Tolerable upper intake level for dietary sugars

Following a request from five European Nordic countries, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was tasked to provide scientific advice on a tolerable upper intake level (UL) or a safe level of intake for dietary (total/added/free) sugars based on available data on chronic metabolic diseases, pregnancy-related endpoints and dental caries. Specific sugar types (fructose) and sources of sugars were also addressed. The intake of dietary sugars is a well-established hazard in relation to dental caries in humans. Based on a systematic review of the literature, prospective cohort studies do not support a positive relationship between the intake of dietary sugars, in isocaloric exchange with other macronutrients, and any of the chronic metabolic diseases or pregnancy-related endpoints assessed. Based on randomised control trials on surrogate disease endpoints, there is evidence for a positive and causal relationship between the intake of added/free sugars and risk of some chronic metabolic diseases: The level of certainty is moderate for obesity and dyslipidaemia (> 50-75% probability), low for non-alcoholic fatty liver disease and type 2 diabetes (> 15-50% probability) and very low for hypertension (0-15% probability). Health effects of added vs. free sugars could not be compared. A level of sugars intake at which the risk of dental caries/chronic metabolic diseases is not increased could not be identified over the range of observed intakes, and thus, a UL or a safe level of intake could not be set. Based on available data and related uncertainties, the intake of added and free sugars should be as low as possible in the context of a nutritionally adequate diet. Decreasing the intake of added and free sugars would decrease the intake of total sugars to a similar extent. This opinion can assist EU Member States in setting national goals/recommendations.

The effects of probiotics administration on the gut microbiome in adolescents with anorexia nervosa-A study protocol for a longitudinal, double-blind, randomized, placebo-controlled trial

Objective

Knowledge on gut–brain interaction might help to develop new therapies for patients with anorexia nervosa (AN), as severe starvation‐induced changes of the microbiome (MI) do not normalise with weight gain. We examine the effects of probiotics supplementation on the gut MI in patients with AN.

Method

This is a study protocol for a two‐centre double‐blind randomized‐controlled trial comparing the clinical efficacy of multistrain probiotic administration in addition to treatment‐as‐usual compared to placebo in 60 patients with AN (13–19 years). Moreover, 60 sex‐ and age‐matched healthy controls are included in order to record development‐related changes. Assessments are conducted at baseline, discharge, 6 and 12 months after baseline. Assessments include measures of body mass index, psychopathology (including eating‐disorder‐related psychopathology, depression and anxiety), neuropsychological measures, serum and stool analyses. We hypothesise that probiotic administration will have positive effects on the gut microbiota and the treatment of AN by improvement of weight gain, gastrointestinal complaints and psychopathology, and reduction of inflammatory processes compared to placebo.

Conclusions

If probiotics could help to normalise the MI composition, reduce inflammation and gastrointestinal discomfort and increase body weight, its administration would be a readily applicable additional component of multi‐modal AN treatment.

Patients with anorexia nervosa face profound alterations of the gut microbiome which does not normalise with weight gain.

Alterations in the gut microbiome in patients with anorexia nervosa are linked to psychopathological symptoms and neurophysiological deficits, for example, related to the reward system.

This is the first study examining the effects of probiotics administration in adolescents with anorexia nervosa using a randomized controlled trial design.

Brainfood cluster

Brainfood cluster The mission of EBRA brainfood is to increase awareness of the importance of research exploring the bidirectional links between brain health and nutrition, including the mediating systems, and to use this knowledge to identify novel nutritional, neuropsychological and neuropharmacological intervention strategies. The BRAINFOOD cluster builds new bridges across research disciplines and strengthens links to relevant stakeholders across Europe, including those involved in health and food policy. It gathers experts on brain health and nutrition that by combining and integrating strengths and complimentary expertise has the volume and capacity to develop novel intervention strategies that improve brain health of European citizens, working together with public health and the food industry. BRAINFOOD is built upon an existing network that includes: 1 Discovery, with expertise in human genetics, metabolomics, nutrition, the microbiome and brain health that utilizes existing data from a variety of population and disease cohorts across the lifespan and aims to propose testable hypotheses; 2 Mechanism, with expertise in animal models, metabolomics, the microbiome and neuroscience that tests hypothesis of how the microbiome and nutrients impact on performance in different behavioral domains; 3 Experimental medicine, with expertise in psychiatry, neurology and nutrition with capacity to run randomized controlled trials; 4 Implementation, with expertise in dissemination and policy making and behavior change, to ensure that EU citizens benefit from novel insights gained in the project.

