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Caffeine ingestion

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https://www.readbyqxmd.com/read/28196026/caffeine-inhibits-fluid-secretion-by-interlobular-ducts-from-guinea-pig-pancreas
#1
Yuka Mochimaru, Akiko Yamamoto, Miyuki Nakakuki, Makoto Yamaguchi, Ituka Taniguchi, Hiroshi Ishiguro
OBJECTIVES: Caffeine is contained in coffee, tea, and a lot of beverages and foods. We examined the direct effects of caffeine on the physiological function of pancreatic duct cells by using interlobular duct segments isolated from guinea pig pancreas. METHODS: The rate of fluid secretion was continuously measured by monitoring the luminal volume of isolated duct segments. Changes in intracellular Ca concentration ([Ca]i) were estimated by microfluorometry in ducts loaded with fura-2...
February 14, 2017: Pancreas
https://www.readbyqxmd.com/read/28150478/effects-of-silk-peptides-administration-on-fat-utilization-over-a-whole-day-in-mice
#2
Jisu Kim, Jonghoon Park, Bokyung Kim, Chi-Ho Lee, Kiwon Lim
Purpose: The aim of the present narrative review was to consider the evidence on the timing, optimal dose and intake duration of the main dietary supplements β-alanine, nitrate, caffeine, creatine, sodium bicarbonate, carbohydrate and protein. Methods: This review article will focuses on timing, optimal dose and intake duration of main dietary supplements for consuming. Results: This paper reviewed the evidence to determine the optimal time, efficacy doses and intake duration for sports supplements verified by scientific evidence that report a performance enhancing effect in both situation of laboratory and training settings...
December 31, 2016: Journal of Exercise Nutrition & Biochemistry
https://www.readbyqxmd.com/read/28150472/timing-optimal-dose-and-intake-duration-of-dietary-supplements-with-evidence-based-use-in-sports-nutrition
#3
REVIEW
Alireza Naderi, Erick P de Oliveira, Tim N Ziegenfuss, Mark E T Willems
Purpose: The aim of the present narrative review was to consider the evidence on the timing, optimal dose and intake duration of the main dietary supplements β-alanine, nitrate, caffeine, creatine, sodium bicarbonate, carbohydrate and protein. Methods: This review article will focuses on timing, optimal dose and intake duration of main dietary supplements for consuming. Results: This paper reviewed the evidence to determine the optimal time, efficacy doses and intake duration for sports supplements verified by scientific evidence that report a performance enhancing effect in both situation of laboratory and training settings...
31, 2016: Journal of Exercise Nutrition & Biochemistry
https://www.readbyqxmd.com/read/28096758/effects-of-acute-ingestion-of-a-pre-workout-dietary-supplement-with-and-without-p-synephrine-on-resting-energy-expenditure-cognitive-function-and-exercise-performance
#4
Y Peter Jung, Conrad P Earnest, Majid Koozehchian, Elfego Galvan, Ryan Dalton, Dillon Walker, Christopher Rasmussen, Peter S Murano, Mike Greenwood, Richard B Kreider
BACKGROUND: The purpose of this study was to examine the effects of acute ingestion of a pre-workout dietary supplement (PWS) with and without p-synephrine (S) on perceptions of readiness to perform, cognitive function, exercise performance, and markers of safety. METHODS: In a randomized, double-blind, and counterbalanced manner; 25 healthy and recreationally active male and female participants ingested a flavored maltodextrin placebo (PLA), a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg) with 2 g of maltodextrin and flavoring; or, the PWS with Citrus aurantium (PWS + S) extract standardized for 30% p-synephrine (20 mg)...
2017: Journal of the International Society of Sports Nutrition
https://www.readbyqxmd.com/read/28096757/effects-of-ingesting-a-pre-workout-dietary-supplement-with-and-without-synephrine-for-8%C3%A2-weeks-on-training-adaptations-in-resistance-trained-males
#5
Y Peter Jung, Conrad P Earnest, Majid Koozehchian, Minye Cho, Nick Barringer, Dillon Walker, Christopher Rasmussen, Mike Greenwood, Peter S Murano, Richard B Kreider
BACKGROUND: The purpose of this study was to examine whether ingesting a pre-workout dietary supplement (PWS) with and without synephrine (S) during training affects training responses in resistance-trained males. METHODS: Resistance-trained males (N = 80) were randomly assigned to supplement their diet in a double-blind manner with either a flavored placebo (PLA); a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg); or, the PWS supplement with Citrus aurantium extract containing 20 mg of synephrine (PWS + S) once per day for 8-weeks during training...
