What is a sustainable diet in the Norwegian context?

INTRODUCTION: Sustainable diets promote health and wellbeing and have low environmental impact. They should be accessible, affordable, safe, equitable and culturally acceptable. Translating these general principles into Norwegian-specific dietary recommendations is essential, as foods beneficial for health tend to also be environmentally sustainable. Following the dietary recommendations is an important step towards sustainability. AIM: To identify challenges and potential solutions for transitioning towards more sustainable diets in Norway. METHODS: We used scientific articles, reports, policy documents, and statistics on Norwegian food production and consumption to discuss a sustainable diet in a Norwegian context. RESULTS AND DISCUSSION: There is a large gap between dietary guidelines and actual consumption. More than 60% of the calories in the Norwegian diet are based on imported foods and feed. Changing people's diet is identified as central in transforming the food system to become more sustainable, as is prioritizing the use of local resources. Good animal health and welfare are also fundamental premises for a sustainable food system. CONCLUSIONS: Transitioning to a more sustainable diet requires comprehensive efforts at multiple levels. There is considerable room for action to increase the use of Norwegian resources in a sustainable and responsible way. Potential strategies include reducing meat intake in favour of plant-based foods and fish, consuming more local products, decreasing food waste and supporting agricultural practices that promote environmental and social sustainability. A more sustainable diet may also lead to significantly increased self-sufficiency and food security in Norway.

Gestational thyroid hormone concentrations and risk of attention-deficit hyperactivity disorder in the Norwegian Mother, Father and Child Cohort Study.

BACKGROUND: Maternal thyroid function plays an important role in foetal brain development; however, little consensus exists regarding the relationship between normal variability in thyroid hormones and common neurodevelopmental disorders, such as attention-deficit hyperactivity disorder (ADHD). OBJECTIVE: We sought to examine the association between mid-pregnancy maternal thyroid function and risk of clinically diagnosed ADHD in offspring. METHODS: We conducted a nested case-control study in the Norwegian Mother, Father and Child Cohort Study. Among children born 2003 or later, we randomly sampled singleton ADHD cases obtained through linkage with the Norwegian Patient Registry (n = 298) and 554 controls. Concentrations of maternal triiodothyronine (T3), thyroxine (T4), T3-Uptake, thyroid-stimulating hormone (TSH) and thyroid peroxidase antibody (TPO-Ab) were measured in maternal plasma, collected at approximately 17 weeks' gestation. Indices of free T4 (FT4i) and free T3 (FT3i) were calculated. We used multivariable adjusted logistic regression to calculate odds ratios and accounted for missing covariate data using multiple imputation. We used restricted cubic splines to assess non-linear trends and provide flexible representations. We examined effect measure modification by dietary iodine and selenium intake. In sensitivity analyses, we excluded women with clinically significant thyroid disorders (n = 73). RESULTS: High maternal T3 was associated with increased risk of ADHD (5th vs 1st quintile odds ratio  2.27, 95% confidence interval 1.21, 4.26). For FT4i, both the lowest and highest quintiles were associated with an approximate 1.6-fold increase in risk of ADHD, with similar trends found for T4. The FT4i association was modified by dietary iodine intake such that the highest risk strata were confined to the low intake group. CONCLUSIONS: Both high and low concentrations of maternal thyroid hormones, although within population reference ranges, increase the risk of ADHD in offspring. Increased susceptibility may be found among women with low dietary intake of iodine and selenium.

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.

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.

Iron status in mid-pregnancy and associations with interpregnancy interval, hormonal contraceptives, dietary factors and supplement use.

