Challenges and opportunities when moving food production and consumption toward sustainable diets in the Nordics: a scoping review for Nordic Nutrition Recommendations 2023.

The terms 'Nordic countries' or 'The Nordics' include the five countries Denmark, Finland, Island, Norway, and Sweden. This review includes evaluation of the Nordic countries against Food and Agricultural Organisation (FAO)/World Health Organizations' (WHO) guiding principles for healthy, sustainable diets with respect to environmental impact (principles #9 - #13) and sociocultural aspects (principles #14 - #16). A food systems perspective is taken to summarize and discuss the most important challenges and opportunities for achieving sustainable diets. Food system, food security, self-sufficiency, and resilience perspectives are applied. The information can underpin decisions when developing and implementing Food Based Dietary Guidelines (FBDG) in the Nordics. None of the Nordic countries are on track to reach the 2030 UN climate and biodiversity goals. We describe how food production, processing, and consumption contribute to these and other environmental challenges, and what kinds of dietary changes/transitions consistent with these goals are required. A major challenge is the high production and consumption of meat and too low consumption of fish, vegetables, and fruits. Meat production is a major source of emissions and, together with farmed fish, heavily dependent on imported feed ingredients, leaving a large land-use and water footprint in exporting countries while domestic land resources are not used optimally. Dietary patterns have changed drastically over the past 50 years, and in large parts of the population, meat consumption has doubled since the 1970s, rendering historic food culture less useful as a basis for present-day recommendations. The Nordics have Europe's lowest use of antibiotics in animal and fish production and have made some progress in reducing food waste along the food chain. A major opportunity is better alignment of food production and consumption based on local or regional production potentials, in conjunction with better and more constructive integration with the global food system while integrating novel technologies to reduce emissions and resource use.

Early life exposure to mercury and relationships with telomere length and mitochondrial DNA content in European children.

BACKGROUND: Telomere length (TL) and mitochondrial function expressed as mitochondrial DNA copy number (mtDNAcn) are biomarkers of aging and oxidative stress and inflammation, respectively. Methylmercury (MeHg), a common pollutant in fish, induces oxidative stress. We hypothesized that elevated oxidative stress from exposure to MeHg decreases mtDNAcn and shortens TL. METHODS: Study participants are 6-11-year-old children from the HELIX multi-center birth cohort study, comprising six European countries. Prenatal and postnatal total mercury (THg) concentrations were measured in blood samples, TL and mtDNAcn were determined in child DNA. Covariates and confounders were obtained by questionnaires. Robust regression models were run, considering sociodemographic and lifestyle covariates, as well as fish consumption. Sex, ethnicity, and fish consumption interaction models were also run. RESULTS: We found longer TL with higher pre- and postnatal THg blood concentrations, even at low-level THg exposure according to the RfD proposed by the US EPA. The prenatal association showed a significant linear relationship with a 3.46 % increase in TL for each unit increased THg. The postnatal association followed an inverted U-shaped marginal non-linear relationship with 1.38 % an increase in TL for each unit increased THg until reaching a cut-point at 0.96 µg/L blood THg, from which TL attrition was observed. Higher pre- and postnatal blood THg concentrations were consistently related to longer TL among cohorts and no modification effect of fish consumption nor children's sex was observed. No association between THg exposure and mtDNAcn was found. DISCUSSION: We found evidence that THg is associated with TL but the associations seem to be time- and concentration-dependent. Further studies are needed to clarify the mechanism behind the telomere changes of THg and related health effects.

Maternal vitamin D status and risk of childhood overweight at 5 years of age in two Nordic cohort studies.

