Impact of Blueberry Consumption on the Human Fecal Bileacidome: A Pilot Study of Bile Acid Modulation by Freeze-Dried Blueberry.

Cholesterol-derived bile acids (BAs) affect numerous physiological functions such as glucose homeostasis, lipid metabolism and absorption, intestinal inflammation and immunity, as well as intestinal microbiota diversity. Diet influences the composition of the BA pool. In the present study, we analyzed the impact of a dietary supplementation with a freeze-dried blueberry powder (BBP) on the fecal BA pool composition. The diet of 11 men and 13 women at risk of metabolic syndrome was supplemented with 50 g/day of BBP for 8 weeks, and feces were harvested before (pre) and after (post) BBP consumption. BAs were profiled using liquid chromatography coupled with tandem mass spectrometry. No significant changes in total BAs were detected when comparing pre- vs. post-BBP consumption samples. However, post-BBP consumption samples exhibited significant accumulations of glycine-conjugated BAs (p = 0.04), glycochenodeoxycholic (p = 0.01), and glycoursodeoxycholic (p = 0.01) acids, as well as a significant reduction (p = 0.03) in the secondary BA levels compared with pre-BBP feces. In conclusion, the fecal bileacidome is significantly altered after the consumption of BBP for 8 weeks. While additional studies are needed to fully understand the underlying mechanisms and physiological implications of these changes, our data suggest that the consumption of blueberries can modulate toxic BA elimination.

Health Benefits of Apple Juice Consumption: A Review of Interventional Trials on Humans.

Although numerous studies have reported the benefits of apple consumption on cardiometabolic health parameters and chronic disease prevention, few have focused on the effects of apple juice specifically. Juice consumption may be a convenient way to take advantage of the health effects of the bioactive components present in apples. The present review aims to summarize the current literature on health benefits of apple juice as reported in clinical trials in humans. Of the 67 studies retained, 20 interventional studies on humans were reviewed. Overall, cloudy apple juice consumption was found to be associated with several markers of cardiovascular health that may ultimately be relevant for cancer and neurodegenerative diseases. Most of the documentation was found regarding oxidative stress, as well as observations with other parameters such as markers of inflammation, lipid profile, and diabetes. This review suggests that, in 20 studies, apple juice consumed in moderation exerts positive effects on markers of cardiovascular disease risk (particularly on oxidative stress).

An 8-week freeze-dried blueberry supplement impacts immune-related pathways: a randomized, double-blind placebo-controlled trial.

BACKGROUND: Blueberries contain high levels of polyphenolic compounds with high in vitro antioxidant capacities. Their consumption has been associated with improved vascular and metabolic health. PURPOSE: The objective was to examine the effects of blueberry supplement consumption on metabolic syndrome (MetS) parameters and potential underlying mechanisms of action. METHODS: A randomized double-blind placebo-controlled intervention trial was conducted in adults at risk of developing MetS. Participants consumed 50 g daily of either a freeze-dried highbush blueberry powder (BBP) or a placebo powder for 8 weeks (n = 49). MetS phenotypes were assessed at weeks 0, 4 and 8. Fasting blood gene expression profiles and plasma metabolomic profiles were examined at baseline and week 8 to assess metabolic changes occurring in response to the BBP. A per-protocol analysis was used. RESULTS: A significant treatment effect was observed for plasma triglyceride levels that was no longer significant after further adjustments for age, sex, BMI and baseline values. In addition, the treatment*time interactions were non-significant therefore suggesting that compared with the placebo, BBP had no statistically significant effect on body weight, blood pressure, fasting plasma lipid, insulin and glucose levels, insulin resistance (or sensitivity) or glycated hemoglobin concentrations. There were significant changes in the expression of 49 genes and in the abundance of 35 metabolites following BBP consumption. Differentially regulated genes were clustered in immune-related pathways. CONCLUSION: An 8-week BBP intervention did not significantly improve traditional markers of cardiometabolic health in adults at risk of developing MetS. However, changes in gene expression and metabolite abundance suggest that clinically significant cardiometabolic changes could take longer than 8 weeks to present and/or could result from whole blueberry consumption or a higher dosage. BBP may also have an effect on factors such as immunity even within a shorter 8-week timeframe. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov, NCT03266055 , 2017.

