Dietary fat intake is associated with psychosocial and cognitive functioning of school-aged children in the United States

Sex-specific impulsivity, but not other facets of executive function, predicts fat and sugar intake two-years later amongst adolescents with a healthy weight: Findings from the ABCD study

During adolescence, processes that control food intake (executive functions [EF]) undergo extensive refinement; underlying differences in EF may explain the inability to resist overeating unhealthy foods. Yet, overeating fat and sugar also causes changes to EF and cognition but disentangling these relationships has been difficult, as previous studies included youth with obesity. Here, amongst youth initially of a healthy weight, we evaluate whether 1) sex-specific underlying variation in EF/cognition at 9/10-years-old predict fat/sugar two-years later (Y2) and 2) if these relationships are moderated by body mass index (BMI), using linear mixed effects models (controlled for puberty, caregiver education; random effect: study site). Data were leveraged from Adolescent Brain Cognitive Development Study (n = 2987; 50.4% male; 15.4% Latino/a/x; 100% healthy weight at baseline; 12.4% overweight/obese by Y2, data release 4.0). EF and cognition (e.g., inhibition, cognition, motor, memory, impulsivity) were assessed with the NIH toolbox, Rey Auditory Verbal Learning Task, Little Man Task, the BIS/BAS, and UPPS-P. A saturated fat/added sugar (kcals) composite score was extracted from the validated Kids Food Block Screener. For males, greater baseline impulsivity (e.g., Positive Urgency, Lack of Planning and Perseverance) and reward (e.g., Fun seeking, Drive) was related to greater Y2 intake. For both sexes, greater baseline Negative Urgency and higher BMI was related to greater Y2 intake. No other relationships were observed. Our findings highlight a phenotype that may be more at risk for weight gain due to overconsumption of fat/sugar. Thus, prevention efforts may wish to focus on impulsive tendencies for these foods.

Children with lower ratings of executive functions have a greater response to the portion size effect

Deficits in executive functions (EFs), a set of cognitive processes related to self-regulation, are associated with the development of obesity. Prior studies from our group showed that lower food-cue related activation in brain regions implicated in self-regulation was related to a larger portion size effect. We tested the hypothesis that lower EFs in children would be positively related to the portion size effect. Healthy weight children aged 7-8 y (n = 88), who varied by maternal obesity status, participated in a prospective study. At baseline, the parent primarily in charge of feeding completed the Behavior Rating Inventory of Executive Function (BRIEF2) to assess child EFs, including Behavioral (BRI), Emotional (ERI), and Cognitive (CRI) indices. At 4 baseline sessions, children consumed meals in which the portion sizes of foods (pasta, chicken nuggets, broccoli, and grapes) varied by visit (total meal weight of 769, 1011, 1256, or 1492g). Intake increased with increasing portions in a linear trajectory (p < 0.001). EFs moderated the portion size effect such that lower BRI (p = 0.003) and ERI (p = 0.006) were associated with steeper increases in intake as portions increased. As amount of food increased, children in the lowest functioning tertiles for BRI and ERI increased intake by 35% and 36%, respectively, compared to children in the higher tertiles. Increases in intake among children with lower EFs were for higher- but not lower-energy-dense foods. Thus, in healthy weight children who varied by obesity risk, lower parentally reported EFs were associated with a larger portion size effect, and these results were independent of child and parent weight status. Therefore, EFs may be target behaviors that could be strengthened to help children moderate excess intake in response to large portions of energy-dense foods.

Xylooligosaccharides and aerobic training regulate metabolism and behavior in rats with streptozotocin-induced type 1 diabetes

Type 1 diabetes mellitus is characterized with decreased microbial diversity. Gut microbiota is essential for the normal physiological functioning of many organs, especially the brain. Prebiotics are selectively fermentable oligosaccharides [xylooligosaccharides (XOS), galactooligosaccharides, etc.] that promote the growth and activity of gut microbes and influence the gut-brain axis. Aerobic exercise is a non-pharmacological approach for the control of diabetes and could improve cognitive functions. The potential beneficial effect of XOS and/or aerobic training on cognition, the lipid profile and oxidative stress markers of experimental rats were evaluated in this study. Male Wistar rats were randomly divided into three streptozotocin-induced diabetic groups and a control group. Some of the rats, either on a XOS treatment or a standard diet, underwent aerobic training. The results showed that the aerobic training independently lowered the total cholesterol levels compared to the sedentary diabetic rats (p = 0.032), while XOS lowers the malondialdehyde levels in the trained diabetic rats (p = 0.034). What is more the exercise, independently or in combination with XOS beneficially affected all parameters of the behavioral tests. We conclude that aerobic exercises alone or in a combination with the prebiotic XOS could ameliorate the dyslipidemia, oxidative stress, and cognitive abilities in experimental type 1 diabetic animals.

The EAT-Lancet reference diet and cognitive function across the life course

The EAT-Lancet Commission devised a sustainable reference diet with the aim of reducing the incidence of non-communicable diseases and mortality globally while improving food system sustainability. The extent to which the reference diet supports cognitive function across the life course, however, has not yet been evaluated. This Review assesses the evidence for diet supporting cognitive function from childhood into old age. A comprehensive but non-exhaustive literature search was done, synthesising studies that investigated the effect of whole foods on cognition in healthy, community-dwelling human participants. We found that the current evidence base is weak with mixed conclusions and multiple methodological caveats, which precludes strong conclusions pertaining to the suitability of dietary recommendations for each food group per age group. Long-term intervention and prospective cohort studies are needed to reduce this knowledge deficit. Revising dietary recommendations with the aim of maintaining an adequate nutrient intake to sustain healthy cognitive function across the life course could be worthwhile. This Review outlines recommendations for future work to help improve the current knowledge deficit regarding dietary intake and cognitive function across the life course and its implications for dietary guidelines such as the EAT-Lancet Commission.

Association between dietary quality and executive functions in school-aged children with autism spectrum disorder

Background

It is well known that children with autism spectrum disorder (ASD) had executive functions deficit. However, it is still unclear whether the poor dietary quality is related to the impairment of executive functions. The current study aimed to explore the association between dietary quality and executive functions in children with ASD.

Methods

A total of 106 children with ASD (7.7 ± 1.3 years) and 207 typically developing (TD) children (7.8 ± 1.3 years) were enrolled from Guangzhou, China. The Chinese version of Behavior Rating Scale of Executive function (BRIEF), the working memory subscales of the Chinese version of Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV), and the Stroop Color-Word Test (SCWT) were used to measure the participant's executive functions. The food frequency questionnaire (FFQ) was used to collect the dietary intake information, and the Chinese Diet Balance Index (DBI_16) was used to evaluate the dietary quality. Generalized linear models were used to estimate the association between dietary quality and executive functions.

Results

In children with ASD, Low Bound Score (LBS) was positively correlated with the working memory subscale score of BRIEF (β = 0.23, 95% CI: 0.02–0.44, P < 0.05), while High Bound Score (HBS) and LBS were positively correlated with the organizable subscale score of BRIEF (β = 0.44, 95% CI: 0.11–0.77, P < 0.01; β = 0.19, 95% CI: 0.01–0.37, P < 0.05). Compared to TD children, children with ASD had a higher proportion of moderate and high levels of insufficient dietary intake (moderate level, 37.7% vs. 23.2%, high level, 4.7% vs. 1.4%) and moderate level of unbalanced dietary intake (36.8% vs.21.3%), higher scores on all subscales of BRIEF (P < 0.01), and lower score on the working memory (81.3 ± 32.3 vs. 104.6 ± 12.5, P < 0.01), while there was no difference on the SCWT.

Conclusion

Poor dietary quality was associated with the impairment of working memory and organizational capacity in children with ASD. This study emphasized the importance of dietary quality in executive functions among children with ASD, and attention should be paid to improving their dietary quality.

Dietary Intervention in Infancy and Cognitive Function in Young Adulthood: The Special Turku Coronary Risk Factor Intervention Project

OBJECTIVE

Consumption of saturated fatty acids (SAFAs), polyunsaturated fatty acids (PUFAs), cholesterol, and fiber have been linked with cognitive function in adults. We evaluated these associations from childhood by leveraging data from the Special Turku Coronary Risk Factor Intervention Project (STRIP).

