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Effects of Purple Tea on Muscle Hyperemia and Oxygenation, Serum Markers of Nitric Oxide Production and Muscle Damage, and Exercise Performance

Authors:
  • AxoGen, Inc.
  • Center for Applied Health Sciences (CAHS)
  • Center for Applied Health Sciences (CAHS)

Abstract and Figures

Introduction: Purple tea exhibits a unique composition of chemical constituents that may exert favorable outcomes related to recovery from muscle damage, improvements in blood flow, perfusion, and recovery. The purpose of this study was to examine the impact of a brief oral dosing period of purple tea in exercising humans after stressful, damaging exercise. Methods: Using a randomized, placebo-controlled, double-blind, crossover study design, 30 healthy men (33.5 ± 11.4 years, 178.4 ± 7.6 cm, 92.5 ± 13.3 kg) completed an eight day supplementation regimen consisting of either a maltodextrin placebo or 100 mg of purple tea extract (PurpleForce™, Oryza Oil & Fat, Ltd.) interspersed with a two week washout period. After five and eight days of supplementation, changes in muscle oxygenation, body composition, reactive hyperemia, visual analog responses, exercise performance, and muscle damage markers were assessed. Data were analyzed using mixed factorial ANOVA, t-tests with 95% confidence intervals, and effect sizes (ES). Results: Lactate dehydrogenase was significantly reduced (p = 0.04) in PT in comparison to PLA after eight days of supplementation and exercise performance challenge. In comparison to PT, arm circumference increased in PLA after five days of supplementation (p=0.04) and tended to be greater after eight days (p=0.06). Significantly greater decreases in impedance were observed in PT (p=0.02) while between-group differences in oxygen saturation post-leg extension exercise were greater in PT 30s into recovery (p=0.04) and tended to be greater 60s after recovery (p=0.06). Total bench press repetitions completed were greater in purple tea than PLA (p = 0.001). Total leg extension repetitions completed tended to be different between groups (p=0.09) while the total number of repetitions completed in purple tea increased from day five to day eight (p<0.001) with no change in PLA (p=0.37). No between-group changes were observed in the visual analog scales; however, only the PT condition experienced a significant improvement in Willingness to Exercise (p=0.02). Conclusions: Acute supplementation of PT decreased lactate dehydrogenase, a marker of muscle damage, while also improving lower body muscle endurance performance.
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2020, Volume 3 (Issue 3): 13 OPEN ACCESS
Journal of Exercise and Nutrition ISSN 2640-2572
Effects of Purple Tea on Muscle Hyperemia
and Oxygenation, Serum Markers of Nitric
Oxide Production and Muscle Damage, and
Exercise Performance
Original Research
Kyle Cesareo1, Tim Ziegenfuss1, Betsy Raub1, Jennifer Sandrock1, Hector Lopez1,2
1The Center for Applied Health Sciences, Canfield, OH USA
2Supplement Safety Solutions, Bedford, MA USA
Abstract
Introduction: Purple tea exhibits a unique composition of chemical constituents that
may exert favorable outcomes related to recovery from muscle damage,
improvements in blood flow, perfusion, and recovery. The purpose of this study was
to examine the impact of a brief oral dosing period of purple tea in exercising humans
after stressful, damaging exercise.
Methods: Using a randomized, placebo-controlled, double-blind, crossover study
design, 30 healthy men (33.5 ± 11.4 years, 178.4 ± 7.6 cm, 92.5 ± 13.3 kg) completed
an eight day supplementation regimen consisting of either a maltodextrin placebo or
100 mg of purple tea extract (PurpleForce™, Oryza Oil & Fat, Ltd.) interspersed with
a two week washout period. After five and eight days of supplementation, changes in
muscle oxygenation, body composition, reactive hyperemia, visual analog responses,
exercise performance, and muscle damage markers were assessed. Data were analyzed
using mixed factorial ANOVA, t-tests with 95% confidence intervals, and effect sizes
(ES).
Results: Lactate dehydrogenase was significantly reduced (p = 0.04) in PT in
comparison to PLA after eight days of supplementation and exercise performance
challenge. In comparison to PT, arm circumference increased in PLA after five days
of supplementation (p=0.04) and tended to be greater after eight days (p=0.06).
Significantly greater decreases in impedance were observed in PT (p=0.02) while
between-group differences in oxygen saturation post-leg extension exercise were
greater in PT 30s into recovery (p=0.04) and tended to be greater 60s after recovery
(p=0.06). Total bench press repetitions completed were greater in purple tea than PLA
(p = 0.001). Total leg extension repetitions completed tended to be different between
groups (p=0.09) while the total number of repetitions completed in purple tea
increased from day five to day eight (p<0.001) with no change in PLA (p=0.37). No
between-group changes were observed in the visual analog scales; however, only the
PT condition experienced a significant improvement in Willingness to Exercise
(p=0.02).
Conclusions: Acute supplementation of PT decreased lactate dehydrogenase, a
marker of muscle damage, while also improving lower body muscle endurance
performance.
Key Words: blood flow, dietary supplement, nitrates
Corresponding author: Hector Lopez, MD, hl@appliedhealthsciences.org
Published September 9, 2020
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Introduction
Consumption of tea and variations of the tea plant (Camellia sinensis) can be traced back thousands of
years. In present day, black, oolong, and green tea are all commonly consumed with each type of plant
being touted for the composition of nutrients found within its roots, stems, and most commonly the
leaves. Purple tea, a relatively new cultivar of tea, was developed by the Tea Research Foundation of
Kenya. Unique growing conditions (i.e., grown typically at 1,500 2,500 meters above sea level resulting
in high exposure to ultraviolet light) contribute to this tea variation presenting with colorful red-purple
leaves. These leaves are rich in anthocyanins and polyphenols such as epigallocatechin gallate (EGCG)
and epicatechin gallate (ECG), compounds that are valued for their caffeine content and ability to
function in a variety of biological roles 1. Purple tea has a higher proportion (16.5%) of polyphenols by
weight of dry tea leaves in comparison to green tea (9.1%), oolong tea (7.4%), and black tea (10.1%) while
also containing lower amounts of caffeine 2,3. Purple tea also contains various anthocyanidins (malvidin,
peralgonodin and cyanidin 3-O-galactoside) and also contains 1,2-di-O-galloyl-4,6-O- (S)-
hexahydroxydiphenoyl-β-D-glucose (GHG), a hydrolyzable tannin (Figure 1) that is not found in other
commonly consumed forms of tea. Non-published, internal ‘proof of concept’ experiments highlighted
GHG’s potential to impact body weight, skin health, and blood flow.
Figure 1. Chemical structure of 1,2-di-Galloyl-4,6-Hexahydroxydiphenoyl-β-D-Glucose, a unique
constituent found in parts of the purple tea plant.
Additional work by Shimoda and colleagues 4 have reported that purple tea ingestion (two times per day
from a 1.5 gram portion of tea leaves into 100 200 mL of water) by humans over four weeks may aid
in reducing body weight, body mass index, and body fat. In animals, a 200 mg/kg dose significantly
suppressed gains in body weight, abdominal fat, and triglycerides while also increasing the expression of
carnitine palmitoyltransferase I 4. Beyond its potential weight loss benefits, in vitro work has highlighted
the ability of purple tea to improve nitric oxide production, assist exercise recovery, and mitigate muscle
damage through anti-oxidant and anti-inflammatory mechanisms 5,6. A narrative review by Harty and
colleagues 7 highlighted previous research which examined the potential for tea supplementation and/or
its constituents to impact various aspects of the exercise recovery process such as reductions in creatine
kinase 8, oxidative stress 6,9, and perceived soreness 8,10. Because not all research supports these
outcomes, more research is needed to clarify potential benefits. Currently, no controlled scientific
investigations using human participants have been published in peer-reviewed literature investigating
the impact of purple tea ingestion on changes in exercise performance, exercise recovery, and
components of the muscle damage process. Therefore, the purpose of this study was to examine the
ability of oral Purple Tea supplementation (PurpleForce™, Oryza Oil & Fat Chemical. Co. Ltd, Japan)
to impact muscle hyperemia and oxygenation, serum markers of nitric oxide production and muscle
damage, and exercise performance in healthy human participants. It was hypothesized that purple tea
supplementation may modulate the inflammatory response and enhance recovery from intense (muscle-
damaging) exercise stress.
