ArticlePDF Available

Beneficial Effects of Oolong Tea Consumption on Diet-induced Overweight and Obese Subjects

Authors:
Article

Beneficial Effects of Oolong Tea Consumption on Diet-induced Overweight and Obese Subjects

Abstract and Figures

To determine the anti-obesity effects of oolong tea on diet-induced overweight or obesity. A total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight or obese subjects. The body fat level of the subjects was determined at the same time by taking body weight, height and waist measurements. The thickness of the subcutaneous fat layer was also determined on the abdomen 3 cm to the right of the navel by the ultrasonic echo method. On the other hand, effects of oolong tea ingestion on plasma triglyceride (TG) and total cholesterol (TC) were determined. Inhibitions of pancreatic lipase by oolong tea extract and catechins in vitro were also determined. A total of 70% of the severely obese subjects did show a decrease of more than 1 kg in body weight, including 22% who lost more than 3 kg. Similarly, 64% of the obese subjects and 66% of the overweight subjects lost more than 1 kg during the experiment, and the subcutaneous fat content decreased in 12% of the subjects. The correlation between weight loss and subcutaneous fat decrease in men (r=0.055) was obviously lower than that in women (r=0.440, P<0.01). Body weight loss was signifificantly related to the decrease of the waist size in men (r=0.730, P<0.01) and women (r=0.480, P<0.01). Also, the correlation between subcutaneous fat reduction and decreased waist size was signifificant in women (r=0.554, P<0.01), but not in men (r=0.050, P>0.05). Moreover, the plasma levels of TG and TC of the subjects with hyperlipidemia were remarkably decreased after ingesting oolong tea for 6 weeks. In vitro assays for the inhibition of pancreatic lipase by oolong tea extract and catechins suggest that the mechanism for oolong tea to prevent hyperlipidemia may be related to the regulative action of oolong tea catechins in lipoprotein activity. Oolong tea could decrease body fat content and reduce body weight through improving lipid metabolism. Chronic consumption of oolong tea may prevent against obesity.
Content may be subject to copyright.
34 Chin J Integr Med 2009 Feb;15(1):34-41
Obesity, a risk factor for many diseases, has
represented a prevalent tendency around the world,
especially in developed countries, such as Europe,
the United States and Japan(1). Diet-induced obesity
is generally considered due to excessive calorie
intake, decreased energy utilization and reduced
basal metabolism. In this type of obesity, either the
number or the size of fat cells shows a remarkable
increase because of the excessive storage of energy
consequent on the imbalance between energy
intake and expenditure(2). Excessive body fat may
trigger various chronic diseases that are called life-
style related diseases, such as hyperlipidemia,
hypertension and non-insulin dependent diabetes
mellitus, and increase the risk of coronary heart
disease(3). As a result, not only is one's quality of life
affected, but also his life span is shortened.
Variations in total energy intake and diet
composition are important in the regulation of
metabolic processes. Furthermore, dietary fat
promotes more effective fat storage in body than
dietary carbohydrate does. Consistent with these
suggestions, high fat diets may increase body weight
and cause adiposity in both humans and animals(4).
Thus, either inhibiting the digestion and absorption
of dietary fat or promoting fat oxidation is conducive
to treating obesity. Usually, dietary fat is not easily
absorbed from the intestine unless it has been
hydrolyzed by pancreatic lipase, so that gastric and
pancreatic lipases serve as the key enzymes for the
ORIGINAL ARTICLE
Beneficial Effects of Oolong Tea Consumption on Diet-induced
Overweight and Obese Subjects
HE Rong-rong (何蓉蓉)1, CHEN Ling ( )2, LIN Bing-hui (林炳辉)2,
MATSUI Yokichi (松井阳吉)3, YAO Xin-sheng (姚新生)1,4 and KURIHARA Hiroshi (栗原 )4
1. School of Traditional Chinese Materia Medicine, Shenyang
Pharmaceutical University, Shenyang (110016), China; 2. Fujian
Institute of Traditional Chinese Medicine, Fuzhou (350003),
China; 3. Products Development Center, Suntory Ltd., 5-2-5,
Yamazaki, Shimamoto-cho, Mishima-gun, Osaka 618-0001,
Japan; 4. Institute of Traditional Chinese Medicine and Natural
Products, Jinan University, Guangzhou (510632), China
Correspondence to: Prof. KURIHARA Hiroshi, Tel:
86-20-85221352, E-mail: hiroshi_Kurihara@163.com
DOI: 10.1007/s11655-009-0034-8
ABSTRACT
ABSTRACT
Objective:
Objective:
To determine the anti-obesity effects of oolong tea on diet-induced overweight or
To determine the anti-obesity effects of oolong tea on diet-induced overweight or
obesity.
obesity.
