Post-exercise hypotension and skeletal muscle oxygenation is regulated by nitrate-reducing activity of oral bacteria.

Post-exercise hypotension (PEH) is a common physiological phenomenon leading to lower blood pressure after acute exercise, but it is not fully understood how this intriguing response occurs. This study investigated whether the nitrate-reducing activity of oral bacteria is a key mechanism to trigger PEH. Following a randomized, double blind and crossover design, twenty-three healthy individuals (15 males/8 females) completed two treadmill trials at moderate intensity. After exercise, participants rinsed their mouth with antibacterial mouthwash to inhibit the activity of oral bacteria or a placebo mouthwash. Blood pressure was measured before, 1h and 2 h after exercise. The microvascular response to a reactive hyperaemia test, as well as blood and salivary samples were taken before and 2 h after exercise to analyse nitrate and nitrite concentrations and the oral microbiome. As expected, systolic blood pressure (SBP) was lower (1 h: -5.2 ±â€¯1.0 mmHg; P < 0.001); 2 h: -3.8 ±â€¯1.1 mmHg, P = 0.005) after exercise compared to baseline in the placebo condition. This was accompanied by an increase of circulatory nitrite 2 h after exercise (2h: 100 ±â€¯13 nM) compared to baseline (59 ±â€¯9 nM; P = 0.013). Additionally, an increase in the peak of the tissue oxygenation index (TOI) during the reactive hyperaemia response was observed after exercise (86.1 ±â€¯0.6%) compared to baseline levels (84.8 ±â€¯0.5%; P = 0.010) in the placebo condition. On the other hand, the SBP-lowering effect of exercise was attenuated by 61% at 1 h in the recovery period, and it was fully attenuated 2 h after exercise with antibacterial mouthwash. This was associated with a lack of changes in circulatory nitrite (P > 0.05), and impaired microvascular response (peak TOI baseline: 85.1 ±â€¯3.1%; peak TOI post-exercise: 84.6 ±â€¯3.2%; P > 0.05). Diversity of oral bacteria did not change after exercise in any treatment. These findings show that nitrite synthesis by oral commensal bacteria is a key mechanism to induce the vascular response to exercise over the first period of recovery thereby promoting lower blood pressure and greater muscle oxygenation.

Knowledge, interest, predisposition and evaluation of functional foods in Spanish dietitians-nutritionists and experts in human nutrition and dietetics.

INTRODUCTION: Little research has been conducted into the attitudes and knowledge of dietitians-nutritionists (DN) or of experts in human nutrition and dietetics (EHND) regarding functional foods (FFs). OBJECTIVES: To evaluate the knowledge of, interest in and predisposition towards FFs in Spanish DN and EHND, and how these professionals rate the potential benefits and risks associated with consuming FFs. METHODS: 2100 DN and 122 EHND were asked to participate in a self-administered questionnaire. The results were expressed using percentages and the DN responses were compared with those of the EHND by means of chi-squared test. A significant difference was regarded as having been obtained if P < 0.05. RESULTS: 204 DN and 112 EHND responded. After eliminating 45 surveys due to anomalies, 268 surveys were analyzed (170 from the DN, 8.1% participation; 98 from the EHND, 80.3% participation). No statistically significant differences were observed between the responses of the DN and the EHND except in: 1) the view that it was "dangerous" to consume certain FFs ≥ 4 times a day; and 2) the knowledge of the population regarding in which situations certain FFs should be consumed. Most of the professionals demonstrated good knowledge of FFs, consumed FFs, showed a positive attitude towards FFs and thought that the information provided to the consumer is insufficient. DISCUSSION AND CONCLUSIONS: FFs are generally accepted by nutritional professionals. However, further study is required into the discrepancies between DN and EHND regarding the view that it is "dangerous" to consume certain FFs and regarding their evaluation of whether the public know in which situations certain FFs should be consumed.

Knowledge, interest, predisposition and evaluation of functional foods in Spanish dietitians-nutritionists and experts in human nutrition and dietetics / Conocimientos, interés, predisposición y valoración sobre alimentos funcionales por parte de dietistas-nutricionistas y expertos en nutrición humana y dietética españoles