Food matters: Anorexia nervosa and the microbiome: First findings of a European cooperation

Anorexia nervosa (AN) is one of the most common chronic disorders in adolescence with still high mortality rates. Knowledge on gut-brain interaction might help to develop new treatments, as severe starvation-induced changes of the microbiome in AN-patients have been demonstrated, which do not alleviate with weight gain. In our own pilot study alpha-diversity was increased in patients with AN after short-term weight recovery, while beta diversity showed clear group differences with healthy controls before and after weight gain. A reduction of taxa belonging to Enterobacteriaceae at admission and discharge and an increase in taxa belonging to Lachnospiraceae at discharge were typically found in patients with AN. The work plan of our European project comprises an observational study and two phase II RCTs with the application of omega-3-PUFA and a multistrain psychobiotic to both, humans and rodents. With the help of a well-established animal model for AN (activity-based anorexia, ABA), the effect of stool transplants from patients to rodents will be analysed. Longitudinal MRI will be conducted in rodents together with cellular and molecular brain analyses. In addition, immune response and circulating antibodies associated with the presence of certain bacterial strains and interaction with hunger and satiety hormones will be explored. We hope that by this translational research we may systematically investigate the role of an altered microbiome for the course of AN and to identify new therapeutic tools.

How the COVID-19 pandemic highlights the necessity of animal research

Recently, a petition was offered to the European Commission calling for an immediate ban on animal testing. Although a Europe-wide moratorium on the use of animals in science is not yet possible, there has been a push by the non-scientific community and politicians for a rapid transition to animal-free innovations. Although there are benefits for both animal welfare and researchers, advances on alternative methods have not progressed enough to be able to replace animal research in the foreseeable future. This trend has led first and foremost to a substantial increase in the administrative burden and hurdles required to make timely advances in research and treatments for human and animal diseases. The current COVID-19 pandemic clearly highlights how much we actually rely on animal research. COVID-19 affects several organs and systems, and the various animal-free alternatives currently available do not come close to this complexity. In this Essay, we therefore argue that the use of animals is essential for the advancement of human and veterinary health.

Assessing causal links between metabolic traits, inflammation and schizophrenia: a univariable and multivariable, bidirectional Mendelian-randomization study

BACKGROUND

Blood immunoreactive biomarkers, such as C-reactive protein (CRP), and metabolic abnormalities have been associated with schizophrenia. Studies comprehensively and bidirectionally probing possible causal links between such blood constituents and liability to schizophrenia are lacking.

METHODS

To disentangle putative causal links between CRP blood levels and schizophrenia in both directions, we conducted multiple univariable Mendelian-randomization (MR) analyses, ranging from fixed-effect to inverse variance-weighted (IVW), weighted-median, MR Egger and generalized summary-data-based Mendelian-randomization (GSMR) models. To prioritize metabolic risk factors for schizophrenia, a novel multivariable approach was applied: multivariable Mendelian-randomization-Bayesian model averaging (MR-BMA).

RESULTS

All forward univariable MR analyses consistently showed that CRP has a protective effect on schizophrenia, whereas reverse MR analyses consistently suggested absent causal effects of schizophrenia liability on CRP blood levels. Using MR-BMA, as the top protective factors for schizophrenia we prioritized leucine and as the prime risk-factor triglycerides in medium very-low-density lipoprotein (VLDL). The five best-performing MR-BMA models provided one additional risk factor: triglycerides in large VLDL; and two additional protective factors: citrate and lactate.

CONCLUSIONS

Our results add to a growing body of literature hinting at metabolic changes-in particular of triglycerides-independently of medication status in schizophrenia. We also highlight the absent effects of genetic liability to schizophrenia on CRP levels.

Hypothalamic dopamine signaling regulates brown fat thermogenesis

Dopamine signaling is a crucial part of the brain reward system and can affect feeding behavior. Dopamine receptors are also expressed in the hypothalamus, which is known to control energy metabolism in peripheral tissues. Here we show that pharmacological or chemogenetic stimulation of dopamine receptor 2 (D2R) expressing cells in the lateral hypothalamic area (LHA) and the zona incerta (ZI) decreases body weight and stimulates brown fat activity in rodents in a feeding-independent manner. LHA/ZI D2R stimulation requires an intact sympathetic nervous system and orexin system to exert its action and involves inhibition of PI3K in the LHA/ZI. We further demonstrate that, as early as 3 months after onset of treatment, patients treated with the D2R agonist cabergoline experience an increase in energy expenditure that persists for one year, leading to total body weight and fat loss through a prolactin-independent mechanism. Our results may provide a mechanistic explanation for how clinically used D2R agonists act in the CNS to regulate energy balance.