2017: Journal of the International Society of Sports Nutrition
https://www.readbyqxmd.com/read/28054436/low-dose-of-caffeine-enhances-the-efficacy-of-antidepressants-in-major-depressive-disorder-and-the-underlying-neural-substrates
#6
Qing-Shan Liu, Ran Deng, Yuyan Fan, Keqin Li, Fanggang Meng, Xueli Li, Rui Liu
SCOPE: Caffeine is one of the most frequently used psychoactive substances ingested mainly via beverage or food products. Major depressive disorder is a serious and devastating psychiatric disorder. Emerging evidence indicates that caffeine enhances the antidepressant-like activity of common antidepressant drugs in rodents. However, whether joint administration of low dose of caffeine enhances the antidepressant actions in depressed patients remains unclear. METHODS AND RESULTS: A total of 95 male inpatients were assigned to three groups and were asked to take either caffeine (60, 120mg) or placebo (soymilk powder) daily for 4 weeks on the basis of their current antidepressant medications...
January 5, 2017: Molecular Nutrition & Food Research
https://www.readbyqxmd.com/read/28053881/effect-of-novel-dietary-supplement-on-metabolism-in%C3%A2-vitro-and-in%C3%A2-vivo
#7
Roger A Vaughan, Ailish C White, Jason R Beam, Nicholas P Gannon, Randi Garcia-Smith, Roy M Salgado, Marco Bisoffi, Kristina A Trujillo, Carole A Conn, Christine M Mermier
Obesity is an increasingly prevalent and preventable morbidity with multiple behavioral, surgical and pharmacological interventions currently available. Commercial dietary supplements are often advertised to stimulate metabolism and cause rapid weight and/or fat loss, although few well-controlled studies have demonstrated such effects. We describe a commercially available dietary supplement (purportedly containing caffeine, catechins, and other metabolic stimulators) on resting metabolic rate in humans, and on metabolism, mitochondrial content, and related gene expression in vitro...
January 2017: Journal of Traditional and Complementary Medicine
https://www.readbyqxmd.com/read/28050917/acute-caffeine-ingestion-on-performance-in-young-judo-athletes
#8
Camilla Astley, Diego Souza, Marcos Polito
PURPOSE: To compare the acute effect of caffeine ingestion on performance in young judo athletes. METHODS: In a randomized double-blind design, eighteen judo athletes (16.1 ± 1.4 yrs.) were evaluated on three nonconsecutive days. On the first day, the special judo fitness test (SJFT) was used as a control session. On the second day, the sample was randomly divided into two equal groups. One group received 4 mg.kg(-1) of caffeine (capsule) and the other group received a placebo...
January 4, 2017: Pediatric Exercise Science
https://www.readbyqxmd.com/read/28031026/acute-caffeine-ingestion-reduces-insulin-sensitivity-in-healthy-subjects-a-systematic-review-and-meta-analysis
#9
REVIEW
Xiuqin Shi, Wenhua Xue, Shuhong Liang, Jie Zhao, Xiaojian Zhang
BACKGROUND: According to previous meta-analyses, coffee consumption reduces the risk of type 2 diabetes mellitus. However, the underlying mechanism remains unknown. Whether caffeine, the key ingredient in coffee, has a beneficial effect on the glycemic homeostasis and the anti-diabetic effect is particularly controversial. The aim of this study was to summarize the effect of acute caffeine ingestion on insulin sensitivity in healthy men. METHODS: A comprehensive literature search for papers published before April 2016 was conducted in EMBASE, PubMed, and Cochrane Library databases...
December 28, 2016: Nutrition Journal
https://www.readbyqxmd.com/read/28011360/effects-of-peppermint-tea-consumption-on-the-activities-of-cyp1a2-cyp2a6-xanthine-oxidase-n-acetyltranferase-2-and-udp-glucuronosyltransferases-1a1-1a6-in-healthy-volunteers
#10
Elias Begas, Athanasia Tsioutsiouliti, Evangelos Kouvaras, Serkos A Haroutounian, Konstantinos M Kasiotis, Dimitrios Kouretas, Eftihia Asprodini
Peppermint leaves are widely used for the symptomatic treatment of digestive disorders. Previous studies have shown significant effects of its natural products on human enzyme activity; however, there is no study available concerning the effects of peppermint tea on metabolizing enzymes in humans. Aim of the present study was to investigate the effect of peppermint tea on CYP1A2, CYP2A6, Xanthine Oxidase (XO), N-acetyltranferase-2 (NAT2) and UDP-glucuronosyltransferases-1A1/1A6 (UGT1A1/1A6) activities in healthy subjects...
