Impulsivity-based thrifty eating phenotype and the protective role of n-3 PUFAs intake in adolescents

A mesocorticolimbic insulin receptor gene co-expression network moderates the association between early life adversity and food approach eating behaviour style in childhood

Insulin receptors, located in brain regions associated with reward sensitivity and decision-making, facilitate insulin action in the brain, modulating intracellular signaling cascades, gene expression, and neural activity. Here, we tested if variations in the expression of the insulin receptor gene network in the prefrontal cortex (PFC) and striatum (STR) moderate the association between early life adversity and eating behaviour in childhood and if this moderation is sex-specific. Participants from the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) and Basal Influences on the Baby's Development (BIBO) were included as two independent cohorts. A biologically-informed polygenic score reflecting functional variation of the mesocorticolimbic insulin receptor gene network was created by using insulin receptor co-expression data from the PFC and STR in mice, and validated in humans through filtering by homologous expression in PFC using well-known databases. Early life adversity exposure was measured as a composite score. Eating behaviour was characterized using the Child Eating Behaviour Questionnaire administered to mothers of children aged 4 and 6 years in MAVAN, and 6 years in BIBO. We found that only in those with high expression of the mesocorticolimbic insulin receptor gene network a higher early adversity score associated with a higher desire to drink in 4-year boys and 6-year girls, as well as a higher food approach score and food approach/food avoidance ratio in 4-year girls. Also, a higher early life adversity was associated with higher food responsiveness, food approach score and food approach/food avoidance ratio at 6 years in the MAVAN full sample. The moderation observed on desire to drink was partially replicated in BIBO children aged 6 years. Identifying individual differences in response to early adversity may help to prioritize individuals at high risk for long-term disease and design suitable interventions.

Accumbal μ-opioid receptors and salt taste-elicited hedonic responses in a rodent model of prenatal adversity, and their correlates using human functional genomics

Prenatal adversity is associated with behavioral obesogenic features such as preference for palatable foods. Salt appetite may play a role in the development of adiposity and its consequences in individuals exposed to prenatal adversity, and sodium consumption involves individual differences in accumbal µ-opioid receptors function. We investigated the hedonic responses to salt and the levels of µ-opioid receptors and tyrosine hydroxylase in the nucleus accumbens (Nacc) of pups from an animal model of prenatal dietary restriction. In children, we evaluated the interaction between fetal growth and the genetic background associated with the accumbal µ-opioid receptor gene (OPRM1) expression on sodium consumption during a snack test. Sprague-Dawley dams were randomly allocated from pregnancy day 10 to receive an ad libitum (Adlib) or a 50% restricted (FR) diet. The pups' hedonic responses to a salt solution (NaCl 2%) or water were evaluated on the first day of life. FR and Adlib pups differ in their hedonic responses to salt, and there were decreased levels of accumbal µ-opioid and p-µ-opioid receptors in FR pups. In humans, a test meal and genotyping from buccal epithelial cells were performed in 270 children (38 intrauterine growth restricted-IUGR) at 4 years old from a Canadian prospective cohort (MAVAN). The OPRM1 genetic score predicted the sodium intake in IUGR children, but not in controls. The identification of mechanisms involved in the brain response to prenatal adversity and its consequences in behavioral phenotypes and risk for chronic diseases later in life is important for preventive and therapeutic purposes.

Omega-3 polygenic score protects against altered eating behavior in intrauterine growth-restricted children

BACKGROUND

Alterations in eating behavior are common in infants with intrauterine growth restriction (IUGR); omega-3 polyunsaturated fatty acids (PUFA) could provide protection. We hypothesized that those born IUGR with a genetic background associated with increased production of omega-3-PUFA will have more adaptive eating behaviors during childhood.

METHODS

IUGR/non-IUGR classified infants from MAVAN and GUSTO cohorts were included at the age of 4 and 5 years, respectively. Their parents reported child's eating behaviors using the child eating behavior questionnaire-CEBQ. Based on the GWAS on serum PUFA (Coltell 2020), three polygenic scores were calculated.

