Dietary carbohydrate modification induces alterations in gene expression in abdominal subcutaneous adipose tissue in persons with the metabolic syndrome: the FUNGENUT Study

Seaweed intake modulates the association between VIPR2 variants and the incidence of metabolic syndrome in middle-aged Koreans

Vasoactive intrinsic peptide receptor (VIPR2), a circadian gene, is involved in metabolic homeostasis and metabolic syndrome (MetS). Seaweeds contain polysaccharides that regulate metabolic homeostasis, possibly by altering the effects of VIPR2 variants. We examined the relationship between VIPR2 expression and the incidence of MetS based on seaweed consumption. This study included 4979 Koreans aged ≥40 years using data from the Ansan-Ansung cohort of the Korean Genome and Epidemiology Study. The total seaweeds included were laver, kelp, and sea mustard. A multivariable Cox proportional hazards model was used to analyze the interactions between the VIPR2 rs6950857 genotype associated with MetS incidence and seaweed intake after adjusting for covariates such as region. A total of 2134 patients with MetS were followed for an average of 8.9 years. In men with the GG genotype of rs6950857, the highest quintile of seaweed consumption was associated with a decreased incidence of MetS compared with that of the lowest quintile (hazard ratio, 0.78; 95% confidence interval, 0.62-0.98). We identified a unique association between the rs6950857 genotype, seaweed intake, and MetS. These findings highlight the importance of VIPR2 and the regulatory role of seaweed consumption in MetS incidence.

Omics Technology for the Promotion of Nutraceuticals and Functional Foods

The influence of nutrition and environment on human health has been known for ages. Phytonutrients (7,000 flavonoids and phenolic compounds; 600 carotenoids) and pro-health nutrients—nutraceuticals positively add to human health and may prevent disorders such as cancer, diabetes, obesity, cardiovascular diseases, and dementia. Plant-derived bioactive metabolites have acquired an imperative function in human diet and nutrition. Natural phytochemicals affect genome expression (nutrigenomics and transcriptomics) and signaling pathways and act as epigenetic modulators of the epigenome (nutri epigenomics). Transcriptomics, proteomics, epigenomics, miRNomics, and metabolomics are some of the main platforms of complete omics analyses, finding use in functional food and nutraceuticals. Now the recent advancement in the integrated omics approach, which is an amalgamation of multiple omics platforms, is practiced comprehensively to comprehend food functionality in food science.

Macronutrient modulation of mRNA and microRNA function in animals: A review

Dietary macronutrients have been regarded as a basic source of energy and amino acids that are necessary for the maintenance of cellular homeostasis, metabolic programming as well as protein synthesis. Due to the emergence of “nutrigenomics”, a unique discipline that combines nutritional and omics technologies to study the impacts of nutrition on genomics, it is increasingly evident that macronutrients also have a significant role in the gene expression regulation. Gene expression is a complex phenomenon controlled by several signaling pathways and could be influenced by a wide variety of environmental and physiological factors. Dietary macronutrients are the most important environmental factor influencing the expression of both genes and microRNAs (miRNA). miRNA are tiny molecules of 18 to 22 nucleotides long that regulate the expression of genes. Therefore, dietary macronutrients can influence the expression of genes in both direct and indirect manners. Recent advancements in the state-of-the-art technologies regarding molecular genetics, such as next-generation sequencing, quantitative PCR array, and microarray, allowed us to investigate the occurrence of genome-wide changes in the expression of genes in relation to augmented or reduced dietary macronutrient intake. The purpose of this review is to accumulate the current knowledge focusing on macronutrient mediated changes in the gene function. This review will discuss the impact of altered dietary carbohydrate, protein, and fat intake on the expression of coding genes and their functions. In addition, it will also summarize the regulation of miRNA, both cellular and extracellular miRNA, expression modulated by dietary macronutrients.

Reducing postprandial glucose in dietary intervention studies and the magnitude of the effect on diabetes-related risk factors: a systematic review and meta-analysis

Purpose

Reducing postprandial hyperglycemia has beneficial effects on diabetes-related risk factors, but the magnitude of the reduction needed to achieve such an effect is unknown. The purpose of the study was to quantify the relationship of acute glucose and insulin postprandial responses with longer-term effects on diabetes-related risk factors by performing a systematic review and meta-analysis of dietary intervention studies.

Methods

We systematically searched EMBASE and MEDLINE. Dietary intervention studies among any human population aiming to reduce postprandial glycemia, with actual measures of postprandial glucose (PPG) and/or insulin (PPI) as acute exposures (incremental area under the curve, iAUC) as well as markers of glucose metabolism (fasting glucose, HbA1c) and insulin sensitivity (fasting insulin, HOMA-IR) after at least 4 weeks of diet intervention as outcomes were included. Meta-analyses were performed for the effects on acute exposures and on diabetes-related risk factors. The relationship between changes in acute exposures and changes in risk factor outcomes was estimated by meta-regression analyses.

Results

Out of the 13,004 screened papers, 13 papers with 14 comparisons were included in the quantitative analysis. The dietary interventions acutely reduced mean PPG [mean difference (MD), − 0.27 mmol/l; 95% CI − 0.41 to − 0.14], but not mean PPI (MD − 7.47 pmol/l; 95% CI − 16.79 to 1.86). There were no significant overall effects on fasting glucose and insulin. HbA1c was reduced by − 0.20% (95% CI − 0.35 to − 0.05). Changes in acute PPG were significantly associated with changes in fasting plasma glucose (FPG) [per 10% change in PPG: β = 0.085 (95% CI 0.003, 0.167), k = 14], but not with fasting insulin [β = 1.20 (95% CI − 0.32, 2.71), k = 12]. Changes in acute PPI were not associated with changes in FPG [per 10% change in PPI: β = − 0.017 (95% CI − 0.056, 0.022), k = 11].

Conclusions

Only a limited number of postprandial glucose-lowering dietary intervention studies measured acute postprandial exposures to PPG/PPI during the interventions. In this small heterogeneous set of studies, an association was found between the magnitude of the acute postprandial responses and the change in fasting glucose, but no other outcomes. More studies are needed to quantify the relationship between acute postprandial changes and long-term effects on risk factors.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02240-1) contains supplementary material, which is available to authorized users.

The Combination of Whey Protein and Dietary Fiber Does Not Alter Low-Grade Inflammation or Adipose Tissue Gene Expression in Adults with Abdominal Obesity

BACKGROUND

Abdominal obesity is characterized by low-grade inflammation and plays a central role in the development of type 2 diabetes and cardiovascular diseases. Dietary factors can influence low-grade inflammation and affect adipose tissue function.

AIM

To investigate the separate and combined effects of whey protein and cereal fiber on inflammatory markers and adipose tissue gene expression in abdominal obesity.

