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Cognitive and mood improvements following acute supplementation with purple grape juice in healthy young adults.
Haskell-Ramsay, CF, Stuart, RC, Okello, EJ, Watson, AW
European journal of nutrition. 2017;(8):2621-2631
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PURPOSE Berry-derived phenolic compounds found in grapes have been associated with a number of health benefits, including the augmentation of human brain function and cognition. Previous intervention studies of Concord grape juice have demonstrated improvement to memory and driving ability following 3- to 4-month supplementation in middle-aged and older adults. However, no studies to date have demonstrated acute cognitive benefits of grape juice, and investigation of these effects in young adults is lacking. METHODS This randomised, placebo-controlled, double-blind, counterbalanced-crossover study, assessed the effects of 230 ml purple grape juice or sugar-matched control in 20 healthy young adults. Computerised measures of episodic memory, working memory, attention and mood were completed at baseline and following a 20-min absorption period. RESULTS Purple grape juice significantly improved reaction time on a composite attention measure (p = 0.047) and increased calm ratings (p = 0.046) when compared to placebo. Order effects also indicated an enduring positive effect on pre-dose memory reaction time (p = 0.018) and post-dose calm ratings (p = 0.019) when purple grape was consumed first. CONCLUSIONS These findings in a small sample of healthy young adults suggest that purple grape juice can acutely enhance aspects of cognition and mood. No significant effects of juice were observed on memory measures, suggesting that these may be less susceptible to manipulation following acute supplementation in healthy young adults. Potential mechanisms underlying these effects include modulation of cerebral blood flow, glucoregulation and inhibition of monoamine oxidase activity, all of which require further exploration.
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Acute consumption of organic and conventional tropical grape juices (Vitis labrusca L.) increases antioxidants in plasma and erythrocytes, but not glucose and uric acid levels, in healthy individuals.
Toaldo, IM, Cruz, FA, da Silva, EL, Bordignon-Luiz, MT
Nutrition research (New York, N.Y.). 2016;(8):808-17
Abstract
Bioactive polyphenols in grapes are influenced by grape variety and cultivation conditions. The Vitis labrusca L. varieties are cultivated in tropical regions and used for grape juice production. We hypothesized that polyphenols from tropical grape juices would beneficially affect redox homeostasis in humans. Therefore, the effects of acute consumption of organic and conventional grape juices from V labrusca L. on antioxidants biomarkers were investigated in healthy individuals. In a controlled, randomized, crossover, intervention trial, 24 individuals were assigned to drink 400 mL of conventional juice, organic juice, or water. Each intervention was followed by a 14-day washout period. Blood samples were obtained before and 1 hour after acute intake and analyzed for erythrocyte reduced glutathione, serum total antioxidant capacity, antioxidant enzymes in erythrocytes, and glucose and uric acid in serum. The ingestion of both grape juices resulted in elevated levels of reduced glutathione (P< .001) and serum total antioxidant capacity (P< .05) and increased activity of catalase (P< .001), superoxide dismutase (P< .001), and glutathione peroxidase (P< .05) compared with the control intervention, with no significant differences between grape juices (P< .05). The intake of juices did not affect significantly the concentrations of glucose or uric acid. Grape juice polyphenols were associated with increased antioxidants, and the chemical differences between organic and conventional juices were not predictive of the observed responses. The results suggest a bioactive potential of V labrusca L. juices to improve redox homeostasis, which is involved in defense against oxidative stress in humans.
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Bioactive potential of Vitis labrusca L. grape juices from the Southern Region of Brazil: phenolic and elemental composition and effect on lipid peroxidation in healthy subjects.
Toaldo, IM, Cruz, FA, Alves, Tde L, de Gois, JS, Borges, DL, Cunha, HP, da Silva, EL, Bordignon-Luiz, MT
Food chemistry. 2015;:527-35
Abstract
Grapes are rich in polyphenols with biologically active properties. Although the bioactive potential of grape constituents are frequently reported, the effects of Brazilian Vitis labrusca L. grape juices ingestion have not been demonstrated in humans. This study identified the phenolic and elemental composition of red and white grape juices and the effect of organic and conventional red grape juice consumption on lipid peroxidation in healthy individuals. Concentrations of anthocyanins, flavanols and phenolic acids and the in vitro antioxidant activity were significantly higher in the organic juice. The macro-elements K, Ca, Na and Mg were the most abundant minerals in all juices. The acute consumption of red grape juices promoted significant decrease of lipid peroxides in serum and TBARS levels in plasma. It is concluded that red V. labrusca L. grape juices produced in Southern Brazil showed lipid peroxidation inhibition abilities in healthy subjects, regardless of the cultivation system.
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Postprandial effects of a polyphenolic grape extract (PGE) supplement on appetite and food intake: a randomised dose-comparison trial.
