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Cardiovascular Health and Anti-inflammatory Benefits

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Effect of cranberry extracts on lipid profiles in subjects with Type 2 diabetes

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Authors
Lee IT, Chan YC, Lin CW, Lee WJ, Sheu WH
Journal
Diabet Med 25(12):1473-7
Abstract

AIM: To examine the effect of cranberry ingestion on lipid profiles in Type 2 diabetic patients taking oral glucose-lowering drugs.

METHODS: Thirty Type 2 diabetic subjects (16 males and 14 females; mean age 65 +/- 1 years) who were taking oral glucose-lowering medication regularly were enrolled in this randomized, placebo-controlled, double-blind study. Changes in lipid profiles, oxidized low-density lipoprotein (ox-LDL), glycaemic control, components of the metabolic syndrome, C-reactive protein (CRP) and urinary albumin excretion (UAE) were assessed after cranberry or placebo treatment for 12 weeks.

RESULTS: Low-density lipoprotein (LDL) cholesterol decreased significantly in the cranberry group (from 3.3 +/- 0.2 to 2.9 +/- 0.2 mmol/l, P = 0.005) and the decrease was significantly greater than that in the placebo group (-0.4 +/- 0.1 vs. 0.2 +/- 0.1 mmol/l, P 0.001). Total cholesterol and total : high-density lipoprotein (HDL) cholesterol ratio also decreased significantly (P = 0.020 and 0.044, respectively) in the cranberry group and the reductions were significantly different from those in the placebo group (P 0.001 and P = 0.032, respectively). However, ox-LDL levels did not change significantly in response to cranberry consumption. Neither fasting glucose nor glycated haemoglobin improved in either group. Changes in components of the metabolic syndrome, UAE and CRP were not significantly different between groups.

CONCLUSIONS: Cranberry supplements are effective in reducing atherosclerotic cholesterol profiles, including LDL cholesterol and total cholesterol levels, as well as total : HDL cholesterol ratio, and have a neutral effect on glycaemic control in Type 2 diabetic subjects taking oral glucose-lowering agents.

Effects of a flavonol-rich diet on select cardiovascular parameters in a Golden Syrian hamster model.

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Authors
Kalgaonkar S, Gross HB, Yokoyama W, Keen CL
Journal
J Med Food 13(1):108-15
Abstract

The concept that the consumption of a diet rich in flavonoids can be associated with a reduced risk for cardiovascular disease is becoming increasingly accepted. In the present study we investigated the effects of the following four diets on blood pressure and cholesterol ester levels in hypercholesterolemic Golden Syrian hamsters: a high-fat, high-cholesterol diet (HFHC); a HFHC with 2% cranberry concentrate powder (HFHC+CE); a HFHC with 0.1% rutin (HFHC+Rutin); and a HFHC with 30 mg/kg vitamin E (HFHC+Vit.E). Diets were fed for either 12 or 20 weeks. Over the experimental period, heart rate and blood pressure measurements increased in the animals fed HFHC and HFHC+Vit.E; in contrast, these measurements were not increased in the animals fed HFHC+CE and HFHC+Rutin. Mesenteric and total abdominal fat were significantly lower in the animals fed HFHC+Rutin than in animals fed the other three diets. Ratios of plasma high-density lipoprotein cholesterol (HDL-C) to very-low-density lipoprotein cholesterol and of plasma HDL-C to low-density lipoprotein cholesterol were significantly higher in animals consuming HFHC+Vit.E than in animals fed the other three diets. Aortic cholesteryl ester levels were significantly lower in animals fed HFHC+CE, HFHC+Rutin, and HFHC+Vit.E at 20 weeks than in the animals fed HFHC. Fasting blood glucose concentrations were significantly lower in animals fed HFHC+Rutin and HFHC+Vit.E, and glucose clearance rates improved in animals fed HFHC+Rutin compared to animals fed the other three diets. Results obtained from this study support the concept that the chronic consumption of a flavonoid-rich diet can be beneficial

Long-term effects of three commercial cranberry products on the antioxidative status in rats: a pilot study.

