Iwona Rudkowska

Transcriptomic and metabolomic signatures of an n-3 polyunsaturated fatty acids supplementation in a normolipidemic/normocholesterolemic Caucasian population

OMIC technologies, including transcriptomics and metabolomics, may provide powerful tools for identifying the effects of nutrients on molecular functions and metabolic pathways. The objective was to investigate molecular and metabolic changes following n-3 polyunsaturated fatty acid (PUFA) supplementation in healthy subjects via traditional biomarkers as well as transcriptome and metabolome analyses. Thirteen men and 17 women followed a 2-week run-in period based on Canadas Food Guide and then underwent 6-week supplementation with n-3 PUFA (3 g/day). Traditional biochemical markers such as plasma lipids, inflammatory markers, glycemic parameters and erythrocyte fatty acid concentrations were measured. Changes in gene expression of peripheral blood mononuclear cells were assessed by microarrays, and metabolome profiles were assessed by mass spectrometry assay kit. After supplementation, plasma triglycerides decreased and erythrocyte n-3 PUFA concentrations increased to a similar extent in both genders. Further, plasma high-density lipoprotein cholesterol concentrations and fasting glucose levels increased in women after n-3 PUFA supplementation. N-3 PUFA supplementation changed the expression of 610 genes in men, whereas the expression of 250 genes was altered in women. Pathway analyses indicate changes in gene expression of the nuclear receptor peroxisome proliferator-activated receptor-alpha, nuclear transcription-factor kappaB, oxidative stress and activation of the oxidative stress response mediated by nuclear factor (erythroid-derived 2)-like 2. After n-3 PUFA supplementation, metabolomics profiles demonstrate an increase in acylcarnitines, hexose and leucine in men only and a decrease in saturation of glycerophosphatidylcholine and lysophosphatidylcholine concentrations in all subjects. Overall, traditional and novel biomarkers suggest that n-3 PUFA supplementation exerts cardioprotective effects.

Fish oils for cardiovascular disease: Impact on diabetes

The increasing prevalence of overweight and obesity has led to an epidemic of type 2 diabetes mellitus (T2DM), and is likely to be followed by an epidemic of patients with complications of T2DM such as cardiovascular diseases, neuropathy, retinopathy, and nephropathy. Nutritional interventions that incorporate functional foods, such fish oils - in particular n-3 polyunsaturated fatty acids (n-3 PUFAs) - may be a novel strategy to reduce insulin insensitivity, dyslipidemia, hypertension and pro-inflammatory state. The purpose of this article is to examine the impact of fish oil supplementation on blood lipids, glycemic control, blood pressure and inflammation in subjects with T2DM. Overall, the literature suggests that n-3 PUFA supplementation in diet presents many benefits in T2DM management mainly in terms of dyslipidemia; however, the impact of n-3 PUFAs on glucose control, blood pressure, inflammation and oxidations is less definitive. Overall, n-3 PUFA supplementation represents a reasonable therapeutic strategy in individuals with T2DM to decrease the risk of complications.

Associations between dietary patterns and gene expression profiles of healthy men and women: a cross-sectional study

BackgroundDiet regulates gene expression profiles by several mechanisms. The objective of this study was to examine gene expression in relation with dietary patterns.MethodsTwo hundred and fifty four participants from the greater Quebec City metropolitan area were recruited. Two hundred and ten participants completed the study protocol. Dietary patterns were derived from a food frequency questionnaire (FFQ) by factor analysis. For 30 participants (in fasting state), RNA was extracted from peripheral blood mononuclear cells (PBMCs) and expression levels of 47,231 mRNA transcripts were assessed using the Illumina Human-6 v3 Expression BeadChips®. Microarray data was pre-processed with Flexarray software and analysed with Ingenuity Pathway Analysis (IPA).ResultsTwo dietary patterns were identified. The Prudent dietary pattern was characterised by high intakes of vegetables, fruits, whole grain products and low intakes of refined grain products and the Western dietary pattern, by high intakes of refined grain products, desserts, sweets and processed meats. When individuals with high scores for the Prudent dietary pattern where compared to individuals with low scores, 2,083 transcripts were differentially expressed in men, 1,136 transcripts in women and 59 transcripts were overlapping in men and women. For the Western dietary pattern, 1,021 transcripts were differentially expressed in men with high versus low scores, 1,163 transcripts in women and 23 transcripts were overlapping in men and women. IPA reveals that genes differentially expressed for both patterns were present in networks related to the immune and/or inflammatory response, cancer and cardiovascular diseases.ConclusionGene expression profiles were different according to dietary patterns, which probably modulate the risk of chronic diseases.Trial RegistrationNCT: NCT01343342

Association between Polymorphisms in the Fatty Acid Desaturase Gene Cluster and the Plasma Triacylglycerol Response to an n-3 PUFA Supplementation

