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1.
Biol Sport ; 41(2): 201-208, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38524830

ABSTRACT

There is limited data on the vitamin D status of UK-based professional academy footballers. Therefore, the objective of this study was to report total 25(OH)D, free 25(OH)D and free 1, 25(OH)2D at the end of the winter (March) and summer periods (October) in a cohort (n = 27) of professional academy footballers in northern England. Blood samples were collected to measure total 25(OH)D, parathyroid hormone, vitamin D binding protein, albumin and calcium. Free 25(OH)D and 1, 25(OH)2D were calculated. Dietary vitamin D intake and retrospective summer sunlight exposure were also collected. At the end of winter, 2/27 (7.4%) players were vitamin D deficient (25(OH)D < 30 nmol/l) and 11/27 (40.7%) were insufficient (25(OH)D > 30 nmol/l < 50 nmol/l). By the end of summer, none were deficient but 3/14 (21.4%) were still insufficient. Median total 25(OH)D (82.2 nmol/l [IQR: 50.3-90.2] vs. 54.2 nmol/l [IQR: 36.8-71.9]; P = .02), free 25(OH)D (25.8 pmol/l [IQR: 15.1-33.1] vs. 13.2 pmol/l [IQR: 9.0-14.9]; P = .005) and free 1, 25(OH)2D (389 fmol/l [IQR: 209-594] vs. 212 fmol/l [IQR: 108-278]; P = .034) were significantly higher at the end of summer than the end of winter. At the end of winter, free 25(OH)D was lower (P = .003) in those vitamin D insufficient (8.8 pmol/l [IQR: 5.5-11.8]) vs. sufficient (13.7 pmol/l [IQR: 12.0-17.0]). There was a high prevalence of vitamin D insufficiency at the end of the winter. Free 25(OH)D was also lower at the winter timepoint and in players that were insufficient vs. sufficient.

2.
Eur J Nutr ; 2024 Feb 24.
Article in English | MEDLINE | ID: mdl-38400919

ABSTRACT

PURPOSE: The purpose of this study was to determine whether caffeine gum improves the performance of recreational runners completing parkruns (weekly, 5 km, mass participant running events). METHODS: Thirty-six recreational runners (M = 31, F = 5; age 33.7 ± 10.7 y; BMI 23.1 ± 2.4 kg/m2) capable of running 5 km in < 25 min were recruited to a study at the Sheffield Hallam parkrun, UK. Runners were block randomized into one of three double-blind, placebo-controlled, cross-over intervention trials with caffeine gum as the treatment (n = 6 per intervention trial) or into one of three non-intervention trials that ran concurrently with the intervention trials (n = 6 per non-intervention trial). Changes in conditions across different parkruns were adjusted for using data from the non-intervention trials. Runners in the randomized cross-over intervention trials chewed gum supplying 300 mg of caffeine or a placebo gum for 5 min, starting 30 min before each parkrun. RESULTS: Caffeine gum improved 5 km parkrun performance by a mean of 17.28 s (95% CI 4.19, 30.37; P = 0.01). Adjustment for environmental conditions using data from the non-intervention trials attenuated the statistical significance (P = 0.04). Caffeine gum also decreased RPE by 1.21 (95% CI 0.30, 2.13; P = 0·01) units relative to placebo. CONCLUSIONS: A 300 mg dose of caffeine supplied in chewing gum improved the performance of recreational runners completing 5 km parkruns by an average of 17 s. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov: NCT02473575 before recruitment commenced.

