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Abstract

Intake of the catechin epigallocatechin gallate and caffeine has been shown to enhance exercise-induced fat oxidation. Matcha green tea powder contains catechins and caffeine and is consumed as a drink. We examined the effect of Matcha green tea drinks on metabolic, physiological and perceived intensity responses during brisk walking. Thirteen females (age: 27±8 yr, body mass: 65±7 kg, height: 166±6 cm) volunteered. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.4±0.3 ml·kg-1·min-1). Participants completed an incremental walking protocol to establish the relationship between walking speed and oxygen uptake and individualize the walking speed at 5- or 6-MET. A randomized cross-over design was used with participants tested between day 9 and 11 of the menstrual cycle (follicular phase). Participants consumed 3 drinks (each drink made with 1 gram of Matcha premium grade, OMGTea Ltd UK) the day before, and 1 drink 2 hours before the 30-min walk at 5- (n=10) or 6-METs (walking speed: 5.8±0.4 km·h-1) with responses measured at 8-10, 18-20 and 28-30 min. Matcha had no effect on physiological and perceived intensity responses. Matcha resulted in lower respiratory exchange ratio (control: 0.84±0.04; Matcha: 0.82±0.04) (P < 0.01) and enhanced fat oxidation during a 30-min brisk walk (control: 0.31±0.10; Matcha: 0.35±0.11 g·min-1) (P < 0.01). Matcha green tea drinking can enhance exercise-induced fat oxidation in females. However, when regular brisk walking with 30-min bouts is being undertaken as part of a weight loss program, the metabolic effects of Matcha should not be overstated.
Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
Matcha green tea drinks enhance fat oxidation during brisk walking in females
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Authors: Mark Elisabeth Theodorus Willems1, Mehmet Akif Şahin2, Matthew David Cook3
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Affiliation: 1Department of Sport and Exercise Sciences, University of Chichester,
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College Lane, Chichester, PO19 6PE, United Kingdom
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2Department of Nutrition and Dietetics, Faculty of Health Sciences, Hacettepe
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University, hhiye, Ankara, Turkey
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3University of Worcester, Institute of Sport and Exercise Sciences, Henwick
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Grove, Worcester, WR2 6AJ, United Kingdom
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Running title: Matcha and exercise-induced fat oxidation
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Corresponding author: Professor Mark Willems
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Phone: +44 (0)1243 816468
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Email: m.willems@chi.ac.uk
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ABSTRACT
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Intake of the catechin epigallocatechin gallate and caffeine has been shown to enhance
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exercise-induced fat oxidation. Matcha green tea powder contains catechins and caffeine and
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is consumed as a drink. We examined the effect of Matcha green tea drinks on metabolic,
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physiological and perceived intensity responses during brisk walking. Thirteen females (age:
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27±8 yr, body mass: 65±7 kg, height: 166±6 cm) volunteered. Resting metabolic equivalent
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(1-MET) was measured using Douglas bags (1-MET: 3.4±0.3 ml·kg-1·min-1). Participants
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
completed an incremental walking protocol to establish the relationship between walking
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speed and oxygen uptake and individualize the walking speed at 5- or 6-MET. A randomized
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cross-over design was used with participants tested between day 9 and 11 of the menstrual
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cycle (follicular phase). Participants consumed 3 drinks (each drink made with 1 gram of
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Matcha premium grade, OMGTea Ltd UK) the day before, and 1 drink 2 hours before the 30-
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min walk at 5- (n=10) or 6-METs (walking speed: 5.8±0.4 km·h-1) with responses measured
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at 8-10, 18-20 and 28-30 min. Matcha had no effect on physiological and perceived intensity
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responses. Matcha resulted in lower respiratory exchange ratio (control: 0.84±0.04; Matcha:
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0.82±0.04) (P < 0.01) and enhanced fat oxidation during a 30-min brisk walk (control:
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0.31±0.10; Matcha: 0.35±0.11 g·min-1) (P < 0.01). Matcha green tea drinking can enhance
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exercise-induced fat oxidation in females. However, when regular brisk walking with 30-min
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bouts is being undertaken as part of a weight loss program, the metabolic effects of Matcha
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should not be overstated.
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Key words: catechins; health promotion; treadmill walking
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INTRODUCTION
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The polyphenol composition of green tea leaves is characterised by the flavonoid catechins
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i.e. catechin gallate, epicatechin gallate, epigallocatechin gallate, epicatechin epigallate,
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gallocatechin and gallocatechin gallate (Xu et al., 2004). Due to the processing methods of
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the leaves, green tea has a high content of catechins compared to oolong and black tea. The
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green tea components contribute to the antioxidant capacity (Peluso and Serafini, 2017), with
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epigallocatechin gallate (EGCG) considered the bioactive compound (Khan et al., 2006). The
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antioxidant capacity of green tea likely contributed to reported health benefits by regular
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intake of green tea such as a reduced risk for some cancers (Guo et al., 2017) and
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
cardiovascular and ischemic-related diseases (Pang et al., 2016). Green tea has also been
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implicated in body-weight management (Janssens et al., 2016) by promoting fat oxidation.
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EGCG is considered the bioactive compound to promote fat oxidation (Kapoor et al.,
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2017). Chronic intake of green tea extract enhanced fat oxidation during swimming (Murase
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et al., 2005) and running in mice (Murase et al., 2006). In addition, EGCG has been shown to
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reduce body weight in diet-induced obese mice (Lee et al., 2009), indicative of a change in
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energy balance. In humans, observations on fat oxidation during exercise with short term
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intake of green tea or EGCG intake were inconsistent. Randell et al (2013) did not observe
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enhanced fat oxidation during cycling at 50% of maximum power in men after 1 and 7-day
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intake with no intake on the day of testing. During 2 hr of cycling at 50% of maximum
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power, green tea extract had no effect on the respiratory exchange ratio (Eichenberger et al.,
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2009). However, Venables et al (2008) showed enhanced fat oxidation with green tea extract
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during 30-min cycling exercise at 60% of maximum oxygen uptake in men with the
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supplement taken on the day before and on the day 1 hr before testing.