Eicosapentaenoic and docosahexaenoic acids have been reported to have a variety of beneficial effects on cardiovascular disease risk factors. However, a large inter-individual variability in the plasma lipid response to an omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation is observed in different studies. Genetic variations may influence plasma lipid responsiveness. The aim of the present study was to examine the effects of a supplementation with n-3 PUFA on the plasma lipid profile in relation to the presence of single-nucleotide polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene cluster. A total of 208 subjects from Quebec City area were supplemented with 3 g/day of n-3 PUFA, during six weeks. In a statistical model including the effect of the genotype, the supplementation and the genotype by supplementation interaction, SNP rs174546 was significantly associated (p = 0.02) with plasma triglyceride (TG) levels, pre- and post-supplementation. The n-3 supplementation had an independent effect on plasma TG levels and no significant genotype by supplementation interaction effects were observed. In summary, our data support the notion that the FADS gene cluster is a major determinant of plasma TG levels. SNP rs174546 may be an important SNP associated with plasma TG levels and FADS1 gene expression independently of a nutritional intervention with n-3 PUFA.

The metabolic signature associated with the Western dietary pattern: a cross-sectional study

BackgroundMetabolic profiles have been shown to be associated to obesity status and insulin sensitivity. Dietary intakes influence metabolic pathways and therefore, different dietary patterns may relate to modifications in metabolic signatures. The objective was to verify associations between dietary patterns and metabolic profiles composed of amino acids (AAs) and acylcarnitines (ACs).Methods210 participants were recruited in the greater Quebec City area between September 2009 and December 2011. Dietary patterns had been previously derived using principal component analysis (PCA). The Prudent dietary pattern was characterised by higher intakes of vegetables, fruits, whole grain products, non-hydrogenated fat and lower intakes of refined grain products, whereas the Western dietary pattern was associated with higher intakes of refined grain products, desserts, sweets and processed meats. Targeted metabolites were quantified in 37 participants with the Biocrates Absolute IDQ p150 (Biocrates Life Sciences AG, Austria) mass spectrometry method (including 14 amino acids and 41 acylcarnitines).ResultsPCA analysis with metabolites including AAs and ACs revealed two main components explaining the most variance in overall data (13.8%). PC1 was composed mostly of medium- to long-chain ACs (C16:2, C14:2, C14:2-OH, C16, C14:1-OH, C14:1, C10:2, C5-DC/C6-OH, C12, C18:2, C10, C4:1-DC/C6, C8:1 and C2) whereas PC2 included certain AAs and short-chain ACs (xLeu, Met, Arg, Phe, Pro, Orn, His, C0, C3, C4 and C5). The Western dietary pattern correlated negatively with PC1 and positively with PC2 (r = −0.34, p = 0.05 and r = 0.38, p = 0.03, respectively), independently of age, sex and BMI.ConclusionThese findings suggest that the Western dietary pattern is associated with a specific metabolite signature characterized by increased levels of AAs including branched-chain AAs (BCAAs) and short-chain ACs.Trial registrationNCT01343342

Functional foods for health: focus on diabetes.

Type 2 diabetes is one of the fastest growing public health problems worldwide. Menopause may present additional challenges for women who have diabetes by increasing the risk for cardiovascular disease (CVD) and making blood glucose control more difficult. Functional foods may have the potential to improve glycemic control, but little evidence is known about the efficacy of these foods. The purpose of this literature review is to establish a recommendation for the intake of functional foods in a healthy diet - such as nuts, omega-3 fatty acids (FAs) and cinnamon - for the glycemic control in type 2 diabetes. Nuts and omega-3 FAs appear to have an overall beneficial effect on CVD; however, their effect on glucose homeostasis is uncertain. In addition, cinnamon appears to inconsistently improve glycemic parameters in diabetic patients. Overall, more research on the potential effect of all of these functional foods on patients with type 2 diabetes is needed to able to make specific recommendations. In conclusion, there is reason to consider the inclusion of nuts and fish, as a source of omega-3 FAs, in the diets of individuals with diabetes in view of their potential to reduce CVD risk, even though their ability to influence overall glycemic control remains to be established.

Plant sterols and stanols for healthy ageing

The proportion of elderly is growing worldwide. This trend is in parallel to an increase in diseases, such as cardiovascular disease (CVD). Plant sterols and stanols (PS) consumption is known to decrease low-density lipoprotein-cholesterol (LDL-C) levels by 5-15%, and thus lower CVD risk. Yet, the effect of PS on LDL-C levels differs between individuals. Furthermore, PS have recently been investigated for the prevention of other age-related diseases. The objective of this review is to examine the benefits of PS on CVD as well as ageing-associated diseases. PS have the ability to significantly lower LDL-C; yet, the large inter-individual variability in the lowering of LDL-C may be due to subject characteristics, food matrix of PS, dose of PS, dietary background, frequency of intake of PS, the additive effect of other foods or drugs, as well as genetic factors. Further, PS may also have other potential beneficial effects including anti-atherogenic, anti-inflammatory, antioxidant and anti-cancer activities. Overall, dietary intervention strategies, such as incorporating PS into a healthy diet, should be recommended and implemented in older adult populations in order to prevent ageing-associated diseases and hence promote healthy ageing.