Introduction: Little research has been conducted into the attitudes and knowledge of dietitians-nutritionists (DN) or of experts in human nutrition and dietetics (EHND) regarding functional foods (FFs). Objectives: To evaluate the knowledge of, interest in and predisposition towards FFs in Spanish DN and EHND, and how these professionals rate the potential benefits and risks associated with consuming FFs. Methods: 2100 DN and 122 EHND were asked to participate in a self-administered questionnaire. The results were expressed using percentages and the DN responses were compared with those of the EHND by means of chi-squared test. A significant difference was regarded as having been obtained if P < 0.05. Results: 204 DN and 112 EHND responded. After eliminating 45 surveys due to anomalies, 268 surveys were analyzed (170 from the DN, 8.1% participation; 98 from the EHND, 80.3% participation). No statistically significant differences were observed between the responses of the DN and the EHND except in: 1) the view that it was "dangerous" to consume certain FFs ≥ 4 times a day; and 2) the knowledge of the population regarding in which situations certain FFs should be consumed. Most of the professionals demonstrated good knowledge of FFs, consumed FFs, showed a positive attitude towards FFs and thought that the information provided to the consumer is insufficient. Discussion and conclusions: FFs are generally accepted by nutritional professionals. However, further study is required into the discrepancies between DN and EHND regarding the view that it is "dangerous" to consume certain FFs and regarding their evaluation of whether the public know in which situations certain FFs should be consumed (AU)

Introducción: La actitud y los conocimientos de los dietistas-nutricionistas (DN) o de los expertos en nutrición humana y dietética (ENhD) en relación a los alimentos funcionales (AFs) ha sido poco investigada. Objetivos: Evaluar en DN y en ENhD españoles el conocimiento sobre AFs, el interés y la predisposición hacia ellos, así como su valoración sobre los potenciales beneficios y riesgos asociados a su consumo. Métodos: Se solicitó a 2100 DN y a 122 ENhD su participación en una encuesta autoadministrada. Se valoraron los resultados mediante porcentajes y se compararon las respuestas de DN con las de ENhD mediante el test de chicuadrado. Se consideró diferencia significativa si P < 0,05. Resultados: Respondieron 204 DN y 112 ENhD. Tras eliminar 45 encuestas por incongruencias, se analizaron 268 encuestas (170 de DN, 8,1% de participacion; 98 de ENhD, 80,3% de participacion). No se observaron diferencias estadisticamente significativas entre las respuestas de DN y ENhD excepto en: 1) la consideracion como "peligroso" el hecho de consumir ≥ 4 veces/dia determinados AFs; y 2) el conocimiento de la poblacion acerca de en que situaciones consumir determinados AFs. La mayoria de los profesionales estudiados presentan buenos conocimientos sobre AFs, los consume, muestran una actitud positiva hacia ellos, y considera que la informacion aportada al consumidor es insuficiente. Discusión y conclusiones: Los AFs son en general aceptados por los profesionales de la nutrición. Sin embargo, la discrepancia observada acerca de la consideración como "peligroso" un alto consumo de determinados AFs, y del conocimiento de la población sobre cuándo consumir determinados AFs requiere ser estudiada con mayor profundidad (AU)

Nuts, hypertension and endothelial function.

BACKGROUND AND AIMS: High blood pressure (BP) is considered a major risk factor for cardiovascular disease. Among lifestyle factors, diet plays a key role in the prevention and control of high BP. Therefore, it is important to elucidate which dietary components can exert beneficial effects on BP through modulation of endothelial function (EF) or by other mechanisms. In this paper we review the role of nutrients, foods, particularly nuts, and dietary patterns on BP control. DATA SYNTHESIS: Because nuts are low in sodium and contain significant amounts of mono- and polyunsaturated fatty acids, fiber, minerals such as magnesium, potassium and calcium, and antioxidants, they have been suggested as potentially protective foods against hypertension. Limited evidence from prospective studies and clinical trials suggests that nut consumption has a beneficial effect on both BP and EF. However, BP changes were a secondary outcome in nut feeding trials and no study used ambulatory BP monitoring as the standard for BP measurements. CONCLUSIONS: Further clinical trials, ideally using ambulatory BP monitoring, are needed to establish the potential protective effect of nut consumption on hypertension and vascular reactivity.

Cultural and historical aspects of Mediterranean nuts with emphasis on their attributed healthy and nutritional properties.

BACKGROUND AND AIMS: Nuts have been part of the human diet since prehistoric times. The aim of the present article is to describe the most important historical and cultural aspects of nut consumption throughout history. DATA SYNTHESIS: We discuss the following historical aspects of nuts originating in the Mediterranean: prehistory, the Egyptian civilization, their spread through the Mediterranean region by the Greek, Phoenician and Roman civilizations, and their reintroduction into Europe by means of the Al-Andalus culture. Particular emphasis is placed on the healthy and nutritional attributes that nuts have had throughout history. We also consider the role of the first globalization of food--the exchange of nuts between continents--and discuss the symbolism that nuts have had for humans throughout history in the context of cultural aspects of the Mediterranean region. CONCLUSIONS: Nuts and fruits are probably the earliest foods consumed by humans and are considered to be important because of their nutritional properties. Nuts have also been used in the past by different civilizations as drugs to prevent or treat several diseases.

Cross-sectional association of nut intake with adiposity in a Mediterranean population.

