Effects of nutritional interventions in children and adolescents with autism spectrum disorder: an overview based on a literature review.

Background: Nutrition is important in autism spectrum disorder (ASD). Because nutritional problems of children with ASD can lead to nutritional deficiencies and this can also directly or indirectly affect symptoms related to autism. We investigated the effect of diet and supplementation treatments on gastrointestinal, behavioral or sleep problems based on the results of literature review. Methods: We generated four questions based on literature. We carried out title and abstract-based search using the Web of Science database. Of 4580 abstracts were identified, 192 papers were reviewed and 55 papers precisely meeting the inclusion criteria. Results: The studies examining the effects of vitamins, minerals, probiotics, and other supplements on ASD symptoms had different dosages, different treatment durations, small sample sizes and used different scales for evaluation. The results of the studies of the effectiveness of Gluten-Free and Casein-Free (GFCF) and ketogenic diet to reduce gastrointestinal, behavioral and sleeping problems in children and adolescents were contradictory. Conclusions: It is not possible to suggest the GFCF and/or ketogenic diet, vitamins, minerals and probiotics to individual with ASD based on the available evidence. By planning a sufficient and balanced diet, it should be aimed to prevent nutrient deficiency and to ensure growth in accordance with the age in children with ASD.

The effect of nutritional interventions reducing oxidative stress on behavioural and gastrointestinal problems in autism spectrum disorder.

BACKGROUND AND AIMS: Although the exact cause of autism spectrum disorder (ASD), which is a neurodevelopmental disorder, is not known, it is thought that environmental factors are also effective in addition to genetic risk factors. Studies are showing an increase in oxidative stress markers and a decrease in some antioxidant enzymes in individuals with autism. This study aims to try to explain the effect of nutritional interventions that reduce oxidative stress on behavioural and gastrointestinal problems in ASD based on a literature review. METHODS: All relevant studies from 2000 to 2021 were identified through a systematic search in the PubMed and Web of Science databases by using key search terms. A systematic search of the electronic databases resulted in a total of 3235 potential articles, and data were extracted from 24 studies. RESULTS: There were 9 clinical trials and 15 animal studies. Most studies find statistically significant results for nutritional supplementation compared with placebo ASD symptoms. CONCLUSION: Most studies on the interventions of nutritional supplements that reduce oxidative stress in individuals with ASD have found improving effects on ASD symptoms, and no serious side effects have been observed. However, more interventional studies are needed to determine the precise effects of oxidative stress-reducing nutritional supplementation.

Does severity of intellectual disability affect the nutritional status of intellectually disabled children and adolescents?

Background: Balanced and adequate nutrition is important to improve the quality of life of children with intellectual disability but most of these children are negatively affected by nutritional problems. Objective: This study was conducted to determine the nutritional status and effect of the severity of intellectual disability on nutritional status of children and adolescents with intellectual disabilities. Methods: One hundred twenty-two intellectually disabled children aged 4-18 years from five different special education and rehabilitation centers were included in the study. Their socio-demographic characteristics, body weight, height, body mass index (BMI), mid-upper arm circumference (MUAC), and skinfold thickness were examined, and their three-day food consumption record was taken. Results: Anthropometric scores did not differ significantly according to the severity of intellectual disability. According to evaluations made based on the World Health Organization's 2007 percentile curves, 61.4% of the subjects with mild intellectual disability (MID), 57.1% of those with moderate intellectual disability (MOID), and 53.3% of those with severe intellectual disability (SID) were within the normal BMI range for their age. Conclusion: Rates of malnutrition and shortness in children and adolescents with SID were found to be higher than among children with MID and MOID, though the differences were not statistically significant.

Can we reduce autism-related gastrointestinal and behavior problems by gut microbiota based dietary modulation? A review.

Introduction: Autism is a neurodevelopmental disorder that negatively affects a child's interaction and communication with the environment. The signals between intestine, brain, and microbiota change in autism. Altering the composition of microbiota may contribute to the development of clinical symptoms. Diet is one of the most important factors influencing intestinal microbiota.Aim: This study aimed to investigate the role of intestinal microbiota in gastrointestinal (GI) and behavioral problems seen in children with autism and discuss the potential effect of diet on intestinal microbiota in reducing these problems.Methods: The database Web of Science was searched for relevant studies. The combinations of the following terms were used for the search: 'autism' or 'autistic' and 'microbiome' or 'microbiota' or 'gut bacteria' or 'gut microbiota' or 'gut microbiome.' The analysis included human studies evaluating the relationship between GI problems and/or behavioral problems and intestinal microbiota in autism in the English language with no time limitation.Results: The initial search resulted in 691 studies, with 14 studies fully meeting the inclusion criteria. In these studies, high growth rates of Clostridium histolyticum, C. perfringens, and Sutterella; high ratio of Escherichia/Shigella; and low ratio of Bacteroidetes/Firmicutes were generally related to GI problems, while relative abundance of Desulfovibrio, Clostridium spp., and Bacteroides vulgatus were associated with behavior disorders.Conclusions: Published studies on the relationship of gastrointestinal and behavioral problems with gut microbiota in autism are very limited and contradictory. The fact that the results of the studies are not consistent with each other may be explained by the differences in the age of participants, geographical region, sample size, presence of GI problems in the selected control group, and feces or biopsy samples taken from different regions of GI system. With the available information, it is not yet possible to develop a gut microbiota-based nutritional intervention to treat GI symptoms for people with autism.

