterranean diet on burnout syndrome risk in 94 athletes 8-15 years old. Diet pattern and burnout syndrome risk were assessed through the Athlete Burnout Questionnaire and the KIDMED Questionnaire. 55.3% of girls and 16.1% of boys had a high risk of burnout syndrome and the risk increased with age. Of the 78.7% with low adherence to Mediterranean diet, 31.1% showed no risk of burnout syndrome, 33.8% had a moderate risk, and 35.1% high risk. Of the 21.3% with a high adherence to Mediterranean diet, 35% had no risk of burnout syndrome, 45% had a moderate risk, and 20% had a high risk. Participants with moderate/high burnout syndrome risk were more likely to be girls and spend a higher number of hours watching television or playing video games. There is not enough statistical evidence in this study to reject the independence between the level of adherence to the Mediterranean diet and the risk of burnout syndrome in children, except in the case of daily consumption of fresh or cooked vegetables.

Endocrine Disruptors and Autism Spectrum Disorder in Pregnancy: A Review and Evaluation of the Quality of the Epidemiological Evidence.

Exposure to environmental contaminants during pregnancy has been linked to adverse health outcomes later in life. Notable among these pollutants are the endocrine disruptors chemicals (EDCs), which are ubiquitously present in the environment and they have been measured and quantified in the fetus. In this systematic review, our objective was to summarize the epidemiological research on the potential association between prenatal exposure to EDCs and Autism Spectrum Disorder (ASD) published from 2005 to 2016. The Navigation Guide Systematic Review Methodology was applied. A total of 17 studies met the inclusion criteria for this review, including: five cohorts and 12 case-control. According to the definitions specified in the Navigation Guide, we rated the quality of evidence for a relationship between prenatal exposure to EDCs and ASD as "moderate". Although the studies generally showed a positive association between EDCs and ASD, after considering the strengths and limitations, we concluded that the overall strength of evidence supporting an association between prenatal exposure to EDCs and later ASD in humans remains "limited" and inconclusive. Further well-conducted prospective studies are warranted to clarify the role of EDCs on ASD development.

Comparison of nutritional status between children with autism spectrum disorder and typically developing children in the Mediterranean Region (Valencia, Spain).

This case-control study investigated nutrient intake, healthy eating index with 10 items on foods and nutrients, on 3-day food diaries and anthropometric measurements in 105 children with autism spectrum disorder and 495 typically developing children (6-9 years) in Valencia (Spain). Children with autism spectrum disorder were at a higher risk for underweight, eating more legumes, vegetables, fiber, and some micronutrients (traditional Mediterranean diet) but fewer dairy and cereal products, and less iodine, sodium, and calcium than their typically developing peers. Differences existed in total energy intake but healthy eating index and food variety score differences were not significant. Autism spectrum disorder group failed to meet dietary recommendations for thiamin, riboflavin, vitamin C, or calcium. Risk of inadequate intake of fiber, vitamin E, and sodium was lower in children with autism spectrum disorder than typically developing children. Results suggest that (1) risk of inadequate intake of some micronutrients in children with autism spectrum disorder and (2) cultural patterns and environment may influence food intake and anthropometric characteristics in autism spectrum disorder. Primary care should include anthropometric and nutritional surveillance in this population to identify intervention on a case-by-case basis. Future research should explore dietary patterns and anthropometric characteristics in different autism spectrum disorder populations in other countries, enhancing our understanding of the disorder's impact.

Nutritional Impact of a Gluten-Free Casein-Free Diet in Children with Autism Spectrum Disorder.

We compared anthropometric values, nutrient intake, the Healthy Eating Index and food variety in children with autism spectrum disorder (ASD), 20 on a gluten-free casein-free (GFCF) diet and 85 on a regular diet in Valencia (Spain) using 3-days food diaries. Those on the GFCF diet had a lower weight, body mass index, and total energy, pantothenic acid, calcium, phosphorus and sodium intake, but a higher intake of fiber, legumes, and vegetables. Further, the GFCF diet group had a better quality of fat intake, but needed supplementation with vitamin D. Randomized controlled trials are required to explore long-term effects of this diet on anthropometric and nutritional status (the focus of our study), but also behavioral symptoms, in children with ASD.