Methods
Overview of Study Design
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The study design employed for this protocol was a randomized, double-blind, placebo-controlled,
crossover investigation where each study participant supplemented for eight days with each treatment.
Each participant completed five study visits. The first visit was for screening purposes and consisted of
signing an IRB-approved consent form, completing a medical history, evaluating the presence of inclusion
and exclusion criteria, and assessing routine blood work (comprehensive metabolic panel, complete blood
panel, lipid panel) and resting vitals (heart rate and blood pressure). Participants were randomized into
one of two groups, and subsequently consumed their respective treatment for eight days. After five and
eight days of supplementation within each condition, participants returned for study visits and.
Participants then completed a two-week washout and switched to the other treatment and subsequently
consumed the alternate treatment for eight days while completing study visits and (after five and eight
days of supplementation, respectively). Each study visit consisted of measuring vitals (resting heart and
blood pressure), collection of venous blood for assessment of muscle damage and inflammation, nitric
oxide markers, body composition (via DEXA), reactive hyperemia (via circumference measurements),
fluid shifts (segmental BIA), muscle oxygenation (via NIRS), muscular endurance (via bench press and
leg extension exercises), perceived recovery questionnaire, and visual analog scales for energy, willingness
to exercise, muscle soreness, and sleep quality. A summary of the research design is provided in Table 1.
To facilitate replication for all measured endpoints, study participants were asked to replicate their diet
(including abstention from caffeine and alcohol) for 24 hours prior to each study visit, fast for 10 hours
prior to each visit, and refrain from exercise for 48 hours prior to each study visit. Participants were given
a standardized workout on of supplementation (i.e. general calisthenics using body weight exercises) and
instructed to not participate in physical activity outside the study procedures during both periods of
supplementation, in order to avoid conflating study outcomes.
Table 1. Overview of Study Design
Test Day
Screening
Day 5
Day 8
Day 30
Visit
1
2
3
5
Screening Procedures:
Informed Consent
X
Inclusion/Exclusion Criteria
X
Medical History
X
Physical
X
Height
X
Weight
X
Vitals (BP and HR)
X
X
X
X
Safety Screen8
X
Phlebotomist/Blood Sampling
X
X
X
X
Concomitant Medications
X
X
X
X
Testing Procedures:
Changes in lean mass (DEXA)
X
Reactive Hyperemia
X
X
X
Bioelectrical Impedance
X
X
X
Muscular Endurance
X
X
X
Perceived Recovery Scale
X
X
X
Nitrate Assessment
X
X
Muscle Damage
X
X
X
Muscle Oxygenation
X
X
X
VAS Muscle Soreness
X
X
X
Food Frequency
X
X
X
Diet Records/Analysis
X
X
X
Protocol Compliance
X
X
X
Dispense Test Product
X
X
X
Adverse Events Monitoring
X
X
X
*The safety screen included a metabolic/clinical chemistry panel, complete blood count, and a lipid panel.
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Figure 2. Timeline Schematic of Study Design and Procedures
Participants
Recreationally active men (i.e., intensive resistance training between 1-2 days per week) were recruited as
participants in this study primarily from a local suburban community in Ohio. Complete demographics
of all study participants can be found in Table 2. All participants read and signed an IRB-approved
informed consent form prior to participating in the study (Integreview, Austin, TX, Protocol # Oryza-
001-2019, Approval date: June 4, 2019). All study participants were required to be in good health as
determined by review of their medical history and routine blood chemistries by the study physician.
Inclusion criteria indicated that all participants were between the ages of 18 55, had body mass index
levels between 25 34.99 kg/m2, were normotensive (systolic pressure between 100 139 mm Hg and
diastolic pressure between 65 89 mm Hg) with a normal resting heart rate (<90 beats/min), had not
used a sports supplement product in the four weeks prior to screening, and agreed to abide by all
requirements of the study protocol.
Table 2. Baseline Characteristics of all Study Participants.
Mean ± SD
Minimum
Maximum
Age
(years)
33.5 ± 11.4
18
52
Height
(cm)
178.4 ± 7.6
165
193
Weight
(kg)
92.5 ± 13.3
73.7
126.2
Body Mass Index
(kg/m2)
29.0 ± 3.4
24.2
34.0
Systolic BP
(mm Hg)
127.4 ± 9.4
104
143
Diastolic BP
(mm Hg)
78.3 ± 7.1
64
90
Resting Heart Rate
(beats/min)
64.2 ± 9.0
50
82
Alternatively, participants were excluded if they indicated use of an anabolic/anti-catabolic dietary
supplement products for four weeks prior to testing, excluding a multivitamin and low dose (< 3 g/day)
fish oil. Additionally, any participant with a history of diabetes, malignancy in the previous five years
except for non-melanoma skin cancer, prior gastrointestinal bypass surgery, chronic inflammatory
condition or disease, or any other known gastrointestinal or metabolic diseases that might impact nutrient
absorption, e.g. short bowel syndrome, diarrheal illnesses, history of colon resection, gastro paresis, and
inborn errors of metabolism were excluded. Participants with a concomitant use of corticosteroids or
testosterone replacement therapy were excluded. A CONSORT diagram is provided in Figure 3 for all
study participants through the study protocol.
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Figure 3. Consolidated Standards of Reporting Trials (CONSORT) diagram.
Protocol
Height, Weight, Heart Rate, Blood Pressure
Standing height was determined using a wall-mounted stadiometer with each study participant in their
socks with heels together. Body weight was measured (±0.5 kg) using a Seca 767™ Medical Scale
(Hamburg, Deutschland). Resting heart rate and blood pressure was measured in a sitting position after
resting quietly for approximately ten minutes using an automated blood pressure cuff (Omron HEM-
780).
Assessed for eligibility
(n = 31)
Excluded (n = 1)
AE at screening (n = 1):
Refused to participate (n = 0)
Other reasons (n = 0)
Randomized (n = 30)
Allocated to intervention
(n = 30) Purple Tea (PT)
Received allocated intervention
(n = 28)
Did not receive allocated
intervention (n = 2)
(2 Withdrew consent)
Allocation
Enrollment
Allocated to intervention
(n = 30) Placebo (PLA)
Received allocated intervention
(n = 28)
Did not receive allocated
intervention (n = 2)
(2 Withdrew consent)
Follow up
Lost to follow up
(n = 0)
Discontinued intervention
(n = 0)
Lost to follow up
(n = 0)
Discontinued intervention
(n = 0)
Analysis
Analyzed
(n = 28)
Excluded from analysis
(n = 0)
Analyzed
(n = 28)
Excluded from analysis
(n = 0)
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Venous Blood Collection and Processing
Whole blood and serum samples were collected using standard phlebotomy techniques at all study visits.
Whole blood samples were collected into K2-EDTA treated Vacutainer tubes. Upon collection, each
sample was slowly inverted ten consecutive times prior to immediate refrigeration. Serum samples were
collected in serum separation tubes and allowed to clot for 30 minutes at room temperature prior to being
centrifuged (Horizon mini E Centrifuge, Drucker Diagnostics, Port Matilda, PA) for 15 minutes at 3,200
rpm. An 800 μl aliquot of serum was placed polypropylene centrifuge tubes and frozen at -80oC for later
analysis of total nitrates.