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In human studies on exercise-induced fat oxidation, the delivery mode of green tea
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supplementation has been in capsule form. No studies examined the effect of traditional
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brewed green tea drinks with leaves on fat oxidation during exercise. Matcha green tea
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powder contains catechins and caffeine and when it is consumed as a drink it ensures an oral
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intake of all the green tea leaf components. In addition, the process of powdering green tea
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leaves adds to the potential beneficial effects of Matcha (Fujioka et al., 2016). Therefore, the
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intake of green tea components by Matcha drinking may be higher than brewed green tea
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without the leaf consumption and guarantees intake of water-soluble and water-insoluble
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parts (Xu et al., 2016). In mice fed a high-fat diet, Matcha intake promoted lipid metabolism
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(Xu et al., 2016). No studies have examined the effect of Matcha drinks on substrate
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oxidation during exercise in humans.
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
Regular exercise that is performed to obtain health benefits is recommended to have an
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exercise intensity between 3 and 6 metabolic equivalents i.e. 3 to 6 times the resting energy
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expenditure according to physical activity guidelines (Haskell et al., 2007). Walking is a
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popular physical activity (Paul et al., 2015) and for most people brisk walking meets intensity
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requirements (Fitzsimons et al., 2005). No studies have examined the effect of a nutritional
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ergogenic aid on substrate oxidation during brisk walking. Dietary changes and regular
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exercise may result in a negative energy balance and reduce body weight and body fat.
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Nutritional ergogenic aids could enhance these effects (Arent et al., 2017). For example, a
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decaffeinated green tea extract was associated with a decrease in body fat and enhanced fat
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oxidation during cycling (Roberts et al., 2015). Fat oxidation during brisk walking with green
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tea drinking has not been examined. According to Weiss and Anderton (2003), the
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concentration of EGCG from drinking Matcha green tea is at least 3 times the highest intake
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of EGCG compared to other green teas.
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Therefore, the aim of the present study was to examine the effect of the consumption of
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Matcha on substrate oxidation, physiological responses and perceived intensity during brisk
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walking in females.
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METHODS
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Participants
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A randomised, cross-over experimental design was used. Thirteen recreationally active
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healthy women [age: 27±8 yr, height: 166±6 cm, body mass: 65±7 kg, BMI: 23.5±2.6 kg·m-2
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(range: 19.1-30.2 eleven with 18.9 < BMI < 24.9), means±SD] volunteered and provided
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written informed consent. All participants were non-smokers. Accepted contraceptive
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methods were combined pill, diaphragm or intrauterine device. Ethics approval was obtained
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
from the University of Chichester Research Ethics Committee (ethical approval code
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1617_24).
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Experimental design and preliminary testing
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Participants visited the laboratory on three occasions between 9 and 11 o’clock in the
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morning. During the first visit, height and body mass were measured. Subsequently,
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participants rested in a chair for 30 minutes with 2 x 10 min expired air collections separated
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by 5 minutes using the Douglas bag technique to determine the oxygen consumption at rest
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(i.e. the one metabolic equivalent 1-MET) with the lowest value taken as the 1-MET.
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Subsequently, participants completed an incremental-intensity walking test on a treadmill
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(HP Cosmos Pulsar Bodycare Products UK) with 5 x 8-min stages. Starting speed was 2
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km∙h-1 with a stage increment of 1 km∙h-1 until speed reached 6 km∙h-1. During each stage,
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expired air was collected in the last 3 minutes. The incremental-intensity walking test was
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performed to determine the linear relationship between walking speed and oxygen
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consumption expressed as the metabolic equivalent. For each individual, the linear
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relationship between walking speed and metabolic equivalent (r2 = 0.9353±0.0383) was used
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to calculate the walking speed at 5- or 6-METs (i.e. moderate intensity exercise). For visits
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two and three with either having Matcha or no supplement, participants were tested in the
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follicular phase of the menstrual cycle (i.e. 9-11 days following start of the menstruation).
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Hormonal levels were not measured and determination of the follicular phase was based on
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verbal information provided by the participants. In preparation for all testing sessions,
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participants abstained from strenuous and unaccustomed exercise for 48 hours, no alcohol for
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24 hours before testing and no other caffeine-containing products on the day of testing.
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Exercise testing and supplementation
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
For the Matcha condition, participants consumed 3 x 1 gram of Matcha powder (Matcha
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premium grade OMGTea Ltd, UK) mixed with water at meal times on the day before testing.
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On the day of testing, participants consumed 1 gram of Matcha with water two hours before
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arrival and arrived following an overnight fast. The supplementation strategy was based on
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Venables et al (2008). One gram of Matcha premium grade contains 143 mg total catechins
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and 30 mg caffeine (composition data from OMGTea Ltd, UK). Before visit two, participants
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recorded their dietary intake for 48 hours and were instructed to match the same dietary
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intake 48 hours before arrival for visit three. The intake before visit three was recorded on a
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new food diary. Carbohydrate fat and protein intake and total energy intake (kJ) were
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quantified with Nutritics (Nutritics LTD Dublin Ireland).
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Participants walked on a treadmill at a speed to elicit 5- or 6-MET for 30 minutes with
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expired air collected from 8 to 10, 18 to 20 and 28 to 30 minutes with recording of heart rate
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(Polar Vantage NV Polar Electro Oy Kempele Finland) and rating of perceived exertion
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(Borg 6 to 20 scale) (Borg, 1982). Expired air was analyzed with a three-point calibrated gas
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analyser (Servomex Series 1400 gas analyser Servomex Crowborough United Kingdom) and
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volume measured (Harvard Apparatus Ltd. Edenbridge United Kingdom). Gas volumes were
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corrected to standard temperature and pressure and dry gas conditions (STPD) and calculated
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using Haldane transformation with consideration of inspired fractions of oxygen and carbon
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dioxide at the time of expired air collections. Rates of whole body fat and carbohydrate
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oxidation were calculated with equations 1 and 2 from Jeukendrup and Wallis (2005) and the
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assumption of negligible protein oxidation:
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   
  
 (1)
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    
   (2)
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Statistical analysis
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Analyses were completed using Graphpad Prism version 5.00 for Window (GraphPad
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Software, San Diego, California, USA). A power analysis indicated that a sample size of 13
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was required to allow a detection of a 15% increase in fat oxidation from a baseline value
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of fat oxidation of 0.25 g·min-1 (Dasilva et al., 2011) with a SD of 0.07 for both groups with
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a high statistical power (1−β = 0.80: 0.05 = α level). A two-way ANOVA was used to
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analyse oxygen consumption, carbon dioxide production and substrate oxidation for time
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effects with post-hoc paired samples t-tests. Means were calculated for all parameter values
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collected from 8 to 10, 18 to 20 and 28 to 30 minutes during the 30-min treadmill walk. Data
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normality was assessed with D'Agostino-Pearson normality tests. Paired samples t-tests were
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conducted to compare parameter values between control and Matcha conditions. Statistical
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significance was accepted at P < 0.05.