3.
Public Health Nutr ; 26(10): 2014-2025, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37577941

ABSTRACT

OBJECTIVE: To assess the alignment of YouTube® videos providing dietary recommendations for gout with evidence-based guidelines targeted at the United Kingdom (UK) population and to establish their quality. DESIGN: A content analysis of YouTube® videos providing dietary recommendations for gout was undertaken. Videos were categorised by video source. Each video's dietary recommendations for gout were compared with three evidence-based guidelines for gout, producing a compliance score. Presence of non-guideline advice was assessed. Understandability and actionability were evaluated using the Patient Education Material Assessment Tool for Audio-Visual Materials. Reliability was assessed using an adapted-DISCERN tool and educational quality using the Global Quality Score Five-Point Scale. Differences between video source and continuous variables were assessed using one-way Kruskal-Wallis H tests. For categorical variables, associations were investigated using Fisher-Freeman-Halton tests. SETTING: Online, May-June 2020. PARTICIPANTS: One-hundred thirty-one videos. RESULTS: Alignment of videos with evidence-based guidelines was poor (median compliance score 27 % (interquartile range 17-37 %)). Additionally, 57 % of videos contained non-guideline advice. The health professional source group had the fewest videos containing non-guideline advice, but this was only significantly lower than the naturopath group (31 % v. 81 %, P = 0·009). Almost 70 % of videos were considered poorly actionable and 50 % poorly understandable. Most videos were rated poor for reliability (79 %) and poor to generally poor for educational quality (49 %). CONCLUSIONS: YouTube® videos providing dietary recommendations for gout frequently fail to conform to evidence-based guidelines, and their educational quality, reliability, understandability and actionability are often poor. More high-quality, comprehensive, evidence-based YouTube® videos are required for UK gout patients.


Subject(s)
Diet , Gout , Humans , Reproducibility of Results , Educational Status , Nutrition Policy , Video Recording
4.
J Int Soc Sports Nutr ; 20(1): 2216678, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37227399

ABSTRACT

OBJECTIVE: This study examined the effects of oral and topical (PR Lotion; Momentous) sodium bicarbonate (NaHCO3) during a battery of team sport-specific exercise tests. METHOD: In a block randomized, crossover, double-blind, placebo-controlled design, 14 recreationally trained male team sport athletes performed a familiarization visit and three experimental trials receiving: (i) 0.3 g·kg-1 body mass (BM) NaHCO3 in capsules + placebo lotion (SB-ORAL), (ii) placebo capsules +0.9036 g·kg-1 BM PR Lotion (SB-LOTION), or (iii) placebo capsules + placebo lotion (PLA). Supplements were given ~120 min prior to the team sport-specific exercise tests: countermovement jumps (CMJ), 8 × 25 m repeated sprints and Yo-Yo Intermittent Recovery Level 2 (Yo-Yo IR2). Blood acid-base balance (pH, bicarbonate) and electrolytes (sodium, potassium) were measured throughout. Rating of perceived exertion (RPE) was recorded after each sprint and post-Yo-Yo IR2. RESULTS: Distance covered during the Yo-Yo IR2 was 21% greater for SB-ORAL compared with PLA (+94 m; p = 0.009, d = 0.64) whereas performance was only 7% greater for SB-LOTION compared with PLA (480 ± 122 vs. 449 ± 110 m; p = 0.084). Total completion time for the 8 × 25 m repeated sprint test was 1.9% faster for SB-ORAL compared with PLA (-0.61 s; p = 0.020, d = 0.38) and 2.0% faster for SB-LOTION compared with PLA (-0.64 s; p = 0.036, d = 0.34). CMJ performance was similar between treatments (p > 0.05). Blood acid-base balance and electrolytes were significantly improved for SB-ORAL compared with PLA, but no differences were observed for SB-LOTION. Compared to PLA, RPE was lower for SB-LOTION after the fifth (p = 0.036), sixth (p = 0.012), and eighth (p = 0.040) sprints and for SB-ORAL after the sixth (p = 0.039) sprint. CONCLUSIONS: Oral NaHCO3 improved 8 × 25 m repeated sprint (~2%) and Yo-Yo IR2 performance (21%). Similar improvements in repeated sprint times were observed for topical NaHCO3 (~2%), but no significant benefits were reported for Yo-Yo IR2 distance or blood acid-base balance compared to PLA. These findings suggest that PR Lotion might not be an effective delivery system for transporting NaHCO3 molecules across the skin and into systematic circulation, therefore further research is needed to elucidate the physiological mechanisms responsible for the ergogenic effects of PR Lotion.