Introduction: Maternal vitamin D status during pregnancy has been suggested to have a role in childhood adiposity development, but results are conflicting. Our aims were to investigate [1] the relationships between maternal 25-hydroxyvitamin D (25OHD) during pregnancy and the child's body mass index (BMI) and risk of overweight at 5 years of age, and [2] maternal pre-pregnancy BMI as effect modifier for these associations. Methods: Data sources included a subsample from the Norwegian Mother, Father and Child Cohort Study (MoBa sub-cohort; N = 2,744) and the Swedish GraviD cohort study (N = 891). Maternal 25OHD was analyzed in gestational week 18 in the MoBa sub-cohort and week 10 in the GraviD cohort. In the MoBa sub-cohort, parents reported their child's documented measures of weight and length or height from the health card at routine check-up. In the GraviD cohort, this information was collected directly from medical records. Childhood overweight (including obesity) was identified using the International Obesity Task Force cut-offs. Linear and logistic regression models were used to investigate the association between maternal 25OHD and child's BMI and risk of overweight at 5 years of age in each cohort separately, and in a pooled dataset. Results: In the pooled analysis, maternal 25OHD <30 nmol/L was associated with lower BMI in children at 5 years of age, but not with risk of overweight. Interaction analysis showed that the association was predominant among children of mothers with pre-pregnancy BMI ≥25 kg/m2. Conclusion: Low maternal vitamin D status, particularly in mothers with overweight or obesity, predicted lower BMI in their five-year-old children. However, there was no evidence of an effect on overweight in these children.

Vitamin D intake and determinants of vitamin D status during pregnancy in The Norwegian Mother, Father and Child Cohort Study.

Background: Norwegian data on vitamin D status among pregnant women indicate a moderate to high prevalence of insufficient vitamin D status (25-hydroxyvitamin D (25OHD) concentrations ≤50 nmol/L). There is a lack of population-based research on vitamin D intake and determinants of 25OHD in pregnant women from northern latitudes. The aims of this study were (1) to evaluate total vitamin D intake from both diet and supplements, (2) to investigate determinants of vitamin D status, and (3) to investigate the predicted response in vitamin D status by total vitamin D intake, in pregnant Norwegian women. Methods: In total, 2,960 pregnant women from The Norwegian Environmental Biobank, a sub-study within The Norwegian Mother, Father and Child Cohort Study (MoBa), were included. Total vitamin D intake was estimated from a food frequency questionnaire in gestational week 22. Concentrations of plasma 25OHD was analyzed by automated chemiluminescent microparticle immunoassay method in gestational week 18. Candidate determinant variables of 25OHD were chosen using stepwise backward selection and investigated using multivariable linear regression. Predicted 25OHD by total vitamin D intake, overall and stratified by season and pre-pregnancy BMI, was explored using restricted cubic splines in an adjusted linear regression. Results: Overall, about 61% of the women had a total vitamin D intake below the recommended intake. The main contributors to total vitamin D intake were vitamin D supplements, fish, and fortified margarine. Higher 25OHD concentrations were associated with (in descending order of the beta estimates) summer season, use of solarium, higher vitamin D intake from supplements, origin from high income country, lower pre-pregnancy BMI, higher age, higher vitamin D intake from foods, no smoking during pregnancy, higher education and energy intake. During October-May, a vitamin D intake according to the recommended intake was predicted to reach sufficient 25OHD concentrations >50 nmoL/L. Conclusion: The findings from this study highlight the importance of the vitamin D intake, as one of few modifiable determinants, to reach sufficient 25OHD concentrations during months when dermal synthesis of vitamin D is absent.

Ultra-processed food consumption and associations with biomarkers of nutrition and inflammation in pregnancy: The Norwegian Environmental Biobank.