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RESULTS
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The 1-MET was 3.4±0.3 mL·kg-1·min-1, means±SD range: 2.93.8 ml·kg-1·min-1). There
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were no differences in absolute values of daily dietary intake parameters (i.e. carbohydrate,
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control: 182±71 g, Matcha: 157±49 g; fat, control: 67±23 g, Matcha: 72±22 g, protein,
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control: 70±43 g, Matcha: 75±35 g; total energy intake, control: 6697±2302 kJ, Matcha:
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6604±1796 kJ). Participants were low caffeine consumers (control: 48±57 mg, Matcha:
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40±45 mg).
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Matcha vs control
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Physiological responses and rating of perceived exertion
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
Participants walked in the control and Matcha condition at an individualized walking speed
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for 30 minutes with an exercise intensity of 5- or 6-MET. Ten participants walked at 5-MET
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(walking speed: 5.7±0.4 km·h-1) to avoid those participants willing to jog at the treadmill
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speed of 6-MET. For the three participants walking at 6-MET, the walking speed was 6.0±0.5
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km·h-1. Oxygen uptake (control: 18.1±2.8; Matcha: 18.1±2.8 mL·kg-1·min-1), minute
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ventilation (control: 25.9±3.3; Matcha: 25.2±3.3 L·min-1) and heart rate (control: 119±18;
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Matcha: 120±17 beats·min-1) were not different. Figure 1 shows the oxygen (A) and carbon
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dioxide (B) values over time with no time effects. Rating of perceived exertion during
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walking at an intensity of 5- or 6-MET was not different compared to the Matcha condition
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(control: 11±1; Matcha: 12±1).
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Respiratory exchange ratio and substrate oxidation
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Figure 2 shows substrate oxidation as a function of time during the 30-min walk. Time effects
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for carbohydrate oxidation showed a trend to be lower at 28-30 min compared to 8-10 min in
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the placebo condition (P = 0.07) and lower in the Matcha condition (P = 0.01) (Figure 2A).
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In the placebo condition, there was a trend for fat oxidation at 28-30 min to be higher than fat
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oxidation at 8-10 min (P = 0.06) (Figure 2B). Fat oxidation at 28-30 min was higher than fat
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oxidation at 18-20 min (P = 0.04) (Figure 2B). In the Matcha condition, fat oxidation at 28-
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30 min was higher than fat oxidation at 8-10 min (P = 0.04) and 18-20 min (P < 0.01) (Figure
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2B). The respiratory exchange ratio was 0.02 units lower in the Matcha condition (Figure 3)
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indicating a larger contribution of fat as an energy source. In the Matcha condition,
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carbohydrate oxidation was lower (control: 0.69±0.18; Matcha: 0.56±0.20 g·min-1, P < 0.05)
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(Figure 4) and fat oxidation was higher (control: 0.31±0.10; Matcha: 0.35±0.11 g·min-1, P <
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0.05) (Figure 5) over the full 30-min of the walk. The individual observations on
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carbohydrate (Figure 4) (i.e. 11 participants lower values) and fat oxidation (Figure 5) (i.e. 10
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
participants higher values) seem to indicate that the absolute changes in substrate oxidation
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were not related to the values observed in the control condition.
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4. Discussion
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With Matcha green tea drinking, polyphenol and caffeine intake occurs by whole
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consumption of the powdered green tea leaves. Previous studies on the effects of green tea on
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exercise responses used capsulated intake of green tea extract or EGCG (Dean et al., 2009;
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Eichenberger et al., 2009; Martin et al., 2014; Venables et al., 2008) or enriched canned
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drinks with green tea catechins and caffeine (Hodgson et al., 2013; Randell et al., 2013). We
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are not aware of studies on the effects on exercise responses by traditionally brewed green tea
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drinking by which the intake of catechines and caffeine is not by the consumption of green
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tea leaves. Females in our study consumed 4 normal cups of Matcha green tea in 24 hours.
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We observed an enhanced fat oxidation with Matcha green tea drinking during 30 min of
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brisk walking in females. Our observation is similar to that in a study by Venables et al
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(2008) with effects of green tea extract in enhancing fat oxidation during 30-min cycling at
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60%VO2max in males. In the study by Venables et al (2008) participants were dosed 2 times
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the day before and 1 h before testing with a green tea extract that contained in total 890 mg of
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polyphenols and 408 mg EGCG but was without caffeine. EGCG intake in the present study
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with 4 cups of Matcha green tea over a 24 hour period amounted to a total intake of 292 mg
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EGCG and 120 mg caffeine. The final intake in the present study provided 73 mg of EGCG
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and 30 mg of caffeine, whereas the dose in Venables et al (2008) was 86% higher, i.e. 136
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mg EGCG but no caffeine. It is possible that the components of Matcha provide a synergistic
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effect on exercise-induced fat oxidation. A comparison with other studies on the effects of the
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intake of green tea extract or EGCG is problematic due to differences in dosing strategy i.e.
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amounts, intake duration, intake composition, training status of participants and fed or fasted
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
status testing. For example, Martin et al (2014) did not observe an effect of green tea during
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exercise but as participants were provided with a standardized breakfast 90 min before the
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exercise test, this may have affected the observed substrate oxidation during the exercise.
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Eichenberger et al (2009) examined green tea extract effects during 2 hr cycling in endurance
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trained men cycling > 6 hours per week, and the absence of a green tea effect could be due to
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training status of the subjects. However, observations of enhanced fat oxidation in the present
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study seem to indicate that it is possible to have by a cup of Matcha an intake of essential
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catechins, e.g. EGCG, and caffeine, in amounts that cannot be achieved with a cup of
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traditional brewed green tea. The caffeine intake in our study was very small: a total of 120
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mg over 24 hours. An acute intake of 6 mg/kg of body mass of caffeine reduced the
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respiratory exchange ratio during exercise (Cruz et al., 2015). In the present study, the intake
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of 30 mg of caffeine by Matcha on the day of testing was less than 0.5 mg/kg of body mass,
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an amount for which there is no evidence for affecting exercise-induced fat oxidation.