Omega-3 fatty acids status in human subjects estimated using a food frequency questionnaire and plasma phospholipids levels

BackgroundIntakes of omega-3 (n-3) fatty acids (FA) are associated with several health benefits. The aim of this study was to verify whether intakes of n-3 FA estimated from a food frequency questionnaire (FFQ) correlate with n-3 FA levels measured in plasma phospholipids (PL).MethodsThe study sample consisted of 200 French-Canadians men and women aged between 18 to 55 years. Dietary data were collected using a validated FFQ. Fasting blood samples were collected and the plasma PL FA profile was measured by gas chromatography.ResultsLow intakes of n-3 long-chain FA together with low percentages of n-3 long-chain FA in plasma PL were found in French-Canadian population. Daily intakes of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were similar between men and women. Yet, alpha-linolenic acid (ALA) and total n-3 FA intakes were significantly higher in men compared to women (ALA: 2.28 g and 1.69 g, p < 0.0001, total n-3 FA: 2.57 g and 1.99 g, p < 0.0001; respectively). In plasma PL, DPA and DHA percentages were significantly different between men and women (DPA: 1.03% and 0.88%, p < 0.0001, DHA: 3.00% and 3.43%, p = 0.0005; respectively). Moreover, DHA (men: r = 0.52, p < 0.0001; women: r = 0.57, p < 0.0001) and total n-3 FA (men: r = 0.47, p < 0.0001; women: r = 0.52, p < 0.0001) intakes were positively correlated to their respective plasma PL FA levels. In women, EPA (r = 0.44, p < 0.0001) and DPA (r = 0.23, p = 0.02) intakes were also correlated respectively with EPA and DPA plasma PL FA percentages.ConclusionEstimated n-3 long-chain FA intake among this young and well-educated French-Canadian population is lower than the recommendations. Further, FFQ data is comparable to plasma PL results to estimate DHA and total n-3 FA status in healthy individuals as well as to evaluate the EPA and DPA status in women. Overall, this FFQ could be used as a simple, low-cost tool in future studies to rank n-3 FA status of individuals.

Gene–diet interactions on plasma lipid levels in the Inuit population

The Inuit population is often described as being protected against CVD due to their traditional dietary patterns and their unique genetic background. The objective of the present study was to examine gene-diet interaction effects on plasma lipid levels in the Inuit population. Data from the Qanuippitaa Nunavik Health Survey (n 553) were analysed via regression models which included the following: genotypes for thirty-five known polymorphisms (SNP) from twenty genes related to lipid metabolism; dietary fat intake including total fat (TotFat) and saturated fat (SatFat) estimated from a FFQ; plasma lipid levels, namely total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C) and TAG. The results demonstrate that allele frequencies were different in the Inuit population compared with the Caucasian population. Further, seven SNP (APOA1 - 75G/A (rs670), APOB XbAI (rs693), AGT M235T (rs699), LIPC 480C/T (rs1800588), APOA1 84T/C (rs5070), PPARG2 - 618C/G (rs10865710) and APOE 219G/T (rs405509)) in interaction with TotFat and SatFat were significantly associated with one or two plasma lipid parameters. Another four SNP (APOC3 3238C>G (rs5128), CETP I405V (rs5882), CYP1A1 A4889G (rs1048943) and ABCA1 Arg219Lys (rs2230806)) in interaction with either TotFat or SatFat intake were significantly associated with one plasma lipid variable. Further, an additive effect of these SNP in interaction with TotFat or SatFat intake was significantly associated with higher TC, LDL-C or TAG levels, as well as with lower HDL-C levels. In conclusion, the present study supports the notion that gene-diet interactions play an important role in modifying plasma lipid levels in the Inuit population.

Individualized Weight Management: What Can Be Learned from Nutrigenomics and Nutrigenetics?

The rise in the prevalence of obesity observed over the past decades is taken by many as an indication of the predominance of environmental factors (the so-called obesogenic environment) over genetic factors in explaining why obesity has reached epidemic proportions. While a changing environment favoring increased food intake and decreased physical activity levels has clearly contributed to shifting the distribution of body mass index (BMI) at the population level, not everyone is becoming overweight or obese. This suggests that there are genetic factors interacting with environmental factors to predispose some individuals to obesity. This gene-environment interaction is not only important in determining an individuals susceptibility to obesity but can also influence the outcome of weight-loss programs and weight-management strategies in overweight and obese subjects. This chapter reviews the role of gene-nutrient interactions in the context of weight management. The first section reviews the application of transcriptomics in human nutrition intervention studies on the molecular impact of caloric restriction and macronutrient composition. The second section reviews the effects of various obesity candidate gene polymorphisms on the response of body weight or weight-related phenotypes to weight-loss programs which include nutritional interventions.