Restricting diet for perceived health benefit: A mixed-methods exploration of peripartum food taboos in rural Cambodia.

Food taboos encompass food restrictions practiced by a group that go beyond individual preferences. During pregnancy and lactation, food taboos may contribute to inadequate nutrition and poor maternal and infant health. Restriction of specific fish, meat, fruits and vegetables is common among peripartum women in many Southeast Asian countries, but data from Cambodia are lacking. In this mixed-methods study, 335 Cambodian mothers were asked open-ended questions regarding dietary behaviours during pregnancy and up to 24 weeks postpartum. Descriptive statistics and content analysis were used to characterize food taboos and multiple logistic regression analyses were conducted to identify predictors of this practice. Participants were 18-44 years of age, all of Khmer ethnicity and 31% were primiparous. Sixty-six per cent of women followed food taboos during the first 2 weeks postpartum, whereas ~20% of women restricted foods during other peripartum periods. Pregnancy taboos were often beneficial, including avoidance of sugar-sweetened beverages, coffee and alcohol. Conversely, postpartum avoidances typically included nutrient-dense foods such as fish, raw vegetables and chicken. Food taboos were generally followed to support maternal and child health. No significant predictors of food taboos during pregnancy were identified. Postpartum, each additional live birth a woman had reduced her odds of following food taboos by 24% (odds ratio [95% confidence interval]: 0.76 [0.61-0.95]). Specific food taboo practices and rationales varied greatly between women, suggesting that food taboos are shaped less by a strict belief system within the Khmer culture and more by individual or household understandings of food and health during pregnancy and postpartum.

Predicting child effortful control: An integrative analysis of child physiological, familial, and community factors.

Effortful control (EC) is a regulatory capacity that refers to children's ability to inhibit a dominant response to perform a subdominant response. Although attempts have been made to identify early predictors of children's EC, the confluence and interaction of child-, familial-, and community factors has not been pursued adequately. This study investigated how predictors from different aspects of children's rearing environment interacted to predict later EC. In a sample of 88 primiparous women with elevated depressive symptomotology and low household income, we examined how children's own psychobiology (baseline cortisol), familial relationship (mother-child attachment), and community resources (social support) at 17 months independently and jointly predicted EC at age 5. Our results showed that, controlling for maternal depressive symptomotology and household income, predictors from child-, familial-, and community-aspect function integratively, rather than independently, in predicting later EC. Specifically, within the context of a secure attachment relationship, baseline cortisol positively predicts later EC only for children of mothers who reported low social support. Whereas within the context of an insecure attachment relationship, baseline cortisol negatively predicts later EC, regardless of the perceived social support levels. Our results highlighted the importance of taking into consideration predictors from multiple aspects for intervention designs.

Contributions of early adversity to pro-inflammatory phenotype in infancy: the buffer provided by attachment security.

Adversity early in life is associated with systemic inflammation by adolescence and beyond. At present, few studies have investigated the associations between different forms of adversity and inflammation during infancy, making it difficult to specify the origins of disease vulnerability. This study examined the association between multiple forms of early adversity - socioeconomic status disadvantage, familial stress, maternal depression, and security of attachment - and individual differences in a composite measure of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8, and tumor necrosis factor-alpha) and the inflammatory protein C-reactive protein that were collected via saliva when (n = 49) children were 17 months old. In addition to gauging the direct effects of adversity, we also tested the hypothesis that infants' attachment relationship with their mother might buffer infants against the immunologic effects of early adversity. Results show that familial stress, maternal depression, and security of attachment were directly associated with infant salivary inflammation and that attachment status moderated the effect of maternal depression. The findings suggest that exposure to certain forms of adversity very early in life may engender a pro-inflammatory phenotype with possible life-long implications for health.

Association between early life adversity and inflammation during infancy.

Early life adversity is associated with adult elevations of inflammatory markers such as circulating levels of C-reactive protein (CRP). Few studies have measured inflammation or its association with psychosocial stress during infancy. Existing evidence suggests that early adversity can embed itself into young children's biology with implications for lifelong development. This study examined the association between psychosocial stress and salivary CRP in infants. Early adversity in the form of socioeconomic disadvantage and maternal psychosocial stress were measured when infants were 17 months old. Resting state saliva samples were collected to assess CRP (pg/ml) levels via enzyme immunoassay. Results revealed that both socioeconomic disadvantage and maternal psychosocial stress were independently associated with higher infant CRP levels. These results raise questions about timing of exposure to adversity, and about the potentially lasting effects on inflammatory processes when such exposure occurs early in development.