METHODS

We performed a 12-week, double-blind, randomized controlled dietary intervention in 65 adults with abdominal obesity. The participants were randomized to 4 groups using a 2 × 2 factorial design; they received either 60 g/day of whey protein or maltodextrin in combination with high-fiber wheat bran products (30 g fiber/day) or low-fiber refined wheat products (10 g fiber/day). Plasma concentrations of tumor necrosis factor α (TNF-α), high-sensitivity C-reactive protein (hs-CRP), monocyte chemoattractant protein-1 (MCP-1), interleukin 1 receptor antagonist (IL-1Ra), and adiponectin were measured before and after intervention. Changes in gene expression related to inflammation, insulin signaling, and lipid metabolism were measured in abdominal subcutaneous adipose tissue.

RESULTS

After intervention, TNF-α was reduced for both high-fiber groups compared with baseline, but did not significantly differ from the low-fiber groups. There were no differences in fasting or postprandial inflammatory markers between the groups. The relative gene expression of ribosomal protein S6 kinase B1 (S6K1) was increased after whey protein compared with maltodextrin consumption.

CONCLUSION

Intake of whey protein in combination with high cereal fiber content did not differentially affect low-grade inflammation or adipose tissue gene expression compared with maltodextrin and low fiber content in individuals with abdominal obesity.

IGFBP5 suppresses oleate-induced intramyocellular lipids deposition and enhances insulin signaling

Excess intramyocellular lipids are often accompanied by muscle insulin resistance (IR) and type 2 diabetes. The mechanism of the formation of intramyocellular lipids is unclear yet. In this study, we optimized the cellular model of intramyocellular lipids from differentiated C2C12 cells and identified that the expression of insulin-like growth factor-binding protein 5 (IGFBP5) is diminished in this process. Then, we added exogenous recombinant IGFBP5 during myocyte triglyceride (TAG) formation and found decreased lipids accumulation. In addition, IGFBP5 could promote lipolysis when added to the cellular model after the formation of intramyocellular lipids. Moreover, IGFBP5 could enhance myocyte insulin sensitivity by inhibiting the expression of the thioredoxin-interacting protein (TXNIP) and arrestin domain-containing 4 (ARRDC4), which are a negative regulator of insulin signaling in both cases. Meanwhile, IGFBP5 also inhibited the expression of glycerol-3-phosphate acyltransferase (GPAM) and diglyceride acyltransferase 2 (DGAT2), which were involved in TAG synthesis from a fatty acid. IGFBP5 also reduced TAG storage by promoting lipolysis. Therefore, IGFBP5 may play a role in the excess accumulation of lipid in muscle cells of diabetic patients and serve as a reference for further research and treatment of muscle IR and diabetes.

Effects of NaHCO3 Acclimation on Rye (Secale Cereale) Growth Under Sodic-Alkaline Stress

Sodic-alkalinity is a serious limiting factor in agricultural productivity. This study was conducted to examine the contribution of acclimation to the adaptation of rye (Secale cereale) to sodic-alkalinity. Effects of acclimation were determined in two sets of experiments: One experiment for mineral accumulation, antioxidative capacity, and other physiological parameters; and a vivo experiment for root Evan’s Blue and Na⁺ influx from medium to root. Being exposed to sodic-alkalinity, acclimation did not affect plant dry weight. However, acclimation significantly reduced Na⁺ concentration and maintained a lower Na⁺/K⁺ ratio in all the tissues, increased the Ca²⁺ and Mg²⁺ concentrations in the root tissues, and increased the water uptake ability in comparison to the non-acclimated plants. Acclimation increased the antioxidant capacity represented by the increased activities of the enzymes SOD, GR, CAT, and GPOX in the leaf tissues of acclimated plants in comparison to the non-acclimated plants. Moreover, acclimation increased the root cell viability inhibited the Na⁺ influx to the root tissues in comparison to the non-acclimated plants. Together, these results suggest that rye can acclimate to sodic-alkalinity by increasing root cell viability, and therefore limited Na⁺ influx to root tissues and increased water uptake and antioxidant capacities without any change in the plant growth.

Nutrigenomics: Opportunities & challenges for public health nutrition

The hierarchical information flow through DNA-RNA-protein-metabolite collectively referred to as ‘molecular fingerprint’ defines both health and disease. Environment and food (quality and quantity) are the key factors known to affect the health of an individual. The fundamental concepts are that the transition from a healthy condition to a disease phenotype must occur by concurrent alterations in the genome expression or by differences in protein synthesis, function and metabolites. In other words, the dietary components directly or indirectly modulate the molecular fingerprint and understanding of which is dealt with nutrigenomics. Although the fundamental principles of nutrigenomics remain similar to that of traditional research, a collection of comprehensive targeted/untargeted data sets in the context of nutrition offers the unique advantage of understanding complex metabolic networks to provide a mechanistic understanding of data from epidemiological and intervention studies. In this review the challenges and opportunities of nutrigenomic tools in addressing the nutritional problems of public health importance are discussed. The application of nutrigenomic tools provided numerous leads on biomarkers of nutrient intake, undernutrition, metabolic syndrome and its complications. Importantly, nutrigenomic studies also led to the discovery of the association of multiple genetic polymorphisms in relation to the variability of micronutrient absorption and metabolism, providing a potential opportunity for further research toward setting personalized dietary recommendations for individuals and population subgroups.

The effect of different sources of fish and camelina sativa oil on immune cell and adipose tissue mRNA expression in subjects with abnormal fasting glucose metabolism: a randomized controlled trial

Background/Objectives

Molecular mechanisms linking fish and vegetable oil intakes to their healthy metabolic effects may involve attenuation of inflammation. Our primary aim was to examine in a randomized controlled setting whether diets enriched in fatty fish (FF), lean fish (LF) or ALA-rich camelina sativa oil (CSO) differ in their effects on the mRNA expression response of selected inflammation-related genes in peripheral blood mononuclear cells (PBMCs) and subcutaneous adipose tissue (SAT) in subjects with impaired fasting glucose.

Subjects/Methods

Samples from 72 participants randomized to one of the following 12-week intervention groups, FF (n = 19), LF (n = 19), CSO (n = 17) or a control group (n = 17), were available for the PBMC study. For SAT, 39 samples (n = 8, n = 10, n = 9, n = 12, respectively) were available. The mRNA expression was measured at baseline and 12 weeks by TaqMan® Low Density Array.

Results

In PBMCs, LF decreased ICAM1 mRNA expression (P < 0.05), which was different (P = 0.06, Bonferroni correction) from the observed increase in the FF group (P < 0.05). Also, compared to the control group, LF decreased ICAM1 mRNA expression (P < 0.05). Moreover, the change in ICAM1 mRNA expression correlated positively with the intake of FF (P < 0.05) and negatively with the intake of LF (P < 0.05), independently of study group. A diet enriched in CSO, a rich source of alpha-linolenic acid (ALA), decreased PBMC IFNG mRNA expression (P < 0.01). The intake of CSO in the CSO group, but not the increase in plasma ALA proportions, correlated inversely with the IFNG mRNA expression in PBMCs (P = 0.08). In SAT, when compared with the control group, the effect of FF on decreasing IL1RN mRNA expression was significant (P < 0.03).