Background: A high consumption of ultra-processed foods (UPFs) is often associated with low nutritional quality, but data on associations with biomarkers are scarce. We aimed to explore associations between UPF intake, diet quality, and concentrations of biomarkers of nutrition and inflammation measured in mid-pregnancy. Methods: This cross-sectional study included n = 2,984 pregnant women recruited during 2002-2008 in the Norwegian Mother, Father, and Child Cohort Study (MoBa). Concentrations of C-reactive protein (CRP) and 21 nutritional biomarkers including carotenes (α-carotene, ß-carotene, γ-carotene, α-cryptoxanthin, ß-cryptoxanthin, lutein, lycopene), vitamins [α-tocopherol, γ-tocopherol, 25-hydroxyvitamin D (25-OH-D), retinol], creatinine, elements (K, Na, Co, Cu, Mn, Mo, Se, Zn), and ferritin (Fe) were measured in blood and urine collected in mid-pregnancy. Habitual diet in pregnancy was assessed using a validated semi-quantitative food frequency questionnaire. We calculated the relative (%) energy contribution of UPF to overall intake according to the NOVA classification. We also applied a diet quality index (DQI) adapted to assess adherence to Norwegian dietary guidelines (DQI; min-max: 0-110, higher score meaning higher adherence). We present summary statistics for biomarker concentrations and explored associations between UPF intake or the DQI and measured biomarkers using adjusted linear, logistic, and generalized additive regression models. Results: Ultra-processed food intake was positively associated with biomarker concentrations of vitamin E (γ-tocopherol), creatinine, K, and Na [ßs: 5.6 to 17% increase in biomarker concentration per interquartile range (IQR) increase in UPF intake] and negatively associated with carotenoids (α-carotene, ß-carotene, γ-carotene, α-cryptoxanthin, ß-cryptoxanthin, lutein, lycopene), vitamin A, Mo, and Se (ßs: -2.1 to -18%). Inversely, high diet quality (i.e., the DQI) was positively associated with concentrations of carotenoids, vitamins [vitamin A (retinol) and D (25-OH-D)], and Se (ß: 1.5 to 25%) and negatively associated with vitamin E (γ-tocopherol), creatinine, and Na (ß: -4.8 to -8.3%). A weak, positive association was found between UPF and CRP (ß: 5.4%, 95% CI 0.12-11%). Conclusion: High UPF intake was associated with reduced concentrations of nutrition biomarkers in mid-pregnancy. Associations in the opposite direction were found with high adherence to the Norwegian dietary guidelines, suggesting that the two dietary scoring systems capture diet quality in a mirrored manner in this population.

Maternal vitamin D status in relation to infant BMI growth trajectories up to 2 years of age in two prospective pregnancy cohorts.

Background: Early childhood growth can affect the child's health status later in life. Maternal vitamin D status has been suggested to affect early childhood growth. However, there is a lack of studies investigating the role of maternal vitamin D status on growth trajectories during infancy. By using growth mixture modeling (GMM), maternal vitamin D status during pregnancy can be investigated in relation to different classes of infant growth trajectories. Objectives: To examine the association between maternal 25-hydroxyvitamin D (25OHD) and classes of infant body mass index (BMI) growth trajectories. Methods: Mother-child pairs were included from the Norwegian Mother, Father, and Child Cohort Study (MoBa, n = 2522) and the Swedish GraviD cohort (n = 862). Maternal 25OHD in pregnancy was analyzed by liquid chromatography tandem mass spectrometry. Children's weights and heights were registry-based. GMM identified classes of infant BMI growth trajectories up to 2 years. The association between maternal 25OHD and infant BMI class by cohort was estimated using a log-link generalized linear model. Mixed model analysis estimated the pooled association including both cohorts. Results: Two infant BMI classes were identified, stable normal and stable high. In MoBa, maternal 25OHD <50 and 50-75 nmol/L were associated (RR 2.70, 95% CI 1.26-5.77 and RR 2.56, 95% CI 1.20-5.47) with a higher risk of the infant stable high BMI class, compared with 25OHD >75 nmol/L. In GraviD, no association was found. In pooled analysis, maternal 25OHD ≤75 nmol/L was non-significantly associated with a higher risk of the stable high BMI growth class. Conclusions: Maternal 25OHD ≤75 nmol/L may be associated with a higher class of BMI growth trajectory during infancy.

Mild-to-moderate iodine deficiency and symptoms of emotional distress and depression in pregnancy and six months postpartum - Results from a large pregnancy cohort.

