Effects of a beverage rich in (poly)phenols on established and novel risk markers for vascular disease in medically uncomplicated overweight or obese subjects: A four week randomized placebo-controlled trial.

OBJECTIVE: To determine if (poly)phenols alter cardiovascular risk factors, we assessed the potential of a high (poly)phenol beverage drink, rich in hydroxycinnamates and flavonoids, to modify vascular function in middle aged, overweight or obese subjects without medical co-morbidity in a randomized placebo controlled pilot study. METHODS: Randomly assigned active 250 ml beverages containing 361 mg of (poly)phenols and 120 mg of vitamin C or placebo (no polyphenol/vitamin C) were taken twice daily for 4 weeks. Both beverages contained 40 kcals/250 ml. The primary end-points were pulse wave velocity (PWV) and cutaneous microvascular responses to sodium nitroprusside (SNP) and acetyl choline (ACh) laser doppler iontophoresis. A range of established and novel plasma markers were also measured. RESULTS: Twenty subjects received active beverage and 19 placebo; all completed the study. There was no difference in cutaneous vascular response to either SNP or ACh with mean group differences (logΔ area under perfusion curve) of 0.30 (-0.65, 1.26) and 0.35 (-0.11, 0.81) respectively. Nor was there evidence of a change in log PWV with a mean group difference of 0.029 m/s (-0.042, 0.10). No significant differences were seen in plasma leptin, apolipoproteins, cystatin C, insulin, adiponectin, CRP, ICAM-1, E-Selectin or t-PA, but IL-6 increased in active versus placebo recipients (0.32 vs - 0.18 pg/ml; p=0.010). CONCLUSION: There was no evidence for a short-term beneficial effect of (poly)phenol intervention on microcutaneous vascular response or pulse wave velocity, and no evidence for a benefit on established or novel risk factors in overweight or obese subjects. Our results do not support a short-term benefit of (poly)phenol supplementation on cardiometabolic risk. REGISTRATION: Clinical Trials.gov (NCT00795834).

Chronic administration of a microencapsulated probiotic enhances the bioavailability of orange juice flavanones in humans.

Orange juice (OJ) flavanones are bioactive polyphenols that are absorbed principally in the large intestine. Ingestion of probiotics has been associated with favorable changes in the colonic microflora. The present study examined the acute and chronic effects of orally administered Bifidobacterium longum R0175 on the colonic microflora and bioavailability of OJ flavanones in healthy volunteers. In an acute study volunteers drank OJ with and without the microencapsulated probiotic, whereas the chronic effects were examined when OJ was consumed after daily supplementation with the probiotic over 4 weeks. Bioavailability, assessed by 0-24h urinary excretion, was similar when OJ was consumed with and without acute probiotic intake. Hesperetin-O-glucuronides, naringenin-O-glucuronides, and hesperetin-3'-O-sulfate were the main urinary flavanone metabolites. The overall urinary excretion of these metabolites after OJ ingestion and acute probiotic intake corresponded to 22% of intake, whereas excretion of key colon-derived phenolic and aromatic acids was equivalent to 21% of the ingested OJ (poly)phenols. Acute OJ consumption after chronic probiotic intake over 4 weeks resulted in the excretion of 27% of flavanone intake, and excretion of selected phenolic acids also increased significantly to 43% of (poly)phenol intake, corresponding to an overall bioavailability of 70%. Neither the probiotic bacterial profiles of stools nor the stool moisture, weight, pH, or levels of short-chain fatty acids and phenols differed significantly between treatments. These findings highlight the positive effect of chronic, but not acute, intake of microencapsulated B. longum R0175 on the bioavailability of OJ flavanones.

In vitro colonic catabolism of orange juice (poly)phenols.

SCOPE: The role of colonic microbiota in the breakdown of hesperetin, naringenin, and ferulic acid, compounds found as glycosides in orange juice, was investigated using an in vitro fermentation model. METHODS AND RESULTS: Test compounds were incubated with human fecal slurries cultured under anaerobic conditions, and the production of phenolic acid catabolites were monitored by GC-MS and HPLC-MS(2) . Hesperetin was converted to 3-(3'-hydroxy-4'-methoxyphenyl)propionic acid, 3-(3',4'-dihydroxyphenyl)propionic acid, and 3-(3'-hydroxyphenyl)propionic acid while 3-(phenyl)propionic acid was the major end product derived from naringenin. The data obtained are compared to our previously published data on urinary excretion of phenolic and aromatic acids after acute orange juice consumption (Pereira-Caro et al. Am. J. Clin. Nutr. 2014, 100, 1385-1391). Catabolism pathways are proposed for events occurring in the colon and those taking place postabsorption into the circulatory system with particular reference to the excretion of 3-(3'-hydroxy-4'-methoxyphenyl)hydracrylic acid, which is not formed in fecal incubations. Ferulic acid was also degraded by the colonic microflora being converted principally to 3-(3'-methoxy-4'-hydroxyphenyl)propionic acid, a phenolic acid that appears in urine after orange juice consumption. CONCLUSION: The study provides novel information on the potential involvement of the colonic microbiota in the overall bioavailability of orange juice (poly)phenols through the production of phenylpropionic acids and subsequent hepatic conversions that lead to hippuric acid and its hydroxylated analogues.