The Effect of the Low FODMAP Diet on Gastrointestinal Symptoms, Behavioral Problems and Nutrient Intake in Children with Autism Spectrum Disorder: A Randomized Controlled Pilot Trial.

Some research suggests that GI symptoms seen in children with ASD may relate to behavior problems. The objective of this pilot study was to assess the effect of the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet on GI and behavioral problems in children with ASD. At follow-up, the low FODMAP diet group had significant relief in some GI problems compared with both baseline in the group and control group. At baseline and at follow-up, there were no significant differences in behavioral problems between the low FODMAP diet group and the control group. Randomized controlled studies including larger sample sizes are needed to confirm the effects of low FODMAP diets in children with autism who have gastrointestinal problems.

Assessment of the correlation between the atherogenic index of plasma and cardiometabolic risk factors in children and adolescents: might it be superior to the TG/HDL-C ratio?

BACKGROUND: Most of the studies investigating the correlation between the atherogenic index of plasma (AIP) and cardiometabolic risk factors have been conducted with adults, while only a limited number of related studies that involved children and adolescents has been conducted. The purpose of this study is to assess the correlation between the AIP and other cardiometabolic risk factors in adolescents. METHODS: This study was conducted with 310 girls and 90 boys who were between the ages of 6 and 18 years. After a 10-h fasting period, the biochemical values of the participants were measured in the morning. The anthropometric measurements of the participants were also taken. The AIP was calculated as Log10 (triglycerides/high density lipoprotein-cholesterol; TG/HDL-C). RESULTS: In adolescents between the ages of 12 and 18, the mean AIP of the group with TG ≥130 mg/dL was significantly higher than that of the groups with TG of 90-129 mg/dL and <90 mg/dL. There was a strong correlation between TG and AIP for both boys and girls among the children and adolescents, while there was a strong correlation between the TG/HDL-C ratio and TG only in the boys who were within the 6-11-year-old age group. CONCLUSIONS: An increase in AIP is associated with cardiovascular risk factors in children and adolescents other than those seen in adults. Based on the TG/HDL-C ratio, the AIP may be superior as a complementary index in the assessment of cardiometabolic risks in children and adolescents.

The role of psychological eating styles in obesity among Turkish adolescents: A cross-sectional study.

OBJECTIVE: To determine the relationship between eating behaviours and adiposity indicators including body mass index, waist-hip ratio and waist-height ratio in adolescents. METHODS: This descriptive, cross-sectional study was conducted at Kirklareli University Health College, Kirklareli, Turkey, from April to June 2014, and comprised students of the 2013-14 academic year. Height and weight were measured and students' body mass indexes were calculated. Waist and hip circumferences were measured. Eating behaviours were evaluated using the three-factor eating questionnaire. SPSS 15 was used for data analysis. RESULTS: Of the520, 353(67.9%) were female and 167(32.1%) were male. Cognitive restraint and emotional eating scores of females were significantly higher than those of males (p<0.05). Cognitive restraint scores of participants who were thin according to the body mass index were significantly lower than participants who were at normal weight and who were overweight (p<0.05). Body mass index was significantly and positively correlated to cognitive restraint and emotional eating subscales, whereas there was a significant negative correlation between emotional eating and waist-height ratio (p<0.05 each). Cognitive restraint regarding food intake and tendency to emotional eating increased the risk of obesity (p<0.05). CONCLUSIONS: Being inclined to emotional eating and limiting food intake cognitively increased the risk of obesity.

Dietary habits contributing to the cancer prevention among health college students in Turkey.

This descriptive study was made to evaluate the dietary habits contributing to cancer prevention of 319 health college students. Data collection form included questions about demographic characteristics and 33 statements which evaluate dietary habits contributing to cancer prevention. Among the students, 56.1% consumed fast food outside the home/dormitory twice a week or more and 47% never exercised. Moreover, 63.9% of the students reported that their dietary habits changed negatively and 69% stated that their fruit and vegetable consumption decreased after starting the health college. The students mostly paid attention to preserving food and water consumption while they paid least attention to maintaining healthy weight and whole grain consumption. Female students, those who paid attention to the amount and calorie of the food they consumed, students who did not consume fast food, and students who exercised twice a week or three times a week had better dietary habits contributing to cancer prevention (p<0.05). According to these results we recommend that interventions which will reduce fast food consumption and increase fruit and vegetable consumption and exercising in university students should be implemented. For this purpose, appropriate conditions for preparing and preserving healthy food should be provided as well as increasing the frequency of vegetable containing meals and providing fruits and salads in every meal at school cafeterias.