Subject(s)
Athletic Performance , Running , Humans , Male , Athletes , Athletic Performance/physiology , Double-Blind Method , Exercise Test , Polyesters , Running/physiology , Sodium Bicarbonate/pharmacology , Team Sports , Cross-Over Studies
5.
Proc Nutr Soc ; 82(3): 370-385, 2023 09.
Article in English | MEDLINE | ID: mdl-36603854

ABSTRACT

Present food systems threaten population and environmental health. Evidence suggests reduced meat and increased plant-based food consumption would align with climate change and health promotion priorities. Accelerating this transition requires greater understanding of determinants of plant-based food choice. A thriving plant-based food industry has emerged to meet consumer demand and support dietary shift towards plant-based eating. 'Traditional' plant-based diets are low-energy density, nutrient dense, low in saturated fat and purportedly associated with health benefits. However, fast-paced contemporary lifestyles continue to fuel growing demand for meat-mimicking plant-based convenience foods which are typically ultra-processed. Processing can improve product safety and palatability and enable fortification and enrichment. However, deleterious health consequences have been associated with ultra-processing, though there is a paucity of equivocal evidence regarding the health value of novel plant-based meat alternatives (PBMAs) and their capacity to replicate the nutritional profile of meat-equivalents. Thus, despite the health halo often associated with plant-based eating, there is a strong rationale to improve consumer literacy of PBMAs. Understanding the impact of extensive processing on health effects may help to justify the use of innovative methods designed to maintain health benefits associated with particular foods and ingredients. Furthering knowledge regarding the nutritional value of novel PBMAs will increase consumer awareness and thus support informed choice. Finally, knowledge of factors influencing engagement of target consumer subgroups with such products may facilitate production of desirable, healthier PBMAs. Such evidence-based food manufacturing practice has the potential to positively influence future individual and planetary health.


Subject(s)
Diet , Meat , Humans , Food Preferences/psychology , Food Industry , Food-Processing Industry
6.
J Int Soc Sports Nutr ; 19(1): 336-348, 2022.
Article in English | MEDLINE | ID: mdl-35813849

ABSTRACT

Background: Polyphenol-rich fruit supplements are commonly consumed by recreationally active and athletic populations because of their proposed benefits to both exercise performance and recovery from prior exercise. While it has been proposed that 300 mg of polyphenols pre-exercise enhances performance and 1000 mg per day accelerates recovery from muscle damage, it is difficult for consumers to optimize their intake because the polyphenol content of most fruit supplements is not available. Therefore, this study aimed to profile the phenolic and anthocyanin content and in vitro antioxidant capacity of a range of polyphenol-rich fruit supplements on sale in the UK. Methods: Ten polyphenol-rich fruit supplements (six cherry, two pomegranate, one blueberry, and one New Zealand blackcurrant) commonly consumed by athletes were analyzed for total phenols (Folin-Ciocalteu method), total anthocyanins (pH differential method), and in vitro antioxidant capacity (ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Results: The ten tested supplements varied markedly per serving in total phenolics (range: 13.8-1007.3 mg/gallic acid equivalents), anthocyanin content (range: 0.19-40.52 mg/cyanidin-3-glucoside), ORAC (range: 150-10,072 µmol of trolox equivalents), and FRAP (range: 72-14,320 µmol of Fe2+ equivalents). Different brands of tart cherry concentrate also exhibited a marked variation in their content of total phenolics (208-591 mg/GAE), anthocyanins (1.5-23.7 mg/cyd-3-glu), and antioxidant capacity (FRAP: 1724-4489 µmol of Fe2+ equivalents; ORAC: 6015-10,072 µmol of TE per serving) per serving. Conclusion: As expected, supplements based on different fruits contained different quantities of anthocyanins and polyphenols. However, there was also a substantial variation within different brands of tart cherry supplements. Because limited compositional information is available on the labels of most fruit-based supplements, the data in this article will enable consumers to select the required volume of the ten tested supplements to meet suggested recommendations for polyphenol intake to enhance performance (300 mg pre-exercise) and accelerate recovery (1000 mg per day) from prior exercise.


Subject(s)
Anthocyanins , Sports , Antioxidants/analysis , Fruit/chemistry , Humans , Phenols/analysis , Polyphenols
7.
Nutrients ; 13(9)2021 Aug 27.
Article in English | MEDLINE | ID: mdl-34578866