Fat intake in children with autism spectrum disorder in the Mediterranean region (Valencia, Spain).

OBJECTIVE: Children with autism spectrum disorder (ASD) have been found to have alterations in dietary fat intake and fat quality. The fat intakes of the foods consumed by children with and without ASD were compared, and the deficiency and excess of these nutrients were examined. METHODS: In a matched case-control study, 3-day food diaries were completed by 105 children with ASD and 495 typically developing (TD) 6- to 9-year-old children in Valencia (Spain). We used the probabilistic approach and estimated average requirement cut-point to evaluate the risk of inadequate nutrients intakes. These were compared between groups and with Spanish recommendations using linear and logistic regression, respectively. RESULTS: Groups did not differ significantly in age, total dietary intake, Healthy Eating Index, or food variety score. Children with ASD had lower saturated fatty acids (SFAs) and ω-3 polyunsaturated fatty acids (PUFAs) intakes, but their total PUFAs and (PUFAs + monounsaturated fatty acids (MUFAs)/SFAs, PUFAs/SFAs intakes and ω-6/ω-3 ratios were higher than TD children. The total fat and cholesterol intakes of both groups were slightly above Spanish recommendations. Both groups had low ω-6 intakes, very low ω-3 intakes, and high ω-6/ω-3 ratios. CONCLUSION: Further research is required to clarify associations between ASD symptomatology, fat-eating patterns and health status.

Nutritional status of children with autism spectrum disorders (ASDs): a case-control study.

Children with autism spectrum disorder (ASD) have problems of food selectivity, implying risks of nutritional deficiencies. The aim was to compare intakes of macro and micronutrients and body mass index in ASD and typically developing (TD) children. In a case-control study, 3-day food diaries and anthropometric measurements were completed for ASD (n = 40) and TD (n = 113) children (aged 6-10 years) living in the same area. Body mass indices were below the 5th percentile in 20 % of ASD versus 8.85% of TD children. We found intakes were lower for fluoride (p = 0.017) and higher for vitamin E (p = 0.001). There was limited food variety and inadequacy of some intakes suggests that routine monitoring of ASD children should include assessment of their dietary habits, as well as anthropometric measurements.

Evidence of the gluten-free and casein-free diet in autism spectrum disorders: a systematic review.

In autism spectrum disorders, many parents resort to alternative treatments and these are generally perceived as risk free. Among these, the most commonly used is the gluten-free, casein-free diet. The objective of this work was to conduct a systematic review of studies published from 1970 to date related to the gluten-free, casein-free diet in autism spectrum disorder patients. Few studies can be regarded as providing sound scientific evidence since they were blinded randomized controlled trials, and even these were based on small sample sizes, reducing their validity. We observed that the evidence on this topic is currently limited and weak. We recommend that it should be only used after the diagnosis of an intolerance or allergy to foods containing the allergens excluded in gluten-free, casein-free diets. Future research should be based on this type of design, but with larger sample sizes.

Food selectivity in autism spectrum disorders: a systematic review.

Autism spectrum disorders are characterized by difficulties with reciprocal social interactions and restricted patterns of behavior and interest; one of these characteristic behaviors is food selectivity. The objective of this study was to perform a systematic review of the literature published between 1970 and 2013 concerning this eating behavior. The articles identified were analyzed in terms of sample size, study design, and criteria for assessment and intervention, as well as the results, level of evidence and grade of recommendation. The main search was conducted in Medline, Cochrane Library, Scielo, ScienceDirect, and Embase). There is empirical evidence and an overall scientific consensus supporting an association between food selectivity and autism spectrum disorders.