A repeated cross-sectional analysis of the Icelandic baby food market surveyed in 2016, 2019 and 2021.

World Health Organisation (WHO) has stated that countries need to know their local commercial baby food (CBF) market. Data from other countries suggest rapid changes in CBF options, highlighting the need for repeated analysis. In that context, this repeated cross-sectional study analysed the options and nutrient quality of different CBF types available in Iceland in years 2016, 2019 and 2021. Data was gathered on formulas, porridge flours, foods in jars and pouches, finger-foods, other CBF. They were classified into 26 subgroups based on ingredients and taste (sweet/savoury). Minimum consumer age as suggested by the manufacturers and nutritional content were registered. In each data-collection, 250-275 products were available. Over a third of products (37%-44%) were in pouches. Availability of products intended for 4-11-month-old infants decreased, driven largely by a 65% decrease in availability of food in jars (sweet/savoury) between 2016 and 2021. Availability of products intended from 12+ months or without age-labels increased, driven largely by quadrupling of finger-foods (predominantly sweet) between 2016 and 2021. The overall percentage of products classified as sweet increased from 65% (2016) to 73% (2019) and 77% (2021). Some finger-foods had high sugar content (up to 72 g/100 g), partly from fruit concentrate or sugar/syrup. Like other countries, the Icelandic CBF market has moved towards less availability of food intended in the first year and more availability of sweet finger-foods for an expanded consumer age. As sugar is added to some CBF, stronger regulations on promotion of foods for young consumers and updated recommendations for parents/caregivers may be needed.

[Evidence and lifestyle - New nordic recommendations about nutrition and diet - emphasis on sustainability].

Evaluation of research as basis for recommendations about lifestyle is discussed and especially recommendations about nutrition. Nordic recommendations on nutrients and diet with emphasis on sustainability are published 2023. Randomized trials, the strongest background for evidence based knowledge, are sometimes not possible to use when studying the influence of lifestyle on health. A tool applied in the Nordic recommendations 2023 evaluates the strength of relation between exposures (nutrients and food groups) and outcomes (health and environment), where research methods are observed and an organized quality control applied. The Interngovernmental Panel on Climate Change (IPCC) estimates the share of food systems in global anthropogenic GHG emissions is 31% (23%-42%). Nations now work on cutting GHG emissions from food systems by strengthening food based dietary guidelines and including sustainability, which benefits both health and environment. The recommendations about nutrients 2023 use harmonized methods and new data on body size in the Nordics. The food based dietary guidelines 2023 meet people's requirements for nutrients and are healthy for the environment. Physicians and other health professions will have the possibility to stimulate people´s interest to adhere to the recommendations about nutrition and diet built on a stronger and broader basis than before.

Metabolizable Energy Content of Breastmilk Supports Normal Growth in Exclusively Breastfed Icelandic Infants to Age 6 Months.

BACKGROUND: Neither the global population nor individual countries have reached the World Health Organization (WHO) target of ≥50% of infants exclusively breastfed (EBF) until 6 mo. This may partly be because of the perceptions of insufficient milk and energy supply to meet rapid growth and development needs. OBJECTIVES: In a longitudinal observational study, we aimed to determine whether breastmilk energy content is sufficient to support growth during EBF until 6 mo. METHODS: A sample of 27 EBF infants was dosed with doubly labeled water (DLW) at 5.6 mo to measure body composition, breastmilk intake, energy intake, and the metabolizable energy (ME) content of their mother's breastmilk over the following week. Z-scores were calculated for anthropometry using WHO reference data and for fat-free mass (FFM) and fat mass (FM) using United Kingdom reference data. RESULTS: Anthropometric z-scores from birth indicated normal weight and length growth patterns. At ∼6 mo, the mean ± standard deviation (SD) FFM z-score was 0.22 ± 1.07, and the FM z-score was 0.78 ± 0.70, significantly >0. In the 22 infants with acceptable data, the mean ± SD measured intake of breastmilk was 983 ± 170 g/d and of energy, 318 ± 60 kJ/kg/d, equivalent to 75.9 ± 14.3 kcal/kg/d. The mean ME content of breastmilk was 2.61 kJ/g [standard error (SE) 0.1], equivalent to 0.62 kcal/g (SE 0.02). Mothers were positive toward breastfeeding, on paid maternity leave (planned mean 10 mo), and many (56%) had received specialized breastfeeding support. CONCLUSIONS: The evidence from this study confirms that when mothers are motivated and supported without economic restraints, breastmilk intake and the energy supplied by breastmilk to EBF infants at 6 mo of age is sufficient to support normal growth patterns. There was no evidence of constraint on FFM, and other studies show that high FM in EBF infants is likely to be transient. These data further support the recommendation for EBF ≤6 mo of age for body composition. This trial was registered at clinicaltrials.gov as NCT02586571.