Conclusion

We propose that CSO intake may partly exert its benefits through immuno-inflammatory molecular regulation in PBMCs, while modulation of ICAM1 expression, an endothelial/vascular-related gene, may be more dependent on the type of fish consumed.

Source and amount of carbohydrate in the diet and inflammation in women with polycystic ovary syndrome

High carbohydrate intake and low-grade inflammation cooperate with insulin resistance and hyperandrogenism to constitute an interactive continuum acting on the pathophysiology of polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age characterised by oligo-anovulatory infertility and cardiometabolic disorders. The role of insulin in PCOS is pivotal both in regulating the activity of ovarian and liver enzymes, respectively involved in androgen production and in triggering low-grade inflammation usually reported to be associated with an insulin resistance, dyslipidaemia and cardiometabolic diseases. Although an acute hyperglycaemia induced by oral glucose loading may increase inflammation and oxidative stress by generating reactive oxygen species through different mechanisms, the postprandial glucose increment, commonly associated with the Western diet, represents the major contributor of chronic sustained hyperglycaemia and pro-inflammatory state. Together with hyperinsulinaemia, hyperandrogenism and low-grade inflammation, unhealthy diet should be viewed as a key component of the 'deadly quartet' of metabolic risk factors associated with PCOS pathophysiology. The identification of a tight diet-inflammation-health association makes the adoption of healthy nutritional approaches a primary preventive and therapeutic tool in women with PCOS, weakening insulin resistance and eventually promoting improvements of reproductive life and endocrine outcomes. The intriguing nutritional-endocrine connections operating in PCOS underline the role of expert nutritionists in the management of this syndrome. The aim of the present review is to provide an at-a-glance overview of the possible bi-directional mechanisms linking inflammation, androgen excess and carbohydrate intake in women with PCOS.

The GReat-Child™ Trial: A Quasi-Experimental Intervention on Whole Grains with Healthy Balanced Diet to Manage Childhood Obesity in Kuala Lumpur, Malaysia

Background: The GReat-Child Trial was a quasi-experimental intervention that has emphasized whole grain as a strategy to manage childhood obesity. Methods: Two schools in Kuala Lumpur with similar demographic characteristics were assigned as intervention (IG) and control (CG). Eligibility criteria were overweight/obese children aged 9 to 11 years who had no serious co-morbidity. Children who reported consuming wholegrain foods in their 3-day diet-recall during screening were excluded. A total of 63 children (31 IG; 32 CG) completed the entire intervention program. The IG children underwent six 30-min nutrition education lessons and had school delivery of wholegrain food on a daily basis over a 12-week period. Parents of IG children attended 1-h individual diet counseling. Anthropometric outcomes including BMI-for-age z-score (BAZ), body fat percentage and waist circumference were measured at baseline [T0], post-intervention [T1] (3rd month) and follow-up [T2] (9th month). Results: IG showed significantly lower BAZ (weighted difference: -0.12; 95% CI: -0.21, -0.03; p = 0.009), body fat percentage (weighted difference: -2.6%; 95% CI: -3.7, -1.5; p < 0.001) and waist circumference (weighted difference: -2.4 cm; 95% CI: -3.8, -1.0; p = 0.001) compared to CG. IG reported significantly lower body fat percentage (weighted difference: -3.4%; 95% CI: 1.8, 5.0; p < 0.001) and waist circumference (weighted difference: -2.1 cm; 95% CI: -3.7, -0.5; p = 0.014) at T1 compared to T0. Conclusions: The GReat-Child Trial made a positive impact in managing childhood obesity. It can be incorporated into childhood obesity intervention programs that are being implemented by the policy makers.

The nutritional property of endosperm starch and its contribution to the health benefits of whole grain foods

Purported health benefits of whole grain foods in lowering risk of obesity, type 2 diabetes, cardiovascular disease, and cancer are supported by epidemiological studies and scientific researches. Bioactive components including dietary fibers, phytochemicals, and various micronutrients present in the bran and germ are commonly considered as the basis for such benefits. Endosperm starch, as the major constituent of whole grains providing glucose to the body, has been less investigated regarding its nutritional property and contribution to the value of whole grain foods. Nutritional quality of starch is associated with its rate of digestion and glucose absorption. In whole grain foods, starch digestion and glucose delivery may vary depending on the form in which the food is delivered, some with starch being rapidly and others slowly digested. Furthermore, there are other inherent factors in whole grain products, such as phenolic compounds and dietary fibers, that may moderate glycemic profiles. A good understanding of the nutritional properties of whole grain starch is important to the development of food processing technologies to maximize their health benefits.

Regulation of GIP and Ghrelin in Healthy Subjects Fed on Sun-Dried Raisins: A Pilot Study with a Crossover Trial Design

The comparative effects of glucose and fructose on appetite and specifically on hormones regulating appetite remain controversial, and the role of different types of sugars has not been investigated broadly. To estimate the effect of raisins, a dried fruit rich in fructose, fibers, and phenolics, on hormones involved in the postprandial response. Ten healthy normal-weight subjects received in a crossover design 74 g raisins or 50 g glucose as reference food. Glucose, insulin, and appetite hormones were measured at time 0 and 60, 120, and 180 min after consumption. Glucose and insulin peaked significantly at 60 min in both trials with no difference in two trials. Gastric inhibitory peptide peaked significantly at 60 min in both trials and was found lower in raisin compared to glucose at 60 and 120 min postprandially. Ghrelin was lower in raisin compared to glucose at 120 and at 180 min postingestion. Ghrelin/obestatin ratio was lower at 120 min in raisin compared to glucose. No differences were reported for glucagon-like peptide-1, apelin, and obestatin in either trial. Raisin consumption could be favorable in terms of regulating appetite compared to refined sugars or glucose-based products in normal-weight healthy subjects.

Plasma alkylresorcinols, biomarkers of whole-grain wheat and rye intake, and risk of type 2 diabetes in Scandinavian men and women

BACKGROUND

Studies that use dietary biomarkers to investigate the association between whole-grain intake and the risk of developing type 2 diabetes (T2D) are lacking.

OBJECTIVE

We examined the association between plasma total alkylresorcinols and the alkylresorcinol C17:0-to-C21:0 ratio, biomarkers of whole-grain wheat and rye intake and relative whole-grain rye over whole-grain wheat intake, respectively, and the risk of T2D among Scandinavian men and women.

DESIGN

A nested case-control study was established within the Northern Sweden Health and Disease Study and the Danish Diet, Cancer and Health cohort. Alkylresorcinol concentrations and the ratios of C17:0 to C21:0 were determined in plasma samples from 931 case-control pairs. ORs for T2D were calculated for plasma total alkylresorcinol concentration or C17:0-to-C21:0 ratio in quartiles with the use of conditional logistic regression that was adjusted for potential confounders. Additional analyses with whole-grain wheat and rye intake estimated from food-frequency questionnaires (FFQs) as exposures were also performed.

