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Dietetics, Nutrition and Biological Sciences

Permanent URI for this collectionhttps://eresearch.qmu.ac.uk/handle/20.500.12289/23

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Start date: 2000Has files: No

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    The influence of moderate red wine consumption on antioxidant status and indices of oxidative stress associated with CHD in healthy volunteers
    (Cambridge University Press, 2007-03-08) Tsang, Catherine; Higgins, Siobhan; Duthie, Garry G.; Duthie, Susan J.; Howie, Moira; Mullen, William; Lean, Michael E. J.; Crozier, Alan
    The effects of moderate red wine consumption on the antioxidant status and indices of lipid peroxidation and oxidative stress associated with CHD were investigated. A randomised, controlled study was performed with twenty free-living healthy volunteers. Subjects in the red wine group consumed 375 ml red wine daily for 2 weeks. We measured the total concentration of phenolics and analysed the individual phenolics in the wine and plasma by HPLC with tandem MS. The antioxidant capacity of plasma was measured with electron spin resonance spectroscopy while homocysteine and fasting plasma lipids were also determined. The production of conjugated dienes and thiobarbituric acid-reactive substances (TBARS) were measured in Cu-oxidised LDL. Plasma total phenolic concentrations increased significantly after 2 weeks of daily red wine consumption (P≤0·001) and trace levels of metabolites, mainly glucuronides and methyl glucuronides of (+)-catechin and (−)-epicatechin, were detected in the plasma of the red wine group. These flavan-3-ol metabolites were not detected in plasma from the control group. The maximum concentrations of conjugated dienes and TBARS in Cu-oxidised LDL were reduced (P≤0·05) and HDL cholesterol concentrations increased (P≤0·05) following red wine consumption. The findings from the present study provide some evidence for potential protective effects of moderate consumption of red wine in healthy volunteers.
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    The absorption, metabolism and excretion of flavan-3-ols and procyanidins following the ingestion of a grape seed extract by rats
    (Cambridge University Press, 2007-03-08) Tsang, Catherine; Auger, Cyril; Mullen, William; Bornet, Aurélie; Rouanet, Jean-Max; Crozier, Alan; Teissedre, Pierre-Louis
    Rats were fed a grape seed extract (GSE) containing (+)-catechin, (−)-epicatechin and dimers, trimers, tetramers and polymeric procyanidins. Liver, kidney, brain and gastrointestinal (GI) tract together with plasma, urine and faeces were collected over a 24 h period and their flavan-3-ol content was analysed by HPLC with tandem mass spectrometry and diode array detection. Small amounts of the GSE flavan-3-ols moved out of the stomach and into the duodenum/jejunum, and to a greater extent the ileum 1 h after ingestion, and into the caecum after 2 h with relatively small amounts being detected in the colon after 3 h. The GI tract contained the parent GSE flavan-3-ols and procyanidins with only trace amounts of metabolites and there were no indications that proanthocyanidins were depolymerised in the GI tract releasing monomeric flavan-3-ols. Plasma contained exclusively catechin glucuronides and methylated glucuronide metabolites which were also detected in the liver and kidneys. These metabolites were also present in urine together with sulphated metabolites and low amounts of the procyanidin dimers B1, B2, B3 and B4 as well as the trimer C2 and an unknown GSE trimer. The amounts of (+)-catechin and (−)-epicatechin metabolites excreted in urine relative to the quantity of the monomers ingested were 27 and 36 %, respectively, after 24 h. This is similar to the levels of urinary excretion reported to occur by other investigators after feeding (−)-epicatechin to rats and provides further, albeit indirect, evidence that the procyanidin oligomers in the GSE were not depolymerised to monomers to any extent after ingestion. No convincing analytical data were obtained for the presence of flavan-3-ol metabolites in the brain.