Biochemical Analysis
For screening purposes, blood collected at visit 1 was analyzed for a comprehensive metabolic panel,
complete blood count with platelet differentials, and lipid panel. Components of the comprehensive
metabolic panels consists of glucose, blood urea nitrogen [BUN], creatinine, aspartate aminotransaminase
[AST], alanine aminotransaminase [ALT], total bilirubin, alkaline phosphatase [ALP], sodium, chloride,
calcium, potassium, carbon dioxide, total protein, albumin, and globulin. Complete blood counts were
analyzed for absolute cell number and percentage of each cell type contributing to the total sample for
neutrophils, eosinophils, basophils, lymphocytes, and monocytes in addition to overall white blood cell
and red blood cell count, hemoglobin, hematocrit, mean corpuscle volume, mean corpuscle hemoglobin,
red cell dimension width, and mean corpuscle hemoglobin content. Lipid panel components consist of
triglycerides [TG], total cholesterol [TC], LDL cholesterol, HDL cholesterol. All analyses were completed
using automated clinical chemistry analyzers (LabCorp, Dublin, OH branch) and can be found in
Supplementary Data Table 1. In addition, pre-exercise creatine kinase, lactate dehydrogenase, and C-
reactive protein were analyzed on days 5 and 8 using an automated clinical chemistry analyzer at the same
commercial diagnostic laboratory (See Table 3). All aforementioned blood samples were batch-analyzed
with test-retest reliabilities commonly reported using internal quality control data from clinical
laboratories and associated automated analyzers within a range of 57%. Total nitrate content was
determined using a microplate-based approach. During batch analysis, serum was de-proteinized using 30
kD cutoff filter tubes and centrifugation at 12,000 g at 4°C for 20 minutes. Filtered serum was then
analyzed in duplicate for total nitrates using a commercially-available kit (kit #780001, Cayman Chemical,
Ann Arbor, MI, USA), and absorbance was read at 545 nm using a spectrophotometer (BioTek Synergy
H1; BioTek, Winooski, VT, USA). All samples were within the linear standard curve range, and duplicate
coefficient of variation values were less than 5%.
Circumference Measurements
To measure reactive hyperemia of the active muscle group, circumference measurements were taken
around the upper arm and thigh pre and post testing at visits 2 - 5 with a Gulick spring loaded tape
measure. Specifically, arm measurements were taken at half the distance between the acromion process
and the olecranon process, and leg measurements were taken at half the distance between the inguinal
crease and the proximal border of the patella. Arm circumference was obtained pre-bench press and
immediately post-bench press of the last set, and leg circumference was obtained pre-leg extension and
post-leg extension of the last set. All measurements were taken on the left side of the body. In our
laboratory, ICC for repeated measures of thigh girth are >0.85.
Body Composition
Total and regional lean mass, fat mass, and % fat were determined by dual-energy x-ray absorptiometry
(DEXA; General Electric Lunar DPX Pro). All DEXA scans were performed by the same technician and
analyzed by the manufacturer's software (enCORE version 13.31). Briefly, participants were positioned
in the scanner according to standard procedures and remained motionless for approximately 15 minutes
while scans were being completed. DEXA segments for the trunk and upper and lower limbs were
demarcated using standard anatomical landmarks. Percent fat was calculated by dividing total fat mass by
total scanned mass. Lean to fat mass ratio was computed using a simple ratio between the two values.
Quality control calibration procedures were performed prior to all scans using a calibration block and
procedures provided by the manufacturer. Prior to this study, we determined testretest reliability for
repeated measurements of lean mass, bone mineral content, and fat mass using this DEXA using intra-
class correlation coefficients; all values were >0.98
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Bioelectrical Impedance Analysis
To measure changes in segmental fluid shifts of intra/extracellular fluids, a bioelectrical impedance
analysis (BIA) of the thigh was used (ImpediMed SFB7). The SFB7 model scans 256 frequencies between
3 kHz and 1000 kHz and, using Cole modelling with Hanai mixture theory, determines total body water,
extracellular fluid and intracellular fluid. Initial placement of electrodes was measured and recorded for
each participant to replicate positioning during future visits. Four electrodes were placed on the left side
of the body, two injecting and two receiving. The first injecting electrode was placed medially 5 cm below
the medial malleolus of the tibia. The second injecting electrode was placed medially 5 cm below the
styloid process of the ulna. The first receiving electrode was placed medially 5 cm above the proximal
border of the patella. The second receiving electrode was placed medially 5 cm below the iliac crest. BIA
was administered twice at both timepoints (pre and post) to measure resistance at a frequency of zero
hertz (R zero, which reflects changes in extracellular fluid resistance), resistance at infinity frequency (R
infinity, which reflects changes in intracellular fluid resistance), and resistive index (RI = stature in meters
divided by resistance of each arm). The average value was used for data analysis. ICCs for this procedure
are >0.97.
Muscle Oxygenation
A Moxy Monitor™ (www.moxymonitor.com, Fortiori Design, LLC, Hutchinson, MN) was used to
measure muscle oxygen saturation (SmO2) and total hemoglobin/ myoglobin (THMb) using near-infrared
spectroscopy. For bench press testing, the Moxy Monitor was placed on the lateral head of the triceps,
equidistant between the olecranon process of the ulna and acromion process of the scapula, and for leg
extension testing it was placed on the middle portion of the vastus lateralis, equidistant between the
superior border of the patella and iliac crest. Both sites were on the right side of the body and adhered
with an elastic, adhesive wrap (Coban®, 3M, St. Paul, MN) to keep secure. The Moxy Monitor was paired
with a Garmin Fenix 5 watch to display SmO2 and THMb. Muscle oxygenation was measured pre and
post exercise. Specially, resting values were recorded for 60 seconds prior to the first set on the bench
press and leg extension. Lowest saturation values were recorded immediately after each set, and recovery
values were obtained at 30 and 60 seconds following the bench press and leg extension for both sets.
Muscular Endurance
Muscular endurance was assessed for the upper body using a Smith machine bench press, and the lower
body using a bilateral leg extension exercise. To standardize the exercises, a relative load was used.
Specifically, 65% of body weight for the bench press, and 30% for the leg extension was used to assess
muscular endurance. Participants were instructed to perform five repetitions with the Smith machine bar
for a warm-up. Following a brief rest and return to baseline SmO2 levels, the participant then completed
as many repetitions to failure (RTF). Following one minute of seated rest, a final set of RTF was
performed. A complete repetition was considered from full extension of the elbows with bar held over
the chest to where the bar touches the sternum. Procedures for the leg extension were identical to the
bench press whereby a complete repetition went from approximately 90 degrees of knee flexion to
approximately 180 degrees of knee extension. No more than two seconds were allowed between
repetitions. A trained researcher was present at all times to ensure safety, proper form and execution of
each repetition.
Visual Analog Scales
Visual analog scales (VAS) were completed by each study participant before performance testing. All
visual analog scales were similarly constructed using a 100-mm line anchored by “Lowest Possible” and
“Highest Possible” to assess subjective ratings of energy, willingness to exercise, muscle soreness, and
sleep quality. The validity and reliability of VAS to assess fatigue and energy have been previously
established 11 and our methods have been published elsewhere 12-15.
Dietary Intake and Physical Activity Monitoring
No changes in dietary habits were prescribed as part of this study investigation. As a result, all participants
were instructed to continue their typical diet throughout the entire study protocol. During baseline
screening, participants were asked to complete 24-hour dietary recall. Dietary records were analyzed for
average daily energy and macronutrient intake by trained study investigators and NutriBase IX (Clinical
Edition) software (CyberSoft, Inc. Phoenix, AZ).The recalled log of food and fluid intake was copied and
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provided back to the study participant. Study participants were then instructed to duplicate their food and
fluid intake for the 24 hours prior to each subsequent study visit.