Shin, HS, Kindleysides, S, Yip, W, Budgett, SC, Ingram, JR, Poppitt, SD
Nutrition journal. 2015;:96
Abstract
BACKGROUND There is recent evidence that glucose delivered to the distal small intestine (SI) may stimulate the ileal brake and inhibit appetite. High polyphenolic grape extract (PGE) has been shown to inhibit α-amylase and α-glucosidase activity, two key enzymes required for starch digestion, in vitro. It is hypothesised to slow digestion and absorption of starch in the proximal SI such that glucose may be delivered distally into the ileum and suppress appetite. This study investigated the safety and efficacy of a PGE supplement, delivered within a capsule and consumed with a high-starch breakfast, on appetite ratings and ad libitum energy intake (EI) at a subsequent lunch meal. METHODS Twenty healthy, non-obese (BMI 18-28 kg/m(2)) male volunteers participated in a randomised, double blind, placebo controlled, three arm, cross-over study. Participants were administered (i) low dose PGE500 (500 mg), (ii) high dose PGE1500 (1500 mg), and (iii) matched placebo with a 2 MJ high-starch breakfast (white bread); followed 3 h later by a single item buffet-style lunch meal (pasta and meat sauce). Outcome variables were feelings of hunger, fullness, prospective thoughts of food (TOF) and satisfaction assessed using visual analogue scales (VAS); and ad lib energy and macronutrient intake at the lunch meal. RESULTS There was no detectable effect of PGE500 or PGE1500 compared with placebo (all, time*supplement interaction, P > 0.05) on VAS-assessed hunger, fullness, TOF or satisfaction. There was also no evidence that PGE significantly altered ad lib energy or macronutrient intake at the lunch meal relative to placebo (P > 0.05). EI following PGE500 was +164 kJ higher than placebo (+5.3%, P > 0.05); and EI following PGE1500 was -51 kJ lower than placebo (-1.7%, P > 0.05). CONCLUSIONS Whilst well tolerated, there was no evidence that encapsulated low dose PGE500 or high dose PGE1500 consumed with a high starch breakfast meal altered postprandial hunger, fullness, TOF or satisfaction relative to a matched placebo. Nor was there evidence that either dose altered ad lib energy or macronutrient intake at an outcome meal. TRIAL REGISTRATION ACTRN12614000041651.
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Feasibility and preliminary efficacy of the effects of flavanoid-rich purple grape juice on the vascular health of childhood cancer survivors: a randomized, controlled crossover trial.
Blair, CK, Kelly, AS, Steinberger, J, Eberly, LE, Napurski, C, Robien, K, Neglia, JP, Mulrooney, DA, Ross, JA
Pediatric blood & cancer. 2014;(12):2290-6
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BACKGROUND Childhood cancer survivors have an increased risk of developing cardiovascular disease following treatment, yet few interventions have been evaluated to reduce this risk. Purple grape juice (pGJ), a rich source of flavonoids with antioxidant properties, has been shown in adults to reduce oxidative stress and improve endothelial function. We examined the effects of supplementing meals with pGJ on microvascular endothelial function and markers of oxidative stress and inflammation in 24 cancer survivors (ages 10-21 years). PROCEDURE In a randomized controlled crossover trial consisting of two, 4 week intervention periods, each preceded by a 4 week washout period, subjects received in random order 6 ounces twice daily of pGJ and clear apple juice (cAJ; similar in calories but lower in flavonoids). Measurements were obtained before and after each supplementation period; change was evaluated using mixed effects ANOVA. RESULTS pGJ did not improve endothelial function, measured using digital reactive hyperemia, compared with cAJ (mean change: pGJ 0.06, cAJ 0.22; difference of mean change [95% CI]: -0.16 [-0.42 - 0.11], P = 0.25). No significant changes in plasma concentrations of oxidized-LDL, myeloperoxidase, or high sensitivity C-reactive protein were observed. CONCLUSION After 4 weeks of daily consumption of flavonoid-rich pGJ, no measurable change in vascular function was observed in these childhood cancer survivors.
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Grape resveratrol increases serum adiponectin and downregulates inflammatory genes in peripheral blood mononuclear cells: a triple-blind, placebo-controlled, one-year clinical trial in patients with stable coronary artery disease.