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    The effect of green-coffee-bean extract rich in chlorogenic acid on antioxidant status of healthy human volunteers
    (Cambridge University Press, 2010-01) Almoosawi, Suzana; Tsang, Catherine; Davidson, Isobel M; Fyfe, Lorna
    Several studies have linked consumption of green-coffee-bean extract (GCBE) rich in chlorogenic acid (CGA) with reduced blood pressure(Reference Watanabe, Arai and Mitsui1–Reference Ochiai, Jokura and Suzuki3). It is hypothesised that increased antioxidant activity could be one of the underlying mechanisms by which GCBE reduces blood pressure. To test this hypothesis a GCBE preparation rich in CGA was assessed by three extraction methods for antioxidant activity. In vivo antioxidant activity was also determined in a group of healthy volunteers. The phenolic content of GCBE, as determined by the Folin-Ciocalteu method, varied greatly between the ethanolic acidified water (0.2% (v/v) formic acid) and acetonitrile extract (acetonitrile–water containing 0.2% (v/v) formic acid; 50:50, v/v): 123 (sd 0.23), 131 (sd 0.66) and 211 (sd 0.51) mg gallic acid equivalents (GAE)/g extract respectively. Similar findings were observed with the Fe3+-reducing ability of plasma (FRAP) assay, wherein the acetonitrile extract exhibited a stronger Fe3+-reducing ability than the ethanolic extract (0.067 mmol/g extract v. 0.048 mmol/g extract). The 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) radical-scavenging activity of the ethanolic extract of GCBE was 70.4% at 50 μm as compared with ascorbic acid (86.1% inhibition at 50 μm) and GAE (82.2% at 50 μm). To examine in vivo antioxidant properties of GCBE thirteen healthy volunteers (age 36 (sd 11) years, BMI 28 (sd 2.5) kg/m2) consumed 200 mg GCBE containing 90 mg CGA twice daily for 2 weeks. In vivo antioxidant activity was determined using the Folin-Ciocalteu method and FRAP. There was a significant correlation between urinary polyphenols excretion as determined by the Folin-Ciocalteu method and FRAP (0.664, P<0.0001). However no significant increase in urinary antioxidant activity was observed (total phenolics: 173.2 (sd 137.8) mg GAE/g creatinine v. 175.20 (sd 115.7) mg GAE/g creatinine, P>0.05; FRAP: 2.07 (sd 0.9) mmol Fe2+/g creatinine v. 1.56 (sd 0.7) mmol Fe2+/g creatinine, P>0.05). Systolic blood pressure decreased from 119 (sd 10.5) to 114 (sd 9.1) mmHg (P=0.05) following the 2-week treatment. In conclusion, green coffee bean extract has a high antioxidant activity. However, no changes in antioxidant activity are observed in urine. This finding is consistent with previous findings of poor antioxidant activity of hippuric acid, the main urinary metabolite of chlorogenic acid(Reference Olthof, Hollman and Buijsman4). Further research is required to identify the mechanism(s) of reduction in blood pressure. The antioxidant activity of plasma should also be determined.
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    PP431 ANTIOXIDANT POTENTIAL OF PAEDIATRIC TUBE FEEDS
    (Elsevier, 2010-09-29) Mckenzie, Jane M.; Tsang, Catherine
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    Effect of a tomato-rich diet on markers of cardiovascular disease risk in moderately overweight, disease-free, middle-aged adults: a randomized controlled trial
    (Elsevier, 2012-04-04) Thies, Frank; Masson, Lindsey F; Rudd, Amelia; Vaughan, Nicholas; Tsang, Catherine; Brittenden, Julie; Simpson, William G; Duthie, Susan; Horgan, Graham W; Duthie, Garry
    Background: Cardiovascular disease (CVD) is a major cause of mortality in the United Kingdom. Epidemiologic studies suggest that consumption of tomato-based foods may lower CVD risk. Such potential benefits have been ascribed in part to high concentrations of lycopene in the tomatoes. However, these findings have not yet been validated by comprehensive intervention trials. Objective: The aim of this study was to conduct a single-blind, randomized controlled intervention trial with healthy middle-aged volunteers to assess whether the consumption of tomato-based foods affects recognized biomarkers of CVD risk. Design: After a 4-wk run-in period with a low-tomato diet, 225 volunteers (94 men and 131 women) aged 40–65 y were randomly assigned into 1 of 3 dietary intervention groups and asked to consume a control diet (low in tomato-based foods), a high-tomato-based diet, or a control diet supplemented with lycopene capsules (10 mg/d) for 12 wk. Blood samples were collected at baseline, at 6 wk, and after the intervention and were analyzed for carotenoid and lipid profiles and inflammatory markers. Blood pressure, weight, and arterial stiffness were also measured. Dietary intake was also determined during the intervention. Results: None of the systemic markers (inflammatory markers, markers of insulin resistance and sensitivity) changed significantly after the dietary intervention. Moreover, lipid concentrations and arterial stiffness were also unaffected by the interventions. Conclusion: These data indicate that a relatively high daily consumption of tomato-based products (equivalent to 32–50 mg lycopene/d) or lycopene supplements (10 mg/d) is ineffective at reducing conventional CVD risk markers in moderately overweight, healthy, middle-aged individuals. This trial was registered at isrctn.org as ISRCTN34203810.
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    Encapsulation of ascorbic acid promotes the reduction of Maillard reaction products in UHT milk
    (Royal Society of Chemistry, 2016-05-17) Troise, Antonio Dario; Vitiello, Daniele; Tsang, Catherine; Fiore, Alberto
    The presence of amino groups and carbonyls renders fortified milk with ascorbic acid particularly susceptible to the reduction of available lysine and to the formation of Maillard reaction products (MRPs), as Nε-(carboxyethyl)-L-lysine (CEL), Nε-(carboxymethyl)-L-lysine (CML), Amadori products (APs) and off-flavors. A novel approach was proposed to control the Maillard reaction (MR) in fortified milk: ascorbic acid was encapsulated in a lipid coating and the effects were tested after a lab scale UHT treatment. Encapsulation promoted a delayed release of ascorbic acid and a reduction in the formation of MRPs. Total lysine increased up to 45% in milk with encapsulated ascorbic acid, while reductions in CML, CEL and furosine ranged from 10% to 53% compared with control samples. The effects were also investigated towards the formation of amide-AGEs (advanced glycation end products) by high resolution mass spectrometry (HRMS) revealing that several mechanisms coincide with the MR in the presence of ascorbic acid.