STUDY DESIGN

STRIP recruited children aged 5 months and randomly assigned them into intervention/control groups. The intervention introduced a heart-healthy diet, characterized mainly by low consumption of SAFAs and cholesterol, through counseling at least biannually between age 7 months and 20 years. Diet was assessed repeatedly using food diaries. Six years after the end of the intervention phase, at age 26 years, the participants were invited to the first postintervention follow-up, which included cognitive testing that covered learning and memory, verbal memory, short-term working memory, reaction time, information processing, and cognitive flexibility and inhibitory control. We studied the associations of the STRIP intervention and the consumptions of SAFAs, PUFAs, cholesterol, and fiber within these cognitive domains.

RESULTS

Participants in the STRIP intervention group had better cognitive flexibility and inhibitory control and were better able to manage conflicting information and ignore task-irrelevant information (0.18 SD higher in the intervention group, adjusted for sex and socioeconomic status). No associations were observed with the dietary components studied.

CONCLUSIONS

The infancy-onset STRIP intervention, which promoted a heart-healthy diet, was favorably associated with cognitive flexibility and inhibitory control at age 26 years. No associations were found for the intervention targets studied, indicating that these specific dietary components did not underlie the observed effect of the intervention.

Association between maternal smoking during pregnancy and offspring overweight in U.S.-born children

BACKGROUND

The criticism of the literature on smoking during pregnancy and offspring overweight was the confounding from postnatal factors. Interaction between gestational age and prenatal maternal smoking has not yet assessed.

METHODS

We used the Third National Health and Nutrition Examination Survey (1988-1994), linked with natality files of US-born singletons aged 2 to 6 years. A body mass index in the 85th percentile or higher were considered overweight, including obesity. Gestational age was dichotomized as preterm (<37 weeks, n = 240) or full-term (n = 2125). Smoking status during pregnancy was ascertained by a questionnaire-based interview during National Health and Nutrition Examination Survey.

RESULTS

The prevalence of offspring overweight and obesity combined was 17.3% (SE = 1.3%). And 24.0% (1.3%) of mothers smoked while pregnant. A significant interaction was observed between maternal smoking and gestational age. In preterm children, a higher prevalence of overweight (34.3% [6.7%]) was found among the offspring of smoking mothers compared to non-smoking mothers (15.8% [3.6%]). After adjustment for socio-demographics, prenatal and postnatal factors, in preterm born offspring, the odds ratio of being born to smoking mothers was 2.46 (95% confidence intervals: 1.13-5.37) among children with overweight/obesity compared to children with healthy weight born to non-smoking mothers. In full-term children, the OR of being born to smoking mothers was 0.72 (0.50-1.03) among offspring with overweight/obesity relative to offspring with healthy weight born to non-smoking mothers.

CONCLUSIONS

Maternal smoking during pregnancy was strongly associated with offspring overweight and obesity in preterm births after control for postnatal factors. Preterm children of smoking mothers should be prioritized for obesity prevention.

Dietary Inflammatory Potential and the Risk of Neurodegenerative Diseases in Adults

Nutrition and diet have been suggested to enhance or inhibit cognitive performance and the risk of several neurodegenerative diseases. We conducted a systematic review to elucidate the relationship between the inflammatory capacity of a person's diet and the risk of incident neurodegenerative diseases. We searched major medical databases for articles published through June 30, 2018. Original, full-text, English-language articles on studies with human participants which investigated the link between dietary inflammatory potential and risk of developing neurodegenerative diseases were included. Duplicate and irrelevant studies were removed, and data were compiled through critical analysis. Initially, 457 articles were collected via the searching method, of which 196 studies remained after removal of duplicates. Fourteen articles were screened and found to be relevant to the scope of the review. After critical analysis, 10 were included in the final review. In all studies but one, a higher dietary inflammatory index (DII) was related to higher risk of developing neurodegenerative disease symptoms, including memory and cognition decline and multiple sclerosis. Of 3 studies that assessed the association of DII with levels of circulating inflammation markers, 2 indicated that DII was positively correlated with inflammatory marker levels. Low literacy, an unhealthy lifestyle, and individual nutritional status were the factors involved in a diet with inflammatory potential. These findings enhance confidence that DII is an appropriate tool for measurement of dietary inflammatory potential and validate the role of diets with inflammatory potential in the pathophysiology of neurodegenerative diseases. DII may be correlated with levels of circulating inflammatory markers.

Changes of fat-mass and obesity-associated protein expression in the hippocampus in animal models of high-fat diet-induced obesity and D-galactose-induced aging

Fat-mass and obesity-associated protein (Fto) is highly expressed in the brain including, the hippocampus, and its expression is significantly decreased in the brain of Alzheimer’s disease patients. In the present study, we measured Fto immunoreactivity and protein levels in the hippocampus of obese and aged mice, which were induced by high-fat diet for 12 weeks and D-galactose treatment for 10 weeks, respectively. The obesity and aging phenotypes were assessed by physiological parameters and Morris water maze test, respectively. High fat diet fed mice showed significant increases in body weight and blood glucose levels compared to that in the control or D-galactose-induced aged mice. In addition, treatment with D-galactose significantly decreased the spatial memory. Fto immunoreactivity in the control group was mainly detected in the pyramidal cells of the CA1 and CA3 regions and in the granule cells of the dentate gyrus. In the hippocampus of high-fat diet-fed mice, Fto immunoreactive structures were similarly found in the hippocampus compared to that in the control group, but Fto immunoreactivity in high-fat diet-fed mice was also found in the stratum oriens and radiatum of the CA1 and CA3 regions and the polymorphic layer of the dentate gyrus. In the hippocampus of D-galactose-induced aged mice, fewer Fto immunoreactive structures were detected in the granule cell layer of the dentate gyrus compared to the control group. Fto mRNA and protein levels based on quantitative real-time polymerase chain reaction and western blot assays were slightly increased in the hippocampus of high-fat diet-fed mice compared to that in control mice. In addition, Fto mRNA and protein levels were significantly decreased in the aged hippocampus compared to that in the control group. Fto protein levels are susceptible to the aging process, but not in the hippocampus of high-fat diet-induced obesity. The reduction of Fto in aged mice may be associated with reduced memory impairment in mice.

Associations of dietary carbohydrate and fatty acid intakes with cognition among children

OBJECTIVE

To investigate the cross-sectional associations of dietary carbohydrate and fatty acid intakes with cognition in mid-childhood.

DESIGN

Dietary carbohydrate and fatty acid intakes were assessed using 4-d food records, and cognition was evaluated using the Raven's Coloured Progressive Matrices (RCPM) score. The cross-sectional associations of dietary carbohydrate and fatty acid intakes with cognition were investigated using linear regression analyses adjusted for age, sex, body fat percentage, household income, parental education and daily energy intake.

SETTING

The baseline examinations of the Physical Activity and Nutrition in Children study.

PARTICIPANTS

A population-based sample of 487 children (250 boys, 237 girls) aged 6-8 years living in the city of Kuopio, Finland.

RESULTS

A higher dietary intake of fructose (standardised regression coefficient, β = 0·24, P < 0·001), total fibre (β = 0·16, P = 0·02) and soluble fibre (β = 0·15, P = 0·02) was associated with a higher RCPM score in boys. Other dietary carbohydrates and fatty acids, including total carbohydrates, glucose, sucrose, starch, insoluble fibre, total fat, SFAs, MUFAs, PUFAs, palmitic acid (C16), stearic acid (C18), linoleic acid (C18:2), α-linoleic acid (C18:3), arachidonic acid (C20:4), EPA (C20:5n-3) and DHA (C22:6n-6), were not associated with the RCPM score in boys. Dietary carbohydrates or fatty acids were not associated with the RCPM score in girls.

CONCLUSIONS

Higher dietary fructose and fibre intakes were associated with better cognition in boys, but not in girls. Dietary fatty acids were not related to cognition in boys or in girls.