Methods:
Methods:
A total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight
A total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight
or obese subjects. The body fat level of the subjects was determined at the same time by taking body weight,
or obese subjects. The body fat level of the subjects was determined at the same time by taking body weight,
height and waist measurements. The thickness of the subcutaneous fat layer was also determined on the
height and waist measurements. The thickness of the subcutaneous fat layer was also determined on the
abdomen 3 cm to the right of the navel by the ultrasonic echo method. On the other hand, effects of oolong
abdomen 3 cm to the right of the navel by the ultrasonic echo method. On the other hand, effects of oolong
tea ingestion on plasma triglyceride (TG) and total cholesterol (TC) were determined. Inhibitions of pancreatic
tea ingestion on plasma triglyceride (TG) and total cholesterol (TC) were determined. Inhibitions of pancreatic
lipase by oolong tea extract and catechins
lipase by oolong tea extract and catechins
in vitro
in vitro
were also determined.
were also determined.
Results:
Results:
A total of 70% of the severely
A total of 70% of the severely
obese subjects did show a decrease of more than 1 kg in body weightincluding 22% who lost more than 3
obese subjects did show a decrease of more than 1 kg in body weightincluding 22% who lost more than 3
kg. Similarly, 64% of the obese subjects and 66% of the overweight subjects lost more than 1 kg during the
kg. Similarly, 64% of the obese subjects and 66% of the overweight subjects lost more than 1 kg during the
experiment, and the subcutaneous fat content decreased in 12% of the subjects. The correlation between
experiment, and the subcutaneous fat content decreased in 12% of the subjects. The correlation between
weight loss and subcutaneous fat decrease in men (
weight loss and subcutaneous fat decrease in men (
r
=0.055) was obviously lower than that in women (
=0.055) was obviously lower than that in women (
r
=0.440,
=0.440,
P
<0.01). Body weight loss was significantly related to the decrease of the waist size in men (
<0.01). Body weight loss was significantly related to the decrease of the waist size in men (
r
=0.730,
=0.730,
P
<0.01)
<0.01)
and women (
and women (
r
=0.480,
=0.480,
P
<0.01). Also, the correlation between subcutaneous fat reduction and decreased waist
<0.01). Also, the correlation between subcutaneous fat reduction and decreased waist
size was significant in women (
size was significant in women (
r
=0.554,
=0.554,
P
<0.01), but not in men (
<0.01), but not in men (
r
=0.050,
=0.050,
P>
P>
0.05). Moreover, the plasma levels
0.05). Moreover, the plasma levels
of TG and TC of the subjects with hyperlipidemia were remarkably decreased after ingesting oolong tea for 6
of TG and TC of the subjects with hyperlipidemia were remarkably decreased after ingesting oolong tea for 6
weeks.
weeks.
In vitro
In vitro
assays for the inhibition of pancreatic lipase by oolong tea extract and catechins suggest that
assays for the inhibition of pancreatic lipase by oolong tea extract and catechins suggest that
the mechanism for oolong tea to prevent hyperlipidemia may be related to the regulative action of oolong tea
the mechanism for oolong tea to prevent hyperlipidemia may be related to the regulative action of oolong tea
catechins in lipoprotein activity.
catechins in lipoprotein activity.
Conclusions:
Conclusions:
Oolong tea could decrease body fat content and reduce body
Oolong tea could decrease body fat content and reduce body
weight through improving lipid metabolism. Chronic consumption of oolong tea may prevent against obesity.
weight through improving lipid metabolism. Chronic consumption of oolong tea may prevent against obesity.
KEY WORDS
KEY WORDS
oolong tea, overweight, obesity, cholesterol, triglyceride, pancreatic lipase
oolong tea, overweight, obesity, cholesterol, triglyceride, pancreatic lipase
35
Chin J Integr Med 2009 Feb;15(1):34-41
absorption of dietary fat. Of course, the absorption of
dietary fat from the intestine is also dependent on the
concerted action of other digestive lipases and bile(5, 6).
Oolong tea is mainly produced and consumed in
China, especially in South China. As one of popular
teas for the Chinese, oolong tea is traditionally
considered to have anti-obesity and hypolipidemic
effects. Recently, the pharmacological effects and
relative mechanisms of oolong tea have been studied
widely. For example, oolong tea could facilitate
lipid metabolism and prevent from obesity and fatty
liver in mice by the oral administration of a high-fat
diet for 10 weeks(7). Oolong tea fed orally to male
Sprague-Dawley rats for 30 weeks led to significant
suppression of body weights and decrease in the
levels of triglyceride (TG) and total cholesterol (TC)(8).