Tomé-Carneiro, J, Gonzálvez, M, Larrosa, M, Yáñez-Gascón, MJ, García-Almagro, FJ, Ruiz-Ros, JA, Tomás-Barberán, FA, García-Conesa, MT, Espín, JC
Cardiovascular drugs and therapy. 2013;(1):37-48
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PURPOSE The grape and wine polyphenol resveratrol exerts cardiovascular benefits but evidence from randomized human clinical trials is very limited. We investigated dose-depending effects of a resveratrol-containing grape supplement on stable patients with coronary artery disease (CAD) treated according to currently accepted guidelines for secondary prevention of cardiovascular disease. METHODS In a triple-blind, randomized, placebo-controlled, one-year follow-up, 3-arm pilot clinical trial, 75 stable-CAD patients received 350 mg/day of placebo, resveratrol-containing grape extract (grape phenolics plus 8 mg resveratrol) or conventional grape extract lacking resveratrol during 6 months, and a double dose for the following 6 months. Changes in circulating inflammatory and fibrinolytic biomarkers were analyzed. Moreover, the transcriptional profiling of inflammatory genes in peripheral blood mononuclear cells (PBMCs) was explored using microarrays and functional gene expression analysis. RESULTS After 1 year, in contrast to the placebo and conventional grape extract groups, the resveratrol-containing grape extract group showed an increase of the anti-inflammatory serum adiponectin (9.6 %, p = 0.01) and a decrease of the thrombogenic plasminogen activator inhibitor type 1 (PAI-1) (-18.6 %, p = 0.05). In addition, 6 key inflammation-related transcription factors were predicted to be significantly activated or inhibited, with 27 extracellular-space acting genes involved in inflammation, cell migration and T-cell interaction signals presenting downregulation (p < 0.05) in PBMCs. No adverse effects were detected in relation to the study products. CONCLUSIONS Chronic daily consumption of a resveratrol-containing grape nutraceutical could exert cardiovascular benefits in stable-CAD patients treated according to current evidence-based standards, by increasing serum adiponectin, preventing PAI-1 increase and inhibiting atherothrombotic signals in PBMCs.
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Grape polyphenols prevent fructose-induced oxidative stress and insulin resistance in first-degree relatives of type 2 diabetic patients.
Hokayem, M, Blond, E, Vidal, H, Lambert, K, Meugnier, E, Feillet-Coudray, C, Coudray, C, Pesenti, S, Luyton, C, Lambert-Porcheron, S, et al
Diabetes care. 2013;(6):1454-61
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OBJECTIVE To assess the clinical efficacy of nutritional amounts of grape polyphenols (PPs) in counteracting the metabolic alterations of high-fructose diet, including oxidative stress and insulin resistance (IR), in healthy volunteers with high metabolic risk. RESEARCH DESIGN AND METHODS Thirty-eight healthy overweight/obese first-degree relatives of type 2 diabetic patients (18 men and 20 women) were randomized in a double-blind controlled trial between a grape PP (2 g/day) and a placebo (PCB) group. Subjects were investigated at baseline and after 8 and 9 weeks of supplementation, the last 6 days of which they all received 3 g/kg fat-free mass/day of fructose. The primary end point was the protective effect of grape PPs on fructose-induced IR. RESULTS In the PCB group, fructose induced 1) a 20% decrease in hepatic insulin sensitivity index (P < 0.05) and an 11% decrease in glucose infusion rate (P < 0.05) as evaluated during a two-step hyperinsulinemic-euglycemic clamp, 2) an increase in systemic (urinary F2-isoprostanes) and muscle (thiobarbituric acid-reactive substances and protein carbonylation) oxidative stress (P < 0.05), and 3) a downregulation of mitochondrial genes and decreased mitochondrial respiration (P < 0.05). All the deleterious effects of fructose were fully blunted by grape PP supplementation. Antioxidative defenses, inflammatory markers, and main adipokines were affected neither by fructose nor by grape PPs. CONCLUSIONS A natural mixture of grape PPs at nutritional doses efficiently prevents fructose-induced oxidative stress and IR. The current interest in grape PP ingredients and products by the global food and nutrition industries could well make them a stepping-stone of preventive nutrition.
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Grape polyphenols reduce blood pressure and increase flow-mediated vasodilation in men with metabolic syndrome.
Barona, J, Aristizabal, JC, Blesso, CN, Volek, JS, Fernandez, ML
The Journal of nutrition. 2012;(9):1626-32
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We evaluated the effects of grape polyphenols in individuals classified with metabolic syndrome (MetS). Men (n = 24) aged 30-70 y were randomly assigned to consume either a freeze-dried grape polyphenol powder (GRAPE) or a placebo for 30 d in a double-blind, crossover design, separated by a 3-wk washout period. Participants were asked to maintain their usual diet and physical activity during the study and abstain from consuming polyphenol-rich foods. MetS criteria including blood pressure (BP) and markers of vascular endothelial function including brachial artery flow-mediated vasodilation (FMD), plasma total nitrite + nitrate (NOx) to estimate NO production, plasma soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured at the end of each dietary period. Systolic BP (P < 0.0025) and plasma sICAM-1 concentrations (P < 0.025) were lower, whereas the FMD response was higher (P < 0.0001), during the GRAPE compared with the placebo period. In addition, changes in sVCAM-1 concentrations between periods were positively correlated with changes in systolic BP (r = 0.45; P < 0.05). Although NOx concentrations did not differ between periods, changes in systolic BP were negatively correlated with changes in NOx concentrations (r = -0.44; P < 0.05), indicating the vasodilating properties of NO. Other MetS variables did not differ between the GRAPE and placebo periods. These results suggest that GRAPE polyphenols may potentiate vasorelaxation and reduce BP and circulating cell adhesion molecules, resulting in improvements in vascular function.
