The association between fish consumption and decreased risk of CVD is well-documented. However, studies on health effects of fish consumption, suggest that other components than omega-3 polyunsaturated fatty acids have beneficial cardiometabolic effects, including effects on glucose metabolism. The aim of the present study was to investigate effects of salmon fish protein on cardiometabolic risk markers in a double-blind, randomised controlled parallel trial. We hypothesised that daily intake of a salmon fish protein supplement for eight weeks would improve glucose tolerance in persons with increased risk of type 2 diabetes mellitus. Our primary outcome measure was serum glucose (s-glucose) two hours after a standardized oral glucose tolerance test (OGTT). In total, 88 adults with elevated s-glucose levels were randomised to 7.5 g salmon fish protein/day or placebo, and 74 participants were included in the analysis. We found no significant effect of salmon fish protein supplementation on our primary outcome or other markers related to glucose tolerance, serum lipids, weight or blood pressure compared to placebo. The present study does not support the hypothesis that daily intake of a salmon fish protein supplement for eight weeks improves glucose tolerance in persons with increased risk of type 2 diabetes mellitus. The study was registered at ClinicalTrials.gov (ID: NCT03764423).

Fish consumption is associated with reduced risk of cardiovascular disease (CVD), which may be partly mediated by alterations in plasma lipids, such as high-density lipoprotein cholesterol (HDL-C). However, comprehensive analyses of associations between fatty fish consumption and lipoprotein subclass profile are limited and show inconsistent results. Therefore, the aim of the present exploratory study was to investigate the association between fatty fish consumption and lipoprotein subclass particle concentrations and composition, with emphasis on HDL. We performed a comprehensive plasma metabolite profiling in 517 healthy adults, using a targeted high-throughput nuclear magnetic resonance spectroscopy platform. The participants were divided into tertiles based on consumption of fatty fish, reported through a validated food frequency questionnaire. We compared the concentration of metabolites between the participants in the lowest and highest tertiles of fatty fish consumption. We show that high-consumers of fatty fish (>223 g/week, median intake 294 g/week) had higher particle concentrations and content of total lipids, and phospholipids in large and extra-large HDL particles, and higher content of total cholesterol, free cholesterol, cholesteryl esters and triglycerides in large HDL particles, than low-consumers (<107 g/week, median intake 58 g/week). Using fatty fish consumption as a continuous variable, we found that fatty fish consumption was associated with lower levels of the inflammation marker glycoprotein acetyls. In conclusion, high-consumers of fatty fish, seem to have a more favourable HDL-C-related lipoprotein profile and anti-inflammatory phenotype than low-consumers of fatty fish. Thus, these data support the current Norwegian dietary recommendations for fish consumption regarding CVD risk.

Purpose The main aim of the present study was to examine the effect of a fish protein supplement made from by-products from production of Atlantic salmon, on blood concentration of micronutrients. Methods We conducted an 8-week double-blind parallel-group randomised controlled trial. In total, 88 adults were randomised to a salmon fish protein supplement or placebo, and 74 participants were included in the analysis of vitamin D, omega-3, vitamin B12, selenium, folate, zinc, homocysteine and mercury. Results During the intervention period, geometric mean (GSD) of serum vitamin B12 concentrations increased from 304 (1.40) to 359 (1.42) pmol/L in the fish protein group (P vs. controls = 0.004) and mean (SD) serum selenium increased from 1.18 (0.22) to 1.30 (0.20) μmol/L (P vs. controls = 0.002). The prevalence of low vitamin B12 status (B12 < 148–221 > pmol/L) decreased from 15.4 to 2.6% in the fish protein group, while increasing from 5.9 to 17.6% in the placebo group (P = 0.045). There was no difference between the groups in serum levels of the other micronutrients measured. Conclusion Including a salmon fish protein supplement in the daily diet for 8 weeks, increases serum vitamin B12 and selenium concentrations. From a sustainability perspective, by-products with high contents of micronutrients and low contents of contaminants, could be a valuable dietary supplement or food ingredient in populations with suboptimal intake. Trail Registration The study was registered at ClinicalTrials.gov (ID: NCT03764423) on June 29th 2018.

Food protein or food-derived peptides may regulate blood glucose levels; however, studies have shown inconsistent results. The aim of the present study was to characterize subgroups of individuals with increased risk of type 2 diabetes (T2D) and to investigate the cardiometabolic effects of fish protein in the same subgroups. We first divided participants into high insuliniAUC and low insuliniAUC subjects based on their insulin incremental area under the curve (iAUC) levels after a 2 h oral glucose tolerance test (OGTT), and secondly based on whether they had received 5.2 g salmon fish protein or placebo for 8 weeks, in a previously conducted randomized controlled trial (RCT). We then profiled these groups by analyzing plasma metabolomics and peripheral blood mononuclear cell (PBMC) gene expression. Compared to the low insuliniAUC group, the high insuliniAUC group had higher plasma concentrations of monounsaturated fatty acids (MUFAs) and glycated proteins (GlycA) and lower concentrations of glycine and acetate. After intervention with fish protein compared to placebo, however, only acetate was significantly increased in the low insuliniAUC group. In conclusion, we identified metabolic biomarkers known to be associated with T2D; also, intervention with fish protein did not affect cardiometabolic risk markers in subgroups with increased risk of T2D.

Background Metabotyping is a novel concept to group metabolically similar individuals. Different metabotypes may respond differently to dietary interventions; hence, metabotyping may become an important future tool in precision nutrition strategies. However, it is not known if metabotyping based on comprehensive omic data provides more useful identification of metabotypes compared to metabotyping based on only a few clinically relevant metabolites. Aim This study aimed to investigate if associations between habitual dietary intake and glucose tolerance depend on metabotypes identified from standard clinical variables or comprehensive nuclear magnetic resonance (NMR) metabolomics. Methods We used cross-sectional data from participants recruited through advertisements aimed at people at risk of type 2 diabetes mellitus (n = 203). Glucose tolerance was assessed with a 2-h oral glucose tolerance test (OGTT), and habitual dietary intake was recorded with a food frequency questionnaire. Lipoprotein subclasses and various metabolites were quantified with NMR spectroscopy, and plasma carotenoids were quantified using high-performance liquid chromatography. We divided participants into favorable and unfavorable clinical metabotypes based on established cutoffs for HbA1c and fasting and 2-h OGTT glucose. Favorable and unfavorable NMR metabotypes were created using k-means clustering of NMR metabolites. Results While the clinical metabotypes were separated by glycemic variables, the NMR metabotypes were mainly separated by variables related to lipoproteins. A high intake of vegetables was associated with a better glucose tolerance in the unfavorable, but not the favorable clinical metabotype (interaction, p = 0.01). This interaction was confirmed using plasma concentrations of lutein and zeaxanthin, objective biomarkers of vegetable intake. Although non-significantly, the association between glucose tolerance and fiber intake depended on the clinical metabotypes, while the association between glucose tolerance and intake of saturated fatty acids and dietary fat sources depended on the NMR metabotypes. Conclusion Metabotyping may be a useful tool to tailor dietary interventions that will benefit specific groups of individuals. The variables that are used to create metabotypes will affect the association between dietary intake and disease risk.