Associations of Intake of Free and Naturally Occurring Sugars from Solid Foods and Drinks with Cardiometabolic Risk Factors in a Quebec Adult Population: The PREDISE (PRÉDicteurs Individuels, Sociaux et Environnementaux) Study.

BACKGROUND: Associations between sugar consumption and cardiometabolic health, taking into account the physical form of sugar-containing foods (liquid vs. solid) and the type of sugars consumed [free sugars (FSs) vs. naturally occurring sugars (NOSs)], remain to be thoroughly documented. OBJECTIVE: The objective was to examine whether FS and NOS intakes from drinks and solid foods are associated with cardiometabolic risk factors in a sample of French-speaking adults from the province of Quebec, Canada. METHODS: Data were collected as part of the cross-sectional PREDISE (PRÉDicteurs Individuels, Sociaux et Environnementaux) study (n = 1019, 18-65 y old; 50% women). FS and NOS intakes were assessed by three 24-h dietary recalls using a self-administered, web-based application. Diet quality was assessed using the Alternative Healthy Eating Index-2010. Participants underwent on-site clinical assessment of cardiometabolic risk factors, including blood pressure, waist circumference, BMI, and fasting blood sampling (glucose, insulin, C-reactive protein, blood lipids). Multivariable linear regression models were performed to examine the associations between sugar intake and cardiometabolic risk factors with sociodemographic characteristics, lifestyle variables, and diet quality entered as covariates. RESULTS: In fully adjusted models, FS intake from drinks was associated with fasting insulin (1.06%; 95% CI: 0.30%, 1.84%; P = 0.006) and with insulin resistance as estimated using the HOMA model (1.01%; 95% CI: 0.19%, 1.84%; P = 0.02). All metabolic variables that were significantly associated with NOS intake from solid foods in minimally adjusted models were no longer significant after entering sociodemographic and lifestyle variables (e.g., educational and income levels, smoking, physical activity, daily energy intake) and diet quality in the models. CONCLUSIONS: Our data from an adult sample showed that unfavorable and favorable associations with cardiometabolic risk factors observed, respectively, for FS intake from drinks and NOS intake from foods are mostly explained by sociodemographic and lifestyle variables, as well as by diet quality.

Sex May Modulate the Effects of Combined Polyphenol Extract and L-citrulline Supplementation on Ambulatory Blood Pressure in Adults with Prehypertension: A Randomized Controlled Trial.

Increased blood pressure (BP), vascular dysfunction and inflammation are involved in the etiology of cardiovascular disease (CVD). Although several dietary components such as polyphenols and L-citrulline may help to control BP, their combined impact on ambulatory BP in individuals at risk of CVD remains unknown. The objective of this research was to investigate the short-term impact of supplementation with a combination of polyphenol extract and L-citrulline on ambulatory BP, endothelial function and inflammation. In a randomized double-blind parallel trial, 73 men and women with prehypertension were supplemented with a placebo (cellulose, n = 34, Plac) or 548 mg/day of polyphenols and 2 g/day of L-citrulline (n = 35, Suppl) for 6 weeks. The primary outcome of this study was the difference between groups in 24-h ambulatory diastolic BP (DBP) at week six. Secondary outcomes were a difference between groups at week six in ambulatory systolic BP (SBP), casual BP, serum lipids and high-sensitivity C-reactive protein (hs-CRP) concentrations and skin advanced glycation end products (AGEs). Potential interaction of treatment with sex was examined. Suppl had no impact on mean ambulatory SBP and DBP (p > 0.10 vs. placebo). Daytime and 24-h SBP were reduced with Suppl in women (p ≤ 0.01), but not in men (p ≥ 0.27). A non-significant reduction in AGEs was observed after Suppl compared to Plac among all participants (p = 0.07) and there was no difference in the concentrations of blood lipids (p > 0.20) or CRP (p = 0.36) between treatments at week six. Therefore, supplementation with polyphenol extract and L-citrulline for 6 weeks has no impact on ambulatory BP, blood lipids and CRP in adults with prehypertension. However, the polyphenol extract/L-citrulline supplement may reduce ambulatory SBP in women, but not in men. These preliminary results need further research efforts towards further documenting this sex-dependent BP response to supplementation with polyphenols and L-citrulline.

Supplementation with Resveratrol and Curcumin Does Not Affect the Inflammatory Response to a High-Fat Meal in Older Adults with Abdominal Obesity: A Randomized, Placebo-Controlled Crossover Trial.