February 2017: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/28003203/methylxanthines-enhance-the-effects-of-cocoa-flavanols-on-cardiovascular-function-randomized-double-masked-controlled-studies
#11
Roberto Sansone, Javier I Ottaviani, Ana Rodriguez-Mateos, Yvonne Heinen, Dorina Noske, Jeremy P Spencer, Alan Crozier, Marc W Merx, Malte Kelm, Hagen Schroeter, Christian Heiss
BACKGROUND: Cocoa flavanol intake, especially that of (-)-epicatechin, has been linked to beneficial effects on human cardiovascular function. However, cocoa also contains the methylxanthines theobromine and caffeine, which may also affect vascular function. OBJECTIVE: We sought to determine whether an interaction between cocoa flavanols and methylxanthines exists that influences cocoa flavanol-dependent vascular effects. DESIGN: Test drinks that contained various amounts of cocoa flavanols (0-820 mg) and methylxanthines (0-220 mg), either together or individually, were consumed by healthy volunteers (n = 47) in 4 different clinical studies-3 with a randomized, double-masked crossover design and 1 with 4 parallel crossover studies...
February 2017: American Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28002684/effects-of-caffeine-on-endurance-capacity-and-psychological-state-in-young-females-and-males-exercising-in-the-heat
#12
RANDOMIZED CONTROLLED TRIAL
Silva Suvi, Saima Timpmann, Maria Tamm, Martin Aedma, Kairi Kreegipuu, Vahur Ööpik
Acute caffeine ingestion is considered effective in improving endurance capacity and psychological state. However, current knowledge is based on the findings of studies that have been conducted on male subjects mainly in temperate environmental conditions, but some physiological and psychological effects of caffeine differ between the sexes. The purpose of this study was to compare the physical performance and psychological effects of caffeine in young women and men exercising in the heat. Thirteen male and 10 female students completed 2 constant-load walks (60% of thermoneutral peak oxygen consumption on a treadmill until volitional exhaustion) in a hot-dry environment (air temperature, 42 °C; relative humidity, 20%) after caffeine (6 mg·kg(-1)) and placebo (wheat flour) ingestion in a double-blind, randomly assigned, crossover manner...
January 2017: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
https://www.readbyqxmd.com/read/28002181/effects-of-caffeine-ingestion-on-skill-performance-during-an-international-female-rugby-sevens-competition
#13
Javier Portillo, Juan Del Coso, Javier Abián-Vicén
The aim of this study was to establish the effects of a caffeine-containing energy drink on skills and technical performance during a match in female elite rugby sevens players. On two non-consecutive days of a friendly tournament, sixteen women from the Spanish national rugby-sevens team (mean age = 23±2 yr) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After sixty minutes for caffeine absorption, participants played three rugby sevens matches against another national team...
December 8, 2016: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/27983733/caffeine-intake-is-associated-with-pupil-dilation-and-enhanced-accommodation
#14
S Abokyi, J Owusu-Mensah, K A Osei
PurposeIt is purported that caffeine, an autonomic stimulant, affects visual performance. This study sought to assess whether caffeine intake was associated with changes in pupil size and/or amplitude of accommodation.Patients and methodsA double-masked, crossover study was conducted in 50 healthy subjects of age range 19 to 25 years. Subjects were randomized to treatments such that subjects consumed either 250 mg caffeine drink or vehicle on separate days. Amplitude of accommodation was measured by the push-up technique, and pupil size using a millimeter ruler fixed to a slit lamp biomicroscope in dim illumination (5 lux)...
December 16, 2016: Eye
https://www.readbyqxmd.com/read/27930447/carbohydrate-and-caffeine-improves-high-intensity-running-of-elite-rugby-league-interchange-players-during-simulated-match-play
#15
Jon S Clarke, Jamie Highton, Graeme L Close, Craig Twist
The study examined the effects of carbohydrate and caffeine ingestion on simulated rugby league interchange performance. Eight male elite rugby league forwards completed two trials of a rugby league simulation protocol for interchange players seven days apart in a randomized crossover design, ingesting either carbohydrate (CHO; 40 g·h-1) or carbohydrate and caffeine (CHO-C) (40 g·h-1 + 3 mg·kg-1) drink. Movement characteristics, heart rate, ratings of perceived exertion (RPE), and countermovement jump height (CMJ) were measured during the protocol...