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EGCG is considered the bioactive compound in green tea acting by inhibition of
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catechol-O-methyltransferase (i.e. COMT). In general, inhibition of COMT would reduce the
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breakdown of catecholamines and promote an internal cellular environment for enhanced fat
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oxidation. However, a study by Hodgson et al (2013) observed that 8-day intake of green tea
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extract did not enhance adrenergic stimulation during exercise. Therefore, due to the absence
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of differences in the adrenergic system with intake of green tea extract in-vivo, the inhibition
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of COMT may not be the cause for the observed enhanced fat oxidation. Alternatively,
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EGCG has been linked with activation of the transient receptor potential vanilloid type 1 (i.e.
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TRPV1) and eNOS activation (Guo et al., 2015). In addition, TRPV1 is also linked with
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eNOS activation and NO production (Yu et al., 2017). Activation of eNOS would result in
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increased production of nitric oxide and enhanced blood flow with improved delivery of free
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fatty acids. Interestingly, activation of TRPV1 was associated with enhanced fat oxidation in
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
male mice by capsiate supplementation (Haramizu et al., 2006), possible by contributing to
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functional sympatholysis during exercise (Ives et al., 2017). However, differences in both the
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metabolite profiles in bioavailability of plasma catechins in animal studies and the amount of
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catechins used to examine effects in endothelial cells (Guo et al., 2015), warrants caution to
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generalize from these findings to observations with green tea extracts or powder in humans.
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The exercise modality in the present study was walking in females with an intensity
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known to provide health benefits. In addition, females were tested during the follicular phase
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but evidence on hormonal effects on fat oxidation in females during exercise is inconsistent
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(Kanaley et al., 1992; Vaiksaar et al., 2011; Wenz et al., 1997). In addition, we had no
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objective measurement of the follicular phase by hormonal observations and cannot exclude
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that the variation in individual responses may be due to intra-individual differences in
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hormonal levels. We also did not control the physical activity status of the participants.
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Future studies may want to examine the effects of Matcha green tea drinking for longer
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duration and combined with an exercise intervention in normal weight, overweight, and obese
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individuals. In addition, future studies on nutritional interventions that enhance fat oxidation
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during exercise should address the causality of high responders. It is of interest also to
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explore in future studies whether enhanced fat oxidation by Matcha green tea would affect
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insulin sensitivity. A study by Robinson et al (2015) observed that maximal fat oxidation
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during exercise was associated with insulin sensitivity.
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In summary, Matcha green tea drinking, just 4 cups in 24 hours enhanced fat oxidation
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during brisk walking in healthy females. The composition of Matcha green tea leaves is
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sufficient for habitual Matcha drinking to provide beneficial metabolic responses during brisk
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walking. However, when regular moderate intensity exercise is undertaken as part of a weight
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loss program, the effects of Matcha should not be overstated.
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Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
Acknowledgments: Matcha premium green tea powder was provided by OMGTea Ltd
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(United Kingdom).
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REFERENCES
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Borg, G.A. (1982). Psychophysical bases of perceived exertion. Medicine & Science in
279
Sports & Exercise, 14, 377-381.
280
Cruz, R.S., de Aguiar, R.A., Turnes, T., Guglielmo, L.G., Beneke, R., & Caputo F. (2015).
281
Caffeine Affects Time to Exhaustion and Substrate Oxidation during Cycling at Maximal
282
Lactate Steady State. Nutrients, 7(7), 5254-5264.
283
Dasilva, S.G,, Guidetti, L., Buzzachera, C.F., Elsangedy, H.M., Krinski, K., De Campos,
284
W, Goss, F.L.,& Baldari, C. (2011). Gender-based differences in substrate use during
285
exercise at a self-selected pace. Journal of Strength & Conditioning Research, 25(9), 2544-
286
2551.
287
Dean, S., Braakhuis, A., & Paton C. (2009). The effects of EGCG on fat oxidation and
288
endurance performance in male cyclists. International Journal of Sport Nutrition and
289
Exercise Metabolism, 19(6), 624-644.
290
Eichenberger, P., Colombani, P.C., & Mettler, S. (2009). Effects of 3-week consumption of
291
green tea extracts on whole-body metabolism during cycling exercise in endurance-trained
292
men. International Journal for Vitamin and Nutrition Research, 79(1), 24-33.
293
Fitzsimons, C.F., Greig, C.A., Saunders, D.H., Lewis, S.H., Shenkin, S.D., Lavery, C., &
294
Young, A. (2005). Responses to walking-speed instructions: implications for health
295
promotion for older adults. Journal of Aging and Physical Activity, 13(2), 172-183.
296
Fujioka, K., Iwamoto, T., Shima, H., Tomaru, K., Saito, H., Ohtsuka, M., Yoshidome, A.,
297
Kawamura, Y., Manome, Y. (2016). The Powdering Process with a Set of Ceramic Mills for
298
Accepted version International Journal of Sports Nutrition and Exercise Metabolism, accepted 13 December 2017
Green Tea Promoted Catechin Extraction and the ROS Inhibition Effect. Molecules, 21(4),
299
474.
300
Guo, B.C., Wei, J., Su, K.H., Chiang, A.N., Zhao, J.F., Chen, H.Y., Shyue, S.K., & Lee T.S.
301
(2015). Transient receptor potential vanilloid type 1 is vital for (-)-epigallocatechin-3-gallate
302
mediated activation of endothelial nitric oxide synthase. Molecular Nutrition & Food
303
Research, 59(4), 646-657.
304
Guo, Y., Zhi, F., Chen, P., Zhao, K., Xiang, H., Mao, Q., Wang, X., & Zhang X. (2017).
305
Green tea and the risk of prostate cancer: A systematic review and meta-analysis. Medicine
306
(Baltimore), 96(13), e6426.
307
Haskell, W.L., Lee, I.M., Pate, R.R., Powell, K.E., Blair, S.N., Franklin, B.A., Macera, C.A.,
308
Heath, G.W., Thompson, P.D., & Bauman, A. (2007). Physical activity and public health:
309
updated recommendation for adults from the American College of Sports Medicine and the
310
American Heart Association. Medicine & Science in Sports & Exercise, 39(8), 1423-1434.