Supplementation
After screening, all participants were randomly assigned in a double-blind fashion to one of two
supplementation groups: placebo (maltodextrin) or Purple Tea. All doses were consumed on a daily basis
in the morning. On testing days, the dose was instructed to be consumed approximately 30 60 minutes
prior to testing. Participants consumed one capsule containing 100 mg of purple tea extract as
PurpleForce™ (Oryza Oil & Fat Chemical. Co. Ltd, Japan) per manufacturer recommendations. Placebo
capsules contained maltodextrin and were consumed using an identical timing and dosing schedule. All
study materials were prepared following current good manufacturing practices (cGMP) according to Code
of Federal Regulations of US Food and Drug Administration Title 21 CFR part 111 in blinded capsules
and packaged in coded generic containers for double-blind administration. Compliance to the
supplementation regimen was monitored by daily logs, communication with study participants at each
study visit, and counting all capsules at each subsequent study visit. Purity and potency of the test products
were verified by an independent laboratory.
Adverse Events
During weekly phone calls, the frequency and intensity of local and systemic non-serious and serious
adverse events (AEs) were recorded by study team members. All reported events were coded using the
Medical Dictionary for Regulatory Activities (MedDRA) while the intensity of recorded adverse events
were graded using standardized criteria.
Statistical Analysis
All data were entered into two separate Microsoft Excel spreadsheets (i.e. manual double-key data entry)
and compared to assure data quality prior to analysis. SPSS 23 (Armonk, NY USA) was used for all
analyses. Normality assumptions were checked on all variables using a one-sample Shapiro-Wilk test.
Non-normal distributions were transformed using natural logarithms, cubed, and square root
transformations. Outliers were checked via visual inspection of studentized calculations on the residuals
(threshold value of ± 3 SD) of each dependent variable. Separate mixed factorial ANOVA with repeated
measures on time were assessed for all outcomes. When the sphericity assumption was not met, the
Huynh-Feldt correction was applied when epsilon was greater than 0.75 and the Greenhouse-Geiser
correction was applied when epsilon was less than 0.75. In addition, delta values were computed and
independent t-tests were completed to assess group differences. Mean differences of the change scores
and 95% confidence intervals were calculated on the difference between groups. Within-group effects
were compared using paired samples t-test. Effect sizes (ES) were also used to assess the magnitude of
change, and values of 0.2, 0.5 and 0.8 were considered small, medium and large effects, respectively. All
data are presented as means ± standard deviations. Results were considered statistically significant at P <
0.05 and trends were declared at 0.051 < p < 0.10.
Results
Participant demographics for all study participants is provided in Table 2. Additionally, weekly compliance
checks by the research study team revealed >95% compliance to the supplementation
(data not shown) regimen. A summary table of adverse events (AEs) is provided (See Table 3).
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Table 3. Summary of Adverse Events.
Active
(n=28)
Placebo
(n=28)
Screened
subjects prior
to allocation
(n=31)
Severity
Mild
1
1
1
Moderate
Severe
Relationship to Test Article
Not related
1
Possible
1
1
Definite
Gastrointestinal
Nausea
1
Nervous System
Sleep disturbance; Abnormal dreams
1
Surgical & Medical Procedures
Presyncope; Vagal Reaction
1
Total Number of Adverse Events Experienced
During Study
1
1
1
Total Number of Subjects Experiencing AEs: n (%)
1/28
(3.5%)
1/28
(3.5%)
1/31
(3%)
The data provided in this table are counts of each respective category.
Clinical Safety Markers, Muscle Damage, Inflammation, and Nitrate Content
All variables measured as part of complete blood counts with platelet differentials and comprehensive
metabolic panels were analyzed as part of eligibility screening at the beginning of the study protocol and
are provided in Table 4. No significant group x time interaction or within-group changes were identified
for creatine kinase and C-reactive protein (Table 5). A significant group x time interaction (95% CI: 2.36,
18.29 U/L, ES = 0.34, p = 0.01) was found for lactate dehydrogenase. Within-group analysis revealed a
significant reduction in lactate dehydrogenase concentrations in PT (p = 0.04) from day five to day eight
while no change was shown for PLA (p = 0.16). No significant group x time interaction or within-group
changes were identified for changes in total nitrate concentrations (Table 5).
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Table 4: Serum and whole blood metabolic and hematological markers collected at baseline prior to
supplementation.
Variables
Mean ± SD
Minimum
Maximum
White Blood Cell Count (cells/L)
5.5 ± 1.2
3.4
9.4
Red Blood Cell Count (cells/L)
5.1 ± 0.3
4.6
5.8
Hemoglobin (grams/dL)
15.7 ± 0.7
14.3
17.1
Hematocrit (%)
44.9 ± 1.9
41.6
48.5
Glucose (mg/dL)
93.0 ± 8.0
74
116
Blood Urea Nitrogen (BUN) (mg/dL)
15.5 ± 3.5
9
24
Creatine (mg/dL)
1.00 ± 0.17
0.65
1.43
BUN: Creatinine Ratio
15.8 ± 3.4
8
25
Sodium (mEq/L)
141 ± 1.60
137
143
Potassium (mEq/L)
4.3 ± 0.2
4
4.9
Chloride (mEq/L)
103 ± 2.1
99
107
Carbon Dioxide (mEq/L)
23.8 ± 1.6
21
27
Calcium (mg/dL)
9.5 ± 0.22
8.9
9.9
Protein (g/dL)
7.1 ± 0.3
6.5
7.9
Albumin (g/dL)
4.7 ± 0.2
4.3
5.1
Globulin (g/dL)
2.5 ± 0.3
1.7
3.1
Albumin: Globulin Ratio
1.9 ± 0.3
1.5
2.9
Bilirubin (mg/dL)
0.6 ± 0.3
0.2
1.7
Alkaline Phosphatase (IU/L)
68.7 ± 18.9
38
128
Aspartate Aminotransferase (U/L)
22.9 ± 5.2
14
35
Alanine Aminotransferase (U/L)
27.1 ± 12.0
6
58
Total Cholesterol (mg/dL)
175.5 ± 26.3
117
245
Triglycerides (mg/dL)
133 ± 112
36
582
HDL Cholesterol (mg/dL)
48.4 ± 11.1
30
74
VLDL Cholesterol (mg/dL)
23.3 ± 14.2
7
69
LDL Cholesterol (mg/dL)
102.6 ± 22.1
62
165
Table 5: Markers of Muscle Damage, Inflammation, and Nitrate Content.
Within-
Group
Group x Time
Group
Day 5
Day 8
Delta
p-value
95% CI
p
Creatine Kinase (U/L)
PLA
202 ± 267
262 ± 256
60.8 ± 288
0.27
(-147, 151)
0.98
PT
191 ± 137
250 ± 209
58.7 ± 193
0.12
Lactate Dehydrogenase (U/L)
PLA
170 ± 22
174 ± 28
4.8 ± 17.3
0.16
(2.36, 18.29)
0.01
PT
175 ± 26
170 ± 28
-5.5 ± 13.5
0.04
C-Reactive Protein (mg/L)
PLA
1.24 ± 1.41
1.21 ± 1.28
-0.03 ± 0.79
0.85
(-0.60, 0.39)
0.66
PT
1.01 ± 0.94
1.09 ± 1.11
0.08 ± 0.71
0.56
Nitrates (µM)
PLA
43.9 ± 13.1
41.1 ± 15.6
-2.8 ± 13.6
0.28
(-13.5, 14.3)
0.95
PT
48.3 ± 32.4
45.0 ± 19.5
-3.3 ± 31.5
0.59
95% CI = 95% confidence interval calculated on the differences between conditions
Circumferences, Body Composition, and Impedance Data
No statistically significant changes were reported in either group from day five to day eight (Table 6).