ABSTRACT

Objectives. To determine the effects of consuming polyphenol-rich foods, juices and concentrates on recovery from exercise-induced muscle damage (EIMD). Method. Eligibility criteria. Randomised and quasi-randomised placebo-controlled trials with a parallel or cross-over design evaluating the effects of consuming polyphenol-rich foods, juices and concentrates on recovery from EIMD in humans. Eligible studies included at least one of the primary outcome measures: maximal isometric voluntary contraction; MIVC, delayed onset muscle soreness; DOMS, or countermovement jump; CMJ. Information sources. AMED, Cochrane Central Register of Controlled Trials, International Clinical Trials Registry Platform, PUBMED, SCOPUS (Elsevier), SPORTDiscus (EBSCO), and the UK Clinical Trials Gateway were searched from inception to September 2020. Risk of bias and quality of evidence. Risk of bias was assessed using Cochrane Risk of Bias 2 tool. Quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation framework. Synthesis of results. Random effects models were used to determine the effect of polyphenol supplementation on recovery from EIMD. Data are presented as standardised mean differences (SMD) with 95% confidence intervals (CI). Results. Included studies. Twenty-five studies were included; 15 had a parallel, and 10 had a cross-over design. A total of 527 participants (male: n = 425; female: n = 102) were included in the meta-analysis. Synthesis of results. Consumption of polyphenol-rich foods, juices and concentrates accelerated recovery of MIVC immediately post-exercise (SMD = 0.23, 95% CI 0.04, 0.42; p = 0.02; low-quality evidence), 24 h (SMD = 0.39, 95% CI 0.15, 0.62; p = 0.001; low-quality evidence), 48 h (SMD = 0.48, 95% CI 0.28, 0.67; p < 0.001; moderate-quality evidence), 72 h (SMD = 0.29, 95% CI 0.11, 0.46; p = 0.001; low-quality evidence) and 96 h post-exercise (SMD = 0.50, 95% CI 0.16, 0.83; p = 0.004; very low-quality evidence). DOMS was reduced at 24 h (SMD = -0.29, 95% CI -0.47, -0.11; p = 0.002; low-quality evidence), 48 h (SMD = -0.28, 95% CI -0.46, -0.09; p = 0.003; low-quality evidence) and 72 h post-exercise (SMD = -0.46, 95% CI -0.69, -0.24; p < 0.001; very low-quality evidence). CMJ height was greater immediately post-exercise (SMD = 0.27, 95% CI 0.01, 0.53; p = 0.04; low-quality evidence), at 24 h (SMD = 0.47, 95% CI 0.11, 0.83; p = 0.01; very low-quality evidence), 48 h (SMD = 0.58, 95% CI 0.24, 0.91; p < 0.001; very low-quality evidence) and 72 h post-exercise (SMD = 0.57, 95% CI 0.03, 1.10; p = 0.04; very low-quality evidence). Polyphenol supplementation did not alter creatine kinase, c-reactive protein, and interleukin-6 at any time points. At 72 h post-exercise, protein carbonyls (SMD = -0.64, 95% CI -1.14, -0.14; p = 0.01) were reduced. Discussion. Limitations of evidence. Risk of bias was high for 10 studies and moderate for 15. Sensitivity analyses excluding the high risk of bias studies reduced the SMDs for MIVC and DOMS, and for CMJ effects at 24 and 48 h were no longer statistically significant. Interpretation. Consuming polyphenol-rich foods, juices and concentrates accelerated recovery of muscle function while reducing muscle soreness in humans. Maximal benefit occurred 48-72 h post-exercise, however, the certainty of the evidence was moderate to very low. Supplementation could be useful when there is limited time between competitive events and impaired recovery could negatively impact performance.


Subject(s)
Diet/methods , Exercise , Fruit and Vegetable Juices , Myalgia/drug therapy , Polyphenols/pharmacology , Humans , Muscles/drug effects
8.
J Sport Health Sci ; 9(6): 645-650, 2020 12.
Article in English | MEDLINE | ID: mdl-33308815