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    Anthocyanin-rich Potato Improves Cardiovascular Risk Factors in Healthy Human Adults
    (2017) Tsang, Catherine; Almoosawi, S; Smail, Nacer Foudil; Al-Dujaili, Emad
    Arterial stiffness is an emerging risk factor for cardiovascular disease (CVD), and dietary polyphenols, particularly anthocyanins, may play an important role in mediating vascular tone. The present single-blind randomised cross-over placebo controlled study investigated the effect of consumption of an anthocyanin-rich potato, Purple Majesty (PM) in 14 healthy male and female adults. Participants consumed 200 g of cooked PM containing 114 mg anthocyanins, or placebo (Osprey) with negligible anthocyanin content for 14 days, separated by a 1-week washout period. Non-invasive assessment of vascular tone (arterial stiffness) by pulse wave velocity (PWV) was determined in addition to systolic (SBP) and diastolic blood pressure (DBP), high density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides, glucose, insulin resistance (HOMA-IR) and c-reactive protein (CRP). Arterial stiffness was significantly reduced (p=0.001) following PM consumption. There were no significant changes with any other clinical parameter measured, and no changes were observed following placebo. PM contained higher levels of total phenolics, total anthocyanins and antioxidant capacity and daily consumption of PM over 14 days was well tolerated by participants. The findings from this study suggest improved vascular tone following daily consumption of PM and inclusion in the diet could provide a rich and valuable source of anthocyanins.
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    A meta-analysis of cumin (Cuminum cyminim L.) consumption on metabolic and anthropometric indices in overweight and type 2 diabetics
    (Elsevier, 2018-03-23) Jafarnejad, Sadegh; Tsang, Catherine; Taghizadeh, Mohsen; Asemi, Zatollah; Keshavarz, Seyed Ali
    Objective To conduct a systematic review, including meta-analysis, of published randomised controlled trials (RCTs) of cumin to determine the effect on anthropometric and metabolic indices in overweight and/or type 2 diabetics, relative to controls. Methods Studies were identified by a search of electronic databases before December 2017. Combined and stratified analyses were used. Results Seven trials were identified, and data from 412 subjects were included. Pooled analysis showed improvements in bodyweight, body mass index (BMI) and fasting blood glucose (FBG) by −1.74 kg, −0.67 kg/m2 and −17.82 mg/dL respectively. Significant findings were also observed in triglycerides (TG) [WMD: −21.23 (95% CI: −37.64 to −4.82; P < 0.001, I2 = 92%)] and HDL-c (high-density lipoprotein cholesterol) [WMD: 4.16 (95%CI: 3.30, 5.01; P < 0.001, I2 = 82%)] following cumin intake. No changes were found in controls. Conclusions Cumin improves anthropometric and metabolic indices in overweight and/or type 2 diabetic subjects. The changes were related to the clinical condition and quality assessment.
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    Effect of cinnamon (Cinnamomum Zeylanicum) supplementation on serum C-reactive protein concentrations: A meta-analysis and systematic review
    (Elsevier, 2018-12-07) Vallianou, Natalia; Tsang, Catherine; Taghizadeh, Mohsen; Davoodvandi, Amirhossein; Jafarnejad, Sadegh
    Objective: The effect of cinnamon (Cinnamomum Zeylanicum) on serum C-reactive protein (CRP), an acute phase protein commonly used as a marker of inflammation, is uncertain. Therefore, the objective of the present study was to conduct a systematic review and meta-analysis of published randomised controlled trials (RCTs) of cinnamon to determine the effect on levels of serum CRP, relative to controls. Design: Studies were identified by a search of electronic databases including PubMed, Cochrane Library, Google Scholar and Scopus before August 2018. Combined and stratified analyses were used. Weighted mean differences (WMD) and its 95% confidence interval were estimated for net change in serum CRP by using random-effects model. The heterogeneity of meta-analysis was assessed by χ2 and I2 test. Results: Six studies were identified, and data from 285 participants were included. Pooled analysis showed significant reductions in serum CRP (WMD: −0.81 mg/L, 95% CI: −1.36 to −0.26, p = 0.004), with significant heterogeneity between selected studies. Improvements in sub-group analysis were observed when baseline CRP levels were greater than 3 mg/dL, and in trials of >12 weeks duration. Doses <1500 mg/day and ≥1500 mg/day were effective in lowering serum CRP (WMD: −0.56 mg/dL, 95% CI: −1.01 to -0.10, p = 0.02 and WMD: −2.13 mg/dL, 95% CI: −4.08 to −0.19, p = 0.03), respectively, with significantly reduced heterogeneity in trials with lower doses of cinnamon <1500 mg/day (test for heterogeneity: P = 0.22 and I2 = 33%). No changes were found in controls. Conclusion: Cinnamon supplementation improves levels of serum CRP, particularly in chronic conditions, where basal CRP levels are raised. Further well-designed studies are warranted to confirm or not the above-mentioned findings.