Changes in arm circumference between conditions (PLA vs. PT) were significantly different after five
days of supplementation (p = 0.04) and tended to be different after eight days of supplementation (p =
0.06). In both cases, PLA experienced greater increases in arm circumference than PT, presumably due
to swelling. Changes in DXA lean mass in the legs between conditions tended (p = 0.07) to be different
after eight days of supplementation with PT experiencing larger increases than what was observed in PLA.
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
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Changes in bioimpedance data (Average R Infinity) between conditions tended (p = 0.07) to be different
after eight days of supplementation. Changes in average RI between conditions was significantly different
after eight days of supplementation (p=0.02). In both outcomes, PT experienced greater decreases than
what was observed in PLA.
Table 6: Circumferences and Body Composition
Day 5
Day 8
Pre
Post
Pre
Post
Arm Circumference
PLA
33.5 ± 2.5
34.0 ± 2.9†
33.3 ± 2.3
33.9 ± 2.7†
(cm)
PT
32.8 ± 2.6
33.1 ± 2.8
33.2 ± 2.7
33.3 ± 2.8
Pre
Post
Pre
Post
Thigh Circumference
PLA
53.7 ± 4.1
54.3 ± 4.2
53.4 ± 4.8
54.5 ± 4.0
(cm)
PT
53.3 ± 4.6
54.0 ± 4.3
53.7 ± 4.3
54.0 ± 4.1
Pre
Post
Pre
Post
DXA Lean-Arms
PLA
8.2 ± 1.2
8.2 ± 1.2
8.2 ± 1.2
8.2 ± 1.1
(kg)
PT
8.1 ± 1.3
8.3 ± 1.4
8.1 ± 1.1
8.2 ± 1.2
Pre
Post
Pre
Post
DXA Lean-Legs
PLA
21.7 ± 3.0
21.7 ± 2.9
21.5 ± 3.3
21.7 ± 3.0
(kg)
PT
21.7 ± 2.9
21.7 ± 2.9
21.8 ± 3.1
22.0 ± 3.1
Pre
Post
Pre
Post
R Zero
PLA
42.0 ± 6.2
40.3 ± 5.9
41.9 ± 7.8
40.5 ± 7.2
(ohms)
PT
41.1 ± 6.4
40.1 ± 6.9
42.0 ± 8.0
40.8 ± 7.2
Pre
Post
Pre
Post
R Infinity
PLA
25.3 ± 3.7
24.7 ± 3.6
25.0 ± 4.5
26.0 ± 5.2
(ohms)
PT
25.4 ± 4.0
24.5 ± 4.1
25.7 ± 4.3
25.0 ± 3.9
Pre
Post
Pre
Post
RI Average
PLA
65.6 ± 14.0
65.4 ± 14.5
64.7 ± 14.5
63.8 ± 14.4
(ohms)
PT
67.3 ± 15.0
64.0 ± 13.5
68.0 ± 12.7
64.6 ± 13.1†
† = Different between groups at designated time point (day 5 or day 8). No statistically
significant group x time interactions were observed between groups from day 5 to day 8.
Muscle Oxygenation
As expected, widespread within-group changes were observed in both groups for both THMb and SmO2
skeletal muscle tissue oxygenation. No pattern of between-group changes were observed for either THMb
or SmO2 for bench press (Table 7). Changes between-groups in day five THMb values during the bench
press exercise tended to be different after 60s of recovery (95% CI: -0.01, 0.14, p = 0.10) while day five
SmO2 levels during the bench press also tended to be different (95% CI: -17.03, 1.27, p = 0.09)
immediately after exercise. Changes between-groups in day five SmO2 values during the leg extension
exercise (see Table 8) were not different immediately after exercise (95% CI: -0.97, 8.87, p = 0.11), but
were different after 30s of recovery (95% CI: 0.25, 14.3, p=0.04), and tended to be different after 60s of
recovery (95% CI: -0.16, 9.97, p = 0.06).
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
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Table 7. Muscle Oxygenation Bench Press
TOTAL HEMOGLOBIN/ MYOGLOBIN (THMb)
Group x Time
Day 5 Bench Press
Pre
Immediate Post
Group
Time
95% CI
p
PLA
11.90 ± 0.46
12.22 ± 0.53
0.60
<0.001
(-0.12, 0.19)
0.68
PT
12.02 ± 0.46
12.25 ± 0.53
Pre
30s Recovery
PLA
11.90 ± 0.46
12.17± 0.41
0.54
<0.001
(-0.04, 0.12)
0.31
PT
12.02 ± 0.46
12.20 ± 0.39
Pre
60s Recovery
PLA
11.90 ± 0.46
12.19 ± 0.38
0.66
<0.001
(-0.01, 0.14)
0.10
PT
12.02 ± 0.46
12.19 ± 0.39
Day 8 Bench Press
Pre
Immediate Post
Group
Time
95% CI
p
PLA
12.02 ± 0.46
12.25 ± 0.53
0.11
<0.001
(-0.07, 0.12)
0.55
PT
11.92 ± 0.45
12.14 ± 0.57
Pre
30s Recovery
PLA
12.02 ± 0.46
12.20 ± 0.39
0.09
<0.001
(-0.09, 0.11)
0.78
PT
11.92 ± 0.45
12.09 ± 0.41
Pre
60s Recovery
PLA
12.02 ± 0.46
12.19 ± 0.39
0.12
<0.001
(-0.11, 0.08)
0.71
PT
11.92 ± 0.45
12.11 ± 0.38
MUSCLE TISSUE OXYGEN SATURATION (SmO2)
Day 5 Bench Press
Pre
Immediate Post
Group
Time
95% CI
p
PLA
70.00 ± 10.49
20.02 ± 17.32
0.98
<0.001
(-17.03, 1.27)
0.09
PT
66.10 ± 11.79
24.05 ± 22.22
Pre
30s Recovery
PLA
70.00 ± 10.49
73.48 ± 15.11
0.65
0.004
(-11.56, 1.41)
0.12
PT
66.10 ± 11.79
74.69 ± 14.70
Pre
60s Recovery
PLA
70.00 ± 10.49
84.38 ± 6.04
0.22
<0.001
(-7.36, 3.16)
0.42
PT
66.10 ± 11.79
82.62 ± 9.46
Day 8 Bench Press
Pre
Immediate Post
Group
Time
95% CI
p
PLA
66.38 ± 11.08
19.83 ± 12.98
0.50
<0.001
(-7.23, 4.85)
0.69
PT
67.00 ± 13.03
73.29 ± 13.59
Pre
30s Recovery
PLA
66.38 ± 11.08
72.67 ± 12.08
0.69
0.001
(-5.44, 5.44)
1.00
PT
67.00 ± 13.03
67.03 ± 13.02
Pre
60s Recovery
PLA
66.38 ± 11.08
82.67 ± 7.43
0.35
<0.001
(-6.18, 3.65)
0.60
PT
67.00 ± 13.03
84.55 ± 6.95
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
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Table 8. Muscle Oxygenation Leg Extension
TOTAL HEMOGLOBIN/ MYOGLOBIN (THMb)
Group x Time
Day 5 Leg Extension
Pre
Immediate
Post
Time
95% CI
p
PLA
12.49 ± 0.48
12.61 ± 0.50
0.01
(-0.03, 0.12)
0.23
PT
12.50 ± 0.49
12.58 ± 0.50
Pre
30s Recovery
PLA
12.49 ± 0.48
12.54 ± 0.48
0.50
(-0.08, 0.16)
0.48
PT
12.50 ± 0.49
12.50 ± 0.50
Pre
60s Recovery
PLA
12.49 ± 0.48
12.53 ± 0.46
0.50
(-0.04, 0.12)
0.27
PT
12.50 ± 0.49
12.50 ± 0.48
Day 8 Leg Extension
Pre
Immediate
Post
Time
95% CI
p
PLA
12.50 ± 0.44
12.62 ± 0.46