Adequate iron supply in pregnancy is important for both the woman and the fetus, but iron status is often assessed late in first trimester, if assessed at all. Therefore, identification of factors associated with iron status is important to target vulnerable groups with increased risk of deficiency. Our objectives were to (1) describe iron status in mid-pregnancy and (2) identify sociodemographic and lifestyle predictors of pregnancy iron status. This cross-sectional study uses data from The Norwegian Mother, Father and Child Cohort Study (collected 2002-2008) and The Medical Birth Registry of Norway. Iron status was measured as non-fasting plasma ferritin (P-Fe) and transferrin in gestational week (GW) 18 (n 2990), and by lowest reported Hb in GW 0-30 (n 39 322). We explored predictors of iron status with elastic net, linear and log-binomial regression models. Median P-Fe was 33 µg/l, and 14 % had depleted iron stores (P-Fe <15 µg/l). P-Fe below 30 µg/l was associated with reduced Hb. We identified eleven predictors, with interpregnancy interval (IPI) and parity among the most important. Depleted iron stores was more common among women with IPI < 6 months (56 %) and 6-11 months (33 %) than among those with IPI 24-59 months (19 %) and among nulliparous women (5 %). Positively associated factors with iron status included hormonal contraceptives, age, BMI, smoking, meat consumption and multi-supplement use. Our results highlight the importance of ferritin measurements in women of childbearing age, especially among women not using hormonal contraceptives and women with previous and recent childbirths.

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.

Insufficient maternal iodine intake is associated with subfecundity, reduced foetal growth, and adverse pregnancy outcomes in the Norwegian Mother, Father and Child Cohort Study.

BACKGROUND: Severe iodine deficiency impacts fertility and reproductive outcomes. The potential effects of mild-to-moderate iodine deficiency are not well known. The aim of this study was to examine whether iodine intake was associated with subfecundity (i.e. > 12 months trying to get pregnant), foetal growth, and adverse pregnancy outcomes in a mild-to-moderately iodine-deficient population. METHODS: We used the Norwegian Mother, Father and Child Cohort Study (MoBa) and included 78,318 pregnancies with data on iodine intake and pregnancy outcomes. Iodine intake was calculated using an extensive food frequency questionnaire in mid-pregnancy. In addition, urinary iodine concentration was available in a subsample of 2795 pregnancies. Associations were modelled continuously by multivariable regression controlling for a range of confounding factors. RESULTS: The median iodine intake from food was 121 µg/day and the median urinary iodine was 69 µg/L, confirming mild-to-moderate iodine deficiency. In non-users of iodine supplements (n = 49,187), low iodine intake (< 100-150 µg/day) was associated with increased risk of preeclampsia (aOR = 1.14 (95% CI 1.08, 1.22) at 75 vs. 100 µg/day, p overall < 0.001), preterm delivery before gestational week 37 (aOR = 1.10 (1.04, 1.16) at 75 vs. 100 µg/day, p overall = 0.003), and reduced foetal growth (- 0.08 SD (- 0.10, - 0.06) difference in birth weight z-score at 75 vs. 150 µg/day, p overall < 0.001), but not with early preterm delivery or intrauterine death. In planned pregnancies (n = 56,416), having an iodine intake lower than ~ 100 µg/day was associated with increased prevalence of subfecundity (aOR = 1.05 (1.01, 1.09) at 75 µg/day vs. 100 µg/day, p overall = 0.005). Long-term iodine supplement use (initiated before pregnancy) was associated with increased foetal growth (+ 0.05 SD (0.03, 0.07) on birth weight z-score, p < 0.001) and reduced risk of preeclampsia (aOR 0.85 (0.74, 0.98), p = 0.022), but not with the other adverse pregnancy outcomes. Urinary iodine concentration was not associated with any of the dichotomous outcomes, but positively associated with foetal growth (n = 2795, p overall = 0.017). CONCLUSIONS: This study shows that a low iodine intake was associated with restricted foetal growth and a higher prevalence of preeclampsia in these mild-to-moderately iodine-deficient women. Results also indicated increased risk of subfecundity and preterm delivery. Initiating iodine supplement use in pregnancy may be too late.

Maternal dietary selenium intake is associated with increased gestational length and decreased risk of preterm delivery.