311
Haramizu, S., Mizunoya, W., Masuda, Y., Ohnuki, K., Watanabe, T., Yazawa, S., & Fushiki
312
T. (2006). Capsiate a nonpungent capsaicin analog increases endurance swimming capacity
313
of mice by stimulation of vanilloid receptors. Bioscience, Biotechnology, and Biochemistry,
314
70(4), 774-781.
315
Hodgson, A.B., Randell, R.K., Boon, N., Garczarek, U., Mela, D.J., Jeukendrup, A.E.,
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Jacobs, D.M. (2013). Metabolic response to green tea extract during rest and moderate-
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intensity exercise. Journal of Nutritional Biochemistry, 24(1), 325-334.
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Ives, S.J., Park, S.Y., Kwon, O.S., Gifford, J.R., Andtbacka, R.H.I., Hyngstrom, J.R., &
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Richardson, R.S. (2017). TRPV1 channels in human skeletal muscle feed arteries:
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implications for vascular function. Experimental Physiology, 102(9), 1245-1258.
321
Janssens, P.L., Hursel, R., & Westerterp-Plantenga, M.S. (2016). Nutraceuticals for body-
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weight management: The role of green tea catechins. Physiology & Behavior, 162, 83-87.
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Jeukendrup, A.E., & Wallis G.A. (2005). Measurement of substrate oxidation during exercise
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by means of gas exchange measurements. International Journal of Sports Medicine, 26 Suppl
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1, S28-S37.
326
Kanaley, J.A., Boileau, R.A., Bahr, J.A., Misner, J.E., Nelson, R.A. (1992). Substrate
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oxidation and GH responses to exercise are independent of menstrual phase and status.
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Medicine & Science in Sports & Exercise, 24(8), 873-880.
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Kapoor, M.P., Sugita, M., Fukuzawa, Y., & Okubo, T. (2017). Physiological effects of
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epigallocatechin-3-gallate (EGCG) on energy expenditure for prospective fat oxidation in
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humans: A systematic review and meta-analysis. Journal of Nutritional Biochemistry, 43, 1-
332
10.
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Khan, N., Afaq, F., Saleem, M., Ahmad, N., & Mukhtar, H. (2006). Targeting multiple
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signaling pathways by green tea polyphenol (-)-epigallocatechin-3-gallate. Cancer Research,
335
66(5), 2500-2505.
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Lee, M.S., Kim, C.T., & Kim, Y. (2009). Green tea (-)-epigallocatechin-3-gallate reduces
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body weight with regulation of multiple genes expression in adipose tissue of diet-induced
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obese mice. Annals of Nutrition and Metabolism, 54(2), 151-157.
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Lu, H., Meng, X., & Yang, C.S. (2003). Enzymology of methylation of tea catechins and
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inhibition of catechol-O-methyltransferase by (-)-epigallocatechin gallate. Drug Metabolism
341
& Disposition , 31(5), 572-579.
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Martin, B.J., Tan, R.B., Gillen, J.B., Percival, M.E., & Gibala, M.J. (2014). No effect of
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short-term green tea extract supplementation on metabolism at rest or during exercise in the
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fed state. International Journal of Sport Nutrition and Exercise Metabolism, 24(6), 656-664.
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Murase, T., Haramizu, S., Shimotoyodome, A., Nagasawa, A., & Tokimitsu, I. (2005). Green
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tea extract improves endurance capacity and increases muscle lipid oxidation in mice.
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American Journal of Physiology. Regulatory, Integrative and Comparative Physiology,
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288(3), R708-715.
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Murase, T., Haramizu, S., Shimotoyodome, A., Tokimitsu, I. & Hase, T. (2006). Green tea
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extract improves running endurance in mice by stimulating lipid utilization during exercise.
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American Journal of Physiology. Regulatory, Integrative and Comparative Physiology,
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290(6), R1550-1556.
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Pang, J., Zhang, Z., Zheng, T.Z., Bassig, B.A., Mao, C., Liu, X., Zhu, Y., Shi, K., Ge, J.,
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Yang, Y.J., Dejia-Huang Bai, M., & Peng, Y. (2016). Green tea consumption and risk of
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cardiovascular and ischemic related diseases: A meta-analysis. International Journal of
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Cardiology, 202, 967-974.
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Paul, P., Carlson, S.A., Carroll, D.D., Berrigan, D., & Fulton, J.E. (2015). Walking for
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Transportation and Leisure Among U.S. Adults--National Health Interview Survey 2010.
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Journal of Physical Activity and Health, 12 Suppl 1, S62-69.
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Peluso, I., & Serafini, M. (2017). Antioxidants from black and green tea: from dietary
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modulation of oxidative stress to pharmacological mechanisms. British Journal of
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Pharmacology, 174(11), 1195-1208.
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Randell, R.K., Hodgson, A.B., Lotito, S.B., Jacobs, D.M., Boon, N., Mela, D.J., &
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Jeukendrup, A.E. (2013). Medicine & Science in Sports & Exercise, 45(5), 883-891.
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Roberts, J.D., Weekes, J.C., & Thomas, C.H. (2015). The effect of a decaffeinated green tea
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extract formula on fat oxidation, body composition and exercise performance. Journal of the
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International Society of Sports Nutrition, 12(1), 1.
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Robinson, S.L., Hattersley, J., Frost, G.S., Chambers, E.S., & Wallis, G.A. (2015). Maximal
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fat oxidation during exercise is positively associated with 24-hour fat oxidation and insulin
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sensitivity in young, healthy men. Journal of Applied Physiology (1985), 118(11), 1415-
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1422.
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Vaiksaar, S., Jürimäe, J., Mäestu, J., Purge, P., Kalytka, S., Shakhlina, L., & Jürimäe, T.
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(2011). No effect of menstrual cycle phase on fuel oxidation during exercise in rowers.
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European Journal of Applied Physiology, 111(6), 1027-1034.
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Venables, M.C., Hulston, C.J., Cox, H.R., & Jeukendrup, A.E. (2008). Green tea extract
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ingestion fat oxidation and glucose tolerance in healthy humans. American Journal of
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Clinical Nutrition, 87(3), 778-784.
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Weiss, D.J., & Anderton, C.R. (2003). Determination of catechins in matcha green tea by
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micellar electrokinetic chromatography. Journal of Chromatography A, 1011(1-2), 173-180.
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Wenz, M., Berend, J.Z., Lynch, N.A., Chappell, S., & Hackney A.C. (1997). Substrate
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oxidation at rest and during exercise: effects of menstrual cycle phase and diet composition.