0.01
(-0.03, 0.10)
0.24
PT
12.50 ± 0.45
12.59 ± 0.44
Pre
30s Recovery
PLA
12.50 ± 0.44
12.62 ± 0.42
<0.001
(-0.06, 0.11)
0.53
PT
12.50 ± 0.45
12.59 ± 0.45
Pre
60s Recovery
PLA
12.50 ± 0.44
12.55 ± 0.40
0.12
(-0.04, 0.08)
0.46
PT
12.50 ± 0.45
12.53 ± 0.41
MUSCLE TISSUE OXYGEN SATURATION (SmO2)
Day 5 Leg Extension
Pre
Immediate
Post
Time
95% CI
p
PLA
52.62 ± 9.28
14.67 ± 11.60
<0.001
(-0.97, 8.87)
0.11
PT
55.86 ± 8.50
13.95 ± 8.82
Pre
30s Recovery
PLA
52.62 ± 9.28
49.71 ± 17.11
0.01
(0.25, 14.3)
0.04
PT
55.86 ± 8.50
45.69 ± 14.36
Pre
60s Recovery
PLA
52.62 ± 9.28
67.57 ± 13.52
<0.001
(-0.16, 9.97)
0.06
PT
55.86 ± 8.50
65.90 ± 10.36
Day 8 Leg Extension
Pre
Immediate
Post
Time
95% CI
p
PLA
55.04 ± 8.68
16.07 ± 15.42
<0.001
(-4.38, 7.24)
0.61
PT
53.48 ± 7.96
13.07 ± 10.26
Pre
30s Recovery
PLA
55.04 ± 8.68
46.19 ± 17.28
0.003
(-5.17, 7.51)
0.71
PT
53.48 ± 7.96
43.45 ± 18.45
Pre
60s Recovery
PLA
55.04 ± 8.68
64.86 ± 14.00
0.001
(-5.87, 4.02)
0.70
PT
53.48 ± 7.96
64.21 ± 17.58
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
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Physical Performance
No significant group x time interaction were found in the number of bench press repetitions completed
during either set or for the total number of repetitions completed (Table 9). The purple tea condition was
able to perform approximately 1.28 ± 3.1 more total bench press repetitions from day five to day eight (p
= 0.05, ES = 0.11). A significant group x time interaction effect was observed (95% CI: -7.34, -0.01,
p=0.05, ES = 0.34) for repetitions completed during set 1 of the leg extension exercise. The purple tea
condition was able to complete approximately 4.6 ± 4.4 more repetitions from day five to day eight (p =
0.001, ES = 0.18) while no change was observed in the PLA group. Total leg extension repetitions
completed between groups tended to be different (95% CI: -8.62, 0.70, p=0.09, ES = 0.29). Again, the
total repetitions completed in the purple tea condition significantly increased from day five to day eight
(p < 0.001, ES = 0.44) while no change was observed in PLA (p = 0.37, ES = 0.10).
Table 9: Physical Performance.
Within-
Group
Group x Time
Day 5
Day 8
Delta
p-value
95% CI
p-value
Bench Press Reps to Fatigue Set 1
PLA
19.5 ± 8.6
20.0 ± 8.9
0.52 ± 1.7
0.13
(-1.66, 0.77)
0.46
PT
18.7 ± 7.7
19.6 ± 8.2
1.00 ± 2.8
0.09
Bench Press Reps to Fatigue Set 2
PLA
8.5 ± 3.3
8.6 ± 3.8
0.11 ± 1.9
0.77
(-1.38, 1.01)
0.75
PT
8.9 ± 4.0
9.2 ± 3.7
0.30 ± 1.8
0.40
Bench Press Total Reps
PLA
28.0 ± 11.2
28.7 ± 12.3
0.63 ± 2.4
0.19
(-2.12, 0.86)
0.39
PT
27.6 ± 11.1
28.8 ± 11.2
1.28 ± 3.1
0.05
Leg Extension Reps to Fatigue Set 1
PLA
34.9 ± 13.8‡
35.8 ± 12.3
0.92 ± 7.2
0.53
(-7.34, -0.01)
0.05
PT
29.1 ± 8.0
33.7 ± 8.4
4.6 ± 4.4
<0.001
Leg Extension Reps to Fatigue Set 2
PLA
20.8 ± 4.2
21.4 ± 4.2
0.68 ± 3.1
0.28
(-2.48, 1.92)
0.80
PT
20.9 ± 5.6
21.8 ± 5.0
0.96 ± 3.7
0.21
Leg Extension Reps to Fatigue Total Reps
PLA
55.7 ± 16.2‡
57.3 ± 15.5
1.60 ± 8.7
0.37
(-8.62, 0.70)
0.09
PT
50.0 ± 12.5
55.6 ± 12.7
5.56 ± 5.7
<0.001
Visual Analog Scales
No significant group x time interaction or within-group changes were observed for any of the visual
analog scales (Table 10). The ‘Willingness to Exercise’ scale did exhibit a tendency (95% CI: -0.95, 0.09,
p = 0.10, ES = 0.29) to improve in the purple tea condition from day five to day eight. When changes
across time were viewed individually for each group, the purple tea condition experienced a significant
increase in this scale (p = 0.02).
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
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15
Table 10. Visual Analog Scales
Within-
Group
Group x Time
Group
Day 5
Day 8
Delta
p-value
95% CI
p-value
Perceived Recovery Scale
PLA
8.04 ± 1.86
7.93 ± 1.96
-0.11 ± 2.54
0.83
(-1.84, 1.19)
0.67
PT
8.14 ± 1.56
8.36 ± 1.25
0.21 ± 1.95
0.57
Energy
PLA
6.89 ± 1.48
7.21 ± 1.28
0.31 ± 1.26
0.20
(-0.40, 0.46)
0.89
PT
6.96 ± 1.37
7.25 ± 1.47
0.29 ± 0.95
0.12
Willingness to Exercise
PLA
7.26 ± 1.54
7.32 ± 1.50
0.06 ± 1.03
0.77
(-0.95, 0.09)
0.10
PT
7.39 ± 1.61
7.88 ± 1.34
0.49 ± 1.06
0.02
Soreness
PLA
2.49 ± 2.54
2.88 ± 2.67
0.38 ± 2.81
0.48
(-1.67, 1.42)
0.87
PT
2.35 ± 2.12
2.85 ± 2.36
0.51 ± 2.21
0.23
Sleep
PLA
6.85 ± 1.65
6.68 ± 1.94
-0.17 ± 1.87
0.63
(-1.39, 0.48)
0.32
PT
6.76 ± 1.64
7.05 ± 1.74
0.29 ± 1.37
0.28
Discussion
This randomized, double-blind, placebo-controlled, crossover investigation determined the effects of a
standardized purple tea extract (Purple Force, Oryza Oil & Fat Chemical, Ltd.) on clinical safety, body
composition, hyperemia, muscle damage, exercise performance, and muscle oxygenation. Key findings
from this project revealed an increase in the number of leg extension repetitions completed after one set
and a tendency for more repetitions to be completed across the exercise protocol in addition to an
improvement (i.e. reduction) in the circulating levels of lactate dehydrogenase, a commonly assessed
marker of muscle damage. Additionally, PT supplementation led to an increase in the rating of
‘Willingness to Exercise’. Supplementation was well tolerated as assessed by the general lack of change
exhibited by adverse events, side-effect profiles, clinical assessments during study visits, and blood-based
markers of health and safety.