RESULTS

Significant interactions between IUGR and polygenic score for omega-3-PUFA on emotional overeating (β = -0.15, P = 0.049 GUSTO) and between IUGR and polygenic score for omega-6/omega-3-PUFA on desire to drink (β = 0.35, P = 0.044 MAVAN), pro-intake/anti-intake ratio (β = 0.10, P = 0.042 MAVAN), and emotional overeating (β = 0.16, P = 0.043 GUSTO) were found. Only in IUGR, a higher polygenic score for omega-3-PUFA associated with lower emotional overeating, while a higher polygenic score for omega-6/omega-3-PUFA ratio was associated with a higher desire to drink, emotional overeating, and pro-intake/anti-intake.

CONCLUSION

Only in IUGR, the genetic background for higher omega-3-PUFA is associated with protection against altered eating behavior, while the genetic score for a higher omega-6/omega-3-PUFA ratio is associated with altered eating behavior.

IMPACT

A genetic background related to a higher polygenic score for omega-3 PUFA protected infants born IUGR against eating behavior alterations, while a higher polygenic score for omega-6/omega-3 PUFA ratio increased the risk of having eating behavior alterations only in infants born IUGR, irrespective of their adiposity in childhood. Genetic individual differences modify the effect of being born IUGR on eating outcomes, increasing the vulnerability/resilience to eating disorders in IUGR group and likely contributing to their risk for developing metabolic diseases later in life.

Relationship between insulin and Netrin-1/DCC guidance cue pathway regulation in the prefrontal cortex of rodents exposed to prenatal dietary restriction

Fetal restriction (FR) alters insulin sensitivity, but it is unknown how the metabolic profile associated with restriction affects development of the dopamine (DA) system and DA-related behaviors. The Netrin-1/DCC guidance cue system participates in maturation of the mesocorticolimbic DA circuitry. Therefore, our objective was to identify if FR modifies Netrin-1/DCC receptor protein expression in the prefrontal cortex (PFC) at birth and mRNA in adulthood in rodent males. We used cultured HEK293 cells to assess if levels of miR-218, microRNA regulator of DCC, are sensitive to insulin. To assess this, pregnant dams were subjected to a 50% FR diet from gestational day 10 until birth. Medial PFC (mPFC) DCC/Netrin-1 protein expression was measured at P0 at baseline and Dcc/Netrin-1 mRNA levels were quantified in adults 15 min after a saline/insulin injection. miR-218 levels in HEK-293 cells were measured in response to insulin exposure. At P0, Netrin-1 levels are downregulated in FR animals in comparison to controls. In adult rodents, insulin administration results in an increase in Dcc mRNA levels in control but not FR rats. In HEK293 cells, there is a positive correlation between insulin concentration and miR-218 levels. Since miR-218 is a Dcc gene expression regulator and our in vitro results show that insulin regulates miR-218 levels, we suggest that FR-induced changes in insulin sensitivity could be affecting Dcc expression via miR-218, impacting DA system maturation and organization. As fetal adversity is linked to nonadaptive behaviors later in life, this may contribute to early identification of vulnerability to chronic diseases associated with fetal adversity.

Encapsulation of Docosahexaenoic Acid Oil Substantially Improves the Oxylipin Profile of Rat Tissues

Docosahexaenoic acid (DHA) is a major n-3 polyunsaturated fatty acid (PUFA) particularly involved in cognitive and cardiovascular functions. Due to the high unsaturation index, its dietary intake form has been considered to improve oxidation status and to favor bioaccessibility and bioavailability as well. This study aimed at investigating the effect of DHA encapsulated with natural whey protein. DHA was dietary provided as triacylglycerols to achieve 2.3% over total fatty acids. It was daily supplied to weanling rats for four weeks in omelet as food matrix, consecutively to a 6-hour fasting. First, when DHA oil was encapsulated, consumption of chow diet was enhanced leading to promote animal growth. Second, the brain exhibited a high accretion of 22.8% DHA, which was not improved by dietary supplementation of DHA. Encapsulation of DHA oil did not greatly affect the fatty acid proportions in tissues, but remarkably modified the profile of oxidized metabolites of fatty acids in plasma, heart, and even brain. Specific oxylipins derived from DHA were upgraded, such as Protectin Dx in heart and 14-HDoHE in brain, whereas those generated from n-6 PUFAs were mainly mitigated. This effect did not result from oxylipins measured in DHA oil since DHA and EPA derivatives were undetected after food processing. Collectively, these data suggested that dietary encapsulation of DHA oil triggered a more efficient absorption of DHA, the metabolism of which was enhanced more than its own accretion in our experimental conditions. Incorporating DHA oil in functional food may finally improve the global health status by generating precursors of protectins and maresins.