Shaping emotion regulation: attunement, symptomatology, and stress recovery within mother-infant dyads.

The foundations of emotion regulation are organized, in part, through repeated interactions with one's caregiver in infancy. Less is known about how stress physiology covaries between a mother and her infant within these interactions, leaving a gap in our understanding of how the biological basis of emotion regulation develops. This study investigated physiological attunement between mothers and their 5-month-old infants, as well as the influence of maternal depression and anxiety, during stress recovery. During the reengagement phase of the Still Face Paradigm, mother-infant dyads exhibited negative attunement, as measured by inverse covariation of respiratory sinus arrhythmia (RSA). Increases in maternal RSA corresponded to decreases in infant RSA, underscoring dyadic adjustment during recovery. Moreover, infant regulation differed as a function of maternal anxiety, with more anxious mothers having infants with higher RSA during reengagement. Implications for the consolidation of regulatory capabilities within the context of the early caregiving relationship are discussed.

Rates of motorcycle helmet use and reasons for non-use among adults and children in Luang Prabang, Lao People's Democratic Republic.

BACKGROUND: Motorcycles make up 81 % of the total vehicle population and 74 % of road traffic deaths in Lao PDR. Helmets reduce the risk and severity of injuries resulting from motorcycle accidents by 72 %. Although Lao law mandates motorcycle helmet use among drivers and passengers, the prevalence of helmet use in Luang Prabang, Lao PDR is unknown. This project aimed to measure the prevalence of motorcycle helmet use among riders (i.e., drivers and passengers) in Luang Prabang. METHODS: An observational survey in Luang Prabang was conducted in February 2015 to measure the prevalence of motorcycle helmet use among drivers and passengers. Additionally, non-helmet wearing riders were surveyed to identify the reasons for helmet non-use. RESULTS: Of 1632 motorcycle riders observed, only 16.2 % wore helmets. Approximately 29 % of adults wore helmets while less than 1 % of all children wore helmets. When surveyed about attitudes towards helmet use, the majority of adult drivers indicated that they did not like how adult helmets feel or made them look. Additionally, almost half of motorcyclists who did not own child helmets reported that their child was too young to wear a helmet. CONCLUSIONS: Our finding that children wear helmets at significantly lower rates compared to adults is consistent with findings from neighboring countries in Southeast Asia. Results of this study have implications for public health campaigns targeting helmet use, especially among children.

Why Mothers and Young Children Agree or Disagree in Their Reports of the Child's Problem Behavior.

This study examined multiple determinants of discrepancies between mother and child reports of problem behavior. In 5,414 6-year-olds, child problem behavior was assessed by self-report using the Berkeley Puppet Interview and by maternal report using the Child Behavior Checklist. Patterns in mother-child reports were modeled using latent profile analysis. Four profiles, differing in problem level, and the direction and magnitude of mother-child discrepancies, were identified: one profile representing agreement (46%), another representing slight discrepancies (30%), and two representing higher problem levels and more discrepancies. In the latter two profiles either children (11%) or mothers (13%) reported more problems. Compared to the first profile, the second was predominantly characterized by a positive family environment, the third by child cognitive difficulties, and the fourth by harsh discipline and poor family functioning. Knowledge about specific child/family characteristics that contribute to mother-child discrepancies can help to interpret informants' reports and to make diagnostic decisions.

Poverty, problem behavior, and promise: differential susceptibility among infants reared in poverty.

Do infants reared in poverty exhibit certain physiological traits that make them susceptible to the positive and negative features of their caregiving environment? Guided by theories of differential susceptibility and biological sensitivity to context, we evaluated whether high baseline respiratory sinus arrhythmia (RSA) operates as a susceptibility factor among infants reared in poverty (N = 73). Baseline RSA at 5 months, the quality of the attachment relationship at 17 months, and the interaction of these two factors were included in our models as predictors of problem behavior at 17 months. Consistent with theory, results showed no significant differences in problem behavior among infants with low baseline RSA; however, infants with high baseline RSA exhibited the lowest levels of problem behavior if reared in an environment that fostered security, and they exhibited the highest levels of problem behavior if reared in an environment that fostered disorganization. These results have important implications for the psychological health of infants living in poverty.

Predicting maternal sensitivity: The roles of postnatal depressive symptoms and parasympathetic dysregulation.