Several variations of the tea plant (Camellia sinensis) are consumed worldwide including black, Oolong, and
green tea. Each variation contains compounds such as catechins, polyphenols, and anthocyanins (among
others) that have been purported and, in many instances, demonstrated to have healthy attributes. For
example, tea ingestion has been shown to improve metabolism, increase fat oxidation, and bolster anti-
oxidant, anti-inflammatory, and other cytoprotective functions 16,17. Limited human research, however,
has been completed examining the ability of purple tea to impact health, performance, and recovery.
Purple tea is a unique cultivar of the tea plant, primarily being grown in regions of Eastern Kenya. Reports
have highlighted that purple tea has higher amounts of polyphenols and anthocyanins when compared to
other variations of tea 2,3 and is the only cultivar that contains the hydrolysable tannin, 1,2-di-O-galloyl-
4,6-O- (S)-hexahydroxydiphenoyl-β-D-glucose (GHG). Well-controlled research using purple tea,
however, is limited. Shimoda and colleagues 4 previously published outcomes that indicated human
ingestion of purple tea (two times per day from 1.5 gram portion of tea leaves into 100 200 mL of
water) for four weeks improved reductions in body weight loss, body mass index, and body fat. In the
same paper, animal model data were published, and a 200 mg/kg dose suppressed gains in body weight,
abdominal fat, and triglycerides while also increasing the expression of a key fat metabolism enzyme
(carnitine palmitoyltransferase I).
The ability of purple tea exposure to stimulate nitric oxide production was demonstrated in vitro whereby
human umbilical vein endothelial cells were cultured with either control sera, or sera containing 1, 10, and
100 uM of purple tea. Production of nitrite, nitrate, and total nitrate increased with purple tea exposure
(data not published) which led to the need for a more rigorous investigation to see if purple tea could
impact exercise performance and recovery from stressful exercise. Not surprisingly, results from the
present study contrast previous data published by Shimoda et al. 4 which demonstrated a reduction in
body mass, body mass index, and percent fat. The dosing used between the two investigations were
different with Shimoda using a tea beverage preparation (1.5 grams of tea leaves in 100 200 mL of water,
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
Journal of Exercise and Nutrition
16
two times per day) while the present study used a 100 mg dose in a capsulated formulation. The largest
difference between studies was the length of investigation. To this point, the Shimoda study provided
their beverage for a total of four weeks while the present study used an eight-day supplementation
regimen. While other in vitro and in vivo work has documented the ability of tea, extracts, and constituents
catechins to impact energy expenditure and mechanistic targets of lipolysis 18-20, more research is needed
in an exercising population over the course of several months (12 16 weeks) of supplementation in
conjunction with a hypoenergetic dietary regimen and exercise program to better understand the impact
of purple tea’s ability to impact changes in various body composition parameters.
Catechins and polyphenols have been well studied for their ability to impact cellular responses to stress,
particularly oxidative stress. In light of these potential functions, purple tea administration was
investigated in the present study for its potential ability to improve performance and recovery from
challenging exercise. Upper-body exercise performance did not change, but the number of repetitions
performed using the leg extension exercise was improved. Additionally, circulating levels of lactate
dehydrogenase, a marker of muscle damage, were decreased while no changes in creatine kinase, another
marker of muscle damage and C-reactive protein (a systemic marker of inflammation), were observed.
Scant research has been completed examining the ability of tea or various catechins to impact
performance and no published research is available that has examined purple tea’s ability to impact
exercise performance and recovery. From a human performance perspective, the majority of research has
focused upon the catechin’s ability to function in an anti-oxidant fashion. In this respect, previous work
by Kerksick and colleagues 10 used an isokinetic muscle damage model in healthy college-aged men after
supplementing for 14 days with 1,800 mg of epigallocatechin gallate (EGCG) to identify EGCG’s ability
to improve recovery and mitigate muscle damage, inflammation, and apoptosis. Performance was not
impacted by ECGG and while changes in creatine kinase and various markers of oxidative stress,
inflammation, and apoptosis changed in response to the damage bout, no impact of EGCG was observed.
While these findings do not align with those of the current study, the differences in supplementation and
exercise model made it challenging to closely compare outcomes between the two investigations.
Another area of interest for the present study was to examine more closely if purple tea could enhance
nitrate production and improve muscle oxygenation parameters. These outcomes were of interest due to
previous in vitro work in cultured cells that demonstrated purple tea’s ability to increase nitrate production
and subsequently stimulate nitric oxide release, which has been shown to improve blood flow. The
findings from this study suggest that the lower SmO2 values at 30s recovery post-leg extension exercise
bout with five days of PT supplementation may have been linked to improved vastus lateralis muscle
oxygen extraction and/or utilization (Table 8). It is generally well accepted that changes in the dynamic
balance between skeletal muscle O2 delivery and O2 utilization alter intracellular metabolism, metabolite
accumulation and ultimately contractile muscle function and tolerance during exercise (21, 22). Previous
studies have used the measure of muscle NIRS to assess tissue oxygenation, blood flow and
microcirculation during resistance training, and our exercise induced SmO2 decrease from baseline data
as a time effect are similar to those previously presented (22,23). A short period of PT supplementation
over five days, as demonstrated by the delta of SmO2 from baseline to 30s and 60s recovery post-leg
extensor exercise, may evoke a more rapid adjustment in O2 supply and delivery to match demand of
exercising muscle. The SmO2 data in our present study lend support to one potential mechanism for the
improved lower body muscular endurance and tolerance. Improved oxygen extraction and utilization
from the skeletal muscle tissue vascular bed would be expected to spare the finite anaerobic energy
reserves, and attenuate the accumulation of fatigue-related metabolites, thereby promoting enhanced
exercise tolerance.
No changes, however, were identified in the present study for total plasma nitrate-related outcomes. In
light of these findings, future work should examine more sensitive measures to evaluate blood flow such
as ultrasound and flow-mediated dilation approaches, while also examining more closely if changing the
supplementation regimen may impact outcomes from these areas. In summary, eight days of
supplementing with a purple tea extract resulted in an improvement in lower body muscular endurance
and reductions in circulating levels of a commonly used marker of muscle damage. While preliminary,
this evidence points towards the ability of oral supplementation with a purple tea extract in healthy
previously active men to facilitate recovery from stressful exercise and enhance the ability to perform a
maximal number of exercise repetitions. Future research should expand on these outcomes using well-
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
Journal of Exercise and Nutrition
17
controlled studies that explore in more detail any potential impact on the type of exercise performance,
different athletes, and dosing regimens.
Media-Friendly Summary
Eight days of supplementing with a purple tea extract at a dose of 100 mg resulted in an improvement in
lower body muscular endurance and reductions in circulating levels of a commonly used marker of muscle
damage. Supplementation was well tolerated with no side effects being reported throughout the
investigation. Overall, these findings provide preliminary evidence that oral supplementation with a
purple tea extract in healthy previously active men may help to facilitate recovery from stressful exercise
and enhance the ability to perform a maximal number of exercise repetitions. Clearly more research is
needed using well-controlled randomized, double-blind, placebo-controlled approaches that better
identify what type of exercise performance may be impacted the most, if different type of athletes will be
impacted differently, and what dosing regimen will yield beneficial outcomes.
Acknowledgements
The supplement (Purple Force™), placebo, and funding for this project was received through a restricted
external grant from Oryza Oil & Fat Chemical. Co. Ltd, Japan. The authors would like to thank the study
participants who completed the study protocol. Publication of these results should not be considered as
an endorsement of any product used in this study by the Center for Applied Health Sciences or any of
the organizations where the authors are affiliated.