The combined effect of pre-pregnancy body mass index and gestational weight gain on the risk of pre-labour and intrapartum caesarean section-The ICE-MCH study.

Women who are obese before pregnancy have a higher risk of caesarean section than normal weight women. We investigated the combined effect of pre-pregnancy weight and gestational weight gain on pre-labour and intrapartum caesarean section risk. We collected data on 22,763 singleton, term, live deliveries in 2003-2014 from the Icelandic Maternal and Child Health Study (ICE-MCH), based on Icelandic registries. These were the Icelandic Medical Birth Registry and the Saga Maternal and Child Health Database. Pre-pregnancy body mass index was categorised into underweight, normal weight, overweight and obese. Gestational weight gain was classified according to the Institute of Medicine´s recommendation into below, within and above the recommended range. Logistic regression models, adjusted for maternal and gestational characteristics, were used to calculate adjusted odds ratios (AOR) and 95% confidence intervals (CI) for the risk of caesarean section. Obese women had a higher risk of pre-labour (AOR 1.56, 95% CI 1.34-1.81) and intrapartum caesarean section (AOR 1.92, 95% CI 1.70-2.17) than normal weight women in all categories of gestational weight gain. Gestational weight gain above the recommended range, compared to within the range, increased the risk of intrapartum caesarean section among normal weight (AOR 1.46, 95% CI 1.23-1.73) and overweight women (AOR 1.291, 95% CI 1.04-1.60). Gestational weight gain below the recommended range, compared to within the range, increased the risk of pre-labour caesarean section (AOR 1.64, 95% CI 1.20-2.25), but only among overweight women. Women who are obese before pregnancy have a high risk of caesarean section regardless of gestational weight gain. However, women who are normal weight or overweight before pregnancy and gain weight above the recommended range during pregnancy may also have an increased risk of caesarean section.

Meals, Microbiota and Mental Health in Children and Adolescents (MMM-Study): A protocol for an observational longitudinal case-control study.

Recent studies indicate that the interplay between diet, intestinal microbiota composition, and intestinal permeability can impact mental health. More than 10% of children and adolescents in Iceland suffer from mental disorders, and rates of psychotropics use are very high. The aim of this novel observational longitudinal case-control study, "Meals, Microbiota and Mental Health in Children and Adolescents (MMM-Study)" is to contribute to the promotion of treatment options for children and adolescents diagnosed with mental disorders through identification of patterns that may affect the symptoms. All children and adolescents, 5-15 years referred to the outpatient clinic of the Child and Adolescent Psychiatry Department at The National University Hospital in Reykjavik, Iceland, for one year (n≈150) will be invited to participate. There are two control groups, i.e., sex-matched children from the same postal area (n≈150) and same parent siblings (full siblings) in the same household close in age +/- 3 years (n<150). A three-day food diary, rating scales for mental health, and multiple questionnaires will be completed. Biosamples (fecal-, urine-, saliva-, blood samples, and buccal swab) will be collected and used for 16S rRNA gene amplicon sequencing of the oral and gut microbiome, measurements of serum factors, quantification of urine metabolites and host genotype, respectively. For longitudinal follow-up, data collection will be repeated after three years in the same groups. Integrative analysis of diet, gut microbiota, intestinal permeability, serum metabolites, and mental health will be conducted applying bioinformatics and systems biology approaches. Extensive population-based data of this quality has not been collected before, with collection repeated in three years' time, contributing to the high scientific value. The MMM-study follows the "Strengthening the Reporting of Observational Studies in Epidemiology" (STROBE) guidelines. Approval has been obtained from the Icelandic National Bioethics Committee, and the study is registered with Clinicaltrials.gov. The study will contribute to an improved understanding of the links between diet, gut microbiota and mental health in children through good quality study design by collecting information on multiple components, and a longitudinal approach. Furthermore, the study creates knowledge on possibilities for targeted and more personalized dietary and lifestyle interventions in subgroups. Trial registration numbers: VSN-19-225 & NCT04330703.

Nordic dietary patterns and cardiometabolic outcomes: a systematic review and meta-analysis of prospective cohort studies and randomised controlled trials.