ABSTRACT

BACKGROUND: One-hour postprandial hyperglycemia is associated with increased risk of type 2 diabetes and cardiovascular disease. Physical activity (PA) has short-term beneficial effects on post-meal glucose response. This study compared the oral glucose tolerance test results of 3 groups of people with habitually different levels of PA. METHODS: Thirty-one adults without diabetes (age 25.9 ± 6.6 years; body mass index 23.8 ± 3.8 kg/m2; mean ± SD) were recruited and divided into 3 groups based on self-reported PA volume and intensity: low activity < 30 min/day of moderate-intensity activity (n = 11), moderately active ≥ 30 min/day of moderate-intensity PA (n = 10), and very active ≥ 60 min/day of PA at high intensity (n = 10). Participants completed an oral glucose tolerance test (50 g glucose) with capillary blood samples obtained at baseline, 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min post-ingestion. RESULTS: There were no significant differences between groups for age or body fat percentage or glycated hemoglobin (p > 0.05). The groups were significantly different in terms of baseline glucose level (p = 0.003) and, marginally, for gender (p = 0.053) and BMI (p = 0.050). There was a statistically significant effect of PA on the 1-h postprandial glucose results (p = 0.029), with differences between very active and low activity groups (p = 0.008) but not between the moderately active and low activity groups (p = 0.360), even when baseline glucose level and gender differences were accounted for. For incremental area under the curve there was no significant effect of activity group once gender and body fat percentage had been accounted for (p = 0.401). Those in the low activity group took 15 min longer to reach peak glucose level than those in the very active group (p = 0.012). CONCLUSION: The results suggest that high levels of PA have a beneficial effect on postprandial blood glucose profiles when compared to low and moderate levels of activity.


Subject(s)
Blood Glucose/metabolism , Exercise/physiology , Glucose Tolerance Test , Adult , Area Under Curve , Body Mass Index , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/prevention & control , Glycated Hemoglobin/metabolism , Humans , Pilot Projects , Postprandial Period , Reference Values , Risk Factors , Sex Characteristics , Young Adult
9.
BMJ Open ; 10(3): e035108, 2020 03 15.
Article in English | MEDLINE | ID: mdl-32179562

ABSTRACT

INTRODUCTION: Gout is a painful form of inflammatory arthritis associated with several comorbidities, particularly cardiovascular disease. Cherries, which are rich in anti-inflammatory and antioxidative bioactive compounds, are proposed to be efficacious in preventing and treating gout, but recommendations to patients are conflicting. Cherry consumption has been demonstrated to lower serum urate levels and inflammation in several small studies. One observational case cross-over study reported that cherry consumption was associated with reduced risk of recurrent gout attacks. This preliminary evidence requires substantiation. The proposed randomised clinical trial aims to test the effect of consumption of tart cherry juice on risk of gout attacks. METHODS AND ANALYSIS: This 12-month, parallel, double-blind, randomised, placebo-controlled trial will recruit 120 individuals (aged 18-80 years) with a clinical diagnosis of gout who have self-reported a gout flare in the previous year. Participants will be randomly assigned to an intervention group, which will receive Montmorency tart cherry juice daily for a 12-month period, or a corresponding placebo group, which will receive a cherry-flavoured placebo drink. The primary study outcome is change in frequency of self-reported gout attacks. Secondary outcome measures include attack intensity, serum urate concentration, fractional excretion of uric acid, biomarkers of inflammation, blood lipids and other markers of cardiovascular risk. Other secondary outcome measures will be changes in physical activity and functional status. Statistical analysis will be conducted on an intention-to-treat basis. ETHICS AND DISSEMINATION: This study has been granted ethical approval by the National Research Ethics Service, Yorkshire and The Humber-Leeds West Research Ethics Committee (ref: 18/SW/0262). Results of the trial will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT03621215.


Subject(s)
Fruit and Vegetable Juices , Gout , Prunus avium , Adolescent , Adult , Aged , Aged, 80 and over , Blood Pressure , Gout/diet therapy , Gout/epidemiology , Humans , Middle Aged , Randomized Controlled Trials as Topic , Risk Assessment , Uric Acid/urine , Young Adult
10.
Nutrients ; 11(7)2019 Jul 14.
Article in English | MEDLINE | ID: mdl-31337122