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Authors
Palikova I, Vostalova J, Zdarilova A, Svobodova A, Kosina P, Vecera R, Stejskal D, Proskova J, Hrbac J, Bednar P, Maier V, Cernochova D, Simanek V, Ulrichova J.
Journal
J Agric Food Chem 8(3):1672-8
Abstract

Cranberry (Vaccinium macrocarpon Ait. Ericaceae) fruits and juice are widely used for their antiadherence and antioxidative properties. Little is known however about their effects on clinical chemistry markers after long-term consumption. This study was conducted to evaluate the effect of three commercial cranberry products, NUTRICRAN90S, HI-PAC 4.0, and PACRAN on the antioxidative status of rodents, divided into three experimental groups. The products were given as dietary admixtures (1500 mg of product/kg of stock feed) for 14 weeks to male Wistar rats (Groups 2-4) and a control Group 1 which received only stock feed. There were no significant cranberry treatment-related effects on oxidative stress parameters, catalase, glutathione peroxidase, glutathione reductase, glutathione transferase, superoxide dismutase, total antioxidant capacity, thiobarbituric acid reactive substances, advanced oxidation protein products, total SH-groups, or any other measured clinical chemistry markers. Hematological parameters, body weight, and food consumption were also unaffected by intake of cranberries. Only liver glutathione reductase activity and glutathione levels were significantly lower in Group 4 than in Group 1. Plasma alkaline phosphatase alone was significantly decreased in Group 2. No gross pathology, effects on organ weights, or histopathology were observed. No genotoxicity was found, and total cytochrome P450 level in liver was unaffected in all groups. The levels of hippuric acid and several phenolic acids were significantly increased in plasma and urine in Groups 2-4. The concentration of anthocyanins was under the detection threshold. The dietary addition of cranberry powders for 14 weeks was well tolerated, but it did not improve the antioxidative status in rats.

Cranberries inhibit LDL oxidation and induce LDL receptor expression in hepatocytes

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Authors
Chu YF, Liu RH
Journal
Life Sci 77(15):1892-901
Abstract

Cardiovascular disease (CVD) is the leading cause of death in most industrialized countries. Cranberries were evaluated for their potential roles in dietary prevention of CVD. Cranberry extracts were found to have potent antioxidant capacity preventing in vitro LDL oxidation with increasing delay and suppression of LDL oxidation in a dose-dependent manner. The antioxidant activity of 100 g cranberries against LDL oxidation was equivalent to 1000 mg vitamin C or 3700 mg vitamin E. Cranberry extracts also significantly induced expression of hepatic LDL receptors and increased intracellular uptake of cholesterol in HepG2 cells in vitro in a dose-dependent manner. This suggests that cranberries could enhance clearance of excessive plasma cholesterol in circulation. We propose that additive or synergistic effects of phytochemicals in cranberries are responsible for the inhibition of LDL oxidation, the induced expression of LDL receptors, and the increased uptake of cholesterol in hepatocytes.

The effects of cranberry juice consumption on antioxidant status and biomarkers relating to heart disease and cancer in healthy human volunteers.

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Authors
Duthie SJ, Jenkinson AM, Crozier A, Mullen W, Pirie L, Kyle J, Yap LS, Christen P, Duthie GG
Journal
Eur J Nutr 45(2):113-22
Abstract

BACKGROUND: Consumption of fruit and vegetables is associated with a decreased risk of heart disease and cancer. This has been ascribed in part to antioxidants in these foods inactivating reactive oxygen species involved in initiation or progression of these diseases. Non-nutritive anthocyanins are present in significant amounts in the human diet. However, it is unclear whether they have health benefits in humans.

AIM: To determine whether daily consumption of anthocyanin-rich cranberry juice could alter plasma antioxidant activity and biomarkers of oxidative stress.