RESULTS

The plasma total alkylresorcinol concentration was not associated with T2D risk (OR: 1.34; 95% CI: 0.95, 1.88) for the highest compared with the lowest quartiles in multivariable adjusted models. However, the C17:0-to-C21:0 ratio was associated with a lower diabetes risk (OR: 0.54; 95% CI: 0.37, 0.78). Analyses with whole-grain intake estimated from FFQs yielded similar results.

CONCLUSIONS

Total whole-grain wheat and rye intake, reflected by alkylresorcinols in plasma, was not associated with a lower risk of T2D in a population with high whole-grain intake. In contrast, the proportion of whole-grain rye to whole-grain wheat intake, indicated by the plasma C17:0-to-C21:0 ratio, was inversely associated with T2D. This suggests that whole-grain intake dominated by rye may be favorable for T2D prevention.

Interactions between adipose tissue and the immune system in health and malnutrition

Adipose tissue provides the body with a storage depot of nutrients that is drained during times of starvation and replenished when food sources are abundant. As such, it is the primary sensor for nutrient availability in the milieu of an organism, which it communicates to the body through the excretion of hormones. Adipose tissue regulates a multitude of body functions associated with metabolism, such as gluconeogenesis, feeding and nutrient uptake. The immune system forms a vital layer of protection against micro-organisms that try to gain access to the nutrients contained in the body. Because infections need to be resolved as quickly as possible, speed is favored over energy-efficiency in an immune response. Especially when immune cells are activated, they switch to fast, but energy-inefficient anaerobic respiration to fulfill their energetic needs. Despite the necessity for an effective immune system, it is not given free rein in its energy expenditure. Signals derived from adipose tissue limit immune cell numbers and activity under conditions of nutrient shortage, whereas they allow proper immune cell activity when food sources are sufficiently available. When excessive fat accumulation occurs, such as in diet-induced obesity, adipose tissue becomes the site of pathological immune cell activation, causing chronic low-grade systemic inflammation. Obesity is therefore associated with a number of disorders in which the immune system plays a central role, such as atherosclerosis and non-alcoholic steatohepatitis. In this review, we will discuss the way in which adipose tissue regulates activity of the immune system under healthy and pathological conditions.

Low-grade inflammation, diet composition and health: current research evidence and its translation

The importance of chronic low-grade inflammation in the pathology of numerous age-related chronic conditions is now clear. An unresolved inflammatory response is likely to be involved from the early stages of disease development. The present position paper is the most recent in a series produced by the International Life Sciences Institute's European Branch (ILSI Europe). It is co-authored by the speakers from a 2013 workshop led by the Obesity and Diabetes Task Force entitled ‘Low-grade inflammation, a high-grade challenge: biomarkers and modulation by dietary strategies’. The latest research in the areas of acute and chronic inflammation and cardiometabolic, gut and cognitive health is presented along with the cellular and molecular mechanisms underlying inflammation–health/disease associations. The evidence relating diet composition and early-life nutrition to inflammatory status is reviewed. Human epidemiological and intervention data are thus far heavily reliant on the measurement of inflammatory markers in the circulation, and in particular cytokines in the fasting state, which are recognised as an insensitive and highly variable index of tissue inflammation. Potential novel kinetic and integrated approaches to capture inflammatory status in humans are discussed. Such approaches are likely to provide a more discriminating means of quantifying inflammation–health/disease associations, and the ability of diet to positively modulate inflammation and provide the much needed evidence to develop research portfolios that will inform new product development and associated health claims.

Diet, inflammation and prediabetes-impact of quality of diet

Low grade inflammation has been linked to risk of type 2 diabetes and atherosclerotic vascular diseases. Obesity and, in particular, abdominal obesity increase the risk of diabetes and atherosclerotic vascular diseases. One of the mechanisms could be low grade inflammation and vascular endothelial dysfunction. Permanent weight reduction is the first line of treatment both for obese individuals at increased risk of diabetes and for newly onset type 2 diabetes. Weight reduction lowers the level of several inflammatory factors in the body while increasing the level of adiponectin. Besides weight reduction the quality of diet and physical activity also modifies low grade inflammation. Based on the literature survey and our own studies in humans, it is possible to have dietary patterns that reduce inflammatory stress in the body and improves vascular endothelial dysfunction. There is strong evidence to suggest that IL-1 Ra is a very sensitive marker of low grade inflammation in obesity and related phenotypes; however, its level is markedly lowered by weight reduction and by choosing foods that have been shown to reduce inflammatory stress in the body.

Healthy Nordic diet downregulates the expression of genes involved in inflammation in subcutaneous adipose tissue in individuals with features of the metabolic syndrome

BACKGROUND

Previously, a healthy Nordic diet (ND) has been shown to have beneficial health effects close to those of Mediterranean diets.

OBJECTIVE

The objective was to explore whether the ND has an impact on gene expression in abdominal subcutaneous adipose tissue (SAT) and whether changes in gene expression are associated with clinical and biochemical effects.

DESIGN

Obese adults with features of the metabolic syndrome underwent an 18- to 24-wk randomized intervention study comparing the ND with the control diet (CD) (the SYSDIET study, carried out within Nordic Centre of Excellence of the Systems Biology in Controlled Dietary Interventions and Cohort Studies). The present study included participants from 3 Nordic SYSDIET centers [Kuopio (n = 20), Lund (n = 18), and Oulu (n = 18)] with a maximum weight change of ±4 kg, highly sensitive C-reactive protein concentration <10 mg/L at the beginning and the end of the intervention, and baseline body mass index (in kg/m²) <38. SAT biopsy specimens were obtained before and after the intervention and subjected to global transcriptome analysis with Gene 1.1 ST Arrays (Affymetrix).

RESULTS

Altogether, 128 genes were differentially expressed in SAT between the ND and CD (nominal P < 0.01; false discovery rate, 25%). These genes were overrepresented in pathways related to immune response (adjusted P = 0.0076), resulting mainly from slightly decreased expression in the ND and increased expression in the CD. Immune-related pathways included leukocyte trafficking and macrophage recruitment (e.g., interferon regulatory factor 1, CD97), adaptive immune response (interleukin32, interleukin 6 receptor), and reactive oxygen species (neutrophil cytosolic factor 1). Interestingly, the regulatory region of the 128 genes was overrepresented for binding sites for the nuclear transcription factor κB.

CONCLUSION

A healthy Nordic diet reduces inflammatory gene expression in SAT compared with a control diet independently of body weight change in individuals with features of the metabolic syndrome.