An Overview on the Associations between Health Behaviors and Brain Health in Children and Adolescents with Special Reference to Diet Quality

Unhealthy diet has been associated with overweight, obesity, increased cardiometabolic risk, and recently, to impaired cognition and academic performance. The aim of this review is to provide an overview of the associations between health behaviors and cognition and academic achievement in children and adolescents under 18 years of age with a special reference to diet quality. Dietary patterns with a low consumption of fish, fruits, and vegetables, and high in fast food, sausages, and soft drinks have been linked to poor cognition and academic achievement. The studies on the associations between the high intake of saturated fat and red meat and low intake of fiber and high-fiber grain products with cognition are limited. The available evidence and physiological mechanisms suggest that diet may have direct, indirect, and synergistic effects on brain and cognition with physical activity, sedentary behaviors, cardiometabolic health, and sleep, but the associations have been modest. Therefore, integrating a healthy diet, physically active lifestyle, and adequate sleep may provide optimal circumstances for brain development and learning. We conclude that most of the existing literature is contained in cross-sectional studies, which therefore highlights the need for longitudinal and intervention studies on the effects of diet, physical activity, sedentary behavior, and sleep on cognition and academic performance.

High fat diet deteriorates the memory impairment induced by arsenic in mice: a sub chronic in vivo study

Both arsenic (As) and obesity are associated with brain disorders. However, long term studies to evaluate their concomitant adverse effects on the brain functions are lacking. Present study was conducted to evaluate the long term co-exposure of As and high fat diet (HFD) on memory and brain mitochondrial function in mice. Male mice were randomly divided into 7 groups fed with HFD or ordinary diet (OD) and instantaneously exposed to As (25 or 50 ppm) in drinking water for, 4, 8, 12, 16 or 20 weeks. Step-down passive avoidance method was used for memory assessment and post exposure various parameters including mitochondrial damage, level of reactive oxygen species (ROS), malondialdeid (MDA) and glutathione (GSH) were determined. Results indicated that the retention latency decreased in As (25 and 50 ppm) and HFD received mice after 12 and 16 weeks respectively. Same results were observed at significantly shorter duration (8th week) when As was administered along with HFD as compared to control group. In the HFD alone fed mice increased the mitochondrial membrane damage, levels of ROS and MDA were observed while GSH contents decreased significantly. Concomitant administration of HFD and As amplified those mentioned toxic effects (p < 0.001). In conclusion, our findings demonstrated that the simultaneous HFD and As impaired memory at least three times more than exposing each one alone. These toxic effects could be due to the mitochondria originated oxidative stress along with the depleted antioxidant capacity of the brain of mice.

PARENTS' AND TEACHERS' PERCEPTIONS OF FACTORS AFFECTING LEARNING IN KENYA

INTRODUCTION

Studies have shown that a child's learning in school is affected by several factors, some related to the school environment, others to the home and community while others are as a result of the individual characteristics of the child. This study sought to explore parents' and teachers' perceptions of factors that affect learning of children in primary schools in a rural County in Kenya.

METHODS

This was a qualitative study that adopted the phenomenological approach. It was conducted with parents and teachers of 7 primary schools in rural and semi-rural areas of Kiambu County in Kenya. Using a researcher developed guide, data was collected using focus group discussion with parents and teachers. The discussions were conducted as follows-four were conducted in English language, two in Kiswahili language, and three were conducted in the local language and all were audio taped. Research assistants also took notes during the discussions. Results were transcribed verbatim and those that needed to be translated into English were translated. In analysis, MA, MM and MT read the transcripts and coded the major themes.

RESULTS

Four themes perceived by both parents and teachers to affect a child's learning emerged. These were; school environment, home, community and factors within the child.

CONCLUSION

There is need for both teachers and parents to come together and discuss perceived factors that interfere with learning of the children. Those that form a consensus for both groups, means to address them be found for better academic success of the child.

Exploring correlations between neuropsychological measures and domain-specific consistency in associations with n-3 LCPUFA status in 8-9 year-old boys and girls

Long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) have in some studies been associated with cognitive and socioemotional outcomes in children, but results are inconsistent possibly due to the use of different tests and potential gender-specific effects. The objective of this cross-sectional study was to explore overall patterns in neuropsychological scores as well as correlations between scores within specific domains, and to examine potential gender differences and consistency in associations with n-3 LCPUFA status. In 199 Danish 8–9 year-old children, we performed a large battery of tests and questionnaires on attention, processing speed, executive functions, memory, and socioemotional traits, and measured erythrocyte fatty acid composition. Principal component analyses (PCA) showed that most of the variation in both cognitive performance and socioemotional traits was explained by overall performance, followed by speed-accuracy trade off and externalizing vs. internalizing problems, respectively. Boys had higher speed, lower attention and higher externalizing problem scores than girls. Measures of performance within both processing speed and attention domains correlated moderately, whereas no correlations were found for measures of executive functions apart from some weak correlations for impulsivity. Parent-rated scores for both externalizing and internalizing problems correlated strongly, whereas correlations with child-rated scores were weak. Scores within specific domains did not consistently associate with n-3 LCPUFA, except for processing speed measures which all pointed to faster processing with increased n-3 LCPUFA status. Gender differences in the associations were observed for attention and impulsivity. Child- but not parent-rated internalizing and social problems tended to associate directly with n-3 LCPUFA, supported by increased internalizing problems measured by the PCA component. In conclusion, measures of speed and attention seem to represent these domains in general, whereas single measures of more complex cognitive functions should be interpreted with caution. One approach could be to use multiple tests and create multivariate scores to guide interpretations. Furthermore, the results indicate a need to consider both parent- and child-rated socioemotional scores and gender differences in neuropsychological functions e.g. in investigations of n-3 LCPUFA effects.

Visceral Adiposity and Diet Quality Are Differentially Associated With Cognitive Abilities and Early Academic Skills Among Preschool-Age Children

Background: Visceral adipose tissue (VAT) and diet quality influence cognitive health in preadolescents; however, these relationships remain understudied among preschool-age children. Objectives: Investigate the relationship between VAT, diet quality, academic skills, and cognitive abilities among preschool-age children. Methods: Children between 4 and 5 years (N = 57) were enrolled in a cross-sectional study. Woodcock Johnson Early Cognitive and Academic Development Test (ECAD™) was utilized to assess General Intellectual Ability, Early Academic Skills, and Expressive Language. DXA was used to assess VAT. Diet quality was measured using the Healthy Eating Index-2015 (HEI-2015) based on 7-day food records. Results: Greater VAT was associated with poorer Early Academic Skills (r = -0.28, P = 0.03) whereas a diet pattern that included Fatty Acids, Whole Grains, Saturated Fats, Seafood and Plant Proteins, Total Vegetables, and Dairy was positively associated with General Intellectual Ability (r = 0.26, P = 0.04). Conclusions: Higher VAT is negatively related to Early Academic Skills whereas diet quality was positively and selectively related to intellectual abilities among preschool-age children. These findings indicate that the negative impact of abdominal adiposity on academic skills is evident as early as preschool-age while providing preliminary support for the potentially beneficial role of diet quality on cognitive abilities in early childhood.

Added sugar and dietary fiber consumption are associated with creativity in preadolescent children

Objectives: Creativity requires the ability to combine existing mental representations in new ways and depends, in part, on the hippocampus. Hippocampal function is, in turn, affected by a number of health factors, including aerobic fitness, excess adiposity, and diet. Specifically, in rodent studies, diets high in saturated fatty acids and sugar - hallmarks of a western diet- have been shown to negatively impact hippocampal function and thereby impair performance on cognitive tasks that require the hippocampus. Yet relatively few studies have examined the relationship between diet and hippocampal-dependent cognition in children. Methods: The current study therefore sought to explore the relationship of several diet quality markers including dietary lipids (saturated fatty acids and omega-3 fatty acids), simple carbohydrates (added sugars), and dietary fiber with creativity in preadolescent children. Participants (N = 57; mean age = 9.1 years) completed the Verbal Form of the Torrance Test of Creative Thinking (TTCT), a standardized test of creativity known to require the hippocampus. Additionally, participants completed a 3-day food intake record with the assistance of a parent, underwent dual energy x-ray absorptiometry (DXA) to assess central adiposity, and VO₂max testing to assess aerobic fitness. Results: Added sugar intake was negatively associated, and dietary fiber was positively associated with overall TTCT performance. These relationships were sustained even after controlling for key covariates. Discussion: These findings are among the first to report an association between added sugar consumption and hippocampal-dependent cognition during childhood and, given the key role of the hippocampus in learning and memory, as well as creative thinking, have potential educational and public health implications.