A study conducted in twenty patients with coronary
artery disease who consumed oolong tea (1 000 mL/
day) for one month shows that oolong tea resulted in
a significant increase of plasma adiponectin levels and
decrease in LDL particle size. A significant difference
in hemoglobin A1c levels (7.23±4.45%
vs
6.99±
4.30%,
P
<0.05) was also observed before and after
the intake of oolong tea(9-11).
On the bases of these findings, it is well
presumed that long-term consumption of tea may be
beneficial to the treatment of obesity. However, there
are few clinical studies in the effects of oolong tea on
diet-induced overweight and obesity. In the present
study, a clinical trial was performed to determine the
anti-obesity effects of oolong tea.
METHODS
Selection Criteria
The subjects were selected according to
the World Health Organization (WHO) obesity
classification system based on the average adult
body mass index (BMI; WHO, 1990), which is an
international standard(12). These subjects were then
classified into three types using cut-off points for the
definition of obesity introduced by the WHO in 1995(13)
and 1997(14): within 25<BMI<30, indicating overweight
or preobesity (); 30<BMI<35, indicating obesity ();
and 35<BMI, indicating severe obesity (). Pregnant
women, nursing mothers, people who habitually drink
tea served from more than 4 g of leaf tea per day and
individuals with secondary obesity induced by various
diseases or drugs were excluded.
Subjects
A total of 102 Chinese subjects, including 42
males and 60 females, aged 18 to 65 years with
diet-induced overweight and obesity were recruited
from the general population of Fuzhou city. The
ages and body weight levels of the 102 subjects are
shown in Table 1. All volunteers were selected by
initial screening based on questionnaires related
to their diet, physical activity, family and personal
health histories, and availability for participation.
A cooperating physician performed a general
medical evaluation, and the height and weight were
recorded.
Table 1. Age Group and Weight Classification of
Subjects before Oolong Tea Treatment (Case)
No. of
subjects
Age layer
Weight
classification
by BMI
<30 -30 -40 -50 -65 ⅠⅡⅢ
102 5 12 33 37 15 52 44 6
The cause of being overweight and obese among
the subjects is ascribed as an imbalance between energy
intake and expenditure. A researcher explained the
purpose of the experiment, test protocol and bioactivity
of oolong tea prior to the experiment to all subjects.
Then, informed consent to participate in this study was
obtained. All subjects were given their informed consent
to participate in the study, which was approved by the
Medical Ethics Committee of the Fujian Institute of
Traditional Chinese Medicine, and was performed in
accordance with the Helsinki Declaration. All volunteers
signed for their informed consent. Clinical testing was
carried out in medical facilities of the Fujian Institute of
Traditional Chinese Medicine (Fuzhou, China).
Experimental Protocol
Oolong tea packed in a 2-g bag was provided
by the Fujian Tea Import and Export Co., Ltd. (China).
The tea was brewed by adding 300 mL of boiling
water to a glass container containing the tea bag.
The tea was then steeped for 5 min before intake. It
was ingested twice in the morning and twice in the
afternoon, so that the subjects received 4 servings of
tea bags daily for a total of 8 g a day for 6 weeks.
The protocol was explained to each subject, and
the intake of various anti-obesity drugs, black tea and
green tea was prohibited throughout the test period.
There was no further restriction on meals or daily life
except for the prohibition of intensive exercise.
36 Chin J Integr Med 2009 Feb;15(1):34-41
Measurements of Body Weight, Height, Waist,
Thickness of the Subcutaneous Fat Layer
The body fat level of subjects was determined
before and on the final day of the experiment from 9:00
to 11:00 a.m. by taking body weight, height and waist
measurements. The thickness of the subcutaneous fat
layer was also determined on the abdomen 3 cm to
the right of the navel by the ultrasonic echo method.
Adverse Reaction
Safety was evaluated as follows: safe (no adverse
effects); borderline (slight adverse effects, but safe
to continue); and unsafe (adverse effects, ingestion
discontinued). The test director was instructed to report
cases with serious adverse events related to the test,
and the director was responsible in deciding whether to
discontinue testing after consultation with the subject
who had serious adverse effects related to the testing.
Measurement of Plasma TG and TC
Plasma TG and TC levels in the 102 overweight
and obese subjects were respectively measured before
the treatment initiation as the baseline levels, and the
subjects with high plasma TG or high plasma TC were
monitored on the final day of the experiment. Blood
samples were collected in the morning after fasting
from 21:00 on the previous day into a tube containing
2% sodium heparin. Then, each tube was centrifuged
at 3 000 r/min for 5 min to obtain the supernatant. All
samples were stored at -20 until the assay of plasma
TG and TC was performed by colorimetric analysis
using triglyceride E-test and total cholesterol E-test kits
(Wako Pure Chemical Industries, Ltd.).