AIMS/HYPOTHESIS: Nordic dietary patterns that are high in healthy traditional Nordic foods may have a role in the prevention and management of diabetes. To inform the update of the EASD clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of Nordic dietary patterns and cardiometabolic outcomes. METHODS: We searched MEDLINE, EMBASE and The Cochrane Library from inception to 9 March 2021. We included prospective cohort studies and RCTs with a follow-up of ≥1 year and ≥3 weeks, respectively. Two independent reviewers extracted relevant data and assessed the risk of bias (Newcastle-Ottawa Scale and Cochrane risk of bias tool). The primary outcome was total CVD incidence in the prospective cohort studies and LDL-cholesterol in the RCTs. Secondary outcomes in the prospective cohort studies were CVD mortality, CHD incidence and mortality, stroke incidence and mortality, and type 2 diabetes incidence; in the RCTs, secondary outcomes were other established lipid targets (non-HDL-cholesterol, apolipoprotein B, HDL-cholesterol, triglycerides), markers of glycaemic control (HbA1c, fasting glucose, fasting insulin), adiposity (body weight, BMI, waist circumference) and inflammation (C-reactive protein), and blood pressure (systolic and diastolic blood pressure). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of the evidence. RESULTS: We included 15 unique prospective cohort studies (n=1,057,176, with 41,708 cardiovascular events and 13,121 diabetes cases) of people with diabetes for the assessment of cardiovascular outcomes or people without diabetes for the assessment of diabetes incidence, and six RCTs (n=717) in people with one or more risk factor for diabetes. In the prospective cohort studies, higher adherence to Nordic dietary patterns was associated with 'small important' reductions in the primary outcome, total CVD incidence (RR for highest vs lowest adherence: 0.93 [95% CI 0.88, 0.99], p=0.01; substantial heterogeneity: I2=88%, pQ<0.001), and similar or greater reductions in the secondary outcomes of CVD mortality and incidence of CHD, stroke and type 2 diabetes (p<0.05). Inverse dose-response gradients were seen for total CVD incidence, CVD mortality and incidence of CHD, stroke and type 2 diabetes (p<0.05). No studies assessed CHD or stroke mortality. In the RCTs, there were small important reductions in LDL-cholesterol (mean difference [MD] -0.26 mmol/l [95% CI -0.52, -0.00], pMD=0.05; substantial heterogeneity: I2=89%, pQ<0.01), and 'small important' or greater reductions in the secondary outcomes of non-HDL-cholesterol, apolipoprotein B, insulin, body weight, BMI and systolic blood pressure (p<0.05). For the other outcomes there were 'trivial' reductions or no effect. The certainty of the evidence was low for total CVD incidence and LDL-cholesterol; moderate to high for CVD mortality, established lipid targets, adiposity markers, glycaemic control, blood pressure and inflammation; and low for all other outcomes, with evidence being downgraded mainly because of imprecision and inconsistency. CONCLUSIONS/INTERPRETATION: Adherence to Nordic dietary patterns is associated with generally small important reductions in the risk of major CVD outcomes and diabetes, which are supported by similar reductions in LDL-cholesterol and other intermediate cardiometabolic risk factors. The available evidence provides a generally good indication of the likely benefits of Nordic dietary patterns in people with or at risk for diabetes. REGISTRATION: ClinicalTrials.gov NCT04094194. FUNDING: Diabetes and Nutrition Study Group of the EASD Clinical Practice.

Lower Intake of Saturated Fatty Acids Is Associated with Improved Lipid Profile in a 6-Year-Old Nationally Representative Population.

To strengthen the organization of new national dietary surveys and interventions in childhood, our aim was to study macronutrient intake and blood lipid profile at 6 years of age by comparing results from two earlier population-based cohorts. Subjects were n = 131 and n = 162 in the years 2001−2002 and 2011−2012, respectively. Three-day weighed food records were used to estimate diet and calculate nutrient intake. Total cholesterol, HDL-cholesterol and triacylglycerol were measured in serum and LDL-cholesterol was calculated. The average intake of saturated fatty acids (SFA) and trans FA was lower in 2011−2012 than 2001−2002 (13.3E% vs. 14.7E%, p < 0.001, and 0.8E% vs. 1.4E%, p < 0.001, respectively), replaced by a higher intake of unsaturated fatty acids. Total cholesterol and LDL-cholesterol were significantly lower in 2011−2012 than 2001−2002 (4.6 vs. 4.4 mmol/L, p = 0.003 and 2.8 vs. 2.5 mmol/L, p < 0.001, respectively). In a multiple linear regression model, one E% increase in SFA intake was related to a 0.03 mmol/L increase in LDL cholesterol (p = 0.04). A lower intake of saturated and trans fatty acids, replaced by unsaturated fatty acids, may have contributed to an improved lipid profile in a healthy 6-year-old population. Biological data for analysis of blood lipids are important in national dietary surveys in healthy children to monitor important health outcomes of interventions.