Orange juice (poly)phenols are highly bioavailable in humans.

BACKGROUND: We assessed the bioavailability of orange juice (poly)phenols by monitoring urinary flavanone metabolites and ring fission catabolites produced by the action of the colonic microbiota. OBJECTIVE: Our objective was to identify and quantify metabolites and catabolites excreted in urine 0-24 h after the acute ingestion of a (poly)phenol-rich orange juice by 12 volunteers. DESIGN: Twelve volunteers [6 men and 6 women; body mass index (in kg/m(2)): 23.9-37.2] consumed a low (poly)phenol diet for 2 d before first drinking 250 mL pulp-enriched orange juice, which contained 584 µmol (poly)phenols of which 537 µmol were flavanones, and after a 2-wk washout, the procedure was repeated, and a placebo drink was consumed. Urine collected for a 24-h period was analyzed qualitatively and quantitatively by using high-performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-mass spectrometry (GC-MS). RESULTS: A total of 14 metabolites were identified and quantified in urine by using HPLC-MS after orange juice intake. Hesperetin-O-glucuronides, naringenin-O-glucuronides, and hesperetin-3'-O-sulfate were the main metabolites. The overall urinary excretion of flavanone metabolites corresponded to 16% of the intake of 584 µmol (poly)phenols. The GC-MS analysis revealed that 8 urinary catabolites were also excreted in significantly higher quantities after orange juice consumption. These catabolites were 3-(3'-methoxy-4'-hydroxyphenyl)propionic acid, 3-(3'-hydroxy-4'-methoxyphenyl)propionic acid, 3-(3'-hydroxy-4'-methoxyphenyl)hydracrylic acid, 3-(3'-hydroxyphenyl)hydracrylic acid, 3'-methoxy-4'-hydroxyphenylacetic acid, hippuric acid, 3'-hydroxyhippuric acid, and 4'-hydroxyhippuric acid. These aromatic acids originated from the colonic microbiota-mediated breakdown of orange juice (poly)phenols and were excreted in amounts equivalent to 88% of (poly)phenol intake. When combined with the 16% excretion of metabolites, this percentage raised the overall urinary excretion to ∼ 100% of intake. CONCLUSIONS: When colon-derived phenolic catabolites are included with flavanone glucuronide and sulfate metabolites, orange juice (poly)phenols are much-more bioavailable than previously envisaged. In vitro and ex vivo studies on mechanisms underlying the potential protective effects of orange juice consumption should use in vivo metabolites and catabolites detected in this investigation at physiologic concentrations. The trial was registered at BioMed Central Ltd (www.controlledtrials.com) as ISRCTN04271658.

Low/no calorie sweetened beverage consumption in the National Weight Control Registry.

OBJECTIVE: The aim of this cross-sectional study was to evaluate prevalence of and strategies behind low/no calorie sweetened beverage (LNCSB) consumption in successful weight loss maintainers. METHODS: An online survey was administered to 434 members of the National Weight Control Registry (NWCR, individuals who have lost ≥13.6 kg and maintained weight loss for > 1 year). RESULTS: While few participants (10%) consume sugar-sweetened beverages on a regular basis, 53% regularly consume LNCSB. The top five reasons for choosing LNCSB were for taste (54%), to satisfy thirst (40%), part of routine (27%), to reduce calories (22%) and to go with meals (21%). The majority who consume LNCSB (78%) felt they helped control total calorie intake. Many participants considered changing patterns of beverage consumption to be very important in weight loss (42%) and maintenance (40%). Increasing water was by far the most common strategy, followed by reducing regular calorie beverages. CONCLUSIONS: Regular consumption of LNCSB is common in successful weight loss maintainers for various reasons including helping individuals to limit total energy intake. Changing beverage consumption patterns was felt to be very important for weight loss and maintenance by a substantial percentage of successful weight loss maintainers in the NWCR.

Consumption of mixed fruit-juice drink and vitamin C reduces postprandial stress induced by a high fat meal in healthy overweight subjects.