Diminished insulin sensitivity is associated with altered brain activation to food cues and with risk for obesity - Implications for individuals born small for gestational age

While classically linked to memory, the hippocampus is also a feeding behavior modulator due to its multiple interconnected pathways with other brain regions and expression of receptors for metabolic hormones. Here we tested whether variations in insulin sensitivity would be correlated with differential brain activation following exposure to palatable food cues, as well as with variations in implicit food memory in a cohort of healthy adolescents, some of whom were born small for gestational age (SGA). Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) was positively correlated with activation in the cuneus, and negatively correlated with activation in the middle frontal lobe, superior frontal gyrus and precuneus when presented with palatable food images versus non-food images in healthy adolescents. Additionally, HOMA-IR and insulinemia were higher in participants with impaired food memory. SGA individuals had higher snack caloric density and greater chance for impaired food memory. There was also an interaction between the HOMA-IR and birth weight ratio influencing external eating behavior. We suggest that diminished insulin sensitivity correlates with activation in visual attention areas and inactivation in inhibitory control areas in healthy adolescents. Insulin resistance also associated with less consistency in implicit memory for a consumed meal, which may suggest lower ability to establish a dietary pattern, and can contribute to obesity. Differences in feeding behavior in SGA individuals were associated with insulin sensitivity and hippocampal alterations, suggesting that cognition and hormonal regulation are important components involved in their food intake modifications throughout life.

Association of increased abdominal adiposity at birth with altered ventral caudate microstructure

BACKGROUND

Neonatal adiposity is associated with a higher risk of obesity and cardiometabolic risk factors in later life. It is however unknown if central food intake regulating networks in the ventral striatum are altered with in-utero abdominal growth, indexed by neonatal adiposity in our current study. We aim to examine the relationship between striatal microstructure and abdominal adipose tissue compartments (AATCs) in Asian neonates from the Growing Up in Singapore Toward healthy Outcomes mother-offspring cohort.

STUDY DESIGN

About 109 neonates were included in this study. Magnetic resonance imaging (MRI) was performed for the brain and abdominal regions between 5 to 17 days of life. Diffusion-weighted imaging of the brain was performed for the derivation of caudate and putamen fractional anisotropy (FA). Abdominal imaging was performed to quantify AATCs namely superficial subcutaneous adipose tissue (sSAT), deep subcutaneous adipose tissue (dSAT), and internal adipose tissue (IAT). Absolute and percentage adipose tissue of total abdominal volume (TAV) were calculated.

RESULTS

We showed that AATCs at birth were significantly associated with increased FA in bilateral ventral caudate heads which are part of the ventral striatum (sSAT: β_left = 0.56, p < 0.001; β_right = 0.65, p < 0.001, dSAT: β_left = 0.43, p < 0.001; β_right = 0.52, p < 0.001, IAT: β_left = 0.30, p = 0.005; β_right = 0.32, p = 0.002) in neonates with low birth weights adjusted for gestational age.

CONCLUSIONS

Our study provides preliminary evidence of a potential relationship between neonatal adiposity and in-utero programming of the ventral striatum, a brain structure that governs feeding behavior.

The Association Between Birth Weight and Fat, Sugar, and Vegetable Consumption in a National Sample of U.S. Preschool Age Children

INTRODUCTION

Adverse prenatal development is a contributor to obesity susceptibility in children. Dietary behavior is one mechanism through which adverse prenatal development may promote obesity, but evidence for the role of prenatal overnutrition in dietary intake in young children is scant.