Analysis of the SYSDIET Healthy Nordic Diet randomized trial based on metabolic profiling reveal beneficial effects on glucose metabolism and blood lipids.

BACKGROUND & AIMS: Intake assessment in multicenter trials is challenging, yet important for accurate outcome evaluation. The present study aimed to characterize a multicenter randomized controlled trial with a healthy Nordic diet (HND) compared to a Control diet (CD) by plasma and urine metabolic profiles and to associate them with cardiometabolic markers. METHODS: During 18-24 weeks of intervention, 200 participants with metabolic syndrome were advised at six centres to eat either HND (e.g. whole-grain products, berries, rapeseed oil, fish and low-fat dairy) or CD while being weight stable. Of these 166/159 completers delivered blood/urine samples. Metabolic profiles of fasting plasma and 24 h pooled urine were analysed to identify characteristic diet-related patterns. Principal components analysis (PCA) scores (i.e. PC1 and PC2 scores) were used to test their combined effect on blood glucose response (primary endpoint), serum lipoproteins, triglycerides, and inflammatory markers. RESULTS: The profiles distinguished HND and CD with AUC of 0.96 ± 0.03 and 0.93 ± 0.02 for plasma and urine, respectively, with limited heterogeneity between centers, reflecting markers of key foods. Markers of fish, whole grain and polyunsaturated lipids characterized HND, while CD was reflected by lipids containing palmitoleic acid. The PC1 scores of plasma metabolites characterizing the intervention is associated with HDL (ß = 0.05; 95% CI: 0.02, 0.08; P = 0.001) and triglycerides (ß = -0.06; 95% CI: -0.09, -0.03; P < 0.001). PC2 scores were related with glucose metabolism (2 h Glucose, ß = 0.1; 95% CI: 0.05, 0.15; P < 0.001), LDL (ß = 0.06; 95% CI: 0.01, 0.1; P = 0.02) and triglycerides (ß = 0.11; 95% CI: 0.06, 0.15; P < 0.001). For urine, the scores were related with LDL cholesterol. CONCLUSIONS: Plasma and urine metabolite profiles from SYSDIET reflected good compliance with dietary recommendations across the region. The scores of metabolites characterizing the diets associated with outcomes related with cardio-metabolic risk. Our analysis therefore offers a novel way to approach a per protocol analysis with a balanced compliance assessment in larger multicentre dietary trials. The study was registered at clinicaltrials.gov with NCT00992641.

Growth Rate in Childhood and Adolescence and the Risk of Breast and Prostate Cancer: A Population-Based Study.

Growth rate is regulated by hormonal pathways that might affect early cancer development. We explored the association between rate of growth in height from ages 8 to 13 years (childhood) and from age 13 to attainment of adult height (adolescence), as measured at study entry, and the risk of breast or prostate cancer. Participants were 2,037 Icelanders born during 1915-1935, who took part in the Reykjavik Study, established in 1967. Height measurements were obtained from school records and at study entry. We used multivariable Cox regression models to calculate hazard ratios with 95% confidence intervals of breast and prostate cancer by rates of growth in tertiles. During a mean follow-up of 66 years (women) and 64 years (men), 117 women were diagnosed with breast cancer and 118 men with prostate cancer (45 with advanced disease). Women in the highest growth-rate tertile in adolescence had a higher risk of breast cancer (hazard ratio = 2.4, 95% confidence interval: 1.3, 4.3) compared with women in the lowest tertile. A suggestive inverse association was observed for highest adolescent growth rate in men and advanced prostate cancer: hazard ratio = 0.4, 95% confidence interval: 0.2, 1.0. Rapid growth, particularly in adolescence may affect cancer risk later in life.

Old Question Revisited: Are High-Protein Diets Safe in Pregnancy?

BACKGROUND: A previous randomized dietary intervention in pregnant women from the 1970s, the Harlem Trial, reported retarded fetal growth and excesses of very early preterm births and neonatal deaths among those receiving high-protein supplementation. Due to ethical challenges, these findings have not been addressed in intervention settings. Exploring these findings in an observational setting requires large statistical power due to the low prevalence of these outcomes. The aim of this study was to investigate if the findings on high protein intake could be replicated in an observational setting by combining data from two large birth cohorts. METHODS: Individual participant data on singleton pregnancies from the Danish National Birth Cohort (DNBC) (n = 60,141) and the Norwegian Mother, Father and Child Cohort Study (MoBa) (n = 66,302) were merged after a thorough harmonization process. Diet was recorded in mid-pregnancy and information on birth outcomes was extracted from national birth registries. RESULTS: The prevalence of preterm delivery, low birth weight and fetal and neonatal deaths was 4.77%, 2.93%, 0.28% and 0.17%, respectively. Mean protein intake (standard deviation) was 89 g/day (23). Overall high protein intake (>100 g/day) was neither associated with low birth weight nor fetal or neonatal death. Mean birth weight was essentially unchanged at high protein intakes. A modest increased risk of preterm delivery [odds ratio (OR): 1.10 (95% confidence interval (CI): 1.01, 1.19)] was observed for high (>100 g/day) compared to moderate protein intake (80-90 g/day). This estimate was driven by late preterm deliveries (weeks 34 to <37) and greater risk was not observed at more extreme intakes. Very low (<60 g/day) compared to moderate protein intake was associated with higher risk of having low-birth weight infants [OR: 1.59 (95%CI: 1.25, 2.03)]. CONCLUSIONS: High protein intake was weakly associated with preterm delivery. Contrary to the results from the Harlem Trial, no indications of deleterious effects on fetal growth or perinatal mortality were observed.