Diet quality and attention capacity in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

Adolescence represents an important period for the development of executive functions, which are a set of important cognitive processes including attentional control. However, very little is known regarding the associations of nutrition with components of executive functions in adolescence. Thus, the aim of this study was to investigate associations of dietary patterns and macronutrient composition with attention capacity in European adolescents. This cross-sectional study included 384 (165 boys and 219 girls) adolescents, aged 12·5-17·5 years, from five European countries in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. Attention capacity was examined using the d2 Test of Attention. Dietary intake was assessed through two non-consecutive 24 h recalls using a computer-based self-administered tool. Three dietary patterns (diet quality index, ideal diet score and Mediterranean diet score) and macronutrient/fibre intakes were calculated. Linear regression analysis was conducted adjusting for age, sex, BMI, maternal education, family affluence scale, study centre and energy intake (only for Mediterranean diet score). In these adjusted regression analyses, higher diet quality index for adolescents and ideal diet score were associated with a higher attention capacity (standardised β=0·16, P=0·002 and β=0·15, P=0·005, respectively). Conversely, Mediterranean diet score or macronutrient/fibre intake were not associated with attention capacity (P>0·05). Our results suggest that healthier dietary patterns, as indicated by higher diet quality index and ideal diet score, were associated with attention capacity in adolescence. Intervention studies investigating a causal relationship between diet quality and attention are warranted.

Association between dietary intake and 'school-valued' outcomes: a scoping review

Approximately one in four Australian children aged 5-17 years are overweight or obese. Most of the health effects of overweight and obesity in childhood do not eventuate until into adulthood; therefore, motivation for children to have a healthy diet may be low. This scoping review examined the literature for associations between diet quality in 5-18 year olds and 'school-valued' outcomes including student attendance, academic performance, behaviour at school and mental health. A literature search for studies that assessed dietary intake and at least one 'school-valued' outcome in schoolchildren, in highly developed countries was conducted. After applying selection criteria, 35 studies were included examining academic performance (46%), behaviour (11%), mental health (31%) and 11% examining two of these outcomes each. No relevant studies addressed attendance. In general, dietary factors including consumption of fruit and vegetables, discretionary foods and/or beverages, or overall diet quality, were suggested to be correlates of the 'school-valued' outcomes. However, the evidence is not comprehensive. This review elucidates the extent and nature of available literature, and provides a basis for future research where the potential benefits of diet on 'school-valued' outcomes can be thoroughly explored.

Effects of the duration of hyperlipidemia on cerebral lipids, vessels and neurons in rats

Background

The present study was designed to investigate the effects of hyperlipidemia on the cerebral lipids, vessels and neurons of rats, and to provide experimental evidence for subsequent intervention.

Method

One hundred adult SD rats, half of which were male and half of which were female, were randomly divided into five groups on the basis of serum total cholesterol (TC) levels. Four groups were fed a hypercholesterolemic diet (rat chow supplemented with 4% cholesterol, 1% cholic acid and 0.5% thiouracil – this is also called a CCT diet) for periods of 1 week, 2 weeks, 3 weeks and 4 weeks, respectively. A control group was included. The levels of serum lipids, cerebral lipids, free fatty acids (FFA), interleukin-6 (IL-6), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), oxidized low density lipoprotein (ox-LDL), A-beta precursor proteins (APP), amyloid beta (Aβ), glial fibrillary acidic protein (GFAP) and tight junction protein Claudin-5 were measured after the experiment. The pathologic changes and apoptosis of the rat brains were evaluated.

Results

Compared with the control group, after 1 week of a CCT diet, the levels of serum total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and brain triglycerides had increased by 2.40, 1.29 and 1.75 and 0.3 times, respectively. The serum high density lipoprotein cholesterol (HDL-C) had decreased by 0.74 times (P < 0.05) and the expression of IL-1, TNF-α and GFAP in the brains had increased (P < 0.05). In the second week, the expression of FFA and APP in the brains, and the amount of apoptotic neurons, had increased (P < 0.05). In the third week, the levels of VEGF, Ox-LDL and Aβ had increased, and the expression of Claudin-5 had decreased in the brains (P < 0.05). In the fourth week, the levels of TC, LDL-C and the amount of apoptotic neurons had increased (P < 0.05). The correlation analysis showed a positive correlation among FFA, TNF-α, VEGF, ox-LDL, Aβ, GFAP and neuronal apoptosis in the rat brains, and they all were negatively correlated with Claudin-5 (P < 0.05).

Conclusion

Hyperlipidemia may activate astrocytes by means of high levels of TG that will have direct toxic effects on the cerebral vessels and neurons by causing the secretion of TNF-α and IL-1 in the brains of rats. In the metabolic procession, brain tissue was shown to generate FFA that aggravated the biosynthesis of ox-LDL. With the extension of the duration of hyperlipidemia, high levels of cerebral TC and LDL-C were shown to aggravate the deposition of Aβ, induce the secretion of VEGF, reduce the expression of tight junction protein Claudin-5 and change the permeability of blood–brain barriers to factors that could damage cerebral vessels and neurons.

Plasma polyunsaturated fatty acids are directly associated with cognition in overweight children but not in normal weight children

AIM

Polyunsaturated fatty acids are essential nutrients for the normal development of the brain. We investigated the associations between plasma polyunsaturated fatty acids and cognition in normal weight and overweight children.

METHODS

The study recruited 386 normal weight children and 58 overweight children aged six to eight years and blood samples were drawn after a 12-hour fast. We assessed plasma polyunsaturated fatty acids using gas chromatography, cognition using Raven's Coloured Progressive Matrices, and overweight and obesity using the age-specific and sex-specific cut-offs from the International Obesity Task Force. The data were analysed by linear regression analyses adjusted for age and sex.

RESULTS

Higher proportions of eicosapentaenoic acid in plasma triacylglycerols (β = 0.311, p = 0.020, p = 0.029 for interaction) and docosahexaenoic acid in plasma triacylglycerols (β = 0.281, p = 0.038, p = 0.049 for interaction) were both associated with higher Raven's scores in overweight children but not in normal weight children. Higher eicosapentaenoic acid to arachidonic acid ratios in triacylglycerols (β = 0.317, p = 0.019) and phospholipids (β = 0.273, p = 0.046) were directly associated with the Raven's score in overweight children but not in normal weight children.

CONCLUSION

These findings suggest that increasing the consumption of fish and other sources of eicosapentaenoic acid and docosahexaenoic acid may improve cognition among overweight children.

Event-related potential differences in children supplemented with long-chain polyunsaturated fatty acids during infancy

Long-chain polyunsaturated fatty acids (LCPUFA) have been shown to be necessary for early retinal and brain development, but long-term cognitive benefits of LCPUFA in infancy have not been definitively established. The present study sought to determine whether LCPUFA supplementation during the first year of life would result in group differences in behavior and event-related potentials (ERPs) while performing a task requiring response inhibition (Go/No-Go) at 5.5 years of age. As newborns, 69 children were randomly assigned to infant formulas containing either no LCPUFA (control) or formula with 0.64% of total fatty acids as arachidonic acid (ARA; 20:4n6) and various concentrations of docosahexaenoic acid (DHA; 22:6n3) (0.32%, 0.64% or 0.96%) for the first 12 months of life. At 5.5 years of age, a task designed to test the ability to inhibit a prepotent response (Go/No-Go) was administered, yielding both event-related potentials (ERPs) and behavioral data. Behavioral measures did not differ between groups, although reaction times of supplemented children were marginally faster. Unsupplemented children had lower P2 amplitude than supplemented children to both Go and No-Go conditions. N2 amplitude was significantly higher on No-Go trials than Go trials, but only for supplemented children, resulting in a significant Group × Condition interaction. Topographical analysis of the ERPs revealed that the LCPUFA-supplemented group developed a novel period of synchronous activation (microstate) involving wider anterior brain activation around 200 ms; this microstate was not present in controls. These findings suggest that LCPUFA supplementation during the first 12 months of life exerts a developmental programming effect that is manifest in brain electrophysiology. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=oM2leg4sevs.