The first positive genome-wide association study on gestational length and preterm delivery showed the involvement of an Se metabolism gene. In the present study, we examine the association between maternal intake of Se and Se status with gestational length and preterm delivery in 72 025 women with singleton live births from the population-based, prospective Norwegian Mother, Father and Child Cohort Study (MoBa). A self-reported, semi-quantitative FFQ answered in pregnancy week 22 was used to estimate Se intake during the first half of pregnancy. Associations were analysed with adjusted linear and Cox regressions. Se status was assessed in whole blood collected in gestational week 17 (n 2637). Median dietary Se intake was 53 (interquartile range (IQR) 44-62) µg/d, supplements provided additionally 50 (IQR 30-75) µg/d for supplement users (n 23 409). Maternal dietary Se intake was significantly associated with prolonged gestational length (ß per sd = 0·25, 95 % CI, 0·07, 0·43) and decreased risk of preterm delivery (n 3618, hazard ratio per sd = 0·92, 95 % CI, 0·87, 0·98). Neither Se intake from supplements nor maternal blood Se status was associated with gestational length or preterm delivery. Hence, the present study showed that maternal dietary Se intake but not intake of Se-containing supplements, during the first half of pregnancy was significantly associated with decreased risk of preterm delivery. Further investigations, preferably in the form of a large randomised controlled trial, are needed to elucidate the impact of Se on pregnancy duration.

Maternal probiotic milk intake during pregnancy and breastfeeding complications in the Norwegian Mother and Child Cohort Study.

PURPOSE: During the time of breastfeeding, a third of all women contract (or: fall ill in) mastitis-the leading cause of precocious weaning. Recent studies indicate that probiotics intake may prevent mastitis by altering the breast's bacterial flora. The aim of this study was to examine whether probiotic milk intake during pregnancy is associated with less breastfeeding complications and longer breastfeeding duration. METHODS: This study included 57,134 women, with live singleton term births, participating in the Norwegian Mother and Child Cohort Study. Probiotic milk intake during the first half of pregnancy was self-reported in a validated food frequency questionnaire at gestational week 22. At 6 month postpartum, women reported complications, including mastitis, and duration and exclusivity of breastfeeding. The association between probiotic milk intake and breastfeeding complications and duration was studied by adjusted logistic regression models. RESULTS: Probiotic milk intake was associated with increased risk for mastitis [adjusted odds ratio (aOR) 1.09, 95% confidence interval (CI) 1.02-1.16] and for any breastfeeding problems during the first month (aOR 1.19, 95% CI 1.10-1.21). However, cessation of predominant (aOR 0.95, 95% CI 0.91-0.96) or any (aOR 0.79, 95% CI 0.75-0.84) breastfeeding earlier than at 4 months was less frequent in probiotic milk consumers than in non-consumers. CONCLUSIONS: Even though probiotic milk intake during the first half of pregnancy was statistically associated with increased risk for breastfeeding complications, including mastitis, the association is probably not causal. Probiotics intake was namely associated with longer breastfeeding duration and there was indication of socioeconomic confounding. Further studies, i.e., large randomized-controlled trials, are needed to understand the association between probiotic intake and breastfeeding complications.

Estimating the Strength of Associations Between Prenatal Diet Quality and Child Developmental Outcomes: Results From a Large Prospective Pregnancy Cohort Study.

Our aim in this study was to estimate the strength of associations between prenatal diet quality and child behavioral, language, and motor functions in the Norwegian Mother and Child Cohort Study (1999-2008). We created a prenatal diet quality index (PDQI) based on adherence to Norwegian dietary guidelines. Child outcomes were defined as sum scores on the Child Behavior Checklist, the Ages and Stages Questionnaire, and the Child Development Index at ages 18, 36, and 60 months. Using a longitudinal cohort study design and Bayesian hierarchical modeling, we estimated association strengths using inverse probability weighting to account for selection bias. In total, 27,529 mother-child pairs were eligible for inclusion. A 1-standard-deviation increase in PDQI score was associated with an absolute reduction in outcome sum scores of 0.02-0.21 and a 3%-7% relative decrease, with larger decreases seen for language and motor functions than for behavioral functions. PDQI scores were inversely associated with all child functions, but the estimated strength of each association was low. The results indicate that the observed variations in PDQI scores in an industrialized Western society may not profoundly influence the child functions studied.