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Journal of Physiology and Pharmacology, 48(4), 851-860.
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Xu, J.Z., Yeung, S.Y., Chang, Q., Huang, Y., & Chen, Z.Y. (2004). Comparison of
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antioxidant activity and bioavailability of tea epicatechins with their epimers. British Journal
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of Nutrition 91(6), 873-881.
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Xu, P., Ying, L., Hong, G., & Wang, Y. (2016). The effects of the aqueous extract and
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residue of Matcha on the antioxidant status and lipid and glucose levels in mice fed a high-fat
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diet. Food & Function, 7(1), 294-300.
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Yu, Y.B., Su, K.H., Kou, Y.R., Guo, B.C., Lee, K.I., Wei, J., & Lee, T.S. (2017). Role of
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transient receptor potential vanilloid 1 in regulating erythropoietin-induced activation of
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endothelial nitric oxide synthase. Acta Physiologica (Oxford), 219(2), 465-477.
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speeds at 5-MET (10 participants) or 6-MET (3 participants). A, * different between time
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... Observations from in-vivo studies in humans on the effects of Matcha are limited (e.g. Dietz et al. 2017;Willems et al. 2018). Dietz et al. (2017) reported acute effects of Matcha green tea powder (4 grams) on specific attentional tasks. ...
... Dietz et al. (2017) reported acute effects of Matcha green tea powder (4 grams) on specific attentional tasks. As far as we know, Willems et al. (2018) is the only study that examined the effects of Matcha consumption and exercise-induced metabolic responses. It was observed that the drinking of four cups of Matcha (three cups the day before and 1 cup on the day of testing, each cup made up with 1 gram of Matcha) enhanced fat oxidation by 18% during brisk walking in females and lowered the respiratory exchange ratio (Willems et al. 2018). ...
... As far as we know, Willems et al. (2018) is the only study that examined the effects of Matcha consumption and exercise-induced metabolic responses. It was observed that the drinking of four cups of Matcha (three cups the day before and 1 cup on the day of testing, each cup made up with 1 gram of Matcha) enhanced fat oxidation by 18% during brisk walking in females and lowered the respiratory exchange ratio (Willems et al. 2018). The respiratory exchange ratio provides the relative contribution of carbohydrate and fat oxidation to total energy expenditure, and a lower value by an intervention is considered to be beneficial as there is more reliance of fat as a substrate. ...
Article
Artificial green tea extracts may enhance exercise-induced fat oxidation. Natural Matcha green tea consumption involves the ingestion of the powdered green tea leaves. We examined the effects of three weeks daily intake of Matcha green tea powder on substrate oxidation during moderate-intensity exercise in females. Females with a regular menstrual cycle (n = 12, age: 28 ± 10 yr, body mass: 69 ± 17 kg, height: 163 ± 6 cm) volunteered to complete an incremental walking test to determine the individual moderate exercise intensity (four metabolic equivalent) for the subsequent 30-min treadmill walk. The study had a randomized placebo-controlled cross-over design with participants tested between day 9 and 11 of the menstrual cycle (follicular phase). Participants consumed 3x1 gram capsules of Matcha premium grade, (OMGTea Ltd, UK) per day for three weeks, with the final dose (1 gram) two hours before the 30-min walk (walking speed: 5.8 ± 0.4 km·h-1). Matcha had no effect on physiological responses (e.g. heart rate, placebo: 127 ± 14; Matcha: 124 ± 14 beats·min-1, p = 0.154), but resulted in lower respiratory exchange ratio (placebo: 0.872 ± 0.040; Matcha: 0.839 ± 0.035) (p = 0.033), higher fat oxidation by 35 ± 47% (placebo: 0.21 ± 0.08; Matcha: 0.26 ± 0.06 g·min-1) (p = 0.034), and lower carbohydrate oxidation (placebo: 0.75 ± 0.21; Matcha: 0.60 ± 0.18 g·min-1) (p = 0.048) during the 30-min moderate-intensity walk. Energy expenditure was similar for both conditions. There was no significant correlation between body fat % and the absolute or relative change in Matcha-induced fat oxidation during exercise. Continuous intake of Matcha green tea effects exercise-induced metabolic responses by enhancing fat oxidation during moderate-intensity exercise in adult females, seemingly independent of body composition.
... Treadmill incline was 1%. Participants completed 5 × 8-min stages starting at 2 km·h −1 , progressing by 1 km·h −1 until a speed of 6 km·h −1 was reached [22]. In the last 3 min of each 8 min stage, expired air was collected using Douglas bags. ...
... The present study used a convenience sample of recreationally active female participants as the primary aim was to examine the effect of intake of New Zealand blackcurrant extract on walking-induced fat oxidation. In a previous study from our group, Matcha green tea drinks in females enhanced walking-induced fat oxidation by 18% [22]. It is possible that the mechanisms for enhanced exercise-induced fat oxidation by different supplementations, i.e., Matcha green tea and New Zealand blackcurrant extract, are not similar. ...
... It is possible that the mechanisms for enhanced exercise-induced fat oxidation by different supplementations, i.e., Matcha green tea and New Zealand blackcurrant extract, are not similar. The Matcha green tea study by Willems et al. [22] also had recreationally active females as participants and a follow-up study, with the measurement in another laboratory confirming even higher enhanced fat oxidation of 35% by three weeks' Matcha intake [9]. Future studies should examine the combined intake of supplementations of which single use has been shown to enhance exercise-induced fat oxidation. ...
Article
Full-text available
New Zealand blackcurrant (NZBC) extract enhanced cycling-induced fat oxidation in female endurance athletes. We examined in recreationally active females the effects of NZBC extract on physiological and metabolic responses by moderate-intensity walking and the relationship of fat oxidation changes with focus on body composition parameters. Twelve females (age: 21 ± 2 y, BMI: 23.6 ± 3.1 kg·m−2) volunteered. Bioelectrical bioimpedance analysis was used for body composition measurements. Resting metabolic equivalent (1-MET) was 3.31 ± 0.66 mL·kg−1·min−1. Participants completed an incremental walking test with oxygen uptake measurements to individualize the treadmill walking speed at 5-MET. In a randomized, double-blind, cross-over design, the 30 min morning walks were in the same phase of each participant’s menstrual cycle. No changes by NZBC extract were observed for walking-induced heart rate, minute ventilation, oxygen uptake, and carbon dioxide production. NZBC extract enhanced fat oxidation (10 responders, range: 10–66%). There was a significant correlation for changes in fat oxidation with body mass index; body fat% in legs, arms, and trunk; and a trend with fat oxidation at rest but not with body mass and habitual anthocyanin intake. The NZBC extract responsiveness of walking-induced fat oxidation is body composition-dependent and higher in young-adult females with higher body fat% in legs, arms, and trunk.