ABSTRACT

Tart cherry juice (TC) and pomegranate juice (POM) have been demonstrated to reduce symptoms of exercise-induced muscle damage (EIMD), but their effectiveness has not been compared. This randomized, double-blind, parallel study compared the effects of TC and POM on markers of EIMD. Thirty-six non-resistance trained men (age 24.0 (Interquartile Range (IQR) 22.0, 33.0) years, body mass index (BMI) 25.6 ± 4.0 kg·m-2) were randomly allocated to consume 2 × 250 mL of: TC, POM, or an energy-matched fruit-flavored placebo drink twice daily for nine days. On day 5, participants undertook eccentric exercise of the elbow flexors of their non-dominant arm. Pre-exercise, immediately post-exercise, and at 24 h, 48 h, 72 h and 96 h post-exercise, maximal isometric voluntary contraction (MIVC), delayed onset muscle soreness (DOMS), creatine kinase (CK), and range of motion (ROM) were measured. The exercise protocol induced significant decreases in MIVC (p < 0.001; max decrease of 26.8%, 24 h post-exercise) and ROM (p = 0.001; max decrease of 6.8%, 72 h post-exercise) and significant increases in CK (p = 0.03; max increase 1385 U·L-1, 96 h post-exercise) and DOMS (p < 0.001; max increase of 26.9 mm, 48 h post-exercise). However, there were no statistically significant differences between treatment groups (main effect of group p > 0.05 or group x time interaction p > 0.05). These data suggest that in non-resistance trained men, neither TC nor POM enhance recovery from high-force eccentric exercise of the elbow flexors.


Subject(s)
Exercise/physiology , Fruit and Vegetable Juices , Muscle, Skeletal/drug effects , Pomegranate , Prunus avium , Adult , Double-Blind Method , Humans , Male , Myalgia , Recovery of Function/drug effects , Recovery of Function/physiology , Resistance Training/adverse effects , Young Adult
11.
Food Funct ; 10(4): 1792-1796, 2019 Apr 01.
Article in English | MEDLINE | ID: mdl-30919868

ABSTRACT

The objectives of this study were to estimate the impact of chewing time on caffeine release from gum and to understand caffeine pharmacokinetics. Caffeine release increased with chewing time (2 min < 5 min < 10 min). Furthermore, two plasma caffeine concentration peaks were observed suggesting that caffeine absorption occurs both through the oral mucosa and gastrointestinal tract. This is of practical relevance to maximise caffeine doses and to synchronise effort with peak caffeine concentration.


Subject(s)
Caffeine/pharmacokinetics , Chewing Gum/analysis , Adult , Caffeine/blood , Female , Gastrointestinal Tract/metabolism , Humans , Male , Middle Aged , Mouth Mucosa/metabolism , Young Adult
12.
J Int Soc Sports Nutr ; 15: 22, 2018.
Article in English | MEDLINE | ID: mdl-29743826

ABSTRACT

BACKGROUND: Emerging evidence indicates that fruits rich in polyphenols may attenuate exercise-induced muscle damage and associated markers of inflammation and soreness. This study was conducted to determine whether bilberry juice (BJ), which is particularly rich in polyphenols, reduces markers of muscle damage in runners completing a half marathon. METHODS: A total of 21 recreationally trained runners (age 30.9 ± 10.4 y; mass 71.6 ± 11.0 kg; M = 16; F = 5) were recruited to a single blind, randomised, placebo-controlled, parallel study. Participants were block randomised to consume 2 × 200 ml of BJ or energy-matched control drink (PLA) for 5 d before the Sheffield Half Marathon, on race day, and for 2 days post-race. Measurements of delayed onset muscle soreness (DOMS), muscle damage (creatine kinase; CK) and inflammation (c-reactive protein; CRP) were taken at baseline, pre-race, post-race, 24 h post-race and 48 h post-race. The effect of treatment on outcome measures was analysed using magnitude-based inferences based on data from 19 participants; 2 participants were excluded from the analyses because they did not provide samples for all time points. RESULTS: The half marathon caused elevations in DOMS, CRP and CK. BJ had a possibly harmful effect on DOMS from pre-race to immediately post-race (11.6%, 90% CI ± 14.7%), a likely harmful effect on CRP from pre-race to 24 h post-race (mean difference ES 0.56, 90% CI ± 0.72) and a possibly harmful effect on CRP from pre-race to 48 h post-race (ES 0.12, 90% CI ± 0.69). At other time points, the differences between the BJ and PLA groups in DOMS and CRP were unclear, possibly trivial or likely trivial. Differences in the changes in CK between BJ and PLA were unclear at every time point other than from baseline to pre-race, where BJ had a possibly harmful effect on reducing muscle damage (ES 0.23, 90% CI ± 0.57). CONCLUSION: Despite being a rich source of antioxidant and anti-inflammatory phytochemicals, BJ evoked small to moderate increases in exercise-induced DOMS and CRP. Further larger studies are required to confirm these unexpected preliminary results.