Previous research has established that maternal depression is a risk factor for a variety of negative developmental outcomes among infants and children. Although low levels of maternal sensitivity have been hypothesized to explain this risk, the biological mechanisms underlying the association between maternal depressive symptoms and low levels of maternal sensitivity have been largely underexplored. This study examined the roles of postnatal depressive symptoms and parasympathetic nervous system functioning as predictors of low levels of maternal sensitivity, during a stressful mother-infant interaction-the reunion phase of the Still-Face Paradigm. Depressive symptoms and traitlike predispositions toward parasympathetic dysregulation, as indexed by low resting levels of respiratory sinus arrhythmia, were associated independently with less sensitive parenting. Discussion considers that during stressful mother-infant interactions, both mothers with depressive symptoms and mothers predisposed to parasympathetic dysregulation may have fewer emotional, physiological, and psychological resources with which to respond sensitively to their infants' cues.

Risky shifts: how the timing and course of mothers' depressive symptoms across the perinatal period shape their own and infant's stress response profiles.

We investigated the effects of timing and the course of maternal perinatal depressive symptoms on mother-infant hypothalamic-pituitary-adrenal (HPA) response profiles during an attachment stressor, as well as on within-dyad synchrony of stress profiles: coordination of HPA and sympathetic nervous system and infant-mother HPA attunement. Mothers (n = 86) completed the Center for Epidemiological Studies Depression Scale during pregnancy (Time 1 [T1]) and at 5 months (T2) and 18 months (T3) postnatal. At T3 mother-infant dyads completed the Strange Situation, and four saliva samples collected from both mothers and infants were assayed for cortisol and α-amylase. Hierarchical linear modeling was used to predict mother-infant cortisol response trajectories and within-dyad synchronies by main and interactive effects of T1-T3 Center for Epidemiological Studies Depression Scale scores. Main effects of earlier (T1, T2) depressive symptoms predicted mothers' cortisol trajectories and coordination, and interactions of T1 with postnatal (T2 and T3) symptoms predicted infants' cortisol trajectories, coordination, and attunement. Decomposition of interactions revealed more marked effects on infant cortisol trajectories when the mother shifted from higher to lower depressive symptoms (or vice versa) across the perinatal period. Shifts from lower to higher symptoms also predicted inverse coordination of cortisol with salivary α-amylase and greater attunement of infant with mother cortisol. Implications for the development and transmission of stress dysregulation are discussed.

Assessment of salt intake to consider salt as a fortification vehicle for thiamine in Cambodia.

Thiamine deficiency is a public health issue in Cambodia. Thiamine fortification of salt has been proposed; however, the salt intake of lactating women, the target population, is currently unknown. We estimated salt intakes among lactating women (<6 months postpartum) using three methods: repeat observed-weighed intake records and 24-h urinary sodium excretions (n = 104), and household salt disappearance (n = 331). Usual salt intake was estimated by adjusting for intraindividual intakes using the National Cancer Institute method, and a thiamine salt fortification scenario was modeled using a modified estimated average requirement (EAR) cut-point method. Unadjusted salt intake from observed intakes was 9.3 (8.3-10.3) g/day, which was not different from estimated salt intake from urinary sodium excretions, 9.0 (8.4-9.7) g/day (P = 0.3). Estimated salt use from household salt disappearance was 11.3 (10.7-11.9) g/person/day. Usual (adjusted) salt intake from all sources was 7.7 (7.4-8.0) g/day. Assuming no stability losses, a modeled fortification dose of 275 mg thiamine/kg salt could increase thiamine intakes from fortified salt to 2.1 (2.0-2.2) mg/day, with even low salt consumers reaching the EAR of 1.2 mg/day from fortified salt alone. These findings, in conjunction with future sensory and stability research, can inform a potential salt fortification program in Cambodia.

Thiamine supplementation holds neurocognitive benefits for breastfed infants during the first year of life.

Women reliant on mostly rice-based diets can have inadequate thiamine intake, placing breastfed infants at risk of thiamine deficiency and, in turn, physical and cognitive impairments. We investigated the impact of maternal thiamine supplementation doses on infants' cognitive, motor, and language development across the first year. In this double-blind, four-parallel-arm, randomized controlled trial, healthy mothers of exclusively breastfed newborn infants were recruited in Kampong Thom, Cambodia. At 2 weeks postnatal, women (n = 335) were randomized to one of four treatment groups to consume one capsule/day with varying amounts of thiamine for 22 weeks: 0, 1.2, 2.4, and 10 mg. At 2, 12, 24, and 52 weeks of age, infants were assessed with the Mullen Scales of Early Learning (MSEL) and the Caregiver Reported Early Development Instrument (CREDI). Multiple regression and mixed effects modeling suggest that by 6 months of age, the highest maternal thiamine dose (10 mg/day) held significant benefits for infants' language development, but generally not for motor or visual reception development. Despite having achieved standardized scores on the MSEL that approximated U.S. norms by 6 months, infants showed a significant drop relative to these norms in both language domains following trial completion, indicating that nutritional interventions beyond 6 months may be necessary.