Nutrigenetics and nutrigenomics insights into diabetes etiopathogenesis

Diabetes mellitus (DM) is considered a global pandemic, and the incidence of DM continues to grow worldwide. Nutrients and dietary patterns are central issues in the prevention, development and treatment of this disease. The pathogenesis of DM is not completely understood, but nutrient-gene interactions at different levels, genetic predisposition and dietary factors appear to be involved. Nutritional genomics studies generally focus on dietary patterns according to genetic variations, the role of gene-nutrient interactions, gene-diet-phenotype interactions and epigenetic modifications caused by nutrients; these studies will facilitate an understanding of the early molecular events that occur in DM and will contribute to the identification of better biomarkers and diagnostics tools. In particular, this approach will help to develop tailored diets that maximize the use of nutrients and other functional ingredients present in food, which will aid in the prevention and delay of DM and its complications. This review discusses the current state of nutrigenetics, nutrigenomics and epigenomics research on DM. Here, we provide an overview of the role of gene variants and nutrient interactions, the importance of nutrients and dietary patterns on gene expression, how epigenetic changes and micro RNAs (miRNAs) can alter cellular signaling in response to nutrients and the dietary interventions that may help to prevent the onset of DM.

Position of the Academy of Nutrition and Dietetics: nutritional genomics

It is the position of the Academy of Nutrition and Dietetics that nutritional genomics provides insight into how diet and genotype interactions affect phenotype. The practical application of nutritional genomics for complex chronic disease is an emerging science and the use of nutrigenetic testing to provide dietary advice is not ready for routine dietetics practice. Registered dietitian nutritionists need basic competency in genetics as a foundation for understanding nutritional genomics; proficiency requires advanced knowledge and skills. Unlike single-gene defects in which a mutation in a single gene results in a specific disorder, most chronic diseases, such as cardiovascular disease, diabetes, and cancer are multigenetic and multifactorial and therefore genetic mutations are only partially predictive of disease risk. Family history, biochemical parameters, and the presence of risk factors in individuals are relevant tools for personalizing dietary interventions. Direct-to-consumer genetic testing is not closely regulated in the United States and may not be accompanied by access to health care practitioners. Applying nutritional genomics in clinical practice through the use of genetic testing requires that registered dietitian nutritionists understand, interpret, and communicate complex test results in which the actual risk of developing a disease may not be known. The practical application of nutritional genomics in dietetics practice will require an evidence-based approach to validate that personalized recommendations result in health benefits to individuals and do not cause harm.

Role of PPARs in inflammatory processes associated with metabolic syndrome (Review)

Metabolic syndrome (MS) includes the presence of arterial hypertension, insulin resistance, dyslipidemia, cardiovascular disease (CVD) and abdominal obesity, which is associated with a chronic inflammatory response, characterized by abnormal adipokine production, and the activation of certain pro-inflammatory signaling pathways. Furthermore, the changes presented by the adipose tissue in MS favors the secretion of several molecular mediators capable of activating or suppressing a number of transcription factors, such as the peroxisome proliferator-activated receptors (PPARs), whose main functions include storage regulation and fatty acid catabolization. When they are activated by their ligands (synthetic or endogenous), they control several genes involved in intermediate metabolism, which make them, together with the PPAR gamma coactivator-1-α (PGC-1) and the silent information regulator T1 (SIRT1), good targets for treating metabolic diseases and their cardiovascular complications.

Systems Epidemiology: A New Direction in Nutrition and Metabolic Disease Research

Systems epidemiology applied to the field of nutrition has potential to provide new insight into underlying mechanisms and ways to study the health effects of specific foods more comprehensively. Human intervention and population-based studies have identified i) common genetic factors associated with several nutrition-related traits and ii) dietary factors altering the expression of genes and levels of proteins and metabolites related to inflammation, lipid metabolism and/or gut microbial metabolism, results of high relevance to metabolic disease. System-level tools applied type 2 diabetes and related conditions have revealed new pathways that are potentially modified by diet and thus offer additional opportunities for nutritional investigations. Moving forward, harnessing the resources of existing large prospective studies within which biological samples have been archived and diet and lifestyle have been measured repeatedly within individual will enable systems-level data to be integrated, the outcome of which will be improved personalized optimal nutrition for prevention and treatment of disease.

Mechanisms of chronic state of inflammation as mediators that link obese adipose tissue and metabolic syndrome

The metabolic syndrome is a cluster of cardiometabolic alterations that include the presence of arterial hypertension, insulin resistance, dyslipidemia, and abdominal obesity. Obesity is associated with a chronic inflammatory response, characterized by abnormal adipokine production, and the activation of proinflammatory signalling pathways resulting in the induction of several biological markers of inflammation. Macrophage and lymphocyte infiltration in adipose tissue may contribute to the pathogenesis of obesity-mediated metabolic disorders. Adiponectin can either act directly on macrophages to shift polarization and/or prime human monocytes into alternative M2-macrophages with anti-inflammatory properties. Meanwhile, the chronic inflammation in adipose tissue is regulated by a series of transcription factors, mainly PPARs and C/EBPs, that in conjunction regulate the expression of hundreds of proteins that participate in the metabolism and storage of lipids and, as such, the secretion by adipocytes. Therefore, the management of the metabolic syndrome requires the development of new therapeutic strategies aimed to alter the main genetic pathways involved in the regulation of adipose tissue metabolism.

Nutritionally mediated oxidative stress and inflammation

There are many sources of nutritionally mediated oxidative stress that trigger inflammatory cascades along short and long time frames. These events are primarily mediated via NF κ B. On the short-term scale postprandial inflammation is characterized by an increase in circulating levels of IL-6 and TNF- α and is mirrored on the long-term by proinflammatory gene expression changes in the adipocytes and peripheral blood mononuclear cells (PBMCs) of obese individuals. Specifically the upregulation of CCL2/MCP-1, CCL3/MIP-1 α , CCL4/MIP-1 β , CXCL2/MIP-2 α , and CXCL3/MIP-2 β is noted because these changes have been observed in both adipocytes and PBMC of obese humans. In comparing numerous human intervention studies it is clear that pro-inflammatory and anti-inflammatory consumption choices mediate gene expression in humans adipocytes and peripheral blood mononuclear cells. Arachidonic acid and saturated fatty acids (SFAs) both demonstrate an ability to increase pro-inflammatory IL-8 along with numerous other inflammatory factors including IL-6, TNF α , IL-1 β , and CXCL1 for arachidonic acid and IGB2 and CTSS for SFA. Antioxidant rich foods including olive oil, fruits, and vegetables all demonstrate an ability to lower levels of IL-6 in PBMCs. Thus, dietary choices play a complex role in the mediation of unavoidable oxidative stress and can serve to exacerbate or dampen the level of inflammation.

Mechanisms of chronic state of inflammation as mediators that link obese adipose tissue and metabolic syndrome

The metabolic syndrome is a cluster of cardiometabolic alterations that include the presence of arterial hypertension, insulin resistance, dyslipidemia, and abdominal obesity. Obesity is associated with a chronic inflammatory response, characterized by abnormal adipokine production, and the activation of proinflammatory signalling pathways resulting in the induction of several biological markers of inflammation. Macrophage and lymphocyte infiltration in adipose tissue may contribute to the pathogenesis of obesity-mediated metabolic disorders. Adiponectin can either act directly on macrophages to shift polarization and/or prime human monocytes into alternative M2-macrophages with anti-inflammatory properties. Meanwhile, the chronic inflammation in adipose tissue is regulated by a series of transcription factors, mainly PPARs and C/EBPs, that in conjunction regulate the expression of hundreds of proteins that participate in the metabolism and storage of lipids and, as such, the secretion by adipocytes. Therefore, the management of the metabolic syndrome requires the development of new therapeutic strategies aimed to alter the main genetic pathways involved in the regulation of adipose tissue metabolism.