METHODS: 20 healthy female volunteers aged 18-40 y were recruited. Subjects consumed 750 ml/day of either cranberry juice or a placebo drink for 2 weeks. Fasted blood and urine samples were obtained over 4 weeks. The total phenol, anthocyanin and catechin content of the supplements and plasma were measured. Anthocyanin glycosides were identified by tandem mass spectrometry (MS-MS). Vitamin C, homocysteine (tHcy) and reduced glutathione (GSH) were measured by HPLC. Total antioxidant ability was determined using electron spin resonance (ESR) spectrometry and by the FRAP assay. Plasma total cholesterol, high density lipoprotein (HDL), and low density lipoprotein (LDL) cholesterol and triglycerides (TG) were measured. Glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) activities were measured in erythrocytes. Urine was collected for analysis of malondialdehyde (MDA) by HPLC and 8-oxo-deoxyguanosine (8-oxo-dG) by ELISA. Endogenous and induced DNA damage were measured by single cell gel electrophoresis (SCGE) in lymphocytes.

RESULTS: Vitamin C, total phenol, anthocyanin and catechin concentrations and FRAP and ESR values were significantly higher in the cranberry juice compared with the placebo. Cyanidin and peonidin glycosides comprised the major anthocyanin metabolites [peonidin galactoside (29.2%) > cyanidin arabinoside (26.1%) > cyanidin galactoside (21.7%) > peonidin arabinoside (17.5%) > peonidin glucoside (4.1%) > cyanidin glucoside (1.4 %)]. Plasma vitamin C increased significantly (P0.01) in volunteers consuming cranberry juice. No anthocyanins (plasma) or catechins (plasma or urine) were detectable and plasma total phenols, tHcy,TC,TG,HDL and LDL were unchanged. The antioxidant potential of the plasma, GSH-Px, CAT and SOD activities, and MDA were similar for both groups. Supplementation with cranberry juice did not affect 8-oxo-deoxyguanosine in urine or endogenous or H(2)O(2)-induced DNA damage in lymphocytes.

CONCLUSIONS: Cranberry juice consumption did not alter blood or cellular antioxidant status or several biomarkers of lipid status pertinent to heart disease. Similarly, cranberry juice had no effect on basal or induced oxidative DNA damage. These results show the importance of distinguishing between the in vitro and in vivo antioxidant activities of dietary anthocyanins in relation to human health.

A double-blinded, placebo-controlled, randomized trial of the neuropsychologic efficacy of cranberry juice in a sample of cognitively intact older adults: pilot study findings

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Authors
Crews WD Jr, Harrison DW, Griffin ML, Addison K, Yount AM, Giovenco MA and Hazell J.
Journal
J Altern Complement Med 11(2):305-9
Abstract

OBJECTIVES: The aim of this research was to conduct the first known clinical trial of the short-term (i.e., 6 weeks) efficacy of cranberry juice on the neuropsychologic functioning of cognitively intact older adults.PARTICIPANTS: Fifty (50) community-dwelling, cognitively intact volunteers, > or = 60 years old, who reported no history of dementia or significant neurocognitive impairments, participated in this study.DESIGN: A 6-week, double-blind, placebo-controlled, randomized, parallel-group, clinical trial was utilized. Participants were randomly assigned to receive either 32 ounces/day of a beverage containing 27% cranberry juice per volume (n = 25) or placebo (n = 25) for 6 weeks, and administered a series of neuropsychologic tests at both pretreatment baseline and again after 6 weeks of either cranberry juice or placebo treatment to assess treatment-related changes.OUTCOME MEASURES: Efficacy measures consisted of participants' raw scores on the following standardized neuropsychologic tests: Selective Reminding Test, Wechsler Memory Scale-III Faces I and Faces II subtests, Trail Making Test (Parts A and B), Stroop Color and Word Test, and the Wechsler Adult Intelligence Scale- III Digit Symbol-Coding subtest. A subjective Follow-up Self-report Questionnaire was also administered to participants at the conclusion of the end-of-treatment phase assessments.RESULTS: Two-factor, mixed analyses of variance (ANOVA) revealed no significant group (cranberry juice and placebo) by trial (pretreatment baseline and end-of-treatment assessments) interactions across all of the neuropsychologic tests and measures utilized in this study when a Bonferroni corrected alpha level was used to correct for multiple comparisons (i.e., .05/17 group by trial comparisons = .003). Pearson Chi-Square analyses of the groups' self-reported changes over the 6-week treatment phase in their abilities to remember, thinking processes, moods, energy levels, and overall health on the Follow-up Self-report Questionnaire revealed no significant relationships. However, a nonsignificant trend (X2(1) = 2.373, p = 0.123) was noted for participants' self-reported overall abilities to remember from pretreatment baseline to the end-of-treatment assessment. Specifically, more than twice as many participants in the cranberry group (n = 9, 37.5%) rated their overall abilities to remember by treatment end as "improved" as compared to placebo controls (n = 4, 17.4%).CONCLUSIONS: Taken together, no significant interactions were found between the cranberry and placebo groups and their pretreatment baseline and end-of-treatment phase (after 6 weeks) standardized neuropsychologic assessments. A nonsignificant trend was noted, however, on a subjective, self-report questionnaire where twice as many participants in the cranberry group rated their overall abilities to remember by treatment end as "improved" compared to placebo controls.