Long-chain omega-3 fatty acids and optimization of cognitive performance

Low consumption of the omega-3 fatty acids, eicosapentaenoic and docosahexaenonic acids, is linked to delayed brain development and, in late life, increased risk for Alzheimer's disease. The current review focuses on cognitive functioning during midlife and summarizes available scientific evidence relevant to the hypothesis that adequate dietary consumption of the long-chain omega-3 fatty acids is necessary for optimal cognitive performance. Taken together, the findings suggest that raising the currently low consumption among healthy adults may improve some aspects of cognitive performance. Nonetheless, evidence from randomized clinical trials is comparatively sparse and leaves unclear: (a) whether such effects are clinically significant, (b) whether effects of eicosapentaenoic acid and DHA differ, (c) which dimensions of cognitive function are affected, (d) the dose-response relationships, or (e) the time course of the response. Clarification of these issues through both laboratory and clinical investigations is a priority given the broad implications for public health, as well as for military personnel and other positions of high performance demand and responsibility.

The effect of healthy dietary consumption on executive cognitive functioning in children and adolescents: a systematic review

A systematic review was conducted to evaluate whether healthier dietary consumption among children and adolescents impacts executive functioning. PubMed, Education Resources Information Center, PsychINFO and Thomson Reuters’ Web of Science databases were searched, and studies of executive functioning among children or adolescents aged 6–18 years, which examined food quality, macronutrients and/or foods, were included. Study quality was also assessed. In all, twenty-one studies met inclusion criteria. Among the twelve studies examining food quality (n 9) or macronutrient intakes (n 4), studies examining longer-term diet (n 6) showed positive associations between healthier overall diet quality and executive functioning, whereas the studies examining the acute impact of diet (n 6) were inconsistent but suggestive of improvements in executive functioning with better food quality. Among the ten studies examining foods, overall, there was a positive association between healthier foods (e.g. whole grains, fish, fruits and/or vegetables) and executive function, whereas less-healthy snack foods, sugar-sweetened beverages and red/processed meats were inversely associated with executive functioning. Taken together, evidence suggests a positive association between healthy dietary consumption and executive functioning. Additional studies examining the effects of healthier food consumption, as well as macronutrients, on executive functioning are warranted. These studies should ideally be conducted in controlled environments and use validated cognitive tests.

The influence of fish oil on neurological development and function

Fish oil originates from fish tissue rich in omega-3 fatty acids. These include eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Healthy individuals are advised to consume foods rich in fish oil at least twice a week. However, such intake varies depending on cultural or personal preference, and socio-economic status. Many families and patients with chronic neurological conditions consume supplements containing omega-3 fatty acids. We are frequently requested to give advice and recommendations on using such agents to help improve neurological developmental and cognitive functions. The objective of this review is to discuss the available literature supporting the role of fish oils on brain development and function. There is a growing body of literature suggesting a potential benefit of long chain polyunsaturated fatty acids; however it is still unclear if there are response variations according to the developmental stage, age, and dose.

L'influence de l'huile de poisson sur le développement et la fonction neurologique. L'huile de poisson provient de tissus de poisson riches en acides gras oméga-3, l'acide eicosapentaéno&IUque (EPA) et l'acide docosahexaénoïque (DHA). On conseille aux individus en bonne santé de consommer des aliments riches en huiles de poisson au moins deux fois par semaine. Cependant, leur consommation varie selon les préférences culturelles ou personnelles ainsi que selon le statut socio-économique. Plusieurs familles et plusieurs patients atteints de maladies neurologiques chroniques consomment des suppléments contenant des acides gras oméga-3. On nous demande souvent des conseils et des recommandations sur l'utilisation de ces agents pour aider à améliorer le développement neurologique et les fonctions cognitives. L'objectif de cette revue est de discuter de la littérature disponible en faveur du rôle des huiles de poisson dans le développement et le fonctionnement du cerveau. Il existe une documentation de plus en plus importante qui suggère que les acides gras polyinsaturés à longue chaîne pourraient ětre bénéfiques. Cependant, on ne sait pas si la réponse peut varier selon le stade du développement, l'âge et la dose.

Intakes of fish and polyunsaturated fatty acids and mild-to-severe cognitive impairment risks: a dose-response meta-analysis of 21 cohort studies

BACKGROUND

The intake of fish and polyunsaturated fatty acids (PUFAs) may benefit cognitive function. However, optimal intake recommendations for protection are unknown.

OBJECTIVE

We systematically investigated associations between fish and PUFA intake and mild-to-severe cognitive impairment risk.

DESIGN

Studies that reported risk estimates for mild cognitive impairment (MCI), cognitive decline, dementia, Alzheimer disease (AD), or Parkinson disease (PD) from fish, total PUFAs, total n-3 (ω-3) PUFAs, or at least one n-3 PUFA were included. Study characteristics and outcomes were extracted. The pooled RR was estimated with the use of a random-effects model meta-analysis. A dose-response analysis was conducted with the use of the 2-stage generalized least-squares trend program.

RESULTS

We included 21 studies (181,580 participants) with 4438 cases identified during follow-up periods (2.1-21 y). A 1-serving/wk increment of dietary fish was associated with lower risks of dementia (RR: 0.95; 95% CI: 0.90, 0.99; P = 0.042, I(2) = 63.4%) and AD (RR: 0.93; 95% CI: 0.90, 0.95; P = 0.003, I(2) = 74.8%). Pooled RRs of MCI and PD were 0.71 (95% CI: 0.59, 0.82; P = 0.733, I(2) = 0%) and 0.90 (95% CI: 0.80, 0.99; P = 0.221, I(2) = 33.7%), respectively, for an 8-g/d increment of PUFA intake. As an important source of marine n-3 PUFAs, a 0.1-g/d increment of dietary docosahexaenoic acid (DHA) intake was associated with lower risks of dementia (RR: 0.86; 95% CI: 0.76, 0.96; P < 0.001, I(2) = 92.7%) and AD (RR: 0.63; 95% CI: 0.51, 0.76; P < 0.001, I(2) = 94.5%). Significant curvilinear relations between fish consumption and risk of AD and between total PUFAs and risk of MCI (both P-nonlinearity < 0.001) were observed.

CONCLUSIONS

Fishery products are recommended as dietary sources and are associated with lower risk of cognitive impairment. Marine-derived DHA was associated with lower risk of dementia and AD but without a linear dose-response relation.

Associations of diet quality with cognition in children – the Physical Activity and Nutrition in Children Study

Evidence on the associations of dietary patterns with cognition in children is limited. Therefore, we investigated the associations of the Baltic Sea Diet Score (BSDS) and the Dietary Approaches to Stop Hypertension (DASH) score with cognition in children. The present cross-sectional study sample included 428 children aged 6–8 years (216 boys and 212 girls). The BSDS and the DASH score were calculated using data from 4 d food records, higher scores indicating better diet quality. Cognition was assessed by the Raven's Coloured Progressive Matrices (CPM) score, a higher score indicating better cognition. Among all children, the BSDS (standardised regression coefficient β = 0·122,P =0·012) and the DASH score (β = 0·121,P =0·015) were directly associated with the Raven's CPM score. Among boys, a lower BSDS (β = 0·244,P< 0·001) and a lower DASH score (β = 0·202,P= 0·003) were related to a lower Raven's CPM score. Boys in the lowest quartile of the BSDS (22·5v. 25·3,P= 0·029) and the DASH score (22·4v. 25·7,P= 0·008) had a lower Raven's CPM score than those in the highest quartile of the corresponding score. Among girls, the BSDS or the DASH score were not associated with cognition. In conclusion, a poorer diet quality was associated with worse cognition in children, and the relationship was stronger in boys than in girls.