BACKGROUND: The relationship between iodine intake and depression is unknown. The aim of the present study was to investigate whether iodine intake was associated with symptoms of perinatal emotional distress and depression in a mild- to moderately iodine deficient population. METHODS: The study population comprised 67,812 women with 77,927 pregnancies participating in the Norwegian Mother, Father and Child Cohort Study. Self-reported emotional distress and depressive symptoms were reported in pregnancy and at six months postpartum. Iodine intake was assessed by a food frequency questionnaire in mid-pregnancy. Urinary iodine concentration (UIC) was available for 2792 pregnancies. RESULTS: The median iodine intake from food was 121 µg/day and the median UIC was 68 µg/L. The prevalence of high scores for emotional distress was 6.6 % in pregnancy and 5.8 % six months postpartum, and for high scores on postpartum depression it was 10.3 %. In non-users of iodine supplements (63 %), a low maternal iodine intake from food (lower than ~100-150 µg/day) was associated with increased risk of high scores of emotional distress and depression both in pregnancy and six months postpartum (p < 0.001). Iodine supplement use was associated with increased risk of high scores of emotional distress in pregnancy compared to no supplement use or use of supplements without iodine. LIMITATIONS: Observational design, self-report information, and short scales to assess symptoms of emotional distress and depression. CONCLUSION: A low habitual iodine intake was associated with increased prevalence of perinatal emotional distress and depression. The potential non-beneficial effect of iodine supplements may have biological explanations. More studies are needed.

Enhancing Human Biomonitoring Studies through Linkage to Administrative Registers-Status in Europe.

Record linkage of human biomonitoring (HBM) survey data with administrative register data can be used to enhance available datasets and complement the possible shortcomings of both data sources. Through record linkage, valuable information on medical history (diagnosed diseases, medication use, etc.) and follow-up information on health and vital status for established cohorts can be obtained. In this study, we investigated the availability of health registers in different EU Member States and EEA countries and assessed whether they could be linked to HBM studies. We found that the availability of administrative health registers varied substantially between European countries as well as the availability of unique personal identifiers that would facilitate record linkage. General protocols for record linkage were similar in all countries with ethical and data protections approval, informed consent, approval by administrative register owner, and linkage conducted by the register owner. Record linkage enabled cross-sectional survey data to be used as cohort study data with available follow-up and health endpoints. This can be used for extensive exposure-health effect association analysis. Our study showed that this is possible for many, but not all European countries.

Urinary metabolic biomarkers of diet quality in European children are associated with metabolic health.

Urinary metabolic profiling is a promising powerful tool to reflect dietary intake and can help understand metabolic alterations in response to diet quality. Here, we used 1H NMR spectroscopy in a multicountry study in European children (1147 children from 6 different cohorts) and identified a common panel of 4 urinary metabolites (hippurate, N-methylnicotinic acid, urea, and sucrose) that was predictive of Mediterranean diet adherence (KIDMED) and ultra-processed food consumption and also had higher capacity in discriminating children's diet quality than that of established sociodemographic determinants. Further, we showed that the identified metabolite panel also reflected the associations of these diet quality indicators with C-peptide, a stable and accurate marker of insulin resistance and future risk of metabolic disease. This methodology enables objective assessment of dietary patterns in European child populations, complementary to traditional questionary methods, and can be used in future studies to evaluate diet quality. Moreover, this knowledge can provide mechanistic evidence of common biological pathways that characterize healthy and unhealthy dietary patterns, and diet-related molecular alterations that could associate to metabolic disease.

Diet quality of Norwegian children at 3 and 7 years: changes, predictors and longitudinal association with weight.

BACKGROUND/OBJECTIVES: Poor diet quality in early life can have long-term health effects, but the evidence is largely from cross-sectional studies. Our objective was to examine diet quality of Norwegian children by applying a-priori diet quality indices, identify early life determinants and examine prospective associations with overweight. SUBJECTS/METHODS: We included 34,074 preschoolers (3-year-olds) and 18,350 school-aged children (7-years-olds) from the prospective, population-based Norwegian Mother, Father and Child Cohort Study. Diet quality was assessed as (i) adherence to a Mediterranean diet, estimated by the food frequency-based Mediterranean Diet Score (fMDS, score range: 0-6) and (ii) by the diet quality index (DQI, score range: -33% to 100%), reflecting compliance to food-based dietary guidelines. In multivariate analyses we explored perinatal and childhood characteristics as potential determinants of diet quality. We used logistic regression to examine the associations between diet quality at 3 years and BMI status at 8 years, adjusting for relevant confounders and diet quality at 7 years. RESULTS: One in three children had high MD adherence at 3 and 8 years, and DQI (mean 60%) at 3 and 7 years was strongly correlated (r = 0.48, p < 0.001). Short breastfeeding duration, physical activity and sleep duration and long screentime at 18 months were associated with 2-3% lower DQI at 3 years. At both ages, maternal diet quality was the strongest prospective predictor of DQI (beta = 5%, 95% CI = 4.7, 5.2 and beta = 3.1%, 95% CI = 2.8, 3.4), and screentime was the strongest cross-sectional predictor (beta = -5.2%, 95% CI = -5.9, -4.5 and beta = -4.1%, 95% CI = -5.0, -3.2). High DQI score at 3 years, but not MD adherence, was associated with a lower risk for overweight (including obesity) at 8 years, compared to low DQI (lower tertile) (adjusted OR = 0.77, 95% CI = 0.62, 0.96). CONCLUSIONS: Our study provides evidences that high diet quality in early childhood may reduce the risk for overweight in later childhood, independent of the current dietary behaviors.