Subject(s)
Fruit and Vegetable Juices , Inflammation/blood , Myalgia/prevention & control , Running , Vaccinium myrtillus/chemistry , Adult , C-Reactive Protein/analysis , Creatine Kinase/blood , Dietary Supplements , Female , Humans , Male , Single-Blind Method , Sports Nutritional Physiological Phenomena , Young Adult
13.
Int J Sport Nutr Exerc Metab ; 28(6): 629-634, 2018 Nov 01.
Article in English | MEDLINE | ID: mdl-29584462

ABSTRACT

The purpose of this study was to determine whether caffeinated gum influenced performance in a battery of soccer-specific tests used in the assessment of performance in soccer players. In a double-blind, randomized, crossover design, 10 male university-standard soccer players (age: 19 ± 1 years, stature: 1.80 ± 0.10 m, body mass: 75.5 ± 4.8 kg) masticated a caffeinated (200 mg; caffeine) or control (0 mg; placebo) gum on two separate occasions. After a standardized warm-up, gum was chewed for 5 min and subsequently expectorated 5 min before players performed a maximal countermovement jump, a 20-m sprint test, and the Yo-Yo Intermittent Recovery Test Level 1. Performance on 20-m sprints was not different between trials (caffeine: 3.2 ± 0.3 s, placebo: 3.1 ± 0.3 s; p = .567; small effect size: d = 0.33), but caffeine did allow players to cover 2.0% more distance during Yo-Yo Intermittent Recovery Test Level 1 (caffeine: 1,754 ± 156 m, placebo: 1,719 ± 139 m; p = .016; small effect size: d = 0.24) and increase maximal countermovement jump height by 2.2% (caffeine: 47.1 ± 3.4 cm, placebo: 46.1 ± 3.2 cm; p = .008; small effect size: d = 0.30). Performance on selected physical tests (Yo-Yo Intermittent Recovery Test Level 1 and countermovement jump) was improved by the chewing of caffeinated gum in the immediate period before testing in university-standard soccer players, but the sizes of such effects were small. Such findings may have implications for the recommendations made to soccer players about to engage with subsequent exercise performance.


Subject(s)
Athletic Performance , Caffeine/pharmacology , Chewing Gum , Soccer , Athletes , Caffeine/administration & dosage , Cross-Over Studies , Double-Blind Method , Exercise Test , Humans , Male , Young Adult
14.
Cell Biochem Funct ; 33(5): 266-76, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26059489

ABSTRACT

Consumption of cruciferous vegetables may protect against colorectal cancer. Cruciferous vegetables are rich in a number of bioactive constituents including polyphenols, vitamins and glucosinolates. Before consumption, cruciferous vegetables often undergo some form of processing that reduces their content of bioactive constituents and may determine whether they exert protective effects. The aim of this study was to compare the ability of raw and blanched-frozen broccoli to protect colonocytes against DNA damage, improve antioxidant status and induce xenobiotic metabolizing enzymes (XME). Fifteen Landrace × Large White male pigs were divided into five age-matched and weight-matched sets (79 days, SD 3, and 34·7 kg, SD 3·9, respectively). Each set consisted of siblings to minimize genetic variation. Within each set, pigs received a cereal-based diet, unsupplemented (control) or supplemented with 600 g day(-1) of raw or blanched-frozen broccoli for 12 days. The consumption of raw broccoli caused a significant 27% increase in DNA damage in colonocytes (p = 0·03) relative to the control diet, whereas blanched-frozen broccoli had no significant effect. Both broccoli diets had no significant effect on plasma antioxidant status or hepatic and colonic XME. This study is the first to report that the consumption of raw broccoli can damage DNA in porcine colonocytes.


Subject(s)
Brassica/adverse effects , Colon/cytology , Colon/drug effects , DNA Damage/drug effects , Frozen Foods/adverse effects , Raw Foods/adverse effects , Animals , Brassica/enzymology , Glycoside Hydrolases/metabolism , Male , Swine , Xenobiotics/metabolism
15.
Plant Foods Hum Nutr ; 69(2): 122-7, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24570273