The relation of saturated fats and dietary cholesterol to childhood cognitive flexibility

Identification of health behaviors and markers of physiological health associated with childhood cognitive function has important implications for public health policy targeted toward cognitive health throughout the life span. Although previous studies have shown that aerobic fitness and obesity exert contrasting effects on cognitive flexibility among prepubertal children, the extent to which diet plays a role in cognitive flexibility has received little attention. Accordingly, this study examined associations between saturated fats and cholesterol intake and cognitive flexibility, assessed using a task switching paradigm, among prepubertal children between 7 and 10 years (N = 150). Following adjustment of confounding variables (age, sex, socioeconomic status, IQ, VO2max, and BMI), children consuming diets higher in saturated fats exhibited longer reaction time during the task condition requiring greater amounts of cognitive flexibility. Further, increasing saturated fat intake and dietary cholesterol were correlated with greater switch costs, reflecting impaired ability to maintain multiple task sets in working memory and poorer efficiency of cognitive control processes involved in task switching. These data are among the first to indicate that children consuming diets higher in saturated fats and cholesterol exhibit compromised ability to flexibly modulate their cognitive operations, particularly when faced with greater cognitive challenge. Future longitudinal and intervention studies are necessary to comprehensively characterize the interrelationships between diet, aerobic fitness, obesity, and children's cognitive abilities.

A cross sectional study of the association between walnut consumption and cognitive function among adult US populations represented in NHANES

OBJECTIVE

To examine the association between walnut consumption and measures of cognitive function in the US population.

DESIGN

Nationally representative cross sectional study using 24 hour dietary recalls of intakes to assess walnut and other nut consumption as compared to the group reporting no nut consumption.

SETTING

1988-1994 and 1999-2002 rounds of the National Health and Nutrition Examination Survey (NHANES).

POPULATION

Representative weighted sample of US adults 20 to 90 years of age.

MAIN OUTCOME MEASURE

The Neurobehavioral Evaluation System 2 (NES2), consisting of simple reaction time (SRTT), symbol digit substitution (SDST), the single digit learning (SDLT), Story Recall (SRT) and digit-symbol substitution (DSST) tests.

RESULTS

Adults 20-59 years old reporting walnut consumption of an average of 10.3 g/d required 16.4ms less time to respond on the SRTT, P=0.03, and 0.39s less for the SDST, P=0.01. SDLT scores were also significantly lower by 2.38s (P=0.05). Similar results were obtained when tertiles of walnut consumption were examined in trend analyses. Significantly better outcomes were noted in all cognitive test scores among those with higher walnut consumption (P < 0.01). Among adults 60 years and older, walnut consumers averaged 13.1 g/d, scored 7.1 percentile points higher, P=0.03 on the SRT and 7.3 percentile points higher on the DSST, P=0.05. Here also trend analyses indicate significant improvements in all cognitive test scores (P < 0.01) except for SRTT (P = 0.06) in the fully adjusted models.

CONCLUSION

These significant, positive associations between walnut consumption and cognitive functions among all adults, regardless of age, gender or ethnicity suggest that daily walnut intake may be a simple beneficial dietary behavior.

Dietary fiber is positively associated with cognitive control among prepubertal children

BACKGROUND

Converging evidence now indicates that aerobic fitness and adiposity are key correlates of childhood cognitive function and brain health. However, the evidence relating dietary intake to executive function/cognitive control remains limited.

OBJECTIVE

The current study assessed cross-sectional associations between performance on an attentional inhibition task and dietary fatty acids (FAs), fiber, and overall diet quality among children aged 7-9 y (n = 65).

METHODS

Attentional inhibition was assessed by using a modified flanker task. Three-day food records were used to conduct nutrient-level analyses and to calculate diet quality (Healthy Eating Index-2005) scores.

RESULTS

Bivariate correlations revealed that socioeconomic status and sex were not related to task performance or diet measures. However, age, intelligence quotient (IQ), pubertal staging, maximal oxygen uptake (V̇O2max), and percentage of fat mass (%fat mass) correlated with task accuracy. Hierarchical regression models were used to determine the relation between diet variables and task accuracy and reaction time across both congruent and incongruent trials of the flanker task. After adjustment of confounding variables (age, IQ, pubertal staging, V̇O2max, and %fat mass), congruent accuracy was positively associated with insoluble fiber (β = 0.26, P = 0.03) and total dietary fiber (β = 0.23, P = 0.05). Incongruent response accuracy was positively associated with insoluble fiber (β = 0.35, P < 0.01), pectins (β = 0.25, P = 0.04), and total dietary fiber (β = 0.32, P < 0.01). Higher diet quality was related to lower accuracy interference (β = -0.26, P = 0.03), whereas higher total FA intake was related to greater accuracy interference (β = 0.24, P = 0.04). No statistically significant associations were observed between diet variables and reaction time measures.

CONCLUSION

These results demonstrate that children's diet quality, specifically dietary fiber, is an important correlate of performance on a cognitive task requiring variable amounts of cognitive control.

Omega-3 supplementation during the first 5 years of life and later academic performance: a randomised controlled trial

BACKGROUND/OBJECTIVES

Consumption of oily fish more than once per week has been shown to improve cognitive outcomes in children. However, it is unknown whether similar benefits can be achieved by long-term omega-3 fatty acid supplementation. The objective was to investigate the effect of omega-3 fatty acid supplementation during the first 5 years of life on subsequent academic performance in children by conducting a secondary analysis of the CAPS (Childhood Asthma Prevention Study).

SUBJECTS/METHODS

A total of 616 infants with a family history of asthma were randomised to receive tuna fish oil (high in long-chain omega-3 fatty acids, active) or Sunola oil (low in omega-3 fatty acids, control) from the time breastfeeding ceased or at the age of 6 months until the age of 5 years. Academic performance was measured by a nationally standardised assessment of literacy and numeracy (National Assessment Program Literacy and Numeracy (NAPLAN)) in school years 3, 5, 7 and 9. Plasma omega-3 fatty acid levels were measured at regular intervals until 8 years of age. Between-group differences in test scores, adjusted for maternal age, birth weight and maternal education, were estimated using mixed-model regression.

RESULTS

Among 239 children, there were no significant differences in NAPLAN scores between active and control groups. However, at 8 years, the proportion of omega-3 fatty acid in plasma was positively associated with the NAPLAN score (0.13 s.d. unit increase in score per 1% absolute increase in plasma omega-3 fatty acid (95% CI 0.03, 0.23)).

CONCLUSIONS

Our findings do not support the practice of supplementing omega-3 fatty acids in the diet of young children to improve academic outcomes. Further exploration is needed to understand the association between plasma omega-3 fatty acid levels at 8 years and academic performance.

Effect of supplementation with long-chain ω-3 polyunsaturated fatty acids on behavior and cognition in children with attention deficit/hyperactivity disorder (ADHD): a randomized placebo-controlled intervention trial

OBJECTIVE

To determine whether supplementation with the long-chain omega-3 polyunsaturated fatty acids eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) affects behavioral symptoms and cognitive impairments in children 6-12 years of age diagnosed with attention-deficit/hyperactivity disorder (ADHD).

STUDY DESIGN

The randomized, double-blind placebo-controlled 16 weeks trial was conducted with 95 children diagnosed with ADHD according to DSM-IV criteria. Behavior was assessed by parents, teachers and investigators using standardized rating scales and questionnaires. Further outcome variables were working memory, speed of information processing and various measures of attention. For a subgroup of 81 participants, erythrocyte membrane fatty acid composition was analyzed before and after the intervention.

RESULTS

Supplementation with the omega-3 fatty acid mix increased EPA and DHA concentrations in erythrocyte membranes and improved working memory function, but had no effect on other cognitive measures and parent- and teacher-rated behavior in the study population. Improved working memory correlated significantly with increased EPA, DHA and decreased AA (arachidonic acid).