METHODS

We used data from the National Health and Nutrition Examination Survey 2009-2014. Our study sample included 1782 U.S. children 2-5 years old with available birth weight and two 24-h dietary recalls. We used linear and Poisson regression to examine the association of birth weight (LBW < 2500 g, HBW > 4100 g) and 2-day average intake of dietary variables. We tested interactions between birthweight and breastfeeding (breastfed > 5 months vs. not breastfed or breastfed 0-5 months), and report breastfeeding-specific results.

RESULTS

In multivariable regression analysis, in boys, LBW was associated with 2.4 (95% CI - 4.3, - 0.5) lower percent of kcal from solid fat; lower sugar intake, marginally lower saturated and total fat intake, and 0.6 cup (95% CI 0.1, 1.0) greater vegetable consumption; HBW was marginally associated with lower fat. Birth weight was unrelated to diet in girls. Breastfeeding modified associations between birth weight and dietary intake, but the direction of modification was mixed.

DISCUSSION

Our findings do not support the hypothesis that LBW or HBW are associated with adverse diet consumption in preschool age U.S. children. Improved understanding of the role of early life development of dietary behavior requires further research on the development of appetitive traits and the role of the family and preschool food environments.

Prenatal predictors of objectively measured appetite regulation in low-income toddlers and preschool-age children

BACKGROUND

Prenatal nutrition impacts offspring appetite regulation in animal models. However, evidence from humans is scarce.

OBJECTIVE

To determine associations between indicators of prenatal nutrition and appetite regulation among young children.

METHODS

Participants included 454 low-income mother/child dyads (mean child age = 45.2 months [SD = 9.7]). Children's appetite regulation was ascertained with the maternal-reported Child Eating Behavior Questionnaire and objectively assessed using the Eating in the Absence of Hunger protocol. Using hierarchical linear regression, we modelled child appetite regulation measures as a function of prenatal nutrition indicators (child birthweight z scores [BWz, BWz2 ]; maternal pre-pregnancy body mass index [BMI], gestational weight gain [GWG]), adjusted for sociodemographic characteristics.

RESULTS

Among girls, higher and lower birthweight were associated with greater energy consumed in the absence of hunger, primarily sweet foods, coeff (95% CI): BWz 0.17 (0.05, 0.28), BWz2 0.15 (0.04, 0.26), but not food responsiveness or food enjoyment. Higher birthweight was also associated with greater satiety responsiveness among girls. Among boys, birthweight was unrelated to measures of appetite regulation. Associations between maternal BMI and GWG and child appetite regulation were inconsistent.

CONCLUSIONS

Among low-income girls, but not boys, indicators of adverse prenatal conditions were associated with poor objectively measured appetite regulation during early childhood.

Early environmental influences on the development of children's brain structure and function

The developing brain in utero and during the first years of life is highly vulnerable to environmental influences. Experiences occurring during this period permanently modify brain structure and function through epigenetic modifications (alterations of the DNA structure and chromatin function) and consequently affect the susceptibility to mental disorders. In this review, we describe evidence linking adverse environmental variation during early life (from the fetal period to childhood) and long-term changes in brain volume, microstructure, and connectivity, especially in amygdala and hippocampal regions. We also describe genetic variations that moderate the impact of adverse environmental conditions on child neurodevelopment, such as polymorphisms in brain-derived neurotrophic factor and catechol-O-methyltransferase genes, as well as genetic pathways related to glutamate and monoaminergic signaling. Lastly, we have depicted positive early life experiences that could benefit childhood neurodevelopment and reverse some detrimental effects of adversity in the offspring. WHAT THIS PAPER ADDS: Prenatal, peripartum, and postnatal adversities influence child behavior and neurodevelopment. Exposure to environmental enrichment and positive influences may revert these effects. Putative mechanisms involve alterations in neurotrophic factors and neurotransmitter systems. New tools/big data improved the understanding on how early adversity alters neurodevelopment. This permits better translation/application of the findings from animal models to humans.