Background: High-fat meals induce postprandial inflammation. Resveratrol is a polyphenol known to prevent comorbidities associated with cardiovascular disease and exerts an anti-inflammatory action. There is also an increasing body of evidence supporting the role of curcumin, a polyphenol from the curcuminoid family, as a modulator of proinflammatory processes. Objective: The objectives of this study were to investigate the following: 1) the bioavailability of resveratrol consumed in combination with curcumin after consumption of a high-fat meal; and 2) the acute combined effects of this combination on the postprandial inflammatory response of subjects with abdominal obesity. Methods: In a double blind, crossover, randomized, placebo-controlled study, 11 men and 11 postmenopausal women [mean ± SD age: 62 ± 5 y; mean ± SD body mass index (in kg/m2): 29 ± 3] underwent a 6-h oral fat tolerance test on 2 occasions separated by 1-2 wk: once after consumption of a dietary supplement (200 mg resveratrol and 100 mg curcumin, Res/Cur) and once after consumption of a placebo (cellulose). Plasma concentrations of total resveratrol and its major metabolites as well as inflammatory markers, adhesion molecules, and whole blood NFκB1 and PPARA gene expression were measured during both fat tolerance tests. Results: Kinetics of resveratrol and identified metabolites revealed rapid absorption patterns but also relatively limited bioavailability based on free resveratrol concentrations. Supplementation with Res/Cur did not modify postprandial variations in circulating inflammatory markers (C-reactive protein, IL-6, IL-8, monocyte chemoattractant protein-1) and adhesion molecules [soluble E-selectin, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1] compared to placebo (PTreatment×Time > 0.05). However, Res/Cur significantly decreased the cumulative postprandial response of sVCAM-1, compared to placebo (incremental area under the curve -4643%, P = 0.01). Postprandial variations of whole-blood PPARA and NFKB1 gene expression were not different between Res/Cur and placebo treatments. Conclusions: Acute supplementation with Res/Cur has no impact on the postprandial inflammation response to a high-fat meal in abdominally obese older adults. Further studies are warranted to examine how resveratrol and curcumin may alter the vascular response to a high-fat meal. This trial was registered at clinicaltrials.gov as NCT01964846.

Antioxidant activity and nutrient release from polyphenol-enriched cheese in a simulated gastrointestinal environment.

Green tea polyphenols are recognized for their antioxidant properties and their effects on lipid digestion kinetics. Polyphenols are sensitive to degradation in the intestinal environment. Interactions with dairy proteins could modulate the stability and biological activity of polyphenols during digestion. The objective of this study was to evaluate the release of nutrients (polyphenols, fatty acids and peptides) and the antioxidant activity in polyphenol-enriched cheese containing different levels of calcium in a simulated gastrointestinal environment. The relationship between cheese matrix texture, matrix degradation and nutrient release during digestion was also studied. Green tea extract was added to milk at 0% or 0.1%, and cheeses were produced on a laboratory scale. The level of available calcium was adjusted to low (Ca(low)), regular (Ca(reg)) or high (Ca(high)) during the salting step of the cheese-making process. Cheeses were subjected to simulated digestion. The rate and extent of fatty acid release were 21% lower for Ca(low) cheese than for Ca(reg) and Ca(high) cheeses. The greater adhesiveness of Ca(low) cheese, which resulted in lower rates of matrix degradation and proteolysis, contributed to the reduced rate of lipolysis. The presence of green tea extract in cheese reduced the release of free fatty acids at the end of digestion by 7%. The addition of green tea extract increased cheese hardness but did not influence matrix degradation or proteolysis profiles. The formation of complexes between tea polyphenols and proteins within the cheese matrix resulted in a more than twofold increase in polyphenol recovery in the intestinal phase compared with the control (tea polyphenol extract incubated with polyphenol-free cheese). Antioxidant activity was 14% higher in the digest from polyphenol-enriched cheese than in the control. These results suggest that cheese is an effective matrix for the controlled release of nutrients and for the protection of green tea polyphenol integrity and biological activity in the gastrointestinal environment.

Effect of commercial grape extracts on the cheese-making properties of milk.