November 19, 2016: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/27895607/caffeine-enhances-memory-performance-in-young-adults-during-their-non-optimal-time-of-day
#16
Stephanie M Sherman, Timothy P Buckley, Elsa Baena, Lee Ryan
Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated), college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1). During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not implicit memory. Caffeine did not alter memory performance in the afternoon...
2016: Frontiers in Psychology
https://www.readbyqxmd.com/read/27894020/the-anatomical-mummies-of-mombello-detection-of-cocaine-nicotine-and-caffeine-in-the-hair-of-psychiatric-patients-of-the-early-20th-century
#17
Frank Musshoff, Helena Fels, Alberto Carli, Dario Piombino-Mascali
The Mombello Psychiatric Hospital in Limbiate, near Milan, replaced the old Senavra Hospital as the Psychiatric Hospital for the Province of Milan in the 19th century. During the early 20th century, bodies of several Mombello patients were dissected and preserved by Giuseppe Paravicini, an anatomist who operated within the asylum. The aim of the present study was to examine and memorialize this important assemblage. To this end, we were allowed to sample the head hair of six such preparations for toxicological analysis...
November 14, 2016: Forensic Science International
https://www.readbyqxmd.com/read/27882605/placebo-in-sports-nutrition-a-proof-of-principle-study-involving-caffeine-supplementation
#18
B Saunders, L F de Oliveira, R P da Silva, V de Salles Painelli, L S Gonçalves, G Yamaguchi, T Mutti, E Maciel, H Roschel, G G Artioli, B Gualano
We investigated the effects of supplement identification on exercise performance with caffeine supplementation. Forty-two trained cyclists (age 37 ± 8 years, body mass [BM] 74.3 ± 8.4 kg, height 1.76 ± 0.06 m, maximum oxygen uptake 50.0 ± 6.8 mL/kg/min) performed a ~30 min cycling time-trial 1 h following either 6 mg/kgBM caffeine (CAF) or placebo (PLA) supplementation and one control (CON) session without supplementation. Participants identified which supplement they believed they had ingested ("caffeine", "placebo", "don't know") pre- and post-exercise...
November 23, 2016: Scandinavian Journal of Medicine & Science in Sports
https://www.readbyqxmd.com/read/27864638/effects-of-caffeine-on-neuromuscular-fatigue-and-performance-during-high-intensity-cycling%C3%A2-exercise-in-moderate-hypoxia
#19
Bruno P C Smirmaul, Antonio Carlos de Moraes, Luca Angius, Samuele M Marcora
PURPOSE: To investigate the effects of caffeine on performance, neuromuscular fatigue and perception of effort during high-intensity cycling exercise in moderate hypoxia. METHODS: Seven adult male participants firstly underwent an incremental exercise test on a cycle ergometer in conditions of acute normobaric hypoxia (fraction inspired oxygen = 0.15) to establish peak power output (PPO). In the following two visits, they performed a time to exhaustion test (78 ± 3% PPO) in the same hypoxic conditions after caffeine ingestion (4 mg kg(-1)) and one after placebo ingestion in a double-blind, randomized, counterbalanced cross-over design...
November 18, 2016: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/27851893/caffeine-influences-cadence-at-lower-but-not-higher-intensity-rpe-regulated-cycling
#20
J Matt Green, Alyssa Olenick, Caroline Eastep, Lee Winchester
: Caffeine blunts RPE estimations but effects on selected cycling cadence are unclear. PURPOSE: This study examined influence of caffeine on cycling cadence with intensities prescribed at RPE 4 and 7 (OMNI Scale). METHODS: College-aged (20.5±2.0y) male and female volunteers (n=15) (VO2 peak=40.3±4.0,) completed a maximal cycling test followed by trials where they adjusted cadence (CAD) (clamped resistances) to produce overall feelings equivalent to RPE 4 (RPE4) and RPE 7 (RPE7) (10min each) following caffeine (CAF) (6mg·kg(-1)·min(-1)) and placebo (PLA) (counterbalanced) ingestion...
February 1, 2017: Physiology & Behavior
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