The Nordic Nutrition Recommendations 2022 - prioritisation of topics for de novo systematic reviews.

Background: As part of the process of updating national dietary reference values (DRVs) and food-based dietary guidelines (FBDGs), the Nordic Nutrition Recommendations 2022 project (NNR2022) will select a limited number of topics for systematic reviews (SRs). Objective: To develop and transparently describe the results of a procedure for prioritisation of topics that may be submitted for SRs in the NNR2022 project. Design: In an open call, scientists, health professionals, national food and health authorities, food manufacturers, other stakeholders and the general population in the Nordic and Baltic countries were invited to suggest SR topics. The NNR2022 Committee developed scoping reviews (ScRs) for 51 nutrients and food groups aimed at identifying potential SR topics. These ScRs included the relevant nominations from the open call. SR topics were categorised, ranked and prioritised by the NNR2022 Committee in a modified Delphi process. Existing qualified SRs were identified to omit duplication. Results: A total of 45 nominations with suggestion for more than 200 exposure-outcome pairs were received in the public call. A number of additional topics were identified in ScRs. In order to omit duplication with recently qualified SRs, we defined criteria and identified 76 qualified SRs. The NNR2022 Committee subsequently shortlisted 52 PI/ECOTSS statements, none of which overlapped with the qualified SRs. The PI/ECOTSS statements were then graded 'High' (n = 21), 'Medium' (n = 9) or 'Low' (n = 22) importance, and the PI/ECOTSS statements with 'High' were ranked in a Delphi process. The nine top prioritised PI/ECOTSS included the following exposure-outcome pairs: 1) plant protein intake in children and body growth, 2) pulses/legumes intake, and cardiovascular disease and type 2 diabetes, 3) plant protein intake in adults, and atherosclerotic/cardiovascular disease and type 2 diabetes, 4) fat quality and mental health, 5) vitamin B12 and vitamin B12 status, 6) intake of white meat (no consumption vs. high consumption and white meat replaced with red meat), and all-cause mortality, type 2 diabetes and risk factors, 7) intake of n-3 LPUFAs from supplements during pregnancy, and asthma and allergies in the offspring, 8) nuts intake and cardiovascular disease (CVD) and type 2 diabetes in adults, 9) dietary fibre intake (high vs. low) in children and bowel function. Discussion: The selection of topics for de novo SRs is central in the NNR2022 project, as the results of these SRs may cause adjustment of existing DRVs and FBDGs. That is why we have developed this extensive process for the prioritisation of SR topics. For transparency, the results of the process are reported in this publication. Conclusion: The principles and methodologies developed in the NNR2022 project may serve as a framework for national health authorities or organisations when developing national DRVs and FBDGs. This collaboration between the food and health authorities in Denmark, Estonia, Finland, Iceland, Latvia, Lithuania, Norway and Sweden represents an international effort for harmonisation and sharing of resources and competence when developing national DRVs and FBDGs.

The Nordic Nutrition Recommendations 2022 - structure and rationale of qualified systematic reviews.

