Efecto del ácido linoleico conjugado (CLA) sobre el perfil lipídico en humanos

El término ácido linoleico conjugado (CLA) hace referencia a un grupo de isómeros del ácido linoleico, caracterizados por tener enlaces dobles conjugados en varias posiciones y conformaciones. El CLA se encuentra de forma natural en algunos alimentos, aunque desde que se le atribuyen efectos beneficiosos sobre varios aspectos relacionados con la salud, numerosos grupos investigadores han estudiado los efectos de la suplementación con este ácido graso. En este sentido, el efecto del CLA sobre el perfil lipídico de los animales ha sido extensamente estudiado y existen evidencias confirmadas de beneficios sobre diversos marcadores metabólicos. Sin embargo, los resultados de los ensayos de intervención en humanos son ambiguos. El objetivo de esta revisión fue reunir los datos disponibles y más actuales acerca de los efectos del CLA en el perfil lipídico de humanos. Diversos estudios no hallaron efectos significativos en ninguna de las variables estudiadas; sin embargo, otros trabajos encontraron tanto efectos beneficiosos como desfavorables en el colesterol total, c-LDL, c-HDL, índice aterogénico, triglicéridos y lipoproteína(a). Esta discrepancia podría probablemente deberse a las diferencias en la dosis, composición de isómeros y placebo utilizado, así como a la duración del estudio y al estado nutricional de los sujetos incluidos, entre otros. No obstante, el análisis de los estudios de 12 semanas de duración, realizados con una mezcla en cantidades iguales de los dos isómeros principales del CLA (cis-9, trans-11 y trans-10, cis-12) y con dosis diarias de entre 3 y 4 g aproximadamente, parecen ofrecer los resultados más beneficiosos

Fruit and vegetable consumption and proinflammatory gene expression from peripheral blood mononuclear cells in young adults: a translational study

<p>Abstract</p> <p>Background</p> <p>Fruits and vegetables are important sources of fiber and nutrients with a recognized antioxidant capacity, which could have beneficial effects on the proinflammatory status as well as some metabolic syndrome and cardiovascular disease features. The current study assessed the potential relationships of fruit and vegetable consumption with the plasma concentrations and mRNA expression values of some proinflammatory markers in young adults.</p> <p>Methods</p> <p>One-hundred and twenty healthy subjects (50 men/70 women; 20.8 ± 2.6 y; 22.3 ± 2.8 kg/m²) were enrolled. Experimental determinations included anthropometry, blood pressure and lifestyle features as well as blood biochemical and inflammatory measurements. The mRNA was isolated from peripheral blood mononuclear cells (PBMC) and the gene expression concerning selected inflammatory markers was assessed by quantitative real-time PCR. Nutritional intakes were estimated by a validated semi-quantitative food-frequency questionnaire.</p> <p>Results</p> <p>The highest tertile of energy-adjusted fruit and vegetable consumption (>660 g/d) was associated with lower plasma concentrations of C-reactive protein (CRP) and homocysteine and with lower <it>ICAM1, IL1R1, IL6, TNFα </it>and <it>NFκB1 </it>gene expression in PBMC (<it>P </it>for trend < 0.05), independently of gender, age, energy intake, physical activity, smoking, body mass index, systolic blood pressure and circulating non-esterified fatty acids. In addition, plasma CRP, homocysteine and TNFα concentrations and <it>ICAM1, TNFα </it>and <it>NFκB1 </it>gene expression in PBMC showed a descending trend as increased fiber intake (>19.5 g/d) from fruits and vegetables (<it>P </it>for trend < 0.05). Furthermore, the participants within the higher tertile (>11.8 mmol/d) of dietary total antioxidant capacity showed lower plasma CRP and mRNA values of <it>ICAM1, IL1R1, IL6, TNFα </it>and <it>NFκB1 </it>genes (<it>P </it>for trend < 0.05). The inverse association between fruit and vegetable consumption and study proinflammatory markers followed the same trend and remained statistically significant, after the inclusion of other foods/nutrients in the linear regression models.</p> <p>Conclusion</p> <p>A higher fruit and vegetable consumption was independently associated not only with reduced CRP and homocysteine concentrations but also with a lower mRNA expression in PBMC of some relevant proinflammatory markers in healthy young adults.</p

Implication of miR-612 and miR-1976 in the regulation of TP53 and CD40 and their relationship in the response to specific weight-loss diets