Catechins and Caffeine Analysis
A tea bag containing 2 g of oolong tea was
brewed by adding 300 mL of boiling water to a
glass container, followed by 5-min steeping. The
concentrations of caffeine, gallic acid, flavanols, and
other polyphenols in the oolong tea extract were
analyzed by high-performance liquid chromatography
[HPLC, column: Cosmosil 5PE-MS (Nakalai Tesuque,
Kyoto, Japan, 4.6 x 150 mm, 5 μm), mobile phase:
eluent A: 0.05% trifluoroacetic acid (TFA) in water;
eluent B: 0.05% TFA in acetonitrile using a gradient
program of eluent B content: 10% for 5 min, 21%
for 8 min, 90% for 1 min, and 90% for 6 min,
flow rate: 2 mL/min with ultra-violet spectroscopy
detection at 280 nm and 40 (15)]. The quantification
of caffeine, gallic acid and flavanols was performed
using standard calibration curves of their respective
reagent grade compounds. Other polyphenols were
quantified using a calibration curve derived from other
polyphenols that had been isolated from tea by HPLC.
The components of caffeine and tea polyphenols of
oolong tea are shown in Table 2.
Table 2. Components of Caffeine and
Polyphenols in Oolong Tea
Components Oolong tea (mg/100 mL)
Gallic acid 2.19
Caffeine 23.51
Gallocatechine 6.68
Epigallocatechine 16.14
Catechine 1.65
Epicatechine 5.08
Epigallocatechine gallate 25.73
Allocatechine gallate 1.85
Epicatechine gallate 5.73
Catechine gallate 0.60
Polymerized 33.65
Note: The data are mean amounts of oolong tea components
consumed daily
Measurement of Pancreatic Lipase Activity
in
vitro
Oolong tea was extracted with 15 volumes of
boiling water for 5 min. After filtration and evaporation,
the recovered residue was powdered under frozen-
decompression conditions. The recovery rate was
12.1%, and the extract was then used for the experiment.
(±)-catechin, (-)-epigallocatechin-3-gallate (EGCG),
(-)-epicatechin-3-gallate (ECG), (-)-gallocatechin gallate
(GCG), (-)-gallocatechin (GC) and (-)-catechin gallate
(CG) were purchased from the Sigma Chemical Co.,Ltd,
and used as a positive control. Pancreatic lipase activity
was measured using 4-methylumbelliferyl oleate (4-MU
oleate) as a substrate.
Pancreatic lipase (Type -S, from porcine
pancreas) and 4-MU oleate were purchased from the
Sigma Chem. Co., respectively. A total of 25 mL of
tea extract solution dissolved in water and 50 μL of
0.1 mmol/L 4-MU oleate solution dissolved in a buffer
consisting of 13 mmol/L Tris-HCl, 150 mmol/L NaCl, and
1.3 mmol/L CaCl2 (pH 8.0) were mixed in the well of a
microtiter plate, and then 25 μL of the lipase solution
(50 U/mL) in the buffer was added to start the enzyme
reaction. After incubation at 25 for 30 min, 0.1 mL of
0.1 mol/L sodium citrate (pH 4.2) was added to discontinue
the reaction. The amount of 4-methylumbelliferone
37
Chin J Integr Med 2009 Feb;15(1):34-41
released by the lipase was measured with a fluorometrical
microplate reader (Fluoroskan Ascent, LabSystems
Inc.) at an excitation wavelength of 355 nm and an
emission wavelength of 460 nm(16). The 50% inhibitory
concentration (IC50) of each test sample was obtained
from the least-squares regression line of the plots of the
logarithm of the sample concentration (log) versus the
pancreatic lipase activity (%)(17).
Statistical Analysis
Statistical analysis of data was performed using
SPSS 13.0 statistical package. One-Way analysis of
variance (ANOVA) was applied to analyze for difference
in data of biochemical parameters among the different
groups, followed by Dunnett's significant post-hoc test
for pair-wise multiple comparisons. Differences were
considered to be significant when the probability value
was less than 0.05, and the results were expressed
as the means ± standard deviation. The effect of
oolong tea on overweight or obese subjects was also
examined with regard to body weight, waist size and
subcutaneous fat thickness.