Low birth weight is associated with increased fat intake in school-aged boys

Evidence suggests that both high and low birth weight children have increased the risk for obesity and the metabolic syndrome in adulthood. Previously we have found altered feeding behaviour and food preferences in pre-school children and adults born with low birth weight. In this study, we investigated if birth weight was associated with different intake of fat, carbohydrate and/or protein at 6-12 years of age. This is a cross-sectional study where 255 guardians answered online and telephone questions including anthropometrics and demographic data, parental family food rules (food control, encouragement and restriction) and a complete web-based FFQ for their children (130 boys and 125 girls). Baseline demographic and parental food rules characteristics did not differ accordingly to sex. Linear regression models were conducted separately for each sex, adjusted for income, age and maternal age. There were no differences in total energy intake, but energy density (ED, energy content/g) was negatively associated with birth weight in boys. Macronutrient analysis showed that ED intake was from a greater intake of fat. Birth weight was not a significant predictor of protein and carbohydrate intake in boys. In girls, we saw a positive correlation between fat intake and cholesterol intake v. birth weight, but no association with ED intake (results did not remain after adjustment). The study shows that low birth weight is associated with altered fat intake in childhood in a sex-specific manner. It is likely that biological factors such as fetal programming of homoeostatic and/or hedonic pathways influencing food preferences are involved in this process.

Intrauterine growth restriction increases impulsive behavior and is associated with altered dopamine transmission in both medial prefrontal and orbitofrontal cortex in female rats

Recent studies have implicated a role for impulsivity in the altered eating behaviors and the increased risk for obesity consistently associated with intrauterine growth restriction (IUGR). Changes in dopamine transmission within prefrontal areas are believed to contribute to these adverse outcomes. Here we investigated the impulsive behavior toward a delayed reward and evaluated dopamine levels and its receptors in the medial prefrontal (mPFC) and orbitofrontal (OFC) cortex of female adult rats exposed to IUGR. From day 10 of pregnancy and until birth, Sprague-Dawley dams received either an ad libitum (Adlib) or a 50% food-restricted (FR) diet. At birth, all pups were adopted by Adlib mothers, generating the groups Adlib/Adlib (control) and FR/Adlib (intrauterine growth-restricted). Adult impulsive behavior was evaluated using a Tolerance to Delay of Reward Task. In vivo dopamine responses to sweet food intake were measured by voltammetry, and D1, D2 and DAT levels were accessed by Western Blot. Animals from FR group showed a pronounced aversion to delayed rewards. DA response to sweet food was found to be blunted in the mPFC of FR animals, whereas in the OFC, the DA levels appear to be unaffected by reward consumption. Moreover, FR animals presented reduced D1 receptors in the OFC and a later increase in the mPFC D2 levels. These findings suggest that IUGR female rats are more impulsive and that the associated mechanism involves changes in the dopamine signaling in both the mPFC and OFC.

Intrauterine Growth Restriction Modifies the Accumbal Dopaminergic Response to Palatable Food Intake

Intrauterine growth restriction (IUGR) associates with increased preference for palatable foods and altered insulin sensitivity. Insulin modulates the central dopaminergic response and changes behavioral responses to reward. We measured the release of dopamine in the accumbens during palatable food intake in IUGR rats both at baseline and in response to insulin. From pregnancy day 10 until birth, gestating Sprague-Dawley rats received either an ad libitum (Control), or a 50% food restricted (FR) diet. In adulthood, palatable food consumption and feeding behavior entropy was assessed using an electronic food intake monitor (BioDAQ®), and dopamine response to palatable food was measured by chronoamperometry recordings in the nucleus accumbens (NAcc). FR rats eat more palatable foods during the dark phase, and their eating pattern has a higher entropy compared to control rats. There was a delayed dopamine release in the FR group in response to palatable food and insulin administration reverted this delayed effect. Western blot showed a decrease in suppressor of cytokine signaling 3 protein (SOCS3) in the ventral tegmental area (VTA) and an increase in the ratio of phospho-tyrosine hydroxylase to tyrosine hydroxylase (pTH/TH) in the NAcc of FR rats. Administration of insulin also abolished this latter effect in FR rats. FR rats showed metabolic alterations and a delay in the dopaminergic response to palatable foods. This could explain the increased palatable food intake and behavioral entropy found in FR rats. IUGR may lead to binge eating, obesity and its metabolic consequences by modifying the central dopaminergic response to sweet food.