Reduced-energy cranberry juice increases folic acid and adiponectin and reduces homocysteine and oxidative stress in patients with the metabolic syndrome

The metabolic syndrome (MetS) comprises pathological conditions that include insulin resistance, arterial hypertension, visceral adiposity and dyslipidaemia, which favour the development of CVD. Some reports have shown that cranberry ingestion reduces cardiovascular risk factors. However, few studies have evaluated the effect of this fruit in subjects with the MetS. The objective of the present study was to assess the effect of reduced-energy cranberry juice consumption on metabolic and inflammatory biomarkers in patients with the MetS, and to verify the effects of cranberry juice concomitantly on homocysteine and adiponectin levels in patients with the MetS. For this purpose, fifty-six individuals with the MetS were selected and divided into two groups: control group (n36) and cranberry-treated group (n20). After consuming reduced-energy cranberry juice (0·7 litres/d) containing 0·4 mg folic acid for 60 d, the cranberry-treated group showed an increase in adiponectin (P= 0·010) and folic acid (P= 0·033) and a decrease in homocysteine (P< 0·001) in relation to baseline values and also in comparison with the controls (P< 0·05). There was no significant change in the pro-inflammatory cytokines TNF-α, IL-1 and IL-6. In relation to oxidative stress measurements, decreased (P< 0·05) lipoperoxidation and protein oxidation levels assessed by advanced oxidation protein products were found in the cranberry-treated group when compared with the control group. In conclusion, the consumption of cranberry juice for 60 d was able to improve some cardiovascular risk factors. The present data reinforce the importance of the inverse association between homocysteine and adiponectin and the need for more specifically designed studies on MetS patients.

Berries reduce postprandial insulin responses to wheat and rye breads in healthy women

Starch in white wheat bread (WB) induces high postprandial glucose and insulin responses. For rye bread (RB), the glucose response is similar, whereas the insulin response is lower. In vitro studies suggest that polyphenol-rich berries may reduce digestion and absorption of starch and thereby suppress postprandial glycemia, but the evidence in humans is limited. We investigated the effects of berries consumed with WB or RB on postprandial glucose and insulin responses. Healthy females (n = 13-20) participated in 3 randomized, controlled, crossover, 2-h meal studies. They consumed WB or RB, both equal to 50 g available starch, with 150 g whole-berry purée or the same amount of bread without berries as reference. In study 1, WB was served with strawberries, bilberries, or lingonberries and in study 2 with raspberries, cloudberries, or chokeberries. In study 3, WB or RB was served with a mixture of berries consisting of equal amounts of strawberries, bilberries, cranberries, and blackcurrants. Strawberries, bilberries, lingonberries, and chokeberries consumed with WB and the berry mixture consumed with WB or RB significantly reduced the postprandial insulin response. Only strawberries (36%) and the berry mixture (with WB, 38%; with RB, 19%) significantly improved the glycemic profile of the breads. These results suggest than when WB is consumed with berries, less insulin is needed for maintenance of normal or slightly improved postprandial glucose metabolism. The lower insulin response to RB compared with WB can also be further reduced by berries.

Monitoring of deiodinase deficiency based on transcriptomic responses in SH-SY5Y cells

Iodothyronine deiodinase types I, II, and III (D1, D2, and D3, respectively), which constitute a family of selenoenzymes, activate and inactivate thyroid hormones through the removal of specific iodine moieties from thyroxine and its derivatives. These enzymes are important in the biological effects mediated by thyroid hormones. The expression of activating and inactivating deiodinases plays a critical role in a number of cell systems, including the neuronal system, during development as well as in adult vertebrates. To investigate deiodinase-disrupting chemicals based on transcriptomic responses, we examined differences in gene expression profiles between T3-treated and deiodinase-knockdown SH-SY5Y cells using microarray analysis and quantitative real-time RT-PCR. A total of 1,558 genes, consisting of 755 upregulated and 803 downregulated genes, were differentially expressed between the T3-treated and deiodinase-knockdown cells. The expression levels of 10 of these genes (ID2, ID3, CCL2, TBX3, TGOLN2, C1orf71, ZNF676, GULP1, KLF9, and ITGB5) were altered by deiodinase-disrupting chemicals (2,3,7,8-tetrachlorodibenzo-p-dioxin, polychlorinated biphenyls, propylthiouracil, iodoacetic acid, methylmercury, β-estradiol, methimazole, 3-methylcholanthrene, aminotriazole, amiodarone, cadmium chloride, dimethoate, fenvalerate, octylmethoxycinnamate, iopanoic acid, methoxychlor, and 4-methylbenzylidene-camphor). These genes are potential biomarkers for detecting deiodinase deficiency and predicting their effects on thyroid hormone production.

A high intake of dietary fiber influences C-reactive protein and fibrinogen, but not glucose and lipid metabolism, in mildly hypercholesterolemic subjects

PURPOSE

The aim of the study was to investigate how a diet high in dietary fiber, with several fiber sources included, modulates glucose and lipid metabolism and the inflammatory response in humans.

METHODS

Subjects (n = 25) aged 58.6 (1.1) years (mean and SD) with a BMI of 26.6 (0.5) kg/m(2) and a total cholesterol (TC) of 5.8 (0.1) mmol/L (mean and SEM) were given a high fiber (HF) and low fiber (LF) diet, in a randomized controlled 5-week crossover intervention, separated by a 3-week washout. The HF diet consisted of oat bran, rye bran, and sugar beet fiber incorporated into test food products; one bread roll, one ready meal, and two beverages consumed daily. Equivalent food products, without added fibers, were provided in the LF diet.

RESULTS

Total dietary fiber intake was 48.0 g and 30.2 g per day for the HF and LF diet, respectively. Significant reduction in C-reactive protein (CRP) was observed between the diets (P = 0.017) and a significant reduction in fibrinogen within the HF diet (P = 0.044). There were no significant effects in other measured circulating cytokines or in glucose, insulin, and lipid levels.

CONCLUSIONS

Our study suggests that a 5-week high dietary fiber intake of oat bran, rye bran, and sugar beet fiber might reduce the low-grade inflammatory response measured as CRP which could, together with reduced fibrinogen, help to prevent the risk of cardiovascular disease.

