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Oliver M. Shannon

Bio: Oliver M. Shannon is an academic researcher from Newcastle University. The author has contributed to research in topics: Medicine & Dementia. The author has an hindex of 14, co-authored 46 publications receiving 488 citations. Previous affiliations of Oliver M. Shannon include Leeds Beckett University & University of Bath.

Papers published on a yearly basis

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Journal ArticleDOI
TL;DR: It is suggested that BRJ improves physiological function and exercise performance, but not cognitive function, at simulated moderate and very-high altitude.
Abstract: Purpose: Nitric oxide (NO) bioavailability is reduced during acute altitude exposure, contributing towards the decline in physiological and cognitive function in this environment. This study evaluated the effects of nitrate (NO3-) supplementation on NO bioavailability, physiological and cognitive function, and exercise performance at moderate and very-high simulated altitude. Methods: Ten males (mean (SD): VO2max: 60.9 (10.1) ml·kg-1·min-1) rested and performed exercise twice at moderate (~14.0 % O2; ~3000 m) and twice at very-high (~11.7% O2; ~4300 m) simulated altitude. Participants ingested either 140 ml concentrated NO3--rich (BRJ; ~12.5 mmol NO3-) or NO3--deplete (PLA; 0.01 mmol NO3-) beetroot juice 2 hours before each trial. Participants rested for 45 minutes in normobaric hypoxia prior to completing an exercise task. Exercise comprised a 45 minute walk at 30 % VO2max and a 3 km time-trial (TT), both conducted on a treadmill at a 10 % gradient whilst carrying a 10 kg backpack to simulate altitude hiking. Plasma nitrite concentration ([NO2-]), peripheral oxygen saturation (SpO2), pulmonary oxygen uptake (VO2), muscle and cerebral oxygenation, and cognitive function were measured throughout. Results: Pre-exercise plasma [NO2-] was significantly elevated in BRJ compared with PLA (p = 0.001). Pulmonary VO2 was reduced (p = 0.020), and SpO2 was elevated (p = 0.005) during steady-state exercise in BRJ compared with PLA, with similar effects at both altitudes. BRJ supplementation enhanced 3 km TT performance relative to PLA by 3.8 % (1653.9 (261.3) vs. 1718.7 (213.0) s) and 4.2 % (1809.8 (262.0) vs. 1889.1 (203.9) s) at 3000 m and 4300 m, respectively (p = 0.019). Oxygenation of the gastrocnemius was elevated during the TT consequent to BRJ (p = 0.011). The number of false alarms during the Rapid Visual Information Processing Task tended to be lower with BRJ compared with PLA prior to altitude exposure (p = 0.056). Performance in all other cognitive tasks did not differ significantly between BRJ and PLA at any measurement point (p ≥ 0.141). Conclusion: This study suggests that BRJ improves physiological function and exercise performance, but not cognitive function, at simulated moderate and very-high altitude.

69 citations

Journal ArticleDOI
TL;DR: The findings suggest that BRJ might be ergogenic during shorter distance TTs which allow for a high work rate, but not during longerdistance TTs, completed at a lower work rate.
Abstract: This study evaluated the effects of dietary nitrate (NO3 −) supplementation on physiological functioning and exercise performance in trained runners/triathletes conducting short and longer-distance treadmill running time-trials (TT). Eight trained male runners or triathletes completed four exercise performance tests comprising a 10 min warm up followed by either a 1500 or 10,000 m treadmill TT. Exercise performance tests were preceded 3 h before the exercise by supplementation with either 140 ml concentrated nitrate-rich (~12.5 mmol nitrate) (BRJ) or nitrate-deplete (~0.01 mmol nitrate) (PLA) beetroot juice. BRJ supplementation significantly elevated plasma [NO2 −] (P < 0.05). Resting blood pressure and exercise $$\dot{\text{V}}{{\text{O}}_{\text{2}}}$$ were not significantly different between BRJ and PLA (P > 0.05). However, post-exercise blood [lactate] was significantly greater in BRJ following the 1500 m TT (6.6 ± 1.2 vs. 6.1 ± 1.5 mM; P 0.05). Performance in the 1500 m TT was significantly faster in BRJ vs. PLA (319.6 ± 36.2 vs. 325.7 ± 38.8 s; P 0.05). Acute BRJ supplementation significantly enhanced 1500 m, but not 10,000 m TT performance. These findings suggest that BRJ might be ergogenic during shorter distance TTs which allow for a high work rate, but not during longer distance TTs, completed at a lower work rate.