BACKGROUND: Qualified systematic reviews (SRs) will form the main basis for evaluating causal effects of nutrients or food groups on health outcomes in the sixth edition of Nordic Nutrition Recommendations to be published in 2022 (NNR2022). OBJECTIVE: To describe rationale and structure of SRs used in NNR2022. DESIGN: The SR methodologies of the previous edition of NNR were used as a starting point. Methodologies of recent SRs commissioned by leading national food and health authorities or international food and health organizations were examined and scrutinized. Methodologies for developing SRs were agreed by the NNR2022 Committee in a consensus-driven process. RESULTS: Qualified SRs will be developed by a cross-disciplinary group of experts and reported according to the requirements of the EQUATOR network. A number of additional requirements must also be fulfilled, including 1) a clearly stated set of objectives and research questions with pre-defined eligibility criteria for the studies, 2) an explicit, reproducible methodology, 3) a systematic search that attempts to identify all studies that would meet the eligibility criteria, 4) an assessment of the validity of the findings of the included studies through an assessment of 'risk of bias' of the studies, 5) a systematic presentation and synthesis of the characteristics and findings of the included studies, and 6) a grading of the overall evidence. The complete definition and requirements of a qualified SR are described. DISCUSSION: Most SRs published in scientific journals do not fulfill all criteria of the qualified SRs in the NNR2022 project. This article discusses the structure and rationale for requirements of qualified SRs in NNR2022. National food and health authorities have only recently begun to use qualified SRs as a basis for nutrition recommendations. CONCLUSION: Qualified SRs will be used to inform dietary reference values (DRVs) and food-based dietary guidelines (FBDGs) in the NNR2022 project.

The Nordic Nutrition Recommendations 2022 - principles and methodologies.

BACKGROUND: The Nordic Nutrition Recommendations (NNRs) constitute the scientific basis for national dietary reference values (DRVs) and food-based dietary guidelines (FBDGs) in the Nordic and Baltic countries. OBJECTIVE: To define principles and methodologies for the sixth edition of NNR to be published in 2022 (NNR2022). DESIGN: The principles and methodologies of the previous edition of NNR were used as a starting point. Recent nutrition recommendations commissioned by other national food and health authorities or international food and health organizations were examined and dissected. Updated principles and methodologies were agreed by the NNR2022 Committee in a consensus-driven process. RESULTS: An organizational model with 'checks and balances' was developed to minimize the influence of subjective biases of the committee members and experts. Individual chapters on all included nutrients and food groups will be updated as scoping reviews. Systematic reviews (SRs), which are the main basis for evaluating causal effects of nutrients or food groups on health outcomes, will be embedded in each chapter. A NNR SR Centre will be established for performing de novo SRs on prioritized topics. To avoid duplication and optimize the use of resources, qualified SRs commissioned by other national and international organizations and health authorities will also inform DRVs and FBDGs in NNR2022. DISCUSSION: The evidence-based methods defined in the NNR2022 project are compatible with most contemporary methods used by leading national food and health authorities. Global harmonization of methodological approaches to nutrition recommendations is strongly encouraged. CONCLUSION: Evidence-informed principles and methodologies underpinned by SRs will ensure that DRVs and FBDGs defined in the NNR2022 project are based on the best available evidence and as far as possible free from overt bias.

The Nordic Nutrition Recommendations 2022 - handbook for qualified systematic reviews.

BACKGROUND: Systematic reviews (SRs) constitute a major part of the Nordic Nutrition Recommendations (NNRs). The step-by-step procedure used to develop SRs has evolved considerably over time and is often tailored to fit the exposure and outcomes in focus. OBJECTIVE: To describe a detailed procedure for developing qualified SRs commissioned by the NNR2022 project. DESIGN: Scrutinizing procedures of recent SRs commissioned by leading national food and health authorities or international food and health organizations. RESULTS: The following eight steps must be included when developing qualified SRs for the NNR2022 project: 1) define research question, 2) protocol development, 3) literature search, 4) screening and selection of studies, 5) data extraction, 6) assessing risk of bias, 7) synthesis and grading of total strength of evidence, and 8) reporting according to certain standards. DISCUSSION: This guide is based on the guidelines developed for the fifth edition of NNR but includes some important new domains in order to adhere to more recent, authoritative standards. CONCLUSION: All qualified SRs in the NNR2022 project will follow the protocol described here.

Iodine status of breastfed infants and their mothers' breast milk iodine concentration.

Iodine is an essential nutrient for growth and development during infancy. Data on iodine status of exclusively (EBF) and partially breastfed (PBF) infants as well as breast milk iodine concentration (BMIC) are scarce. We aimed to assess (a) infant iodine nutrition at the age of 5.5 months by measuring urinary iodine concentration (UIC) in EBF (n = 32) and PBF (n = 28) infants and (b) mothers' breast milk iodine concentration (n = 57). Sixty mother-infant pairs from three primary health care centres in Reykjavik and vicinities provided urine and breast milk samples for iodine analysis and information on mothers' habitual diet. The mother-infant pairs were participants of the IceAge2 study, which focuses on factors contributing to infant growth and development, including body composition and breast-milk energy content. The median (25th-75th percentiles) UIC was 152 (79-239) µg/L, with no significant difference between EBF and PBF infants. The estimated median iodine intake ranged from 52 to 86 µg/day, based on urinary data (assuming an average urine volume of 300-500 ml/day and UIC from the present study). The median (25th-75th percentiles) BMIC was 84 (48-114) µg/L. It is difficult to conclude whether iodine status is adequate in the present study, as no ranges for median UIC reflecting optimal iodine nutrition exist for infants. However, the results add important information to the relatively sparse literature on UIC, BMIC, and iodine intake of breastfed infants.