Funding
Funding was provided by Oryza Oil & Fat Chemical. Co. Ltd, Japan through a restricted grant to The
Center for Applied Health Sciences. Outside of initial discussions, the sponsor played no part in designing
the study. Further, the sponsor had no part in collecting the data, analyzing the data, or preparing the
manuscript for publication.
Conflict of Interests
Raub, Cesareo, Kedia, and Sandrock all report no conflicts of interest.
Lopez is an officer and member of The Center for Applied Health Sciences, a privately held contract
research organization that has received external funding from companies that do business in the dietary
supplement, natural products, medical foods and functional foods and beverages industries. He is the co-
founder and member of Supplement Safety Solutions, LLC., serving as an independent consultant for
regulatory compliance, safety surveillance and Nutravigilance to companies in the dietary supplement and
functional foods industry, but not the sponsor of the current research. Lopez is also co-inventor on
multiple patents within the field of dietary supplements, applied nutrition and bioactive compounds.
Ziegenfuss is an officer and member of The Center for Applied Health Sciences, a privately held contract
research organization that has received external funding from companies that do business in the dietary
supplement, natural products, medical foods and functional foods and beverages industries. Ziegenfuss
has received grants and contracts to conduct research on dietary supplements; has served as a paid
consultant for industry; has received honoraria for speaking at conferences and writing articles about
functional foods and dietary supplements; receives royalties from the sale of several sports nutrition
products (none related to the product examined in the present study); and has served as an expert witness
on behalf of the plaintiff and defense in cases involving dietary supplements. Ziegenfuss is also co-
inventor on multiple patents within the field of dietary supplements, applied nutrition and bioactive
compounds.
Authors’ Contributions
HLL and TNZ designed the study, secured funding for the project, and assisted with manuscript
preparation. KC and TZ wrote the initial draft. BR, KC, and JS carried out subject recruitment, data
collection, coordination of the study and compliance. TZ coordinated the statistical analysis. AWK
provided medical oversight. All authors read and approved the final manuscript.
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
Journal of Exercise and Nutrition
18
References
1. Westerterp-Plantenga MS. Green tea catechins, caffeine and body-weight regulation. Physiol
Behav. 2010;100(1):42-46.
2. Cherotich L, Kamunya S, Alakonya A, et al. Variation in catechin composition of popularly
cultivated tea clones in East Africa (Kenya). Paper presented at: 2013 JKUAT Annual Scientific
Conference Proceedings2013; Nairobi, Kenya.
3. Kilel EC, Faraj AK, Wanyoko JK, Wachira FN, Mwingirwa V. Green tea from purple leaf
coloured tea clones in Kenya- their quality characteristics. Food Chem. 2013;141(2):769-775.
4. Shimoda H, Hitoe S, Nakamura S, Matsuda H. Purple Tea and Its Extract Suppress Diet-
induced Fat Accumulation in Mice and Human Subjects by Inhibiting Fat Absorption and
Enhancing Hepatic Carnitine Palmitoyltransferase Expression. Int J Biomed Sci. 2015;11(2):67-
75.
5. Jowko E, Sacharuk J, Balasinska B, et al. Effect of a single dose of green tea polyphenols on the
blood markers of exercise-induced oxidative stress in soccer players. Int J Sport Nutr Exerc Metab.
2012;22(6):486-496.
6. Panza VS, Wazlawik E, Ricardo Schutz G, Comin L, Hecht KC, da Silva EL. Consumption of
green tea favorably affects oxidative stress markers in weight-trained men. Nutrition.
2008;24(5):433-442.
7. Harty PS, Zabriskie HA, Erickson JL, Molling PE, Kerksick CM, Jagim AR. Multi-ingredient
pre-workout supplements, safety implications, and performance outcomes: a brief review. J Int
Soc Sports Nutr. 2018;15(1):41.
8. Herrlinger KA, Chirouzes DM, Ceddia MA. Supplementation with a polyphenolic blend
improves post-exercise strength recovery and muscle soreness. Food Nutr Res. 2015;59:30034.
9. Jowko E, Dlugolecka B, Makaruk B, Cieslinski I. The effect of green tea extract supplementation
on exercise-induced oxidative stress parameters in male sprinters. Eur J Nutr. 2015;54(5):783-
791.
10. Kerksick CM, Kreider RB, Willoughby DS. Intramuscular adaptations to eccentric exercise and
antioxidant supplementation. Amino Acids. 2010;39(1):219-232.
11. Lee KA, Hicks G, Nino-Murcia G. Validity and reliability of a scale to assess fatigue. Psychiatry
research. 1991;36(3):291-298.
12. Ziegenfuss TN, Habowski SM, Sandrock JE, Kedia AW, Kerksick CM, Lopez HL. A Two-Part
Approach to Examine the Effects of Theacrine (TeaCrine(R)) Supplementation on Oxygen
Consumption, Hemodynamic Responses, and Subjective Measures of Cognitive and
Psychometric Parameters. Journal of dietary supplements. 2017;14(1):9-24.
13. Ziegenfuss TN, Kedia AW, Sandrock JE, Raub BJ, Kerksick CM, Lopez HL. Effects of an
Aqueous Extract of Withania somnifera on Strength Training Adaptations and Recovery: The
STAR Trial. Nutrients. 2018;10(11).
14. Ziegenfuss TN, Lopez HL, Sandrock JE, Kedia AW, Habowski S, Kerksick C. Effect of a Multi-
Nutrient Over-the-Counter Supplement on Changes in Metabolic Rate and Markers of
Lipolysis. Journal of dietary supplements. 2017;14(3):288-302.
15. Lopez HL, Cesareo KR, Raub B, et al. Effects of Hemp Extract on Markers of Wellness, Stress
Resilience, Recovery and Clinical Biomarkers of Safety in Overweight, But Otherwise Healthy
Subjects. Journal of dietary supplements. 2020:1-26.
16. Malongane F, McGaw LJ, Mudau FN. The synergistic potential of various teas, herbs and
therapeutic drugs in health improvement: a review. Journal of the science of food and agriculture.
2017;97(14):4679-4689.
17. Naveed M, BiBi J, Kamboh AA, et al. Pharmacological values and therapeutic properties of
black tea (Camellia sinensis): A comprehensive overview. Biomed Pharmacother. 2018;100:521-531.
18. Hodgson AB, Randell RK, Jeukendrup AE. The effect of green tea extract on fat oxidation at
rest and during exercise: evidence of efficacy and proposed mechanisms. Advances in nutrition.
2013;4(2):129-140.
19. Vazquez Cisneros LC, Lopez-Uriarte P, Lopez-Espinoza A, Navarro Meza M, Espinoza-
Gallardo AC, Guzman Aburto MB. Effects of green tea and its epigallocatechin (EGCG)
content on body weight and fat mass in humans: a systematic review. Nutr Hosp. 2017;34(3):731-
737.
2020, Volume 3 (Issue 3): 13 OPEN ACCESS
Journal of Exercise and Nutrition
19
20. Turkozu D, Tek NA. A minireview of effects of green tea on energy expenditure. Crit Rev Food
Sci Nutr. 2017;57(2):254-258.
Copyright, 2020. Published by Capstone Science Inc. under open access distribution rights. Articles are available for download and proper distribution.
... PurpleForce™): This "purple" variation of Camellia sinensis extract was derived from plants grown in a highaltitude mountain area exposed to strong UV rays, which increase the protective properties of the plants. PT has high polyphenol content including delphinidin content and exerts higher antioxidant activity compared to other tea extracts [57]. ...
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