54 citations

Journal ArticleDOI
TL;DR: Evidence is provided that the MedDiet as a whole, or individual elements of this dietary pattern, may influence each hallmark positively—effects which may contribute to the beneficial effects of this Dietary pattern on age-related disease risk and longevity.
Abstract: Ageing is a multifactorial process associated with reduced function and increased risk of morbidity and mortality. Recently, nine cellular and molecular hallmarks of ageing have been identified, which characterise the ageing process, and collectively, may be key determinants of the ageing trajectory. These include genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion and altered intercellular communication. Healthier dietary patterns reduce the risk of age-related diseases and increase longevity and may influence positively one or more of these hallmarks. The Mediterranean dietary pattern (MedDiet) is a plant-based eating pattern that was typical of countries such as Greece, Spain, and Italy pre-globalisation of the food system and which is associated with better health during ageing. Here we review the potential effects of a MedDiet on each of the nine hallmarks of ageing, and provide evidence that the MedDiet as a whole, or individual elements of this dietary pattern, may influence each hallmark positively—effects which may contribute to the beneficial effects of this dietary pattern on age-related disease risk and longevity. We also highlight potential avenues for future research.

54 citations

Journal ArticleDOI
TL;DR: Findings suggests that a high nitrate dose in the form of a BRJ supplement may improve running performance in individuals with a range of aerobic fitness levels conducting moderate and high-intensity exercise in a normobaric hypoxic environment.

47 citations


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01 Nov 2004
TL;DR: Ghrelin infusion increased food intake in obese as well as lean subjects as discussed by the authors, and increased palatability of food in the obese group only (mean increase 36.6±9.4%, P<0.01 in both cases.)
Abstract: OBJECTIVE:To investigate whether effects on food intake are seen in obese subjects receiving exogenous administration of ghrelin.DESIGN:Randomised, double-blind, placebo-controlled study of intravenous ghrelin at doses 1 pmol/kg/min and 5 pmol/kg/min.SUBJECTS:In all, 12 healthy lean subjects (mean body mass index (BMI) 20.5±0.17 kg/m2) and 12 healthy overweight and obese subjects (mean BMI 31.9±1.02 kg/m2).MEASUREMENTS:Food intake, appetite and palatability of food, ghrelin and other obesity-related hormones, growth hormone.RESULTS:Low-dose infusion of ghrelin increased ad libitum energy intake at a buffet meal in the obese group only (mean increase 36.6±9.4%, P<0.01.) High-dose ghrelin infusion increased energy intake in both groups (mean increase 20.1±10.6% in the lean and 70.1±15.5% in the obese, P<0.01 in both cases.) Ghrelin infusion increased palatability of food in the obese group.CONCLUSION:Ghrelin increases food intake in obese as well as lean subjects. Obese people are sensitive to the appetite-stimulating effects of ghrelin and inhibition of circulating ghrelin may be a useful therapeutic target in the treatment of obesity.