Childhood overweight and obesity and the risk of depression across the lifespan.

BACKGROUND: Obesity has been longitudinally associated with depression but only few studies take a life course approach. This longitudinal study investigates whether being overweight or obese at age 8 and 13 years is associated with depressive symptoms more than 60 years later and whether this association is independent of late-life body mass index (BMI). We also investigated the association of being overweight/obese at age 8 or 13 years with ever having major depressive disorder (lifetime MDD). METHOD: This analysis is based on a sub-sample of 889 AGES-Reykjavik participants with measured BMI data from early life. Late-life depressive symptoms were measured with the Geriatric Depression Scale (GDS) and lifetime MDD was assessed at late-life using the Mini International Neuropsychiatric Interview. Logistic regression analysis was used to estimate the relationships between BMI (continuous and categorical) at age 8 or 13 years, and late-life depressive symptoms (measured as GDS ≥ 5) or lifetime MDD, adjusted for sex, education, physical activity, smoking status and alcohol use. In a separate model, additional adjustments were made for late-life BMI. RESULTS: One hundred and one subjects (11%) had depressive symptoms at late-life (GDS ≥ 5), and 39 subjects (4.4%) had lifetime MDD. Being overweight or obese at age 8 or 13 years was not associated with higher depressive symptoms during late-life, irrespective of late-life BMI. Being overweight or obese at age 8 years, but not age 13 years was associated with an increased risk of lifetime MDD (Odds Ratio (OR) (95% confidence interval [CI]) for age 8 = 4.03[1.16-13.96]P = 0.03 and age 13 = 2.65[0.69-10.26] P = 0.16, respectively). CONCLUSION: Being overweight in childhood was associated with increased odds of lifetime MDD, although the magnitude of the risk is uncertain given the small numbers of participants with lifetime MDD. No clear association was observed between childhood and adolescent overweight/obesity and late-life depressive symptoms irrespective of late life BMI.

An Isocaloric Nordic Diet Modulates RELA and TNFRSF1A Gene Expression in Peripheral Blood Mononuclear Cells in Individuals with Metabolic Syndrome-A SYSDIET Sub-Study.

A healthy dietary pattern is associated with a lower risk of metabolic syndrome (MetS) and reduced inflammation. To explore this at the molecular level, we investigated the effect of a Nordic diet (ND) on changes in the gene expression profiles of inflammatory and lipid-related genes in peripheral blood mononuclear cells (PBMCs) of individuals with MetS. We hypothesized that the intake of an ND compared to a control diet (CD) would alter the expression of inflammatory genes and genes involved in lipid metabolism. The individuals with MetS underwent an 18/24-week randomized intervention to compare a ND with a CD. Eighty-eight participants (66% women) were included in this sub-study of the larger SYSDIET study. Fasting PBMCs were collected before and after the intervention and changes in gene expression levels were measured using TaqMan Array Micro Fluidic Cards. Forty-eight pre-determined inflammatory and lipid related gene transcripts were analyzed. The expression level of the gene tumor necrosis factor (TNF) receptor superfamily member 1A (TNFRSF1A) was down-regulated (p = 0.004), whereas the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) subunit, RELA proto-oncogene, was up-regulated (p = 0.016) in the ND group compared to the CD group. In conclusion, intake of an ND in individuals with the MetS may affect immune function.

Quantitative assessment of betainized compounds and associations with dietary and metabolic biomarkers in the randomized study of the healthy Nordic diet (SYSDIET).