... It is presupposed that tea molecules reduce fat stores through several pathways (Huang et al. 2014, Rothenberg et al. 2018, Silvester et al. 2018, Willems et al. 2018): ...
... • they influence neuroendocrine metabolic regulators of appetite and reduce food consumption (Huang et al. 2014), • they reduce emulsion and absorption of lipids and protein in gastrointestinal system and consequently reduce calorie intake (Huang et al. 2014), • they act on gastrointestinal microbiota (lactoand bifidobacteria), which are responsible for digestion. For example, they produce short fatty acids, which increase the rate of lipid metabolism , Rothenberg et al. 2018), • they inhibit the differentiation and proliferation of preadipocytes, ), • they reduce lipid production (Huang et al. 2014), • they promote lipolysis and lipid metabolism ), • they stimulate conversion of white adipose tissue to brown, increase its oxidation, burning and expenditure of energy through heat production (Huang et al. 2014, Silvester et al. 2018, Willems et al. 2018), • they promote fecal lipid excretion (Huang et al. 2014). However, it is necessary to take into consideration that the effect of green tea and its molecules manifests only when large doses are consumed. ...
Article
This paper reviews provenance, chemical composition and properties of tea (Camelia sinensis L.) and coffee (Coffee arabica, L. and Coffea caniphora, L.), their general health effects, as well as the currently available knowledge concerning their action on fat storage, physiological mechanisms of their effects, as well as their safety and recommended dosage for treatment of obesity. Both tea and coffee possess the ability to promote health and to prevent, to mitigate and to treat numerous disorders. This ability can be partially due to presence of caffeine in both plants. Further physiological and medicinal effects could be explained by other molecules (theaflavins, catechins, their metabolites and polyphenols in tea and polyphenol chlorogenic acid in coffee). These plants and plant molecules can be efficient for prevention and treatment of numerous metabolic disorders including metabolic syndrome, cardiovascular diseases, type 2 diabetes and obesity. Both plants and their constituents can reduce fat storage through suppression of adipocyte functions, and support of gut microbiota. In addition, tea can prevent obesity via reduction of appetite, food consumption and food absorption in gastrointestinal system and through the changes in fat metabolism.
... Exercise-induced fat oxidation was reported to be increased by the consumption of caffeine, EGCG and catechin which are the key ingredients of Matcha. Consumption of 1 g of matcha in different drinks by female participants caused the increased fat oxidation, which was associated with balancing metabolic effects (Willems, Ş ahin, & Cook, 2018). Another study also reported that green tea consumption can boost the fat oxidation in resting as well as in post exercise (Gahreman, Wang, Boutcher, & Boutcher, 2015). ...
Article
Background The interest in the plant-derived healthy foods, nutraceuticals, functional foods and food supplements is increasing in recent times as potential agents in maintenance of health and the prevention and treatment of diseases. Matcha tea powder is obtained from the leaves of tea plant (Camellia sinensis (L.) Kuntze) grown under specific condition using about 90% shade. As compared to green tea, a hot water extract of tea leaves, matcha is consumed as a whole powder of leaves. Matcha powder is reported to have higher content of some bioactive components such as catechins, theanine and caffeine. In recent years, there is an increased market demand and consumption of matcha as a drink and as a component in various beverages, snacks and other food products. Scope and approach In this review, the available scientific information of the chemical constituents and their analysis and biological activities are critically analyzed. These results may help to understand current status of research on matcha and the gaps which help to guide future research related to evidence based product formulations. Key findings and conclusions Various studies have reported the difference in bioactive compounds in matcha as compared to green tea and other tea formulations. The content and composition were mostly affected by the cultivation and processing techniques. Analysis of marketed samples in various countries have shown the variable content of the bioactive compounds. Thus, there is a need for proper standardization for maintaining the quality. Matcha as a whole, its extract and compounds have shown promising biological activities in in vitro and animal studies. However, comparatively only a few clinical studies are performed, which need future attention. There should also be detailed study regarding matcha-containing foods’ formulation.
... Previous studies suggested that matcha plays an important role as an antioxidant, anticarcinogen, anti-inflammatory, and anti-hypercholesterolemia [18][19][20][21]. More relevantly, dietary matcha supplement could inhibit lipid accumulation and ameliorate metabolic damage in obese mice induced by HFD [22,23]. Matcha is a potential intervention against obesity and related NAFLD. ...
Article
Full-text available
Lately, matcha green tea has gained popularity as a beverage and food additive. It has proved to be effective in preventing obesity and related metabolic syndromes. However, the underlying mechanisms of its control effects against non-alcoholic fatty liver disease (NAFLD) are complicated and remain elusive. In the present study, we performed an in vivo experiment using male C57BL/6 mice fed with a high-fat diet and simultaneously treated with matcha for six weeks. Serum biochemical parameters, histological changes, lipid accumulation, inflammatory cytokines, and relevant indicators were examined. Dietary supplementation of matcha effectively prevented excessive accumulation of visceral and hepatic lipid, elevated blood glucose, dyslipidemia, abnormal liver function, and steatosis hepatitis. RNA sequencing analyses of differentially expressed genes in liver samples indicated that matcha treatment decreased the activity of lipid droplet-associated proteins and increased the activity of cytochrome P450 enzymes, suggesting improved metabolic capacity and liver function. The current study provided evidence for new dietary strategies based on matcha supplementation to ameliorate lipotoxicity-induced obesity and NALFD.
... In this regard, we only selected crossover experiments in which the workload used was identical in the placebo and caffeine conditions in order to isolate the effect of caffeine on the substrate oxidation effect of caffeine during exercise from its ergogenic effect. Furthermore, we excluded investigations that used caffeine-containing multi-ingredient supplements, as these supplements contain potentially active substances that may affect the ability of caffeine to shift substrate oxidation during exercise [54,55]. Finally, we set a fasting period of 5 h before exercise to assure that the intake of fat or carbohydrates did not affect caffeine's effect on substrate oxidation [24,25]. ...