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Effect of muscadine grape seed supplementation on vascular function in subjects with or at risk for cardiovascular disease: a randomized crossover trial.
Mellen, PB, Daniel, KR, Brosnihan, KB, Hansen, KJ, Herrington, DM
Journal of the American College of Nutrition. 2010;(5):469-75
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BACKGROUND Muscadine grape seeds have high concentrations of polyphenolic compounds with antioxidant and other properties that would be expected to have favorable effects on endothelial function. OBJECTIVES To evaluate the effect of muscadine grape seed supplementation on endothelial function and cardiovascular risk factors in subjects with increased cardiovascular risk. DESIGN In a randomized, double-blind, placebo-controlled crossover trial, 50 adults with coronary disease or ≥1 cardiac risk factor received muscadine grape seed supplementation (1300 mg daily) and placebo for 4 weeks each, with a 4-week washout. Resting brachial diameter and brachial flow-mediated dilation (FMD) and biomarkers of inflammation, lipid peroxidation, and antioxidant capacity were determined at the beginning and end of each period and compared in mixed linear models. RESULTS There was no evidence of improved FMD (% change) with muscadine grape seed (muscadine grape seed: pre 5.2% ± 0.3%, post 4.6% ± 0.3%, p = 0.06; placebo: pre 5.3% ± 0.4%, post 5.2% ± 0.4%, p = 0.82; p for muscadine grape seed vs. placebo = 0.25). However, there was a significant increase in baseline diameter (mm) with muscadine grape seed supplementation (muscadine grape seed: pre 4.05 ± 0.09, post 4.23 ± 0.10, p = 0.002; placebo: pre 4.12 ± 0.11, post 4.12 ± 0.10, p = 0.93; p for muscadine grape seed vs. placebo = 0.026). All other biomarkers were not significantly altered by muscadine grape seed supplementation. CONCLUSIONS Four weeks of muscadine grape seed supplementation in subjects with increased cardiovascular risk did not produce a statistically significant increase in brachial flow-mediated vasodilation or a significant change in other biomarkers of inflammation, lipid peroxidation, or antioxidant capacity. However, the muscadine grape seed supplement did result in a significant increase in resting brachial diameter. The clinical significance of the effect on resting diameter is not yet established. More research is warranted to fully characterize the vascular effects of this and other grape-derived nutritional supplements and to determine whether these vascular effects translate into important clinical benefits.
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Comparative effects of dietary supplementation with red grape juice and vitamin E on production of superoxide by circulating neutrophil NADPH oxidase in hemodialysis patients.
Castilla, P, Dávalos, A, Teruel, JL, Cerrato, F, Fernández-Lucas, M, Merino, JL, Sánchez-Martín, CC, Ortuño, J, Lasunción, MA
The American journal of clinical nutrition. 2008;(4):1053-61
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BACKGROUND Atherosclerotic cardiovascular disease is the most common cause of death among hemodialysis patients; it has been attributed to increased oxidative stress, dyslipidemia, malnutrition, and chronic inflammation. Activation of neutrophils is a well-recognized feature in dialysis patients, and superoxide-anion production by neutrophil NADPH oxidase may contribute significantly to oxidative stress. OBJECTIVE The aim of the study was to compare the effects of dietary supplementation with concentrated red grape juice (RGJ), a source of polyphenols, and vitamin E on neutrophil NADPH oxidase activity and other cardiovascular risk factors in hemodialysis patients. DESIGN Thirty-two patients undergoing hemodialysis were recruited and randomly assigned to groups to receive dietary supplementation with RGJ, vitamin E, or both or a control condition without supplementation or placebo. Blood was obtained at baseline and on days 7 and 14 of treatment. RESULTS RGJ consumption but not vitamin E consumption reduced plasma concentrations of total cholesterol and apolipoprotein B and increased those of HDL cholesterol. Both RGJ and vitamin E reduced plasma concentrations of oxidized LDL and ex vivo neutrophil NADPH oxidase activity. These effects were intensified when the supplements were used in combination; in that case, reductions in the inflammatory biomarkers intercellular adhesion molecule 1 and monocyte chemoattractant protein 1 also were observed. CONCLUSIONS Regular ingestion of concentrated RGJ by hemodialysis patients reduces neutrophil NADPH-oxidase activity and plasma concentrations of oxidized LDL and inflammatory biomarkers to a greater extent than does that of vitamin E. This effect of RGJ consumption may favor a reduction in cardiovascular risk.