351 citations

Journal ArticleDOI
28 Aug 2020-Biology
TL;DR: Traditional medicine performed a good clinical practice and is showing a bright future in the therapy of diabetes mellitus, and some new bioactive drugs isolated from plants showed antidiabetic activity with more efficacy than oral hypoglycemic agents used in clinical therapy.
Abstract: Natural products, including organisms (plants, animals, or microorganisms) have been shown to possess health benefits for animals and humans. According to the estimation of the World Health Organization, in developing countries, 80% of the population has still depended on traditional medicines or folk medicines which are mostly prepared from the plant for prevention or treatment diseases. Traditional medicine from plant extracts has proved to be more affordable, clinically effective and relatively less adverse effects than modern drugs. Literature shows that the attention on the application of phytochemical constituents of medicinal plants in the pharmaceutical industry has increased significantly. Plant-derived secondary metabolites are small molecules or macromolecules biosynthesized in plants including steroids, alkaloids, phenolic, lignans, carbohydrates and glycosides, etc. that possess a diversity of biological properties beneficial to humans, such as their antiallergic, anticancer, antimicrobial, anti-inflammatory, antidiabetic and antioxidant activities Diabetes mellitus is a chronic disease result of metabolic disorders in pancreas β-cells that have hyperglycemia. Hyperglycemia can be caused by a deficiency of insulin production by pancreatic (Type 1 diabetes mellitus) or insufficiency of insulin production in the face of insulin resistance (Type 2 diabetes mellitus). The current medications of diabetes mellitus focus on controlling and lowering blood glucose levels in the vessel to a normal level. However, most modern drugs have many side effects causing some serious medical problems during a period of treating. Therefore, traditional medicines have been used for a long time and play an important role as alternative medicines. Moreover, during the past few years, some of the new bioactive drugs isolated from plants showed antidiabetic activity with more efficacy than oral hypoglycemic agents used in clinical therapy. Traditional medicine performed a good clinical practice and is showing a bright future in the therapy of diabetes mellitus. World Health Organization has pointed out this prevention of diabetes and its complications is not only a major challenge for the future, but essential if health for all is to be attained. Therefore, this paper briefly reviews active compounds, and pharmacological effects of some popular plants which have been widely used in diabetic treatment. Morphological data from V-herb database of each species was also included for plant identification.

122 citations

01 Jan 2011
TL;DR: In this paper, the effect of increasing exercise intensity on the magnitude and location of any changes in electrocortical current density was investigated on a cycle ergometer, and the results indicated that the combined active EEG/LORETA method allows for the recording of brain cortical activity during complex movements and incremental exercise.
Abstract: While the effects of exercise on brain cortical activity from pre-to post-exercise have been thoroughly evaluated, few studies have investigated the change in activity during exercise. As such, it is not clear to what extent changes in exercise intensity influence brain cortical activity. Furthermore, due to the difficulty in using brain-imaging methods during complex whole-body movements like cycling, it is unclear to what extent the activity in specific brain areas is altered with incremental exercise intensity over time. Latterly, active electroencephalography (EEG) electrodes combined with source localization methods allow for the assessment of brain activity, measured as EEG current density, within specific cortical regions. The present study aimed to investigate the application of this method during exercise on a cycle ergometer, and to investigate the effect of increasing exercise intensity on the magnitude and location of any changes in electrocortical current density. Subjects performed an incremental cycle ergometer test until subjective exhaustion. Current density of the EEG recordings during each test stage, as well as before and after exercise, was determined. Spatial changes in current density were localized using low-resolution brain electromagnetic tomography (LORETA) to three regions of interest; the primary motor cortex, primary sensory cortex and prefrontal cortex, and were expressed relative to current density within the local lobe. It was demonstrated that the relative current density of the primary motor cortex was intensified with increasing exercise intensity, whereas activity of the primary sensory cortex and that of the prefrontal cortex were not altered with exercise. The results indicate that the combined active EEG/LORETA method allows for the recording of brain cortical activity during complex movements and incremental exercise. These findings indicate that primary motor cortex activity is elevated with incremental exercise intensity during a whole-body movement, like cycling.

85 citations

Journal ArticleDOI
TL;DR: The MedDiet showed a general preventive effect, which was reproduced to varying degrees for certain intermediate cardiovascular outcomes such as blood pressure, lipids, obesity, metabolic syndrome and diabetes, and benefits were also found for several types of cancer, brain function, and mortality.

75 citations