Moderating effect of PLIN4 genetic variant on impulsivity traits in 5-year-old-children born small for gestational age

Poor fetal growth is associated with long-term behavioral, metabolic and psychiatric alterations, including impulsivity, insulin resistance, and mood disorders. However, the consumption of omega-3 polyunsaturated fatty acid (n-3 PUFA) seems to be protective for this population, improving inhibitory control and behavioral reactivity. We investigated whether the presence of the A allele of rs8887 SNP (PLIN4 gene), known to be associated with increased sensitivity to the consumption of n-3 PUFAs, interacts with fetal growth influencing inhibitory control. 152 five-year-old children were genotyped and performed the Stop Signal Task (SSRT). There was a significant interaction between birth weight and the presence of the A allele on SSRT performance, in which lower birth weight associated with poorer inhibitory control only in non-carriers. These results suggest that a higher responsiveness to n-3 PUFAS protects small for gestational age children from developing poor response inhibition, highlighting that optimizing n-3 PUFA intake may benefit this population.

Birth weight and catch up growth are associated with childhood impulsivity in two independent cohorts

Individuals born after intrauterine growth restriction (IUGR) are more impulsive towards palatable foods, but it is not clear 1) if IUGR-related impulsivity is specific for foods and solely based on response inhibition and 2) if the development of impulsivity is due to being born IUGR per se or to growing up fast in the first few years of life (catch up growth). Children were classified in the IUGR group if the birth weight ratio was below 0.85. Delta z score for BMI was used as a measure of catch up growth. In MAVAN (N = 274), impulsivity was measured by the Information Sampling Task from the Cambridge Neuropsychological Test Automated Battery (IST - CANTAB), and in GUSTO using the Sticker Delay Task (N = 327). There is a significant effect of interaction between being born IUGR and the magnitude of catch up growth on the reflection impulsivity from IST-CANTAB at 60 months, in which greater catch up growth associates with greater impulsivity in the IST fixed condition in IUGR children. The finding was reproduced in children from the GUSTO cohort using the Sticker Delay Task. We confirmed that catch up growth interacts with IUGR, having a major role in the development of impulsivity in the first years of life and influencing inhibitory control and decision making processes.

Annual Research Review: On the relations among self-regulation, self-control, executive functioning, effortful control, cognitive control, impulsivity, risk-taking, and inhibition for developmental psychopathology

BACKGROUND

Self-regulation (SR) is central to developmental psychopathology, but progress has been impeded by varying terminology and meanings across fields and literatures.

METHODS

The present review attempts to move that discussion forward by noting key sources of prior confusion such as measurement-concept confounding, and then arguing the following major points.

RESULTS

First, the field needs a domain-general construct of SR that encompasses SR of action, emotion, and cognition and involves both top-down and bottom-up regulatory processes. This does not assume a shared core process across emotion, action, and cognition, but is intended to provide clarity on the extent of various claims about kinds of SR. Second, top-down aspects of SR need to be integrated. These include (a) basic processes that develop early and address immediate conflict signals, such as cognitive control and effortful control (EC), and (b) complex cognition and strategies for addressing future conflict, represented by the regulatory application of complex aspects of executive functioning. Executive function (EF) and cognitive control are not identical to SR because they can be used for other activities, but account for top-down aspects of SR at the cognitive level. Third, impulsivity, risk-taking, and disinhibition are distinct although overlapping; a taxonomy of the kinds of breakdowns of SR associated with psychopathology requires their differentiation. Fourth, different aspects of the SR universe can be organized hierarchically in relation to granularity, development, and time. Low-level components assemble into high-level components. This hierarchical perspective is consistent across literatures.

CONCLUSIONS

It is hoped that the framework outlined here will facilitate integration and cross-talk among investigators working from different perspectives, and facilitate individual differences research on how SR relates to developmental psychopathology.