The evolution of nutrition research

"The doctor of the future will no longer treat the human frame with drugs, but will rather cure and prevent disease with nutrition". Thomas Edison's contemplation may come to fruition if the nutritional revolution continues in its current course. Two realizations have propelled the world into a new age of personalized nutrition: (i) food can provide benefits beyond its intrinsic nutrient content, and (ii) we are not all created equal in our ability to realize to these benefits. Nutrigenomics is concerned with delineating genomic propensities to respond to various nutritional stimuli and the resulting impact on individual health. This review will examine the current technologies utilized by nutrigeneticists, the available literature regarding nutrient-gene interactions, and the translation of this new awareness into public health.

Molecular nutrition research: the modern way of performing nutritional science

In spite of amazing progress in food supply and nutritional science, and a striking increase in life expectancy of approximately 2.5 months per year in many countries during the previous 150 years, modern nutritional research has a great potential of still contributing to improved health for future generations, granted that the revolutions in molecular and systems technologies are applied to nutritional questions. Descriptive and mechanistic studies using state of the art epidemiology, food intake registration, genomics with single nucleotide polymorphisms (SNPs) and epigenomics, transcriptomics, proteomics, metabolomics, advanced biostatistics, imaging, calorimetry, cell biology, challenge tests (meals, exercise, etc.), and integration of all data by systems biology, will provide insight on a much higher level than today in a field we may name molecular nutrition research. To take advantage of all the new technologies scientists should develop international collaboration and gather data in large open access databases like the suggested Nutritional Phenotype database (dbNP). This collaboration will promote standardization of procedures (SOP), and provide a possibility to use collected data in future research projects. The ultimate goals of future nutritional research are to understand the detailed mechanisms of action for how nutrients/foods interact with the body and thereby enhance health and treat diet-related diseases.

Slowly and rapidly digestible starchy foods can elicit a similar glycemic response because of differential tissue glucose uptake in healthy men

BACKGROUND

Previously we observed that the consumption of pasta and bread resulted in a similar glycemic response, despite a slower intestinal influx rate of glucose from the pasta. Underlying mechanisms of this effect were not clear.

OBJECTIVE

The objective was to investigate the differences in glucose kinetics and hormonal response after consumption of products with slow and rapid in vivo starch digestibility but with a similar glycemic response.

DESIGN

Ten healthy male volunteers participated in a crossover study and consumed (13)C-enriched wheat bread or pasta while receiving a primed-continuous D-[6,6-(2)H(2)]glucose infusion. The dual-isotope technique enabled calculation of the following glucose kinetics: rate of appearance of exogenous glucose (RaE), endogenous glucose production, and glucose clearance rate (GCR). In addition, postprandial plasma concentrations of glucose, insulin, glucagon, and glucose-dependent insulinotropic polypeptide (GIP) were analyzed.

RESULTS

GIP concentrations after pasta consumption were lower than after bread consumption and strongly correlated with the RaE (r = 0.82, P < 0.01). The insulin response was also lower after pasta consumption (P < 0.01). In accordance with the low insulin response, the GCR was lower after pasta consumption, which explained the high glycemic response despite a low RaE.

CONCLUSIONS

Slower intestinal uptake of glucose from a starchy food product can result in lower postprandial insulin and GIP concentrations, but not necessarily in a lower glycemic response, because of a slower GCR. Even without being able to reduce postprandial glycemia, products with slowly digestible starch can have beneficial long-term effects. These types of starchy products cannot be identified by using the glycemic index and therefore another classification system may be necessary. This trial was registered at controlled-trials.com as ISRCTN42106325.

Impact of postprandial glycaemia on health and prevention of disease

Postprandial glucose, together with related hyperinsulinemia and lipidaemia, has been implicated in the development of chronic metabolic diseases like obesity, type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). In this review, available evidence is discussed on postprandial glucose in relation to body weight control, the development of oxidative stress, T2DM, and CVD and in maintaining optimal exercise and cognitive performance. There is mechanistic evidence linking postprandial glycaemia or glycaemic variability to the development of these conditions or in the impairment in cognitive and exercise performance. Nevertheless, postprandial glycaemia is interrelated with many other (risk) factors as well as to fasting glucose. In many studies, meal-related glycaemic response is not sufficiently characterized, or the methodology with respect to the description of food or meal composition, or the duration of the measurement of postprandial glycaemia is limited. It is evident that more randomized controlled dietary intervention trials using effective low vs. high glucose response diets are necessary in order to draw more definite conclusions on the role of postprandial glycaemia in relation to health and disease. Also of importance is the evaluation of the potential role of the time course of postprandial glycaemia.

Whole grain wheat sourdough bread does not affect plasminogen activator inhibitor-1 in adults with normal or impaired carbohydrate metabolism

BACKGROUND AND AIMS

Epidemiological studies suggest whole grain consumption is associated with a reduced risk of cardiovascular disease (CVD), possibly through alterations in glucose metabolism and subsequent effects on plasminogen activator inhibitor (PAI)-1, a novel biomarker for CVD. Our aim was to investigate the effect of 6 wk of whole grain wheat sourdough bread consumption versus refined white bread on PAI-1.

METHODS AND RESULTS

Normoglycemic/normoinsulinemic (NGI; n = 14; age 53 ± 6 y; BMI 26.5 ± 2.9 kg/m(2)) and hyperglycemic/hyperinsulinemic (HGI; n = 14; age 57 ± 7 y; BMI 35.7 ± 5.7 kg/m(2)) adults incorporated whole grain wheat sourdough (162.5 g) or white (168.8 g) bread into their diet, for 6 wk in a randomized crossover study. Pre- and post-intervention, fasting blood samples were analyzed for PAI-1 (primary outcome), as well as glucose, insulin and glucagon (secondary outcomes) at fasting and postprandially after an oral glucose tolerance test (OGTT). Anthropometric measures, fasting glucose, insulin, glucagon and PAI-1 antigen and activity were not different between treatments in either NGI or HGI adults. Glucose incremental area under the curve (iAUC) was lower (19%, P = 0.02) after 6 wk consumption of whole grain wheat sourdough bread compared to white bread in the HGI group, with no differences in insulin or glucagon iAUC in either group.

CONCLUSION

Our data showed decreased glucose iAUC after an OGTT following 6 wk whole grain wheat bread consumption in adults with differing glycemic/insulinemic status, but no improvements in PAI-1 or fasting glycemic parameters.

Phaseolus beans: impact on glycaemic response and chronic disease risk in human subjects

Consumption of Phaseolus vulgaris bean species such as pinto, black, navy or kidney may be beneficial in the prevention and treatment of chronic diseases. In particular, conditions that are promoted by increased glycaemic stress (hyperglycaemia and hyperinsulinaemia) including diabetes, CVD and cancer seem to be reduced in individuals who eat more of these beans. The present paper discusses the influence of P. vulgaris species on glycaemic response and the impact that relationship may have on the risk of developing diabetes, CVD and cancer.

Gene expression of peripheral blood mononuclear cells as a tool in dietary intervention studies: What do we know so far?