Grape extracts can be added to milk to produce cheese with a high concentration of polyphenols. Four commercial extracts from whole grape, grape seed, and grape skin (2 extracts) were characterized and added to milk at concentrations of 0, 0.1, 0.2, and 0.3% (wt/vol). The effect of grape extracts on the kinetics of milk clotting, milk gel texture, and syneresis were determined, and model cheeses were produced. Whole grape and grape seed extracts contained a similar concentration of polyphenolic compounds and about twice the amount found in grape skin extracts. Radical scavenging activity was directly proportional to the phenolic compounds content. When added to milk, grape extracts increased rennet-induced clotting time and decreased the clotting rate. Although differences were observed between the extracts, the concentration added to milk was the main factor influencing clotting properties. With increasing concentrations of grape extracts, milk gels showed increased brittleness and reduced firmness. In addition, syneresis of milk gels decreased with increasing concentrations of grape extracts, which resulted in cheeses with a higher moisture content. The presence of grape extracts in milk slightly increased protein recovery in cheese but had no effect on fat recovery. With whole grape or grape seed extracts added to milk at 0.1% (wt/vol), the recovery coefficient for polyphenols was about 0.63, and decreased with increasing extract concentration in milk. Better polyphenol recovery was observed for grape seed extracts (0.87), with no concentration effect. Commercial extracts from whole grape, grape seed, or grape skin can be added to milk in the 0.1 to 0.3% (wt/vol) concentration range to produce cheese with potential health benefits, without a negative effect on cheese yield.

Interaction of green tea polyphenols with dairy matrices in a simulated gastrointestinal environment.

The consumption of polyphenols in green tea has been associated with beneficial health effects. Although polyphenols are unstable in the intestinal environment, they may be protected by interactions with dairy proteins during digestion. The objectives of this study were to evaluate the effect of a green tea extract on the digestibility of different dairy matrices and to monitor the antioxidant activity of these matrices with or without the green tea extract during digestion in a simulated gastrointestinal environment. Milk, yogurt and cheese with similar fat-to-protein ratios were subjected to simulated digestion. Matrix degradation, protein and fat hydrolysis, polyphenol concentration and radical scavenging activity were analyzed during gastric and intestinal digestion phases. Cheese was the matrix most resistant to protein and fat digestion. The addition of the green tea extract significantly decreased proteolysis in the gastric phase but had no effect in the intestinal phase. The kinetics of fatty acid release was reduced by the presence of the green tea extract. Transition from the gastric phase to the intestinal phase induced a 50% decrease in the antioxidant activity of the control (tea extract dispersed in water) due to the degradation of polyphenols. The presence of dairy matrices significantly improved polyphenol stability in the intestinal phase and increased the antioxidant activity by 29% (cheese) to 42% (milk) compared to the control. These results suggest that simultaneous consumption of green tea and dairy products helps to maintain the integrity and antioxidant activity of polyphenols during digestion.

Blood pressure and endothelial function in healthy, pregnant women after acute and daily consumption of flavanol-rich chocolate: a pilot, randomized controlled trial.

BACKGROUND: Several randomized clinical trials (RCTs) indicate that flavanol-rich chocolate has beneficial effects on flow-mediated dilation (FMD) and blood pressure (BP). However, no RCTs have evaluated these outcomes in pregnant women. The objective of this 2-group, parallel, double-blind RCT was to examine the effects of flavanol-rich chocolate on FMD and BP in pregnant women with normal BP. METHODS: Forty-four healthy, pregnant women were randomized to the high-flavanol (n = 23) or low-flavanol (n = 21) chocolate consumption for 12 weeks. At randomization (0, 60, 120 and 180 min after a single 40-g dose of chocolate), 6 and 12 weeks after daily 20-g chocolate intake, we evaluated plasma concentrations of flavanols and theobromine, as well as the FMD and BP. RESULTS: Plasma epicatechin was significantly increased (p < 0.001) 180 min after the consumption of 40-g high-flavanol chocolate compared to low-flavanol chocolate. Theobromine concentrations were significantly higher 180 min and 12 weeks after the intake of experimental chocolate or low-flavanol chocolate (p < 0.001). FMD was not different between the 2 groups at all pre-defined time periods. No other significant within-group or between-group changes were observed. CONCLUSION: These results confirm the feasibility of a large-scale RCT comparing daily consumption of flavanol-rich chocolate to an equivalent placebo during pregnancy and demonstrate higher plasma epicatechin and theobromine concentration in the intervention group after acute ingestion TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01659060.