ABSTRACT

Tart cherries are a particularly rich source of anthocyanins. Evidence indicates that dietary intake of anthocyanins is inversely associated with arterial stiffness. We conducted an open-label randomised placebo controlled study to determine whether a tart cherry juice concentrate (Cherry Active) reduced arterial stiffness, inflammation and risk markers for cardiovascular disease in 47 healthy adults (30-50 years). Participants consumed 30 ml of cherry concentrate diluted to a volume of 250 ml with water or the same volume of an energy matched control drink daily for six weeks. Measurements were taken at baseline and at the end of the intervention. There was no effect of the intervention on arterial stiffness (P = 0.218), c-reactive protein (P = 0.220), systolic blood pressure (P = 0.163), diastolic blood pressure (P = 0.121), total cholesterol (P = 0.342) and high density lipoprotein cholesterol (P = 0.127). At the end of the intervention, plasma antioxidant capacity (measured as the ferric reducing ability of plasma (FRAP)) was significantly higher in the intervention group than the control group (P = 0.012). We conclude that a tart cherry juice concentrate rich in anthocyanins has no effect on arterial stiffness, c-reactive protein and risk markers for cardiovascular disease, but evokes a minor increase in antioxidant status in healthy adults.


Subject(s)
Beverages , Dietary Supplements , Inflammation/diet therapy , Prunus/chemistry , Vascular Stiffness/drug effects , Adult , Antioxidants/analysis , Blood Pressure/drug effects , C-Reactive Protein/analysis , Cholesterol/blood , Female , Humans , Male , Middle Aged
16.
Plant Foods Hum Nutr ; 67(3): 309-14, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22648092

ABSTRACT

Pomegranate juice may improve cardiovascular risk because of its content of antioxidant polyphenols. We conducted a randomized placebo-controlled parallel study to examine the effect of pomegranate juice on pulse wave velocity (PWV), blood pressure (BP) and plasma antioxidant status (ferric reducing power; FRAP) in 51 healthy adults (30-50 years). Participants consumed 330 ml/day of pomegranate juice or control drink for four weeks. Measurements were made at baseline and at four weeks. There was no effect of the intervention on PWV (P = 0.694) and plasma FRAP (P = 0.700). However, there was a significant fall in systolic blood pressure (-3.14 mmHg, P < 0.001), diastolic blood pressure (-2.33 mmHg P < 0.001) and mean arterial pressure (-2.60 mmHg, P < 0.001). Change in weight was similar in the two groups over the intervention period (P = 0.379). The fall in BP was not paralleled by changes in concentration of serum angiotensin converting enzyme. We conclude that pomegranate juice supplementation has benefits for BP in the short term, but has no effect on PWV. The mechanism for the effect is uncertain.


Subject(s)
Antioxidants/pharmacology , Blood Pressure/drug effects , Dietary Supplements , Fruit/chemistry , Heart Rate/drug effects , Lythraceae/chemistry , Polyphenols/pharmacology , Adult , Beverages , Female , Humans , Male , Middle Aged , Plant Preparations/pharmacology , Pulse , Reference Values
17.
Proc Nutr Soc ; 65(1): 135-44, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16441953

ABSTRACT

Cruciferous vegetables have been studied extensively for their chemoprotective effects. Although they contain many bioactive compounds, the anti-carcinogenic actions of cruciferous vegetables are commonly attributed to their content of glucosinolates. Glucosinolates are relatively biologically inert but can be hydrolysed to a range of bioactive compounds such as isothiocyanates (ITC) and indoles by the plant-based enzyme myrosinase, or less efficiently by the colonic microflora. A number of mechanisms whereby ITC and indoles may protect against colo-rectal cancer have been identified. In experimental animals cruciferous vegetables have been shown to inhibit chemically-induced colon cancer. However, the results of recent epidemiological cohort studies have been inconsistent and this disparity may reflect a lack of sensitivity of such studies. Possible explanations for the failure of epidemiological studies to detect an effect include: assessment of cruciferous vegetable intake by methods that are subject to large measurement errors; the interaction between diet and genotype has not been considered: the effect that post-harvest treatments may have on biological effects of cruciferous vegetables has not been taken into account.


Subject(s)
Anticarcinogenic Agents/pharmacology , Brassicaceae , Colorectal Neoplasms/prevention & control , Glucosinolates/metabolism , Glucosinolates/pharmacology , Apoptosis/drug effects , Brassicaceae/chemistry , Cell Division/drug effects , Food Handling/methods , Glucosinolates/administration & dosage , Glycoside Hydrolases/metabolism , Humans , Isothiocyanates/metabolism
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