Article
Full-text available
A number of previous investigations have been designed to determine the effect of acute caffeine intake on the rate of fat oxidation during exercise. However, these investigations have shown contradictory results due to the differences in the exercise protocols used or the co-ingestion of caffeine with other substances. Hence, to date, there is no consensus about the effect of caffeine on fat oxidation during exercise. The purpose of this study was to conduct a systematic review followed by a meta-analysis to establish the effect of acute intake of caffeine (ranging from 2 to 7 mg/kg of body mass) on the rate of fat oxidation during exercise. A total of 19 studies published between 1978 and 2020 were included, all of which employed crossover experimental designs in which the ingestion of caffeine was compared to a placebo. Studies were selected if the exercise intensity was consistent in the caffeine and placebo trials and if these were preceded by a fasting protocol. A subsequent meta-analysis was performed using the random effects model to calculate the standardized mean difference (SMD). The meta-analysis revealed that caffeine significantly (p = 0.008) increased the fat oxidation rate (SMD = 0.73; 95% CI = 0.19 to 1.27). This increment was consistent with a significant (p = 0.04) reduction of the respiratory exchange ratio (SMD = −0.33; 95% CI = −0.65 to −0.01) and a significant (p = 0.049) increase in the oxygen uptake (SMD = 0.23; 95% CI = 0.01 to 0.44). The results also showed that there was a dose–response effect of caffeine on the fat oxidation rate, indicating that more than 3.0 mg/kg is necessary to obtain a statistically significant effect of this stimulant on fat oxidation during exercise. Additionally, the ability of caffeine to enhance fat oxidation during exercise was higher in sedentary or untrained individuals than in trained and recreational athletes. In conclusion, pre-exercise intake of a moderate dose of caffeine may effectively increase fat utilization during aerobic exercise of submaximal intensity performed after a fasting period. However, the fitness level of the participant may modulate the magnitude of the effect of caffeine on fat oxidation during exercise.
... Garnier et al. mentioned that 16 weeks of brisk walking was more effective than baseline for increasing cardiorespiratory fitness in moderately obese postmenopausal women (Garnier et al., 2015). In addition, Willems Met & Cook (2018) reported that green tea combined with brisk walking was able to reduce the respiratory exchange ratio and enhanced fat oxidation in women. ...
... This study is in accordance with previous studies regarding the use of green tea for weight-loss. Green tea and its active component, epigallocatechin-3-gallate, decrease body weight by promoting fat oxidation and decreasing fat synthesis in clinical trials (Willems et al., 2018;Chen et al., 2016;Mielgo-Ayuso et al., 2014;Hsu et al., 2008). ...
Article
Ethnopharmacological relevance: Mexico ranks second in the world for obesity prevalence. In Mexico, obese and overweight subjects commonly seek alternative treatments for weight-loss, including the use of herbal products. Aim of the study: The main objective of this study was to evaluate the prevalence of self-medication with herbal products for weight-loss among overweight and obese subjects residing in four states (Guanajuato, San Luis Potosi, State of Mexico, and Mexico City) from central Mexico. In addition, the factors related to self-medication among patients were studied. Materials and methods: A total of 1404 overweight and obese subjects were interviewed. A chi-square test examined associations between socio-demographic and socio-economic information, and self-medication with herbal products for weight-loss. Results: The prevalence of self-medication was 42.9% among the participants who used herbal products for weight-loss. The female gender was the strongest factor (OR: 2.20 (1.75–2.77) associated with self-medication for weight-loss, followed by a low educational level (elementary and middle school) [OR: 1.80 (1.31–2.44)], and a middle-socioeconomic status [OR: 1.75 (1.21–2.52)]. The main herbal products used for weight-loss were based on: i) green tea, Camellia sinensis (12.7% of frequency), ii) aceitilla, Bidens odorata (6.6%), and iii) soybean, Glycine max (5.3%). In addition, 65% of the respondents considered herbal products ineffective for weight-loss after 6 months of use. Conclusion: Due to the high incidence of overweight and obesity in Mexico, there is a high prevalence (42.9%) of self-medication using natural products for weight-loss, particularly in women from Central Mexico. This study indicates the important need to educate patients about the harmful effects of consuming these products.
Article
Matcha (MT), the finely ground powder of green tea leaves, is increasingly used as a nutritional food ingredient due to its large content of polyphenols. In this work, rice noodles were fortified with 0, 0.5, 1.0, 1.5 and 2.0% (w/w) of MT, and assessed for in vitro starch digestibility. Addition of MT significantly (p<0.05) decreased rapidly digestible starch (74.97 to 62.59%), increased resistant starch (7.56 to 25.94%), and decreased the glycemic index (84.78 to 68.34). MT gifted the rice noodles with higher antioxidant capacity and volatiles ((E)-2-hexenal, butyl acetate, 6-methyl-5-heptan-2-one and limonene). After gastrointestinal digestion, the polyphenols retention rate was as high as 57.84%. Furthermore, CLSM revealed that MT polyphenols-starch-protein interactions could interfere with the reassociation of starch chains, leading to the formation of low-ordered crystalline structures (confirmed by DSC, XRD and FT-IR), and the formation of a dense microstructures as revealed by SEM. Thus, rice noodles were endowed with lower cooking losses, higher chewability and stretchability. This work demonstrated the potential use of MT as food ingredient to improve the nutritional properties and eating qualities of rice noodles.
Article
The present study compared the microbial population in the samples of steamed green tea and its superfine green tea powder by determining and analyzing microbial changes during ball milling, which is the key step of producing superfine green tea powder. The results showed that after ball milling the microbial counts of superfine green tea powder were dramatically decreased than steam green teas in which the total aerobic count were more than 10⁴ CFU/g in 14/19 samples. With the duration of ball milling, the microbial population of superfine green tea powder was correspondingly decreased till below 10³ CFU/g. To study the mechanism of ball milling on microbial counts’ decreasing, a mold strain was isolated, purified and identified from the samples. Subsequently, the mold strain was cultured and individually ball-milled. The results indicated that fungal cell wall was disrupted and then microbial DNA was released during the process. Moreover, microbial populations in the tea samples were negatively correlated with cell wall breakage ratio. It was suggested that the ball milling was effective strategy for controlling the microbial contamination during the processing of superfine green tea powder.
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