Prenatal mercury exposure, fish intake and child emotional behavioural regulation in the Norwegian Mother, Father and Child Cohort Study.

Objective: While maternal fish consumption in pregnancy has consistently been linked to better cognitive and emotional outcomes in children, fish is also a primary source of exposure to methyl mercury (MeHg), which has been linked to poorer child cognitive outcomes. The aim of this study was to evaluate the associations between MeHg exposure, using calculated MeHg exposure from maternal diet and total mercury (Hg) concentration in maternal blood during pregnancy, and child internalising and externalising behaviours at 3 and 5 years of age. Design and participants: The study sample comprised 51 238 mother-child pairs in the Norwegian Mother, Father and Child Cohort Study. Data on maternal blood Hg concentration in gestational week 18 were available for a sub-sample of 2936 women. Maternal MeHg exposure from diet was calculated from a validated Food Frequency Questionnaire answered in mid-pregnancy. Mothers reported children's emotional behaviour at age 3 and 5 years by questionnaires including twenty items from the Child Behaviour Checklist. Longitudinal associations were examined using generalised estimating equations, adjusted for potential confounders and stratified by maternal fish intake. Results: Maternal blood Hg concentration (median=1.02 µg/L, 90th percentile=2.22, range=0-13.8) was not associated with emotional behaviour in children. Increasing dietary MeHg intake (median 0.15 µg/kg body weight/week, 90th percentiles=0.31, range=0-1.86) was significantly associated with lower internalising ß=-0.03 (95% CI -0.05 to -0.00) and externalising child behaviours ß=-0.04 (95% CI -0.07 to -0.02) in adjusted models. The inverse associations were also apparent when stratifying by low/high maternal fish intake (<400 and ≥400 g/week). Conclusions: The results indicated that prenatal MeHg exposure, well below the weekly tolerable intake established by European Food Safety Authority (1.3 µg/kg bw), did not adversely affect child emotional regulation. Children of mothers consuming fish regularly were less likely to show signs of emotional behavioural problems.

Maternal vitamin D intake and BMI during pregnancy in relation to child's growth and weight status from birth to 8 years: a large national cohort study.

OBJECTIVES: To examine the associations between maternal vitamin D intake and childhood growth and risk of overweight up to 8 years. We further examined the effect modification by maternal prepregnancy body mass index (BMI). DESIGN: Prospective population-based pregnancy cohort study. SETTING: The Norwegian Mother, Father and Child Cohort Study. PARTICIPANTS: In total, 58 724 mothers and 66 840 singleton children, with information on maternal vitamin D intake during the pregnancy and minimum one postnatal anthropometric measurement. OUTCOME MEASURES: Predicted weight and height growth trajectories and velocities from 1 month to 8 years, rapid growth during infancy and toddlerhood, and risk of overweight in preschool and school age. RESULTS: Overall, maternal vitamin D intake was associated with lower weight trajectory, lower odds of rapid weight growth and higher odds of childhood overweight. In children of mothers with prepregnancy normal weight, maternal vitamin D intake was negatively associated with weight trajectory and lower OR of a rapid weight growth during the first year, compared with reference (<5 µg/day). Children of mothers with normal weight, with maternal vitamin D intakes of 10-15 and >15 µg/day, also had 0.86 (95% CI 0.77 to 0.97) and 0.88 (95% CI 0.79 to 0.99) lower odds for overweight at 3 years, compared with reference. In contrast, in children of mothers with prepregnancy overweight (BMI ≥25 kg/m2), vitamin D intake was positively associated with weight trajectory. Children of mothers with overweight, with maternal vitamin D intake of 5-9.9 µg/day, also had (1.09 (95% CI 1.01 to 1.18) and 1.12 (95% CI 1.02 to 1.23)) higher odds for overweight at 5 years and 8 years, compared with reference. CONCLUSIONS: Maternal vitamin D intake affects postnatal growth and is inversely associated with childhood overweight in children of mothers with normal weight. Associations between maternal vitamin D intake and child growth and risk of overweight varied by prepregnancy BMI.