BACKGROUND: Recently, a group of betainized compounds have been suggested to play a role in health effects in relation to a whole-grain-rich diet. OBJECTIVES: The aims of this study were to develop a quantitative mass spectrometric method for selected betainized compounds in human plasma, and to investigate their association with nutrient intake and measures of metabolic health in participants of the SYSDIET study. METHODS: The SYSDIET study was a controlled randomized intervention including individuals with metabolic syndrome, where the healthy Nordic diet (HND) group increased intakes of whole grains, canola oil, berries, and fish, whereas the control diet (CD) group consumed low-fiber cereal products, milk fat, and restricted amounts of fish and berries. A quantitative LC combined with triple quadrupole MS method for betainized compounds was developed and applied to fasting plasma samples from baseline (week 0) and the end of the intervention (week 18 or 24). Concentrations of betainized compounds were correlated with intakes of selected nutrients and fiber and measures of metabolic health. RESULTS: Pipecolic acid betaine (PAB) concentrations were significantly higher in the HND group than in the CD group (P = 0.00032) at the end of the intervention and correlated directly (P < 0.0001) with intakes of dietary fiber (r = 0.376) and a biomarker related to whole-grain rye intake, namely the ratio of alkylresorcinol C17:0 to C21:0 (r = 0.442). PAB was associated inversely with fasting plasma insulin consistently at the beginning and at the end of the intervention (P < 0.001, r = -0.300; P < 0.01, r = -0.250, respectively), as well as IL-1 receptor antagonist (P < 0.01, r = -0.232 at the beginning; P < 0.01, r = -0.236 at the end) and serum LDL/HDL cholesterol (P < 0.01, r = -0.239 at the beginning; P < 0.01, r = -0.241 at the end). CONCLUSIONS: Among adults with the metabolic syndrome, PAB plasma concentrations were associated with fasting insulin, inflammation, and lipids and were significantly increased with adoption of the HND. Further studies are needed to clarify the biological functions of betainized compounds. This trial was registered at clinicaltrials.gov as NCT00992641.

Infant Feeding, Vitamin D and IgE Sensitization to Food Allergens at 6 Years in a Longitudinal Icelandic Cohort.

Nordic Nutrition Recommendations (NNR) recommend exclusive breastfeeding until 6 months, partial breastfeeding until 1 year or longer and irrespective of breastfeeding, avoiding solid foods before 4 months. Strong evidence was found for benefits of breastfeeding regarding growth and infections but limited/inconclusive evidence regarding atopic disease and asthma. Vitamin D is of special interest in the Nordic diet. The aim of this prospective study was to compare infant feeding and vitamin D between immunoglobulin E (IgE) sensitized (n = 14) and non-sensitized (n = 130) children at 6 years. Information on diet and vitamin D supplement use were collected with dietary recall (<5 months), 1-d food records (5 and 6 months) and 3-d weighed food records (12 months and 6 years). Serum-specific IgE-antibodies against milk, egg, cod, wheat, soy and peanut (cut-off specific IgE ≥ 0.35 kUA/L) were measured at 6 years and serum 25-hydroxyvitamin D at 12 months and 6 years. At 4 months, 57% of IgE sensitized vs. 23% of non-sensitized children (p < 0.01) had received solid food. At 12 months, IgE sensitized children had a lower intake of vitamin D (median (25th, 75th percentiles): 3.9 µg/d (3.2, 7.2) vs. 8.1 µg/d (4.4, 12.3), p = 0.03) and at 6 years, fewer used vitamin D supplements regularly (23% vs. 56%, p = 0.03). Introduction of solid foods prior to 4 months increased the odds of IgE-sensitization, OR = 4.9 (95%, CI = 1.4-16.6) and vitamin D supplement at 6 years decreased the odds of IgE-sensitization, OR = 0.2 (95%, CI = 0.1-0.98), adjusting for maternal smoking. These observations support the NNR in their recommendation against introducing complementary solid foods before the age of 4 months. Furthermore, they support encouraging vitamin D intake for young children at northern latitudes.

Healthy Nordic Diet Modulates the Expression of Genes Related to Mitochondrial Function and Immune Response in Peripheral Blood Mononuclear Cells from Subjects with Metabolic Syndrome-A SYSDIET Sub-Study.

SCOPE: To explore the effect of a healthy Nordic diet on the global transcriptome profile in peripheral blood mononuclear cells (PBMCs) of subjects with metabolic syndrome. METHODS AND RESULTS: Subjects with metabolic syndrome undergo a 18/24 week randomized intervention study comparing an isocaloric healthy Nordic diet with an average habitual Nordic diet served as control (SYSDIET study). Altogether, 68 participants are included. PBMCs are obtained before and after intervention and total RNA is subjected to global transcriptome analysis. 1302 probe sets are differentially expressed between the diet groups (p-value < 0.05). Twenty-five of these are significantly regulated (FDR q-value < 0.25) and are mainly involved in mitochondrial function, cell growth, and cell adhesion. The list of 1302 regulated probe sets is subjected to functional analyses. Pathways and processes involved in the mitochondrial electron transport chain, immune response, and cell cycle are downregulated in the healthy Nordic diet group. In addition, gene transcripts with common motifs for 42 transcription factors, including NFR1, NFR2, and NF-κB, are downregulated in the healthy Nordic diet group. CONCLUSION: These results suggest that benefits of a healthy diet may be mediated by improved mitochondrial function and reduced inflammation.