Postprandial stress induced by acute consumption of meals with a high fat content results in an increase of markers of cardiometabolic risk. Repeated acute dietary stress may induce a persistent low-grade inflammation, playing a role in the pathogenesis of functional gut diseases. This may cause an impairment of the complex immune response of the gastrointestinal mucosa, which results in a breakdown of oral tolerance. We investigated the effect of ingestion of a fruit-juice drink (FJD) composed by multiple fruit juice and extracts, green tea extracts and vitamin C on postprandial stress induced by a High Fat Meal (HFM) in healthy overweight subjects. Following a double blind, placebo controlled, cross-over design, 15 healthy overweight subjects were randomized to a HFM providing 1334 Kcal (55% fat, 30% carbohydrates and 15% proteins) in combination with 500 mL of a placebo drink (HFM-P) or a fruit-juice drink (HFM-FJD). Ingestion of HFM-P led to an increase in circulating levels of cholesterol, triglycerides, glucose, insulin, TNF-α and IL-6. Ingestion of HFM-FJD significantly reduced plasma levels of cholesterol and triglycerides, decreasing inflammatory response mediated by TNF-α and IL-6. Ingestion of a fruit-juice drink reduce markers of postprandial stress induced by a HFM.

Findings from an online behavioural weight management programme provided with or without a fortified diet beverage.

The present multi-centre randomised weight-loss trial evaluated the efficacy of a low-intensity 12-week online behavioural modification programme, with or without a fortified diet beverage using a 2 × 2 factorial design. A total of 572 participants were randomised to: (1) an online basic lifestyle information (OBLI) intervention, consisting of one online informational class about tips for weight management; (2) an online behavioural weight management (OBWM) intervention, entailing 12 weekly online classes focused on weight-loss behaviour modification; (3) an OBLI intervention plus a fortified diet cola beverage (BEV) containing green tea extract (total catechin 167 mg), soluble fibre dextrin (10 g) and caffeine (100 mg) (OBLI+BEV); (4) OBWM+BEV. Assessments included height, weight, dual-energy X-ray absorptiometry-derived body composition, and waist circumference (WC). Attrition was 15·7 %. Intention-to-treat (ITT) models demonstrated a main effect for type of Internet programme, with those assigned to the OBWM condition losing significantly more weight (F= 7·174; P= 0·008) and fat mass (F= 4·491; P= 0·035) than those assigned to the OBLI condition. However, there was no significant main effect for the OBWM condition on body fat percentage (F= 2·906; P= 0·089) or WC (F= 3·351; P= 0·068), and no significant main effect for beverage use or significant interactions between factors in ITT models. A 12-week, low-intensity behaviourally based online programme produced a greater weight loss than a basic information website. The addition of a fortified diet beverage had no additional impact.

Bioavailability of dietary (poly)phenols: a study with ileostomists to discriminate between absorption in small and large intestine.

A feeding study was carried out in which six healthy ileostomists ingested a juice drink containing a diversity of dietary (poly)phenols derived from green tea, apples, grapes and citrus fruit. Ileal fluid and urine collected at intervals over the ensuing 24 h period were then analysed by HPLC-MS. Urinary excretions were compared with results obtained in an earlier study in which the juice drink was ingested by ten healthy control subjects with an intact colon. Some polyphenol components, such as (epi)catechins and (epi)gallocatechin(s), were excreted in urine in similar amounts in ileostomists and subjects with an intact colon, demonstrating that absorption took place principally in the small intestine. In the urine of ileostomists, there were reduced levels of other constituents, including hesperetin-7-O-rutinoside, 5-O-caffeoylquinic acid and dihydrochalcones, indicating their absorption in both the small and large intestine. Ileal fluid analysis revealed that even when absorption occurred in the small intestine, in subjects with a functioning colon a substantial proportion of the ingested components still pass from the small into the large intestine, where they may be either absorbed before or after catabolism by colonic bacteria.

Bioavailability of multiple components following acute ingestion of a polyphenol-rich juice drink.

A healthy diet involves eating fruit and vegetables on a daily basis, the benefits of which are in part linked to the ingestion of bioactive compounds including polyphenols. As a convenient means of delivering additional polyphenols to the diet, a polyphenol-rich (P-R) juice drink was prepared and the bioavailability of its diverse spectrum of constituents investigated. Ten human volunteers followed a low-flavonoid diet for 2 days before drinking 350 mL of the P-R beverage. Plasma and urine were collected for 24 h and analyzed by HPLC-PDA-MS. The plasma pharmacokinetics and recoveries of urinary metabolites of flavan-3-ols, flavanones, dihydrochalcones and 5-O-caffeoylquinic acid, both in terms of their identity and quantity, were, in most instances, not markedly different to those reported in other feeding studies with green tea, orange juice, apple cider and coffee. This indicates that the combination of polyphenolic compounds in the P-R beverage are absorbed and excreted to a similar extent whether fed individually or together in a single beverage. It is concluded that the P-R beverage can deliver the intended blend of bioavailable polyphenols, which would normally require consumption of several different plant-derived foods.