Dietary lipids are differentially associated with hippocampal-dependent relational memory in prepubescent children

BACKGROUND

Studies in rodents and older humans have shown that the hippocampus-a brain structure critical to relational/associative memory-has remarkable plasticity as a result of lifestyle factors (eg, exercise). However, the effect of dietary intake on hippocampal-dependent memory during childhood has remained unexamined.

OBJECTIVE

We investigated the cross-sectional relation of dietary components characteristic of the Western diet, including saturated fatty acids (SFAs), omega-3 (n-3) fatty acids, and refined sugar, with hippocampal-dependent relational memory in prepubescent children.

DESIGN

Participants aged 7-9 y (n = 52) reported their dietary intake by using the Youth-Adolescent Food-Frequency Questionnaire and completed memory tasks designed to assess relational (hippocampal-dependent) and item (hippocampal-independent) memory. Performance on the memory tasks was assessed with both direct (accuracy) and indirect (eye movement) measures.

RESULTS

Partial correlations adjusted for body mass index showed a positive relation between relational memory accuracy and intake of omega-3 fatty acids and a negative relation of both relational and item memory accuracy with intake of SFAs. Potential confounding factors of age, sex, intelligence quotient, socioeconomic status, pubertal timing, and aerobic fitness (maximal oxygen volume) were not significantly related to any of the dietary intake measures. Eye movement measures of relational memory (preferential viewing to the target stimulus) showed a negative relation with intake of added sugar.

CONCLUSIONS

SFA intake was negatively associated with both forms of memory, whereas omega-3 fatty acid intake was selectively positively associated with hippocampal-dependent relational memory. These findings are among the first to show a link between habitual dietary intake and cognitive health as pertaining to hippocampal function in childhood. The Fitness Improves Thinking Kids (FITKids) and FITKids2 trials were registered at www.clinicaltrials.gov as NCT01334359 and NCT01619826, respectively.

Postnatal exposure to methyl mercury and neuropsychological development in 7-year-old urban inner-city children exposed to lead in the United States

BACKGROUND

The most common route for general population exposure to methyl mercury (MeHg) is fish consumption. Recommendations to pregnant women about consuming fish contaminated with MeHg are also applied to children, but there are few studies available about the effects of low-level postnatal MeHg exposure in them.

OBJECTIVES

To investigate the association between postnatal methyl mercury exposure and neuropsychological development in a study of children also exposed to lead, both measured at 7 years.

METHODS

We measured MeHg concentrations in blood samples from the Treatment of Lead-Exposed Children (TLC) trial in which 780 children with elevated concentrations of lead in blood were followed with neuropsychological tests from ages 12-33 months through 7 years. Here we examine blood MeHg concentration and neuropsychological test scores, both measured at age 7 years. We used a maximum likelihood method to estimate geometric mean MeHg concentration and generalized linear regression models to analyze MeHg and neuropsychological test scores.

RESULTS

Geometric mean MeHg concentration was 0.56 (95% confidence interval: 0.52, 0.59) μ g/L. A 1  μ g/L increase in MeHg was associated with a 2.1 (95% confidence interval: 0.4, 3.8) point increase in Full-Scale IQ and 0.2 (95% confidence interval: 0.02, 0.4) point increase in Learning Slopeindex T-score on a test of verbal memory.

CONCLUSIONS

Our results suggest that the relatively low MeHg exposure in US school-aged children from this population has no detectable adverse effect on neuropsychological development. The positive associations observed between MeHg and neurodevelopment may indirectly reflect consumption of beneficial polyunsaturated fatty acids from seafood.

Self-reported learning difficulties and dietary intake in Norwegian adolescents

Aim: The academic performance of children impacts future educational attainment which may increase socioeconomic status which again influences their health. One of several factors that might affect academic performance is the diet. The aim of this study was to investigate the cross sectional relation between diet and self-reported reading-, writing-, and mathematical difficulties in Norwegian adolescents. Methods: In total, 475 ninth- and tenth-grade students out of 625 eligible ones from four different secondary schools in three different municipalities in Vest-Agder County, Norway, participated, giving a participation rate of 77%. The students filled in a questionnaire with food frequency questions of selected healthy and unhealthy food items, questions of meal frequency and different learning difficulties. Results: Regular breakfast was significantly associated with decreased odds of both writing and reading difficulties (OR: 0.44 (0.2–0.8), p = 0.01) and mathematical difficulties (OR: 0.33 (0.2–0.6), p ≤ 0.001). In addition, having lunch, dinner and supper regularly were associated with decreased odds of mathematical difficulties. Further, a high intake of foods representing a poor diet (sugar-sweetened soft drinks, sweets, chocolate, savory snacks, pizza and hot dogs) was significantly associated with increased odds of mathematical difficulties. Conclusions: Having a less-frequent intake of unhealthy foods and not skipping meals are associated with decreased odds of self-reported learning difficulties in Norwegian adolescents in this study. The results of this study support the need for a larger study with a more representative sample.

Fast-food consumption and educational test scores in the USA

BACKGROUND

  Children in the USA are experiencing obesity and overweight at epidemic rates. Schools have started to make policy decisions based on a popularly presumed connection between nutrition and academic achievement. This study aimed to determine whether such a relationship exists, and if so, its nature.

METHODS

  Data from the Food Consumption Questionnaire administered to approximately 12 000 fifth graders as part of the nationally representative Early Childhood Longitudinal Study-Kindergarten Cohort was analysed using regression analysis. The analysis used propensity score matching to examine the relationship between students' reported fast-food consumption and their test scores in reading and mathematics. Propensity score matching attempts to control for a host of background characteristics that might be correlated with both fast-food consumption and test scores.

RESULTS

  Standard ordinary least squares regression showed that test scores decreased as reported fast-food consumption increased. In the propensity-score-matched analysis, which controlled for 25 student background characteristics, higher-than-average fast-food consumption ('four to six times in the last 7 days' or more) was associated with significantly lower test scores in both reading (-11.15 points or 0.48 SD) and math (-11.13 points or 0.52 SD), even when teacher experience, school poverty level and school urbanicity were also included in the model.

CONCLUSIONS

  Although this study is preliminary, its results indicate that the relationship between poor nutrition and test scores may in fact be quite negative, strengthening the impetus for schools to consider policies that support students' healthy eating. In order to strengthen these findings and investigate possible mechanisms through which poor nutrition might affect test scores, there is a need for further research.

Intakes and adequacy of potentially important nutrients for cognitive development among 5-year-old children in the Seychelles Child Development and Nutrition Study

OBJECTIVE

To assess the nutritional adequacy of Seychellois children in relation to nutrients reported to be important for cognitive development.

DESIGN

Dietary intakes were assessed by 4 d weighed food diaries and analysed using dietary analysis software (WISP version 3·0; Tinuviel Software, UK). Individual nutrient intakes were adjusted to usual intakes and, in order to investigate adequacy, were compared with the UK Estimated Average Requirements for children aged 4-6 years.

SETTING

Children 5 years old were followed up as part of the Seychelles Child Development Nutrition Study (SCDNS), located in the high-fish-consuming population of Mahé, Republic of Seychelles.

SUBJECTS

Analysis was carried out on a sample of 229 children (118 boys, 111 girls).

RESULTS

Children consumed a diet of which fortified cereal and milk products contributed the most to nutrient intakes. The majority (≥80 %) of children met requirements for several nutrients important for child development including Fe, folate and Se. Adjusted dietary intakes of Cu, Zn, iodine, niacin and vitamin A were below the Estimated Average Requirement or Recommended Nutrient Intake. Mean adjusted energy intakes (boys 4769 kJ/d (1139·84 kcal/d), girls 4759 kJ/d (1137·43 kcal/d)) were lower than the estimated energy requirement (boys 5104 kJ/d (1220 kcal/d), girls 5042 kJ/d (1205 kcal/d)) for 88 % of boys and 86 % of girls.

CONCLUSIONS

Nutrition was adequate for most children within the SCDNS cohort. Low intakes of some nutrients (including Zn, niacin and vitamin A) could reflect nutritional database inaccuracies, but may require further investigation. The study provides valuable information on the adequacy of intakes of nutrients which could affect the growth and development of Seychellois children.