Maternal selenium intake and selenium status during pregnancy in relation to preeclampsia and pregnancy-induced hypertension in a large Norwegian Pregnancy Cohort Study.

BACKGROUND: Pregnancy-induced hypertensive disorders (PIHD), including preeclampsia, cause maternal and perinatal morbidity and mortality worldwide. Several studies have linked selenium supplementation and selenium status to the risk of preeclampsia, but there are no published prospective population-based studies examining associations between dietary selenium intake and preeclampsia. AIM: To examine associations between selenium intake from diet and supplements and selenium blood status and PIHD incidence, with sub-analyses for pregnancy-induced hypertension (PIH) and preeclampsia, in a large pregnancy cohort. METHOD: The study is based on 69,972 singleton pregnancies from the Norwegian Mother, Father and Child Cohort Study. Maternal dietary selenium intake was assessed with a validated, semi-quantitative food frequency questionnaire at about gestational week 22. Maternal selenium concentrations were measured in whole blood collected around gestational week 18 in a subset of 2572 women. Preeclampsia and PIH diagnosges were obtained from the Medical Birth Registry of Norway. RESULTS: Participants had a median dietary selenium intake of 53 µg/day (IQR 44-62). Dietary selenium intake was not significantly associated with PIHD (adjusted (a) OR 1.03, 95% CI 0.98, 1.08 per SD of selenium intake), preeclampsia or PIH. Threshold analyses for deciles of dietary selenium intake did not show any significant associations. Neither inorganic (aOR 1.01, 95% CI 0.98, 1.05) or organic selenium supplement intake (aOR 0.98, 95% CI 0.95, 1.02) or selenium blood status was significantly associated with PIHD (aOR 1.03, 95% CI 0.86, 1.22) or PIHD subgroups. CONCLUSION: No significant associations were found between reported selenium intake from diet, or dietary supplements or whole-blood selenium status and PIHD in general or preeclampsia specifically. Hence, the results of this large population-based study, with selenium intake close to the recommended daily intake, do not support previous findings indicating a possible protective effect of selenium supplementation or selenium status with regard to preeclampsia incidence.

Maternal Dietary Selenium Intake during Pregnancy and Neonatal Outcomes in the Norwegian Mother, Father, and Child Cohort Study.

Properly working antioxidant defence systems are important for fetal development. One of the nutrients with antioxidant activity is selenium. Increased maternal selenium intake has been associated with reduced risk for being small for gestational age and preterm delivery. Based on the Norwegian Mother, Father, and Child Cohort Study and the Medical Birth Registry of Norway, we investigated the association of maternal selenium intake from food and dietary supplements during the first half of pregnancy (n = 71,728 women) and selenium status in mid-pregnancy (n = 2628 women) with neonatal health, measured as two composite variables (neonatal morbidity/mortality and neonatal intervention). Low maternal dietary selenium intake (<30 µg/day) was associated with increased risk for neonatal morbidity/mortality (adjusted odds ratio (adjOR) 1.36, 95% confidence interval (95% CI) 1.08-1.69) and neonatal intervention (adjOR 1.16, 95% CI 1.01-1.34). Using continuous variables, there were no associations between maternal selenium intake (from diet or supplements) or whole-blood selenium concentration and neonatal outcome in the adjusted models. Our findings suggest that sufficient maternal dietary selenium intake is associated with neonatal outcome. Adhering to the dietary recommendations may help ensure an adequate supply of selenium for a healthy pregnancy and optimal fetal development.