Peripheral blood mononuclear cells (PBMCs) generally refer to monocytes and lymphocytes, representing cells of the innate and adaptive immune systems. PBMCs are a promising target tissue in the field of nutrigenomics because they seem to reflect the effects of dietary modifications at the level of gene expression. In this review, we describe and discuss the scientific literature concerning the use of gene expression at the mRNA level measured from PBMCs in dietary interventions studies conducted in humans. A search of literature was undertaken using PubMed (last assessed November 24, 2011) and 20 articles were selected for discussion. Currently, results from these studies showed that PBMCs seem to reflect liver environment and complement adipose tissue findings in transcriptomics. PBMC gene expression after dietary intervention studies can be used for studying the response of certain genes related to fatty acid and cholesterol metabolism, and to explore the response of dietary interventions in relation to inflammation. However, PBMC transcriptomics from dietary intervention studies have not resulted yet in clear confirmation of candidate genes related to disease risk. Use of microarray technology in larger well-designed dietary intervention studies is still needed for exploring PBMC potential in the field of nutrigenomics.

Nutrigenomics and personalized diets: What will they mean for food?

The modern food system feeds six billion people with remarkable diversity, safety, and nutrition. Yet, the current rise in diet-related diseases is compromising health and devaluing many aspects of modern agriculture. Steps to increase the nutritional quality of individual foods will assist in personalizing health and in guiding individuals to achieve superior health. Nutrigenomics is the scientific field of the genetic basis for varying susceptibilities to disease and the diverse responses to foods. Although some of these genetic determinants will be simple and amenable to personal genotyping as the means to predict health, in practice most will not. As a result, genotyping will not be the secret to personalizing diet and health. Human assessment technologies from imaging to proteomics and metabolomics are providing tools to both understand and accurately assess the nutritional phenotype of individuals. The business models are also emerging to bring these assessment capabilities to industrial practice, in which consumers will know more about their personal health and seek personal solutions.

Nuclear magnetic resonance-based metabolomics enable detection of the effects of a whole grain rye and rye bran diet on the metabolic profile of plasma in prostate cancer patients

Prostate cancer (PC) is the most common cancer in the Western world and the second most important cancer causing male deaths, after lung cancer, in the United States and Britain. Lifestyle and dietary changes are recommended for men diagnosed with early-stage PC. It has been shown that a diet rich in whole grain (WG) rye reduces the progression of early-stage PC, but the underlying mechanism is not clear. This study sought to identify changes in the metabolic signature of plasma in patients with early-stage PC following intervention with a diet rich in WG rye and rye bran product (RP) compared with refined white wheat product (WP) as a tool for mechanistic investigation of the beneficial health effects of RP on PC progression. Seventeen PC patients received 485 g RP or WP in a randomized, controlled, crossover design during a period of 6 wk with a 2-wk washout period. At the end of each intervention period, plasma was collected after fasting and used for (1)H NMR-based metabolomics. Multilevel partial least squares discriminant analysis was used for paired comparisons of multivariate data. A metabolomics analysis of plasma showed an increase in 5 metabolites, including 3-hydroxybutyric acid, acetone, betaine, N,N-dimethylglycine, and dimethyl sulfone, after RP. To understand these metabolic changes, fasting plasma homocysteine, leptin, adiponectin, and glucagon were measured separately. The plasma homocysteine concentration was lower (P = 0.017) and that of leptin tended to be lower (P = 0.07) after RP intake compared to WP intake. The increase in plasma 3-hydroxybutyric acid and acetone after RP suggests a shift in energy metabolism from anabolic to catabolic status, which could explain some of the beneficial health effects of WG rye, i.e., reduction in prostate-specific antigen and reduced 24-h insulin secretion. In addition, the increase in betaine and N,N-dimethylglycine and the decrease in homocysteine show a favorable shift in homocysteine metabolism after RP intake.

Whole grain products, fish and bilberries alter glucose and lipid metabolism in a randomized, controlled trial: the Sysdimet study

Background

Due to the growing prevalence of type 2 diabetes, new dietary solutions are needed to help improve glucose and lipid metabolism in persons at high risk of developing the disease. Herein we investigated the effects of low-insulin-response grain products, fatty fish, and berries on glucose metabolism and plasma lipidomic profiles in persons with impaired glucose metabolism.

Methodology/Principal Findings

Altogether 106 men and women with impaired glucose metabolism and with at least two other features of the metabolic syndrome were included in a 12-week parallel dietary intervention. The participants were randomized into three diet intervention groups: (1) whole grain and low postprandial insulin response grain products, fatty fish three times a week, and bilberries three portions per day (HealthyDiet group), (2) Whole grain enriched diet (WGED) group, which includes principally the same grain products as group (1), but with no change in fish or berry consumption, and (3) refined wheat breads (Control). Oral glucose tolerance, plasma fatty acids and lipidomic profiles were measured before and after the intervention. Self-reported compliance with the diets was good and the body weight remained constant. Within the HealthyDiet group two hour glucose concentration and area-under-the-curve for glucose decreased and plasma proportion of (n-3) long-chain PUFAs increased (False Discovery Rate p-values <0.05). Increases in eicosapentaenoic acid and docosahexaenoic acid associated curvilinearly with the improved insulin secretion and glucose disposal. Among the 364 characterized lipids, 25 changed significantly in the HealthyDiet group, including multiple triglycerides incorporating the long chain (n-3) PUFA.

Conclusions/Significance

The results suggest that the diet rich in whole grain and low insulin response grain products, bilberries, and fatty fish improve glucose metabolism and alter the lipidomic profile. Therefore, such a diet may have a beneficial effect in the efforts to prevent type 2 diabetes in high risk persons.

Trial Registration

ClinicalTrials.gov NCT00573781

Soy food supplementation, dietary fat reduction and peripheral blood gene expression in postmenopausal women--a randomized, controlled trial

SCOPE

The effect of soy food supplementation or dietary fat reduction on gene expression is not well studied.

METHODS AND RESULTS

We evaluated the potential of gene expression profiling in peripheral blood mononuclear cells (PBMCs) collected at baseline and at the completion of an 8-wk controlled dietary intervention. Healthy postmenopausal women were randomized to a very-low-fat diet (VLFD; 11% of energy as fat) (n=21), a Step 1 diet (25% energy as fat) supplemented with soy food (SFD; 50 mg isoflavones per day) (n=20), or a control Step 1 diet (CD; 27% energy as fat) with no SFD (n=18). All diets were prepared at the General Clinical Research Center of the University of Southern California. We did not observe any gene that showed variable response across the three dietary interventions. However, there were notable changes in gene expression associated with the intervention in the VLFD and SFD groups. Our findings suggest that the expression of nicotinamide phosphoribosyltransferase (NAMPT) and genes related to Fc γ R-mediated phagocytosis and cytokine interactions may be significantly altered in association with dietary fat reduction and soy supplementation. Gene expression changes in NAMPT were somewhat dampened with adjustment for weight but changes related to Fc γ R-mediated phagocytosis and cytokine interactions remained largely unchanged.

CONCLUSION

PBMCs can reveal novel gene expression changes in association with controlled dietary intervention.