Identification of metabolites in human plasma and urine after consumption of a polyphenol-rich juice drink.

A polyphenol-rich (P-R) juice drink was developed as a potential approach to increase intake of dietary polyphenols. Analysis of the beverage by HPLC with PDA, fluorescence, and MS detection facilitated the identification/partial identification of 40 flavonoids and related phenolic compounds. The main constituents were (-)-epigallocatechin and other green tea flavan-3-ols, phloretin-2'-O-glucoside, gallic acid, hesperetin-7-O-rutinoside, 5-O-caffeoylquinic acid, and procyanidins, with trace levels of several flavonols and purple grape juice anthocyanins also being present. Healthy human subjects (n = 10) consumed 350 mL of the P-R juice drink, after which plasma and urine samples were collected over a 0-24 h period. HPLC-MS analysis identified 13 metabolites in plasma and a further 20 in urine. Qualitatively, the profiles of the glucuronide, sulfated, and methylated metabolites were very similar to those detected in earlier investigations when the main components in the juice drink were consumed separately in feeding studies with coffee, green tea, orange juice, and apple cider.

A low-calorie beverage supplemented with low-viscosity pectin reduces energy intake at a subsequent meal.

The addition of fiber to foods and beverages has been linked with greater satiety and reduced energy intakes at the next meal. However, measures of satiety can be influenced by the time interval between beverage consumption and the next meal. The objective of this study was to determine how the time interval between consumption and a subsequent test meal impacts the satiating power of a low-calorie beverage supplemented with low-viscosity pectin fiber. Forty-two participants (20 men, 22 women) each participated in 4 study sessions. Study preloads were 2 low-calorie beverages (355 mL, 8 kcal) containing either 0 g fiber (no fiber) or 8 g low-viscosity fiber (added fiber). These preloads were consumed either 90 min before lunch or 15 min before lunch. Every 15 min, participants rated hunger, desire to eat, fullness, and thirst using 100-mm visual analogue scales. A test lunch was served and plate waste was measured. Beverages with added fiber reduced energy intakes at lunch relative to those without fiber. A short delay (15 min) between beverage consumption and a subsequent meal was associated with higher satiety ratings and reduced energy intakes, regardless of fiber content. The addition of low-viscosity pectin to low-calorie beverages reduced energy intakes at the next meal, presenting a possible tool for intake regulation. A short time interval between consumption of a low-calorie beverage and a meal also increased satiety and decreased food intake, reflecting the short-lived effect of volume.

In vivo regulation of phenylalanine hydroxylation to tyrosine, studied using enrichment in apoB-100.

Phenylalanine hydroxylation is necessary for the conversion of phenylalanine to tyrosine and disposal of excess phenylalanine. Studies of in vivo regulation of phenylalanine hydroxylation suffer from the lack of a method to determine intrahepatocyte enrichment of phenylalanine and tyrosine. apoB-100, a hepatic export protein, is synthesized from intrahepatocyte amino acids. We designed an in vivo multi-isotope study, [(15)N]phenylalanine and [2H2]tyrosine to determine rates of phenylalanine hydroxylation from plasma enrichments in free amino acids and apoB-100. For independent verification of apoB-100 as a reflection of enrichment in the intrahepatocyte pool, [1-(13)C]lysine was used as an indicator amino acid (IAA) to measure in vivo changes in protein synthesis in response to tyrosine supplementation. Adult men (n = 6) were fed an amino acid-based diet with low phenylalanine (9 mg.kg(-1).day(-1), 4.54 mumol.kg(-1).,h(-1)) and seven graded intakes of tyrosine from 2.5 (deficient) to 12.5 (excess) mg.kg(-1).day(-1). Gas chromatography-quadrupole mass spectrometry did not detect any tracer in apoB-100 tyrosine. A new and more sensitive method to measure label enrichment in proteins using isotope ratio mass spectrometry demonstrated that phenylalanine hydroxylation measured in apoB-100 decreased linearly in response to increasing tyrosine intake and reached a break point at 6.8 mg.kg(-1).day(-1). IAA oxidation decreased with increased tyrosine intake and reached a break point at 6.0 mg.kg(-1).day(-1). We conclude: apoB-100 is an accurate and useful measure of changes in phenylalanine hydroxylation; the synthesis of tyrosine via phenylalanine hydroxylation is regulated to meet the needs for protein synthesis; and that plasma phenylalanine does not reflect changes in protein synthesis.