Association between increased BMI and severe school absenteeism among US children and adolescents: findings from a national survey, 2005-2008

OBJECTIVE

School absenteeism may be an underlying cause of poor school performance among overweight and obese children. We examined the associations between school absenteeism and body mass index (BMI) in a nationally representative sample.

DESIGN AND SUBJECTS

We analyzed the data of 1387 children (6-11 years) and 2185 adolescents (12-18 years), who completed an interview and anthropometric measurement as a part of the National Health and Nutrition Examination Survey, 2005-2008. The CDC 2000 growth chart was used to categorize BMI status, and the number of school days missed during the past 12 months was assessed by asking the proxies or interviewees.

RESULTS

The prevalence of obesity and overweight were 18.96±1.44% (s.e.) and 16.41±0.78%, respectively, among study populations. The means of school days missed in the last 12 months were not statistically different between the normal-weight, overweight and obese groups, 3.79±0.56, 3.86±0.38 and 4.31±0.01 days, respectively. However, when >2 days missed per school month was defined as severe absence, the prevalence of severe absence were 1.57%, 2.99% and 4.94% respectively, among 6-11-year-old children with normal, overweight and obese. The adjusted odds of severe school absence were 2.27 (95% confidence interval=0.64-8.03) and 3.93 (1.55-9.95), respectively, among overweight and obese children compared with normal-weight peers (P for trend test <0.01). No significant association was found among adolescents.

CONCLUSION

Increased body weight is independently associated with severe school absenteeism in children but not adolescents. Future research is needed to determine the nature, and academic and social significance of this association.

Dietary protein and protein-rich food in relation to severely depressed mood: A 10 year follow-up of a national cohort

High-protein diets are advocated to facilitate weight loss, and improve cardiovascular risk factors, but data on psychiatric effects are lacking. We analyzed data from 1947 men and 2909 women aged 25-74 years when examined in 1971-1975 as the baseline of the National Health and Nutrition Examination Follow-Up Study. The amounts of macronutrients were obtained from a 24-hour recall, and frequencies of eating protein-rich foods were estimated using a 3-month food frequency questionnaire. Severely depressed mood (SDM) was defined as Center for Epidemiologic Studies Depression Scale score ≥ 22 or taking anti-depression medication after an average of 10.6 years of follow-up. A significant gender difference was observed in the prevalence of SDM and its association with protein intake. The weighted prevalence of SDM was 11.45 (SE = 0.96) % and 17.45(1.05) % respectively among men and women. Among men, the relative risk (RRs) of SDM were 1.00, 0.46 (95% CI = 0.22-0.99) and 0.38 (0.16-0.92) respectively for the lowest, middle and highest third protein intake (p for trend=0.0347). Among women, the RRs were 1.00, 1.93 (1.23-3.08) and 2.47 (1.24-4.90) respectively with lowest, middle and the highest third intakes (p for trend = 0.0023). These estimates were adjusted for cigarette smoking, alcohol consumption, BMI, socioeconomic status at baseline, and the history of cancer, stroke, heart attack and diabetes assessed at follow-up interview. The authors concluded that increased intake of protein demonstrated a protective effect among men but a deleterious effect among women.

Effects of long-chain polyunsaturated fatty acid supplementation on neurodevelopment in childhood: a review of human studies

Omega-3 and omega-6 long-chain polyunsaturated fatty acids (LCPUFA) are critical for infant and childhood brain development, but levels of the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are often low in the Western diet. Increasing evidence from both epidemiological and intervention studies, reviewed here, indicates that DHA supplementation, during pregnancy, lactation, or childhood plays an important role in childhood neurodevelopment. Arachidonic acid (ARA) is also important for infant growth and development. Several studies have demonstrated positive associations between blood DHA levels and improvements on tests of cognitive and visual function in healthy children. Controlled trials also have shown that supplementation with DHA and EPA may help in the management of childhood psychiatric disorders, and improve visual and motor functions in children with phenylketonuria. In all studies, DHA and EPA supplementation is typically well tolerated. Further research is needed to determine optimal doses for efficacy at different developmental ages. The potential long-term benefits of early LCPUFA supplementation also require consideration.

Dietary linoleic and oleic fatty acids in relation to severe depressed mood: 10 years follow-up of a national cohort

The influence of dietary fatty acids (FAs) other than omega-3 FAs on mood has been largely overlooked. The authors prospectively assessed the association between dietary linoleic and oleic FAs and the risk of severe depressed mood (SDM) among 4856 adults aged 25-74 years who were examined in 1971-1975 as a part of a national survey. Intakes of FAs were obtained at baseline from a 24-hour recall and categorized into thirds. SDM was defined as Center for Epidemiologic Studies Depression Scale scores at follow-up survey >or=22 or taking anti-depression medication. After an average of 10.6 years of follow-up, the proportion of individuals with SDM were 11.45 (SE=0.96) % and 17.45(1.05) % respectively among 1947 men and 2909 women. The odds ratios (ORs) were 1 (reference), 1.64(95% CI=1.06, 2.54) and 2.34 (1.41, 3.87) respectively for men with lowest, middle and highest third of linoleic FA intake (p for trend=0.001); the ORs were 1 (reference), 0.88 (0.56, 1.38) and 0.48 (0.25, 0.95) respectively for women with lowest, middle and highest third of oleic FA intake (p for trend=0.0347). No association was observed from saturated FA. These estimates were adjusted for fish consumption at baseline and major physical diseases at follow-up. The authors concluded that increased intake of oleic FA was associated with reduced risk among women while increased intake of linoleic FA was associated with increased risk of SDM among men.

Evaluating the relationship between breakfast pattern and short-term memory in junior high school girls

The aim of this study was to evaluate the relationship between breakfast pattern and short-term memory in guidance-school students. Memory improves for subjects who have eaten breakfast. It appears that breakfast consumption influences cognition via several mechanisms. What children eat for breakfast before going to school is very important. A total of 150 junior high school girls were taken from a subject pool in four schools in Shiraz (capital of the Fars Province in Iran). They filled out the socio-economic questionnaires as well as food frequency questionnaires for breakfast and provided two-three day breakfast records in two different seasons and their short-term memories were evaluated by Weksler test socio-economic conditions and dietary intakes were analyzed. The results of the study showed that there was no correlation between parents job, students mean age and their school grades with their memory scores. Dietary analysis demonstrated a negative correlation between local soup consumption in breakfast and memory scores. Food record analysis showed no correlation between fat, cholesterol, protein, vitamin B6, B12, calorie and iodine intake in breakfast and memory scores, but there was a positive correlation between carbohydrate, iron and vitamin B3 intake in breakfast and memory scores, similarly there was a positive correlation between B12 intake in the breakfast and students' average school grades during the year.

Effects of a saturated fat and high cholesterol diet on memory and hippocampal morphology in the middle-aged rat

Diets rich in cholesterol and/or saturated fats have been shown to be detrimental to cognitive performance. Therefore, we fed a cholesterol (2%) and saturated fat (hydrogenated coconut oil, Sat Fat 10%) diet to 16-month old rats for 8 weeks to explore the effects on the working memory performance of middle-aged rats. Lipid profiles revealed elevated plasma triglycerides, total cholesterol, HDL, and LDL for the Sat-Fat group as compared to an iso-caloric control diet (12% soybean oil). Weight gain and food consumption were similar in both groups. Sat-Fat treated rats committed more working memory errors in the water radial arm maze, especially at higher memory loads. Cholesterol, amyloid-beta peptide of 40 (Abeta40) or 42 (Abeta42) residues, and nerve growth factor in cortical regions was unaffected, but hippocampal Map-2 staining was reduced in rats fed a Sat-Fat diet, indicating a loss of dendritic integrity. Map-2 reduction correlated with memory errors. Microglial activation, indicating inflammation and/or gliosis, was also observed in the hippocampus of Sat-Fat fed rats. These data suggest that saturated fat, hydrogenated fat and cholesterol can profoundly impair memory and hippocampal morphology.