Evidence that cranberry juice may improve augmentation index in overweight men.

The stiffening of arteries is a key step in atherogenesis leading to cardiovascular disease. It has been suggested that dietary polyphenols may be cardioprotective through possible favorable effects on oxidative stress and vascular function. The present study was undertaken in order to examine the effect of consuming low-calorie cranberry juice cocktail (CJC), a source of polyphenols, on arterial stiffness in abdominally obese men. We hypothesize that regular CJC consumption will reduce circulating oxidized low-density lipoproteins concentrations and have a beneficial impact on endothelial function. Thirty-five men (mean age ± SD: 45 ± 10 years) were randomly assigned to drink 500 mL CJC/day (27% juice) or 500 mL placebo juice (PJ)/day for 4 weeks in a double-blind crossover design. Augmentation index (AIx), an index of arterial stiffness, was measured by applanation tonometry of the radial artery and the cardiometabolic profile was assessed in each participant before and after each phase of the study. We found no significant difference in AIx changes between men who consumed CJC or PJ for 4 weeks (P = .5820). Furthermore, there was no between-treatment difference in changes in AIx responses to salbutamol (P = .6303) and glyceryl trinitrate (P = .4224). No significant difference was noted in other cardiometabolic variables between men consuming PJ or CJC. However, a significant within group decrease in AIx (mean decrease ± SE; -14.0 ± 5.8%, P = .019) was noted following the consumption of 500 mL CJC/day for 4 weeks. Our results indicate that the effect of chronic consumption of CJC on AIx was not significantly different from changes associated with the consumption of PJ. However, the significant within-group decrease in AIx following CJC consumption in abdominally obese men may deserve further investigation.

Sex differences in postprandial plasma tumor necrosis factor-alpha, interleukin-6, and C-reactive protein concentrations.

Abdominal obesity and insulin resistance are characterized by low-level chronic inflammation most likely implicated in the increased cardiovascular disease risk associated with these conditions. However, not much is known of the acute regulation of circulating inflammatory markers in response to food intake. The aim of this study is to examine changes in inflammatory marker concentrations after the consumption of a high-fat meal in men and women. We measured tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and C-reactive protein concentrations in plasma samples collected at 0, 4, and 8 hours after consumption of the meal in 39 men and 41 women. Associations between these variations and physical as well as metabolic variables were then examined. We noted significant increases in plasma IL-6 concentrations at 4 and 8 hours after the meal in men (+34% and +107%, respectively; P < .005 vs 0 hour) and women (+78% and +153%, respectively; P < .0001 vs 0 hour). Postprandial plasma TNF-alpha concentrations significantly dropped at 4 hours after the high-fat meal in men (-9.5%, P < .0005 vs 0 hour) and women (-5.5%, P < .05 vs 0 hour). Plasma CRP concentrations were not affected by food intake in either men or women. We also found that postprandial plasma concentrations of IL-6 were lower in subjects with a normal glucose tolerance (n = 69) compared with individuals with an impaired glucose tolerance (n = 11). Results of the present study show that consumption of a high-fat meal is associated with a transient reduction in circulating concentrations of TNF-alpha in both men and women as well as an elevation of plasma IL-6 concentrations that was found to be greater in women than in men.

Plasma matrix metalloproteinase (MMP)-9 levels are reduced following low-calorie cranberry juice supplementation in men.