Low-dose thiamine supplementation of lactating Cambodian mothers improves human milk thiamine concentrations: a randomized controlled trial.

BACKGROUND: Infantile beriberi-related mortality is still common in South and Southeast Asia. Interventions to increase maternal thiamine intakes, and thus human milk thiamine, are warranted; however, the required dose remains unknown. OBJECTIVES: We sought to estimate the dose at which additional maternal intake of oral thiamine no longer meaningfully increased milk thiamine concentrations in infants at 24 wk postpartum, and to investigate the impact of 4 thiamine supplementation doses on milk and blood thiamine status biomarkers. METHODS: In this double-blind, 4-parallel arm randomized controlled dose-response trial, healthy mothers were recruited in Kampong Thom, Cambodia. At 2 wk postpartum, women were randomly assigned to consume 1 capsule, containing 0, 1.2 (estimated average requirement), 2.4, or 10 mg of thiamine daily from 2 through 24 weeks postpartum. Human milk total thiamine concentrations were measured using HPLC. An Emax curve was plotted, which was estimated using a nonlinear least squares model in an intention-to-treat analysis. Linear mixed-effects models were used to test for differences between treatment groups. Maternal and infant blood thiamine biomarkers were also assessed. RESULTS: In total, each of 335 women was randomly assigned to1 of the following thiamine-dose groups: placebo (n = 83), 1.2 mg (n = 86), 2.4 mg (n = 81), and 10 mg (n = 85). The estimated dose required to reach 90% of the maximum average total thiamine concentration in human milk (191 µg/L) is 2.35 (95% CI: 0.58, 7.01) mg/d. The mean ± SD milk thiamine concentrations were significantly higher in all intervention groups (183 ± 91, 190 ± 105, and 206 ± 89 µg/L for 1.2, 2.4, and 10 mg, respectively) compared with the placebo group (153 ± 85 µg/L; P < 0.0001) and did not significantly differ from each other. CONCLUSIONS: A supplemental thiamine dose of 2.35 mg/d was required to achieve a milk total thiamine concentration of 191 µg/L. However, 1.2 mg/d for 22 wk was sufficient to increase milk thiamine concentrations to similar levels achieved by higher supplementation doses (2.4 and 10 mg/d), and comparable to those of healthy mothers in regions without beriberi. This trial was registered at clinicaltrials.gov as NCT03616288.

Linking marital conflict and children's adjustment: the role of young children's perceptions.

Young children's (n = 96) perceptions and appraisals of their parents' marital conflict were evaluated at age 5 and again at age 6. Concurrent reports of marital conflict by each parent and teachers' reports of children's classroom adjustment served as criteria against which to evaluate the validity of young children's perceptions. Children's perceptions of their parents' marital relationship were significantly correlated with spouses' reports at ages 5 and 6, as well as correlated with teacher reports of internalizing and externalizing problems. Consistent with the cognitive-contextual theory, children's tendency to blame themselves for their parents' conflict partially mediated the link between marital conflict and children's internalizing symptoms. In contrast, children's reports that they become involved in their parents' conflict partially mediated the effect of marital conflict on externalizing problems.

Thiamine dose response in human milk with supplementation among lactating women in Cambodia: study protocol for a double-blind, four-parallel arm randomised controlled trial.