Background: Non-coding RNAs (i.e., miRNAs) play a role in the development of obesity and related comorbidities and the regulation of body weight. Objective: To identify candidate miRNA biomarkers throughout omics approaches in order to predict the response to specific weight-loss dietary treatments. Design: Genomic DNA and cDNA isolated from white blood cells of a subset from the RESMENA nutritional intervention study (Low-responders (LR) vs High-responders (HR)) was hybridized in Infinium Human Methylation450 BeadChip and in Illumina Human HT-12 v4 gene expression BeadChips arrays respectively. A bioinformatic prediction of putative target sites of selected miRNAs was performed by applying miRBase algorithms. HEK-293T cells were co-transfected with expression vectors containing the 3'-UTR of candidate genes to validate the binding of miRNAs to its target sites. Results: 134 miRNAs were differentially methylated between HR and LR in the methylation array, whereas 44 miRNAs were differentially expressed between both groups in the expression array. Specifically, miR-1237, miR-1976, miR-642, miR-636, miR-612 and miR-193B were simultaneously hypomethylated and overexpressed in HR. miR-612 and miR-1976 showed greatest differences in methylation and expression levels, respectively. The bioinformatic prediction revealed that TP53 was a putative target gene of miR-612 and CD40 of miR-1976. Moreover, TP53 was downregulated in the expression array when comparing HR vs LR expression levels adjusted by sex, diet, age and baseline weight, and CD40 showed a statistical trend. Furthermore, gene expression levels of TP53 and CD40 in white blood cells, when measured by qPCR, were also downregulated in HR. Finally, miR-612 and miR-1976 potently repressed TP53 and CD40 respectively by targeting its 3'-UTR regions. Conclusion: miR-612 and miR-1976 levels could be prospective biomarkers of response to specific weight-loss diets and might regulate the gene expression of TP53 and CD40

Avances en nutrición molecular: nutrigenómica y/o nutrigenética

La aplicación de las técnicas de la biología molecular y el éxito del Proyecto Genoma Humano ha abierto una nueva era tanto en Medicina como en Nutrición. Hasta la fecha, al menos, 1.000 genes humanos causantes de enfermedades han sido identificados y parcialmente caracterizados, el 97% de los cuales sabemos ahora que son causantes de enfermedades monogénicas. Sin embargo, otras patologías como la obesidad, enfermedad cardiovascular, diabetes, cáncer se deben a complejas interacciones entre diversos genes y factores ambientales. A pesar de los numerosos estudios de asociación, más de 600 publicados desde 2002, la base molecular de las enfermedades crónicas es todavía incierta. La información sobre polimorfismos de nucleótidos y mapas de haplotipos son recursos adicionales para identificar genes involucrados en enfermedades. El desarrollo genómico se aproxima, sin embargo, no se conocen con precisión algunos componentes de la dieta y sus mecanismos, que influyen de forma importante en la expresión de la información genética y en las alteraciones patológicas. La industria alimentaria tiene la oportunidad de utilizar los componentes bioactivos de los alimentos para mejorar la salud y evitar las enfermedades teniendo en cuenta la constitución genética de los consumidores. Esta nueva era de la nutrición molecular —interacciones genes-nutrientes— puede crecer en diversas direcciones, aunque hay dos esenciales. De una parte, el estudio de la influencia de los nutrientes sobre la expresión de genes (nutrigenómica) y de otra conocer la influencia de las variaciones genéticas en la respuesta del organismo a los nutrientes (nutrigenética)

A regular curd consumption improves gastrointestinal status assessed by a randomized controlled nutritional intervention

This study evaluated the influence of curd consumption (a dairy product in which most whey proteins are discarded) on nutritional status markers and on gastrointestinal symptoms through an open-label randomized nutritional intervention. A total of 20 males and 20 females were involved in the study. Body weight and plasma levels of different health markers were measured at baseline and at the end of the study. Gastrointestinal symptoms and satiety were assessed by self-reported subjective questionnaires. There were neither relevant changes in body weight and composition, nor in all screened plasma determinations after the intervention. Satiety score analyses revealed no differences between the two experimental groups. The regular consumption of curd-improved abdominal pain (19%) and deposition scores (16%) when compared with those participants non-consuming curd, which may indicate a better tolerability of this product. Curd intake within a balanced diet improved some subjective markers of gastrointestinal status, which may be explained by the nutritional composition of curds

Down-regulation of heart HFABP and UCP2 gene expression in diet-induced (cafeteria) obese rats.

Long-term exposure to hypercaloric high fat diet induced marked tissue fatty acid accumulation and may influence cell function. Previous results in our laboratory showed that uncoupling proteins (UCPs) and fatty acid-binding protein (FABP) gene expression are changed in adipose tissue and skeletal muscle tissue in diet-induced (cafeteria) obese animals. The aim of this study was to examine heart FABP (HFABP) and UCP2 gene expressions in dietary obese rats. Rats fed on a high-fat diet for 65 days had significantly higher fat stores and body weight than control rats. Interestingly, we found that both HFABP and UCP2 mRNA levels were significantly reduced in cafeteria-obese rats when compared to control animals. Moreover, a statistically significant correlation was observed between the two gene expression levels. The down-regulation of heart HFABP and UCP2 parallels the lower lipid utilization which may account for an enhanced fat deposition. It is plausible that these two genes are regulated by the same family of transcription factors

Dietary total antioxidant capacity is inversely related to central adiposity as well as to metabolic and oxidative stress markers in healthy young adults

