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

Vitamina D y enfermedad de hígado graso no alcohólico: nexo de unión y suplementación nutricional

Introducción: la enfermedad de hígado graso no alcohólico (EHGNA) es la patología hepática con mayor prevalencia en la población, caracterizada por la acumulación lipídica e inflamación en los hepatocitos. La vitamina D podría tener un papel beneficioso en EHGNA a través de sus propiedades antiinflamatorias y antifibróticas. Objetivo: revisar la relación entre los niveles sanguíneos de vitamina D y el desarrollo de EHGNA, evaluar los efectos de la suplementación nutricional de vitamina D en los marcadores de afectación hepática y analizar los suplementos y productos alimenticios con vitamina D disponibles en España. Material y Métodos: utilización de la base de datos PubMed como principal fuente bibliográfica mediante la metodología PRISMA, así como la herramienta BotPlus para los complementos alimenticios. Resultados: los pacientes con EHGNA presentan menores niveles sanguíneos de vitamina D en sangre que la población general. La suplementación nutricional con vitamina D ayuda a normalizar sus niveles y disminuye los niveles de marcadores de inflamación (IL-6 y TNF-α), pero no los de enzimas hepáticas. Se observan 455 complementos alimenticios con vitamina D en España, de los cuales un 70% son multivitamínicos, 25% son productos alimenticios y 5% suplementos exclusivos de vitamina D. Conclusiones: la vitamina D podría ser un factor nutricional a considerar en EHGNA, incluyendo la suplementación como una medida adicional a las estrategias nutricionales ya establecidas para esta patología.Introduction: non-alcoholic fatty liver disease (NAFLD) is the most prevalent hepatic pathology in population, characterized by lipid accumulation and inflammation in hepatocytes. Vitamin D could have a beneficial role in NAFLD through anti- inflammatory and antifibrotic features in the liver. Aim: Review the relationship between vitamin D blood levels and NAFLD, evaluate the effects of vitamin D supplementation and hepatic biomarkers and analyse the supplements and nutritional products with vitamin D available in Spain. Material & Methods: Use of database PubMed as the main bibliographic source using PRISMA methodology, as well as BotPlus tool for nutritional products. Results: patients with NAFLD show lower vitamin D blood levels than healthy people. Vitamin D supplementation lowers the levels of inflammatory biomarkers (IL-6 and TNF-α), but not the levels of hepatic enzymes. Conclusions: vitamin D could be a nutritional factor to consider in NAFLD, including supplementation as an additional measure to the nutritional strategies already established for this pathology

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

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)

Chronologically scheduled snacking with high-protein products within the habitual diet in type-2 diabetes patients leads to a fat mass loss: a longitudinal study.

Background: Obesity is the most relevant overnutrition disease worldwide and is associated to different metabolic disorders such as insulin resistance and type-2 diabetes. Low glycemic load foods and diets and moderately high protein intake have been shown to reduce body weight and fat mass, exerting also beneficial effects on LDL-cholesterol, triglyceride concentrations, postprandial glucose curve and HDL-cholesterol levels. The present study aimed at studying the potential functionality of a series of low glycemic index products with moderately high protein content, as possible coadjuvants in the control of type-2 diabetes and weight management following a chronologically planned snacking offer (morning and afternoon). Methods: The current trial followed a single group, sequential, longitudinal design, with two consecutive periods of 4 weeks each. A total of 17 volunteers participated in the study. The first period was a free living period, with volunteers' habitual ad libitum dietary pattern, while the second period was a free-living period with structured meal replacements at breakfast, morning snack and afternoon snack, which were exchanged by specific products with moderately high protein content and controlled low glycemic index, following a scheduled temporal consumption. Blood extractions were performed at the beginning and at the end of each period (free-living and intervention). Parameters analysed were: fasting glucose, insulin, glycosylated hemoglobin, total-, HDL- and LDL-cholesterol, triglyceride, C - reactive protein and Homocysteine concentrations. Postprandial glucose and insulin were also measured. Anthropometrical parameters were monitored each 2 weeks during the whole study. Results: A modest but significant (p = 0.002) reduction on body weight (1 kg) was observed during the intervention period, mainly due to the fat mass loss (0.8 kg, p = 0.02). This weight reduction was observed without apparently associated changes in total energy intake. None of the biochemical biomarkers measured was altered throughout the whole study. Conclusions: Small changes in the habitual dietary recommendations in type-2 diabetes patients by the inclusion of specific low-glycemic, moderately high-protein products in breakfast, morning and afternoon snacks may promote body weight and fat-mass loss, without apparently altering biochemical parameters and cardiovascular risk-related factors