OBJECTIVE: Matrix metalloproteinase (MMP)-9, also known as gelatinase B, is implicated in the development of hypertension and atherosclerotic plaque vulnerability to rupture, an important step in the etiology of cardiovascular diseases. Studies have suggested that flavonoid consumption may be cardioprotective, and its favorable impact on circulating MMP-9 concentrations could partly explain this association. The aim of the present study was to determine the effect of consuming increasing daily doses of low-calorie cranberry juice cocktail (CJC) on plasma MMP-9 concentrations of abdominally obese men. METHODS: Thirty men (mean age +/- SD: 51 +/- 10 years) consumed increasing doses of CJC during 3 successive periods of 4 weeks (weeks 1-4: 125 ml/day, weeks 5-8: 250 ml/day, and weeks 9-12: 500 ml/day). Before the study and after each phase, a series of physical and metabolic variables were measured, including MMP-9. RESULTS: We found that CJC supplementation significantly decreased plasma MMP-9 concentrations (mean +/- SEM: -36% +/- 9%, p < 0.0005; week 12 vs. baseline) while baseline plasma MMP-9 concentrations strongly correlated with the changes noted over the entire intervention (r = -0.71, p < 0.0001). We also show that the reduction in plasma MMP-9 levels was associated with a change in plasma nitrites/nitrates (NOx) concentration over the entire intervention (r = -0.38, p < 0.05; week 12 vs. baseline). Significant correlations were also noted between changes in plasma MMP-9 levels and those of systolic (r = 0.39, p < 0.05) and diastolic (r = 0.60, p < 0.001) blood pressure during the course of the study (week 12 vs. baseline). CONCLUSIONS: Our results show that daily CJC consumption is associated with a decrease in plasma MMP-9 concentrations in abdominally obese men. We hypothesize that polyphenolic compounds from cranberries may be responsible for this effect, supporting the notion that the consumption of flavonoid-rich foods can exert cardioprotective effects.

Evidences of the cardioprotective potential of fruits: the case of cranberries.

Eating a healthy balanced diet, is one of the most important and relevant ways to delay and prevent various health complications including cardiovascular disease (CVD). Among the nutritional factors that have been investigated in recent years, dietary fat intake may be the one that has been most targeted. However, there is also clear epidemiological evidence that increased fruits and vegetables intake can significantly reduce the risk of CVD, an effect that has been suggested to be resulting to a significant extent, from the high polyphenol content of these foods. Numerous polyphenolic compounds such as flavonoids have been identified as having strong antioxidant properties. Most interesting is the fact that, in addition to being one of the largest groups of antioxidant phytochemicals, flavonoids are also an integral part of the human diet as they are found in most fruits and vegetables. Cranberries are one of the most important sources of flavonoids that have a strong antioxidant and anti-inflammatory capacities. Thus, consumption of cranberries or their related products could be of importance not only in the maintenance of health but also in preventing CVD. The following review will present evidences supported for the most part by clinical observations that cranberries can exert potentially healthy effects for your heart.

Postprandial variations of plasma inflammatory markers in abdominally obese men.

OBJECTIVE: Abdominal obesity is associated with a fasting proinflammatory condition. However, not much is known of the potential variations in circulating inflammatory markers after food intake. The purpose of the present study was to examine postprandial changes in plasma tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and C-reactive protein (CRP) concentrations in men and their potential associations with fat distribution and metabolic profile variables. RESEARCH METHODS AND PROCEDURES: Thirty-eight men were given a high-fat meal in the morning after an overnight fast, and TNF-alpha, IL-6, and CRP levels were measured in plasma at 0, 4, and 8 hours after the meal. Physical and metabolic profiles were also assessed for each participant. RESULTS: We observed a substantial increase in circulating IL-6 levels (p < 0.0001) after the meal. Although postprandial variations in circulating TNF-alpha levels across time failed to reach statistical significance (p = 0.02), we noted a significant decrease in plasma TNF-alpha concentrations 4 hours (-10%, p < 0.001 vs. 0 hours) after food intake. Plasma CRP levels were not affected by the fat load. We also noted that insulin-sensitive individuals displayed a less pronounced inflammatory response after food intake than insulin-resistant subjects. DISCUSSION: Results of the present study show that consumption of a high-fat meal leads to an increase in plasma IL-6 concentrations and transient decrease in circulating TNF-alpha levels in overweight men. Our results suggest a possible role of insulin resistance in the modulation of the postprandial inflammatory response, which could, in turn, contribute to worsen the state of insulin resistance.

Favourable impact of low-calorie cranberry juice consumption on plasma HDL-cholesterol concentrations in men.