<p>Abstract</p> <p>Background</p> <p>Dietary total antioxidant capacity (TAC) has been assumed as a useful tool to assess the relationship between the cumulative antioxidant food capacity and several chronic disorders. The aim of this cross-sectional study was to investigate the potential relationships of dietary TAC with adiposity, metabolic and oxidative stress markers in healthy young adults.</p> <p>Methods</p> <p>This study enrolled 266 healthy subjects (105 men/ 161 women; 22 ± 3 years-old; 22.0 ± 2.7 kg/m²). Dietary intake, anthropometry, blood pressure, lifestyle features, and biochemical data were assessed with validated procedures.</p> <p>Results</p> <p>In linear regression analyses, dietary TAC values were inversely associated with glycemia, total cholesterol:HDL-c ratio, triglycerides and oxidized-LDL concentrations, and positively associated with HDL-c concentrations, independently of gender, age, smoking status, physical activity, vitamin use supplement, waist circumference, energy intake, fatty acid intake. In addition, plasma TAC was negatively correlated with ox-LDL concentrations (<it>r</it>= -0.20, <it>P </it>= 0.003), independently of the assessed confounding variables. Finally, dietary TAC values were inversely related to waist circumference values (<it>r</it>= -0.17, <it>P </it>= 0.005) as well as to lower mild central obesity occurrence (waist circumference ≥ 80/ 94 cm for women/ men, respectively).</p> <p>Conclusion</p> <p>Dietary TAC values are inversely associated with glucose and lipid biomarkers as well as with central adiposity measurements in healthy young adults, indicating dietary TAC as a useful tool to assess the health benefits of cumulative antioxidant capacity from food intake. In addition, the independent and inverse relationships of ox-LDL concentrations with dietary and plasma TAC respectively suggest a putative role of antioxidant rich-diet in the link between redox state and atherogenesis at early stage.</p

Relationship of oxidized low density lipoprotein with lipid profile and oxidative stress markers in healthy young adults: a translational study

<p>Abstract</p> <p>Background</p> <p>Despite oxidized low density lipoprotein (ox-LDL) plays important roles in the pro-inflammatory and atherosclerotic processes, the relationships with metabolic and oxidative stress biomarkers have been only scarcely investigated in young adult people. Thus, the aim of this study was to assess plasma ox-LDL concentrations and the potential association with oxidative stress markers as well as with anthropometric and metabolic features in healthy young adults.</p> <p>Methods</p> <p>This study enrolled 160 healthy subjects (92 women/68 men; 23 ± 4 y; 22.0 ± 2.9 kg/m²). Anthropometry, body composition, blood pressure, lifestyle features, biochemical data, and oxidative stress markers were assessed with validated tools. Selenium, copper, and zinc nail concentrations were measured by atomic absorption spectrophotometry.</p> <p>Results</p> <p>Total cholesterol (TC), LDL-c and uric acid concentrations, TC-to-HDL-c ratio, and glutathione peroxidase (GPx) activity were positive predictors of ox-LDL concentrations, while nail selenium level (NSL) was a negative predictor, independently of gender, age, smoking status, physical activity. Those individuals included in the highest tertile of GPx activity (≥611 nmol/[mL/min]) and of NSL (≥430 ng/g of nail) had higher and lower ox-LDL concentrations, respectively, independently of the same covariates plus truncal fat or body mass index, and total cholesterol or LDL-c concentrations.</p> <p>Conclusions</p> <p>Ox-LDL concentrations were significantly associated with lipid biomarkers, GPx activity, uric acid concentration, and NSL, independently of different assayed covariates, in young healthy adults. These findings jointly suggest the early and complex relationship between lipid profile and redox status balance.</p

Different postprandial acute response in healthy subjects to three strawberry jams varying in carbohydrate and antioxidant content: a randomized, crossover trial

PURPOSE: Dietary food composition influences postprandial glucose homeostasis. Thus, the objective was to investigate the effects of an acute intake of three different types of strawberry jam, differing in carbohydrate and antioxidants content, on postprandial glucose metabolism, lipid profile, antioxidant status, and satiety. METHODS: Sixteen healthy adults participated in a randomized, crossover, double-blind study with three arms, receiving 60 g of three different strawberry jams. Blood samples were collected at fasting and at 30, 60, 90, and 120 min after its intake. Blood analyses were performed with validated procedures and satiety was estimated with visual analogue scale (VAS). RESULTS: Blood glucose concentrations were maintained at normal values and without peaks within the 2 h after consumption of low-sugar jams. However, blood glucose and insulin were significantly higher at 30 and 60 min after high-sugar (HS) jam intake versus both low-sugar jams. Furthermore, HS jam produced more satisfaction at short time, but decreased as soon as blood glucose concentration began to decrease. Moreover, HS ingestion produced lower free fatty acid levels (p < 0.05) throughout the trial with respect both the low-sugar jams. However, no additional benefits on oxidative status (malondialdehyde, glutathione peroxidase, total antioxidant capacity, and uric acid), glucose, lipid, and satiety variables were observed due to the inclusion of an antioxidant to low-sugar jam. CONCLUSIONS: This study reinforces the idea that products without added sugars are appropriate for the management of glycemic alterations and provides further insight into the effect of natural antioxidants as a functional ingredient on oxidative status and related metabolic disturbances