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

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

Biomarcadores del estado inflamatorio: nexo de unión con la obesidad y complicaciones asociadas

El objetivo de este trabajo ha consistido en realizar una revisión de los biomarcadores que actualmente se proponen como el nexo de unión entre la inflamación, la obesidad y complicaciones asociadas, seleccionando los estudios llevados a cabo y las cuestiones pendientes. Cada vez hay mayor evidencia científica de que la inflamación puede jugar un papel importante en la etiología de diversas enfermedades crónicas de gran relevancia para la salud pública. En los últimos años, distintos estudios han sugerido que la obesidad podría ser un desorden inflamatorio. Asimismo, el estrés oxidativo se ha propuesto como un potencial inductor de la inflamación y de la susceptibilidad a la obesidad y patología asociadas. Entre los biomarcadores relacionados con la obesidad, la resistencia insulínica, las enfermedades cardiovasculares y el síndrome metabólico se encuentran: el factor de necrosis tumoral alfa, interleuquinas 6 y 18, angiotensinógeno, factor de crecimiento TGF-beta, inhibidor de la activación del plasminógeno, leptina, resistina, proteína C reactiva, amiloide A, ácido siálico, marcadores de disfunción endotelial (factor von Willebrand, ICAMs, vCAMs) factor 3 del sistema del complemento, haptoglobina, glicoproteína zinc-alfa2, eotaxina, visfatina, apelina, alfa1-antitripsina, vaspina, omentina, proteína transportadora de retinol 4, ceruloplasmina, adiponectina y desnutrina. Algunos de estos biomarcadores son buenos predictores de riesgo cardiovascular (inhibidor de la activación de plasminógeno 1, angiotensinógeno, fibrinógeno, ácido siálico, factor 3 del complemento y proteína C reactiva), adiposidad (leptina, visfatina, resistina, haptoglobina) y/o resistencia insulínica (ácido siálico, proteína C reactiva, inhibidor de la activación de plasminógeno 1, factor von Willebrand). Sin embargo, todavía queda por dilucidar el papel de muchos de ellos en la etiología de la obesidad y comorbilidades asociadas en humanos, así como los factores implicados en su regulación

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

Factors Associated with Sarcopenia and 7-Year Mortality in Very Old Patients with Hip Fracture Admitted to Rehabilitation Units: A Pragmatic Study

Background: Admitted bedridden older patients are at risk of the development of sarcopenia during hospital stay (incident sarcopenia). The objective of this study was to assess the factors associated with sarcopenia (incident and chronic) and its impact on mortality in older people with hip fracture. Methods: A multicenter, pragmatic, prospective observational study was designed. Older subjects with hip fracture admitted to two rehabilitation units were included. Sarcopenia was assessed at admission and at discharge according to the revised EWGSOP (European Working Group on Sarcopenia in Older People) consensus definition. The mortality was evaluated after 7 years of follow-up. Results: A total of 187 subjects (73.8% women) age 85.2 ± 6.3 years were included. Risk factors associated to incident and chronic sarcopenia were undernutrition (body mass index-BMI and Mini Nutritional Assessment-Short Form-MNA-SF), hand-grip strength and skeletal muscle index. During follow-up 114 patients died (60.5% sarcopenic vs. 39.5% non-sarcopenic, p = 0.001). Cox regression analyses showed that factors associated to increased risk of mortality were sarcopenia (HR: 1.67, 95% CI 1.11-2.51) and low hand-grip strength (HR: 1.76, 95% CI 1.08-2.88). Conclusions: Older patients with undernutrition have a higher risk of developing sarcopenia during hospital stay, and sarcopenic patients have almost two times more risk of mortality than non-sarcopenic patients during follow-up after hip fracture