A low HDL-cholesterol concentration is an independent risk factor for CVD. Studies have suggested that flavonoid consumption may be cardioprotective, and a favourable impact on circulating HDL-cholesterol concentrations has been suggested to partially explain this association. The aim of the present study was to determine the effect of consuming increasing daily doses of low-calorie cranberry juice cocktail (CJC) on the plasma lipid profile of abdominally obese men. For that purpose, thirty men (mean age 51 (SD 10) years) consumed increasing doses of CJC during three successive periods of 4 weeks (125 ml/d, 250 ml/d, 500 ml/d). Before the study and after each phase, we measured changes in physical and metabolic variables. We noted a significant increase in plasma HDL-cholesterol concentration after the consumption of 250 ml CJC/d (+8.6+/-14.0% v. 0 ml CJC/d; P<0.01), an effect that plateaued during the last phase of the study (500 ml CJC/d: +8.1+/-10.0% v. 0 ml CJC/d; P<0.0001). Multivariate analyses revealed that changes in plasma apo A-I (R(2)=48%, P<0.0001) and triacylglycerol (R(2)=16%, P<0.005) concentrations were the only variables significantly contributing to the variation in plasma HDL-cholesterol concentration noted in response to the intervention. No variation was observed in total as well as in LDL and VLDL cholesterol. The present results show that daily CJC consumption is associated with an increase in plasma HDL-cholesterol concentrations in abdominally obese men. We hypothesise that polyphenolic compounds from cranberries may be responsible for this effect, supporting the notion that the consumption of flavonoid-rich foods can be cardioprotective.

Effects of dietary factors on oxidation of low-density lipoprotein particles.

Oxidized low-density lipoproteins (ox-LDLs) appear to play a significant role in atherogenesis. In fact, circulating ox-LDL concentrations have been recognized as a risk factor for cardiovascular disease (CVD). A higher intake of some nutrients and specific food compounds such as monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs) and flavonoids have also been associated with a lower risk of CVD. These dietary factors could be associated to a lower risk of CVD through a reduction of the atherogenicity of LDL particles through limited oxidation. Therefore, the purpose of this article is to review human clinical studies that evaluated effects of dietary antioxidant vitamins, fatty acids (MUFA, PUFA) and specific flavonoid-rich foods on LDL particle oxidation and describe potential mechanisms by which dietary factors may prevent oxidation of LDL particles. Antioxidant vitamin supplements such as alpha-tocopherol and ascorbic acid as well as beta-carotene and fish-oil supplements have not been clearly demonstrated to prevent oxidation of LDL particles. Moreover, inconsistent documented effects of flavonoid-rich food such as olive oil, tea, red wine and soy on LDL particle oxidizability may be explained by difference in variety and quantity of flavonoid compounds used among studies. However, a healthy food pattern such as the Mediterranean diet, which includes a combination of antioxidant compounds and flavonoid-rich foods, appears effective to decrease LDL particle oxidizability, which may give some insight of the cardiovascular benefits associated with the Mediterranean diet.

Changes in plasma antioxidant capacity and oxidized low-density lipoprotein levels in men after short-term cranberry juice consumption.

Low-density lipoprotein (LDL) oxidation is closely implicated in the development of atherosclerotic cardiovascular disease (CVD), and thus, reducing LDL susceptibility to oxidation with antoxidants could be of importance in CVD prevention. Flavonoids, polyphenolic compounds found in a large selection of fruits and vegetables, have been characterized as having a strong antioxidant potential, and intake of flavonoid-rich foods has been related to decreased morbidity and mortality from heart disease. The present study was therefore undertaken to investigate the effect of flavonoid-rich cranberry juice supplementation on plasma lipoprotein levels and LDL oxidation. For that purpose, 21 men (age +/- SD, 38 +/- 8 years) were enrolled in a 14-day intervention and instructed to drink cranberry juice 7 mL/kg body weight per day. Physical and metabolic measures including plasma lipid and oxidized LDL (OxLDL) concentrations as well as antioxidant capacity were performed before and after the intervention. At baseline, we found that plasma OxLDL levels were significantly associated with waist circumference ( r = 0.47, P = .0296) as well as plasma triglyceride ( r = 0.68, P = .0007) and apolipoprotein B ( r = 0.91, P < .0001) concentrations. The intervention led to a reduction in plasma OxLDL levels (-9.9% +/- 17.8%, P = .0131) and increase in antioxidant capacity (+6.5% +/- 10.3%, P = .0140). However, no relationship was found between both of these changes ( r = -.01, not significant). The intervention did not result in any improvement of plasma lipoprotein-lipid or inflammatory marker concentrations. Our results show that short-term cranberry juice supplementation is associated with significant increase in plasma antioxidant capacity and reduction in circulating OxLDL concentrations. Although the physiological relevance of our observations needs to be further examined, our study supports the potential role of antioxidant-rich foods in maintaining health and preventing CVD.