INTRODUCTION: Thiamine (vitamin B1) deficiency remains a concern in Cambodia where women with low thiamine intake produce thiamine-poor milk, putting their breastfed infants at risk of impaired cognitive development and potentially fatal infantile beriberi. Thiamine fortification of salt is a potentially low-cost, passive means of combating thiamine deficiency; however, both the dose of thiamine required to optimise milk thiamine concentrations as well as usual salt intake of lactating women are unknown. METHODS AND ANALYSIS: In this community-based randomised controlled trial, 320 lactating women from Kampong Thom, Cambodia will be randomised to one of four groups to consume one capsule daily containing 0, 1.2, 2.4 or 10 mg thiamine as thiamine hydrochloride, between 2 and 24 weeks postnatal. The primary objective is to estimate the dose where additional maternal intake of thiamine no longer meaningfully increases infant thiamine diphosphate concentrations 24 weeks postnatally. At 2, 12 and 24 weeks, we will collect sociodemographic, nutrition and health information, a battery of cognitive assessments, maternal (2 and 24 weeks) and infant (24 weeks only) venous blood samples (biomarkers: ThDP and transketolase activity) and human milk samples (also at 4 weeks; biomarker: milk thiamine concentrations). All participants and their families will consume study-provided salt ad libitum throughout the trial, and we will measure salt disappearance each fortnight. Repeat weighed salt intakes and urinary sodium concentrations will be measured among a subset of 100 participants. Parameters of Emax dose-response curves will be estimated using non-linear least squares models with both 'intention to treat' and a secondary 'per-protocol' (capsule compliance ≥80%) analyses. ETHICS AND DISSEMINATION: Ethical approval was obtained in Cambodia (National Ethics Committee for Health Research 112/250NECHR), Canada (Mount Saint Vincent University Research Ethics Board 2017-141) and the USA (University of Oregon Institutional Review Board 07052018.008). Results will be shared with participants' communities, as well as relevant government and scientific stakeholders via presentations, academic manuscripts and consultations. TRIAL REGISTRATION NUMBER: NCT03616288.

Increased levels of inflammation among infants with disorganized histories of attachment.

Early life adversity is associated with adult elevations of inflammatory markers such as circulating levels of C-reactive protein (CRP). Few studies have examined inflammation levels during infancy nor the associations between sources of adversity and concurrent inflammation early in life. Existing evidence suggests that early adversity in the form of compromised caregiving relationships can embed itself into young children's biology with implications for lifelong development. This study examined the association between infants' histories of attachment with their mothers and salivary concentrations of CRP, all of which were assessed when infants were 17 months of age. Results show that infants with disorganized attachments histories and those exhibiting disorganized and avoidant regulatory behaviors when faced with an attachment stressor were all associated with significantly elevated levels of salivary CRP. These results suggest that exposure to significant interpersonal adversity very early in life may engender a proinflamotry phenotype with life-long implications for health.

Links between early baseline cortisol, attachment classification, and problem behaviors: A test of differential susceptibility versus diathesis-stress.

The purpose of the current study was to predict concurrent levels of problem behaviors from young children's baseline cortisol and attachment classification, a proxy for the quality of caregiving experienced. In a sample of 58 children living at or below the federal poverty threshold, children's baseline cortisol levels, attachment classification, and problem behaviors were assessed at 17 months of age. We hypothesized that an interaction between baseline cortisol and attachment classification would predict problem behaviors above and beyond any main effects of baseline cortisol and attachment. However, based on limited prior research, we did not predict whether or not this interaction would be more consistent with diathesis-stress or differential susceptibility models. Consistent with diathesis-stress theory, the results indicated no significant differences in problem behavior levels among children with high baseline cortisol. In contrast, children with low baseline cortisol had the highest level of problem behaviors in the context of a disorganized attachment relationship. However, in the context of a secure attachment relationship, children with low baseline cortisol looked no different, with respect to problem behavior levels, then children with high cortisol levels. These findings have substantive implications for the socioemotional development of children reared in poverty.

Developmental trajectories of co-occurring depressive, eating, antisocial, and substance abuse problems in female adolescents.

Growth trajectories of co-occurring symptomatology were examined in a community sample of 493 female adolescents who were followed annually from early to late adolescence. On average, depression, eating disorder, and substance abuse symptoms increased over time, whereas antisocial behavior decreased. Increases in each symptom domain were associated with relative increases in all other domains. Initial depressive and antisocial behavior symptoms predicted future increases in the other; substance abuse and antisocial behavior symptoms also showed prospective reciprocal relations. Initial depression predicted increases in eating disorder and substance abuse symptoms. Initial eating disorder symptoms predicted increases in substance abuse problems. Finally, the results suggest that the developmental covariation between depressive and eating disorder symptoms and between antisocial behavior and substance abuse symptoms was accounted for by distinct but related 2nd-order growth parameters.

A prospective test of the negative affect model of substance abuse: moderating effects of social support.

The authors tested whether dimensions of negative affect--specifically, trait levels of negative emotionality and state levels of depressive symptoms--increased risk for substance abuse onset and whether perceived social support moderated this relation using data from a 5-year prospective study of 496 school-recruited adolescent girls. Initial negative emotionality, but not depressive symptoms, and deficits in parental, but not peer, support predicted future substance abuse onset in a multivariate hazard model. Tests of the interaction between negative affect dimensions and social support suggested that support did not moderate the relation of negative affect to risk for substance abuse onset. Results provide prospective support for the etiological role in the onset of substance abuse of trait-linked negative affect and of parental support.