Investigation of common, low-frequency and rare genome-wide variation in anorexia nervosa

Anorexia nervosa (AN) is a complex neuropsychiatric disorder presenting with dangerously low body weight, and a deep and persistent fear of gaining weight. To date, only one genome-wide significant locus associated with AN has been identified. We performed an exome-chip based genome-wide association studies (GWAS) in 2158 cases from nine populations of European origin and 15 485 ancestrally matched controls. Unlike previous studies, this GWAS also probed association in low-frequency and rare variants. Sixteen independent variants were taken forward for in silico and de novo replication (11 common and 5 rare). No findings reached genome-wide significance. Two notable common variants were identified: rs10791286, an intronic variant in OPCML (P=9.89 × 10-6), and rs7700147, an intergenic variant (P=2.93 × 10-5). No low-frequency variant associations were identified at genome-wide significance, although the study was well-powered to detect low-frequency variants with large effect sizes, suggesting that there may be no AN loci in this genomic search space with large effect sizes.

Significant Locus and Metabolic Genetic Correlations Revealed in Genome-Wide Association Study of Anorexia Nervosa

OBJECTIVE

The authors conducted a genome-wide association study of anorexia nervosa and calculated genetic correlations with a series of psychiatric, educational, and metabolic phenotypes.

METHOD

Following uniform quality control and imputation procedures using the 1000 Genomes Project (phase 3) in 12 case-control cohorts comprising 3,495 anorexia nervosa cases and 10,982 controls, the authors performed standard association analysis followed by a meta-analysis across cohorts. Linkage disequilibrium score regression was used to calculate genome-wide common variant heritability (single-nucleotide polymorphism [SNP]-based heritability [h²_SNP]), partitioned heritability, and genetic correlations (r_g) between anorexia nervosa and 159 other phenotypes.

RESULTS

Results were obtained for 10,641,224 SNPs and insertion-deletion variants with minor allele frequencies >1% and imputation quality scores >0.6. The h²_SNP of anorexia nervosa was 0.20 (SE=0.02), suggesting that a substantial fraction of the twin-based heritability arises from common genetic variation. The authors identified one genome-wide significant locus on chromosome 12 (rs4622308) in a region harboring a previously reported type 1 diabetes and autoimmune disorder locus. Significant positive genetic correlations were observed between anorexia nervosa and schizophrenia, neuroticism, educational attainment, and high-density lipoprotein cholesterol, and significant negative genetic correlations were observed between anorexia nervosa and body mass index, insulin, glucose, and lipid phenotypes.

CONCLUSIONS

Anorexia nervosa is a complex heritable phenotype for which this study has uncovered the first genome-wide significant locus. Anorexia nervosa also has large and significant genetic correlations with both psychiatric phenotypes and metabolic traits. The study results encourage a reconceptualization of this frequently lethal disorder as one with both psychiatric and metabolic etiology.

Evidence for three genetic loci involved in both anorexia nervosa risk and variation of body mass index

The maintenance of normal body weight is disrupted in patients with anorexia nervosa (AN) for prolonged periods of time. Prior to the onset of AN, premorbid body mass index (BMI) spans the entire range from underweight to obese. After recovery, patients have reduced rates of overweight and obesity. As such, loci involved in body weight regulation may also be relevant for AN and vice versa. Our primary analysis comprised a cross-trait analysis of the 1000 single-nucleotide polymorphisms (SNPs) with the lowest P-values in a genome-wide association meta-analysis (GWAMA) of AN (GCAN) for evidence of association in the largest published GWAMA for BMI (GIANT). Subsequently we performed sex-stratified analyses for these 1000 SNPs. Functional ex vivo studies on four genes ensued. Lastly, a look-up of GWAMA-derived BMI-related loci was performed in the AN GWAMA. We detected significant associations (P-values <5 × 10-5, Bonferroni-corrected P<0.05) for nine SNP alleles at three independent loci. Interestingly, all AN susceptibility alleles were consistently associated with increased BMI. None of the genes (chr. 10: CTBP2, chr. 19: CCNE1, chr. 2: CARF and NBEAL1; the latter is a region with high linkage disequilibrium) nearest to these SNPs has previously been associated with AN or obesity. Sex-stratified analyses revealed that the strongest BMI signal originated predominantly from females (chr. 10 rs1561589; Poverall: 2.47 × 10-06/Pfemales: 3.45 × 10-07/Pmales: 0.043). Functional ex vivo studies in mice revealed reduced hypothalamic expression of Ctbp2 and Nbeal1 after fasting. Hypothalamic expression of Ctbp2 was increased in diet-induced obese (DIO) mice as compared with age-matched lean controls. We observed no evidence for associations for the look-up of BMI-related loci in the AN GWAMA. A cross-trait analysis of AN and BMI loci revealed variants at three chromosomal loci with potential joint impact. The chromosome 10 locus is particularly promising given that the association with obesity was primarily driven by females. In addition, the detected altered hypothalamic expression patterns of Ctbp2 and Nbeal1 as a result of fasting and DIO implicate these genes in weight regulation.