BACKGROUND AND AIMS: Nut intake has been inversely related to body mass index (BMI) in prospective studies. We examined dietary determinants of adiposity in an elderly Mediterranean population with customarily high nut consumption. METHODS AND RESULTS: A cross-sectional study was conducted in 847 subjects (56% women, mean age 67 years, BMI 29.7kg/m(2)) at high cardiovascular risk recruited into the PREDIMED study. Food consumption was evaluated by a validated semi-quantitative questionnaire, energy expenditure in physical activity by the Minnesota Leisure Time Activity questionnaire, and anthropometric variables by standard measurements. Nut intake decreased across quintiles of both BMI and waist circumference (P-trend <0.005; both). Alcohol ingestion was inversely related to BMI (P-trend=0.020) and directly to waist (P-trend=0.011), while meat intake was directly associated with waist circumference (P-trend=0.018). In fully adjusted multivariable models, independent dietary associations of BMI were the intake of nuts inversely (P=0.002) and that of meat and meat products directly (P=0.042). For waist circumference, independent dietary associations were intake of nuts (P=0.002) and vegetables (P=0.040), both inversely, and intake of meat and meat products directly (P=0.009). From the regression coefficients, it was predicted that BMI and waist circumference decreased by 0.78kg/m(2) and 2.1cm, respectively, for each serving of 30g of nuts. Results were similar in men and women. CONCLUSION: Nut consumption was inversely associated with adiposity independently of other lifestyle variables. It remains to be explored whether residual confounding related to a healthier lifestyle of nut eaters might in part explain these results.

Effects of one serving of mixed nuts on serum lipids, insulin resistance and inflammatory markers in patients with the metabolic syndrome.

BACKGROUND AND AIMS: Knowledge of the effect of nut consumption on metabolic syndrome (MetS) components is limited. We assessed the effects of nut intake on adiposity, serum lipids, insulin resistance, and inflammatory biomarkers in patients with MetS. METHODS AND RESULTS: In a randomized, parallel-group, 12-week feeding trial, 50 patients with MetS were given recommendations for a healthy diet with or without supplementation with 30 g/day of raw nuts (15 g walnuts, 7.5 g almonds and 7.5 g hazelnuts) (Nut and Control diet groups, respectively). Adiposity measures, serum lipids, insulin, Homeostasis Model Assessment (HOMA), interleukin-6 (IL-6) and other inflammatory biomarkers, and 48-h fecal fat were determined basally and at study's completion. Moderate weight loss, decreased adiposity, and lower blood pressure occurred similarly after both diets. The Control, but not the Nut diet, was associated with significant (P<0.05) reduction of LDL-cholesterol, with mean changes of -0.36 versus -0.13 mmol/L, respectively (between-group differences, P=0.154). The Nut diet reduced fasting insulin by 2.60 µU/mL (95% CI, -4.62 to -0.59) and HOMA-insulin resistance by 0.72 (-1.28 to -0.16) (P<0.05 versus Control diet; both). Among inflammatory markers, the Nut diet resulted in changes of median plasma IL-6 of -1.1 ng/L (-2.7 to -0.1; P=0.035 versus Control diet), but adjustment for weight loss attenuated the significance of the association. Stool fat decreased with the Control diet and slightly increased with the Nut diet (P<0.05 for between-group differences). CONCLUSION: Patients with MetS show decreased lipid responsiveness but improved insulin sensitivity after daily intake of 30 g of mixed nuts.

Acute effects of three high-fat meals with different fat saturations on energy expenditure, substrate oxidation and satiety.

BACKGROUND & AIMS: To compare the acute effects of three fatty meals with different fat quality on postprandial thermogenesis, substrate oxidation and satiety. METHODS: Twenty-nine healthy men aged between 18 and 30 years participated in a randomised crossover trial comparing the thermogenic effects of three isocaloric meals: high in polyunsaturated fatty acids from walnuts, high in monounsaturated fatty acids from olive oil, and high in saturated fatty acids from fat-rich dairy products. Indirect calorimetry was used to determine resting metabolic rate, respiratory quotient, 5-h postprandial energy expenditure and substrate oxidation. Satiety was estimated by using visual analogue scales and measuring caloric intake in a subsequent ad libitum meal. RESULTS: Five-h postprandial thermogenesis was higher by 28% after the high-polyunsaturated meal (p=0.039) and by 23% higher after the high-monounsaturated meal (p=0.035) compared with the high-saturated meal. Fat oxidation rates increased nonsignificantly after the two meals rich in unsaturated fatty acids and decreased nonsignificantly after the high-saturated fatty acid meal. Postprandial respiratory quotient, protein and carbohydrate oxidation, and satiety measures were similar among meals. CONCLUSIONS: Fat quality determined the thermogenic response to a fatty meal but had no clear effects on substrate oxidation or satiety.