Parenting: roots of the sweet tooth

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.

Thrifty-Eating Behavior Phenotype at the Food Court - Programming Goes Beyond Food Preferences

INTRODUCTION

Prenatal growth impairment leads to higher preference for palatable foods in comparison to normal prenatal growth subjects, which can contribute to increased body fat mass and a higher risk for developing chronic diseases in small-for-gestational-age (SGA) individuals throughout life. This study aimed to investigate the effect of SGA on feeding behavior in children and adolescents, as well as resting-state connectivity between areas related to reward, self-control, and value determination, such as orbitofrontal cortex (OFC), dorsolateral prefrontal cortex (DL-PFC), amygdala and dorsal striatum (DS).

METHODS

Caregivers and their offspring were recruited from two independent cohorts in Brazil (PROTAIA) and Canada (MAVAN). Both cohorts included anthropometric measurements, food choice tasks, and resting-state functional magnetic resonance imaging (fMRI) data.

RESULTS

In the Brazilian sample (17 ± 0.28 years, n=70), 21.4% of adolescents were classified as SGA. They exhibited lower monetary-related expenditure to buy a snack compared to controls in the food choice test. Decreased functional connectivity (n=40) between left OFC and left DL-PFC; and between right OFC and: left amygdala, right DS, and left DS were observed in the Brazilian SGA participants. Canadian SGA participants (14.9%) had non-significant differences in comparison with controls in a food choice task at 4 years old ( ± 0.01, n=315). At a follow-up brain scan visit (10.21 ± 0.140 years, n=49), SGA participants (28.6%) exhibited higher connectivity between the left OFC and left DL-PFC, also higher connectivity between the left OFC and right DL-PFC. We did not observe significant anthropometric neither nutrients' intake differences between groups in both samples.

CONCLUSIONS

Resting-state fMRI results showed that SGA individuals had altered connectivity between areas involved in encoding the subjective value for available goods and decision-making in both samples, which can pose them in disadvantage when facing food options daily. Over the years, the cumulative exposure to particular food cues together with the altered behavior towards food, such as food purchasing, as seen in the adolescent cohort, can play a role in the long-term risk for developing chronic non-communicable diseases.

The fetal programming of food preferences: current clinical and experimental evidence

Increased energy consumption is one of the major factors implicated in the epidemic of obesity. There is compelling evidence, both clinical and experimental, that fetal paucity of nutrients may have programming effects on feeding preferences and behaviors that can contribute to the development of diseases. Clinical studies in different age groups show that individuals born small for their gestational age (SGA) have preferences towards highly caloric foods such as carbohydrates and fats. Some studies have also shown altered eating behaviors in SGA children. Despite an apparent discrepancy in different age groups, all studies seem to converge to an increased intake of palatable foods in SGA individuals. Small nutrient imbalances across lifespan increase the risk of noncommunicable diseases in adult life. Homeostatic factors such as altered responses to leptin and insulin and alterations in neuropeptides associated with appetite and satiety are likely involved. Imbalances between homeostatic and hedonic signaling are another proposed mechanism, with the mesocorticolimbic dopaminergic pathway having differential reward and pleasure responses when facing palatable foods. Early exposure to undernutrition also programs hypothalamic-pituitary-adrenal axis, with SGA having higher levels of cortisol in different ages, leading to chronic hyperactivity of this neuroendocrine axis. This review summarizes the clinical and experimental evidence related to fetal programming of feeding preferences by SGA.