Drive for activity in patients with anorexia nervosa

OBJECTIVE

Hyperactivity and elevated physical activity are both considered symptom characteristics of anorexia nervosa (AN). It has been suggested that a drive for activity (DFA) may underlie these expressions, yet research into DFA in AN remains scant. This study investigated DFA levels in patients with AN and its relation to AN severity. Furthermore, as physical exercise may be a way to reduce negative affect, the influence of negative affect (anxiety) on the role of DFA in AN was tested.

METHOD

Two hundred and forty female patients with AN completed measures for DFA, eating disorder (ED) pathology, anxiety, and clinical parameters.

RESULTS

A strong relation between DFA levels and ED pathology was found, which remained significant even after controlling for negative affect (anxiety).

DISCUSSION

After much theorizing about DFA in AN this study provides empirical evidence for DFA as a hallmark feature of AN, independent of anxiety levels. Future research should shed light on the relationships between DFA, actual physical activity, and the course of AN.

Common genetic variations in CCK, leptin, and leptin receptor genes are associated with specific human eating patterns

Obesity has a heritable component; however, the heterogeneity of obesity complicates dissection of its genetic background. In this study, we therefore focused on eating patterns as specific traits within obesity. These traits have a heritable component; genes associated with a specific eating pattern have not yet been reported at the population level. In this study, we determined whether genetic variations in cholecystokinin (CCK) and leptin genes underlie specific eating patterns. We selected obese individuals showing extreme snacking behavior or use of excessive portion sizes from a large population-based sample (n = 17,357) from the Prospect-EPIC (European Prospective Study into Cancer and Nutrition) study. Using allele-specific PCRs, we tested several single nucleotide polymorphisms in the candidate genes and performed haplotype analysis. Obese carriers of common allelic variations in leptin or the leptin receptor gene had an increased risk to display extreme snacking behavior. In contrast, obese carriers of common allelic variations in CCK had an increased risk to eating increased meal sizes. In conclusion, we identified common allelic variants specifically associated with distinctly different eating patterns, namely extreme snacking behavior or excessive portion size.

Prognostic factors in laryngeal carcinoma. Experience in 296 male patients

BACKGROUND

Laryngeal cancer is the primary cause of death among patients with head and neck cancer in Argentina. Different prognostic factors have been incidentally dealt with in a number of articles, but there are few studies of prognostic variables, such as age, tobacco, and alcohol, using multifactorial analysis.

METHODS

Between 1969-1987, 296 male patients with epidermoid carcinoma of the larynx treated at the Institute of Oncology "Angel H. Roffo" were studied regarding prognostic factors of survival. The effect of age, tobacco, alcohol, histologic grade, extent of primary tumor, and cord mobility on survival were assessed by means of the Cox proportional-hazards model.

RESULTS

The univariate analysis showed that primary tumor extent, nodal involvement, stage, alcohol intake, previous tracheostomy, and cord mobility were statistically significant predictors of survival. Multivariate analysis disclosed only nodal involvement, alcohol intake, and cord mobility as statistically significant variables in regard to survivorship. With these variables, a hazard index was calculated for each patient, and four risk groups were formed. Five-year survival rates were as follows: Group A, 79%; B, 69%; C, 47%; and D, 14% (A versus C, P < 0.005; A versus D, P < 0.005).

CONCLUSIONS

This study confirmed the prognostic impact of nodal involvement and also showed the importance of cord fixation and alcohol drinking as predictors of survival.