The associations between maternal and child diet quality and child ADHD - findings from a large Norwegian pregnancy cohort study.

BACKGROUND: Attention Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder. Effective long-term treatment options are limited, which warrants increased focus on potential modifiable risk factors. The aim of this study was to investigate associations between maternal diet quality during pregnancy and child diet quality and child ADHD symptoms and ADHD diagnosis. METHODS: This study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa). We assessed maternal diet quality with the Prenatal Diet Quality Index (PDQI) and Ultra-Processed Food Index (UPFI) around mid-gestation, and child diet quality using the Diet Quality Index (CDQI) at 3 years. ADHD symptoms were assessed at child age 8 years using the Parent Rating Scale for Disruptive Behaviour Disorders. ADHD diagnoses were retrieved from the Norwegian Patient Registry. RESULTS: In total, 77,768 mother-child pairs were eligible for studying ADHD diagnoses and 37,787 for ADHD symptoms. Means (SD) for the PDQI, UPFI and CDQI were 83.1 (9.3), 31.8 (9.7) and 60.3 (10.6), respectively. Mean (SD) ADHD symptom score was 8.4 (7.1) and ADHD diagnosis prevalence was 2.9% (male to female ratio 2.6:1). For one SD increase in maternal diet index scores, we saw a change in mean (percent) ADHD symptom score of - 0.28 (- 3.3%) (CI: - 0.41, - 0.14 (- 4.8, - 1.6%)) for PDQI scores and 0.25 (+ 3.0%) (CI: 0.13, 0.38 (1.5, 4.5%)) for UPFI scores. A one SD increase in PDQI score was associated with a relative risk of ADHD diagnosis of 0.87 (CI: 0.79, 0.97). We found no reliable associations with either outcomes for the CDQI, and no reliable change in risk of ADHD diagnosis for the UPFI. CONCLUSIONS: We provide evidence that overall maternal diet quality during pregnancy is associated with a small decrease in ADHD symptom score at 8 years and lower risk for ADHD diagnosis, with more robust findings for the latter outcome. Consumption of ultra-processed foods was only associated with increased ADHD symptom score of similar magnitude as for overall maternal diet quality, and we found no associations between child diet quality and either outcome. No causal inferences should be made based on these results, due to potential unmeasured confounding.

In Utero Exposure to Mercury Is Associated With Increased Susceptibility to Liver Injury and Inflammation in Childhood.

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) is the most prevalent cause of liver disease in children. Mercury (Hg), a ubiquitous toxic metal, has been proposed as an environmental factor contributing to toxicant-associated fatty liver disease. APPROACH AND RESULTS: We investigated the effect of prenatal exposure to Hg on childhood liver injury by combining epidemiological results from a multicenter mother-child cohort with complementary in vitro experiments on monocyte cells that are known to play a key role in liver immune homeostasis and NAFLD. We used data from 872 mothers and their children (median age, 8.1 years; interquartile range [IQR], 6.5-8.7) from the European Human Early-Life Exposome cohort. We measured Hg concentration in maternal blood during pregnancy (median, 2.0 µg/L; IQR, 1.1-3.6). We also assessed serum levels of alanine aminotransferase (ALT), a common screening tool for pediatric NAFLD, and plasma concentrations of inflammation-related cytokines in children. We found that prenatal Hg exposure was associated with a phenotype in children that was characterized by elevated ALT (≥22.1 U/L for females and ≥25.8 U/L for males) and increased concentrations of circulating IL-1ß, IL-6, IL-8, and TNF-α. Consistently, inflammatory monocytes exposed in vitro to a physiologically relevant dose of Hg demonstrated significant up-regulation of genes encoding these four cytokines and increased concentrations of IL-8 and TNF-α in the supernatants. CONCLUSIONS: These findings suggest that developmental exposure to Hg can contribute to inflammation and increased NAFLD risk in early life.