Comparison of urinary cytokines after ingestion of cranberry juice cocktail in pregnant subjects: a pilot study.

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Authors
Wing DA, Rumney PJ, Leu SY, Zaldivar F
Journal
Am J Perinatol 27(2):137-42
Abstract

Our objective was to evaluate urinary cytokine excretion after daily cranberry or placebo exposure in pregnant women. Four-hour urine samples were collected from 27 pregnant women subjects who were randomized to cranberry juice cocktail or placebo in three treatment arms: A: Cranberry (C) two times daily (C, C; n = 10 pregnant); B: cranberry in the AM, then placebo (P) in the PM (C, P; n = 9 pregnant); and C: placebo two times daily (P, P; n = 8 pregnant). Urinary cytokines were measured using commercially available kits. There was a statistically significant difference in interleukin (IL)-6 of the urinary cytokines between the multiple daily cranberry dosing group (group A [C, C]): median, 3.16 (range, 0.01 to 7.34) and the placebo group (group C [P, P]): 9.32 (0.53 to 29.61 pg/mL; p = 0.038, Kruskal-Wallis test). We concluded that a difference in IL-6 was found in the multiple daily cranberry dosing groups compared with placebo. Lack of differences based on treatment allocation in the other cytokines may be due to beta error. Further studies are planned to evaluate these assays for the assessment of clinical effect.

Cranberry juice induces nitric oxide-dependent vasodilation in vitro and its infusion transiently reduces blood pressure in anesthetized rats

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Authors
Maher MA, Mataczynski H, Stefaniak HM and Wilson T
Journal
J Med Food 3(3):141-7
Abstract

ABSTRACT Red wine vasodilates rat aortae, an effect attributed to polyphenolic compounds. Cranberry juice (CBJ) is also rich in polyphenols. We determined that CBJ has vasorelaxing properties similar to those of red wine. Rat aortic rings cleaned in Krebs buffer, pH 7.4, bubbled with 95% O(2) and 5% CO(2) were recovered for 30 minutes at 37 degrees C under 2.0 g tension. After phenylephrine (PE, 100 mumol/L) contraction, acetylcholine (3 mumol/L)-induced relaxation of intact vessel was significantly higher than in denuded vessels (59.1 +/- 0.27% versus 10.1 +/- 0.09% of the maximal PE contraction; P .003). After a second PE contraction, a 1:100 dilution of CBJ was added. Intact rings were vasodilated by CBJ with 56.7 +/- 0.26% relaxation, compared to denuded rings with 8.9 +/- 0.06% relaxation (P .002). Addition of L-NAME reversed CBJ-induced vasorelaxation in intact vessels with 0.54 +/- 0.34 g compared to 0.04 +/- 0.04 g in denuded vessels (P .007). Subsequent addition of L-arginine resulted in a return of vasodilation in intact vessels. Additionally, CBJ infusion at a 1:100 dilution of estimated blood volume resulted in a 16% reduction of mean arterial blood pressure in anesthetized rats. This study suggests that, like red wine, CBJ has the capacity to exert in vitro and in vivo vasodilatory effects.