RESULTS
Effects of Oolong Tea Ingestion on Overweight
and Obese Subjects
The correlation coefficient between height and
weight for the 102 subjects with diet-induced obesity
before the ingestion of oolong tea was
r
=0.261 (Figure
1A), and their average weight was 74.1±8.2 kg. After
ingestion for 6 weeks, the average weight decreased
to 71.2±8.1 kg, and the correlation coefficient
between height and weight also increased (
r
=0.620)
as shown in Figure1B. These results show that oolong
tea ingestion slightly improved diet-induced obesity.
The average weight changed from 79.7±6.7 kg to
76.1±7.5 kg in men (Figure 1C and 1D), and from
70.2±6.8 kg to 67.8±6.7 kg in women (Figure 1E and
1F). From the above results, the treatment appeared
to be more effective in women.
The degree of changes before and after oolong
tea ingestion was observed in terms of fat thickness,
weight and waist. The correlation coefficient between
the decreases in weight and subcutaneous fat (fat
thickness) in all subjects was
r
=0.140 (Figure 2A),
and was correlated between them. The weight loss
in males did not directly correlate with a decrease
in subcutaneous fat (
r
=0.055, Figure 2B). However,
in women, it was significantly correlated (
r
=0.440,
P
<0.01, Figure 2C). Although the waist size was only
slightly decreased (average of 2.58 cm), the decrease
was directly correlated with the weight loss (
r
=0.480,
P
<0.01, Figure 3C). The correlation between the
decreases in subcutaneous fat and waist size was
more marked in women (Figure 4C,
r
=0.554,
P
<0.01)
than in men (Figure 4B,
r
=0.050).
After the ingestion of oolong tea for 6 weeks,
70% of the severely obese subjects show decreased
Figure 1. Effects of Oolong Tea Ingestion on the Correlation Coefficient between Weight and Height (102 cases)
Notes: A: all volunteers before the ingestion of oolong tea; B: all volunteers after the ingestion of oolong tea; C: male subjects
before the ingestion of oolong tea; D: male subjects after the ingestion of oolong tea; E: female subjects before the ingestion of oolong
tea; F: female subjects after the ingestion of oolong tea
110
Weight (kg)
Height (cm)
F
90
70
50
150 160 170 180 190
y=0.63x-31.80
r
=0.550,
P
<0.01
110
Weight (kg)
110
Weight (kg)
110
Weight (kg)
Height (cm)
A
90
70
50
150 160 170 180 190
y=0.43x+8.04
r
=0.260,
P
<0.01
110
Weight (kg)
Height (cm)
B
90
70
50
150 160 170 180 190
y=0.74x-49.24
r
=0.620,
P
<0.01
Height (cm)
C
90
70
50
150 160 170 180 190
Height (cm)
D
90
70
50
150 160 170 180 190
y=0.55x-15.95
r
=0.300,
P
<0.1
110
Weight (kg)
Height (cm)
E
90
70
50
150 160 170 180 190
y=0.61x-26.90
r
=0.530,
P
<0.01
y=0.43x+8.04
r
=0.260,
P
<0.1
38 Chin J Integr Med 2009 Feb;15(1):34-41
body weight of more than 1 kg, including 22% with
more than 3 kg loss. Similarly, 64% of the obese
subjects as well as 66% of the overweight ones lost
more than 1 kg of body weight (Figure 5).
Effects of Oolong Tea Ingestion on Plasma TG
and TC Levels
The plasma TG of 22 subjects and the plasma TC
of 51 subjects were over the normal level before the
ingestion of oolong tea. After the ingestion of oolong
tea for 6 weeks, the plasma TG level of the 22 subjects
with hypertriglyceridemia decreased about 20%
Figure 2. Effect of Oolong Tea Ingestion on the Correlation Coefficient
between Weight and Subcutaneous Fat (102 cases)
Notes: Δ(delta): The degree of change before and after oolong tea ingestions. A: all volunteers after the ingestion of oolong tea; B:
male subjects after the ingestion of oolong tea; C: female subjects after the ingestion of oolong tea; the same as in Figures 3 and 4
Fat thickness (mm)
Weight (kg)
25
20
15
10
5
0
03691215
A
y=0.27x+6.02
r
=0.140,
P
<0.2
Fat thickness (mm)
Weight (kg)
Fat thickness (mm)
Weight (kg)
25
20
15
10
5
0
0 3 6 9 12 15
B
y=-0.12x+8.26
r
=0.055,
P
>0.05
25
20
15
10
5
0
03691215
C
y=0.81x+3.92
r
=0.440,
P
<0.01
Figure 3. Effect of Oolong Tea Ingestion on the Correlation Coefficient
between Weight and Waist Size (102 cases)
Waist (cm)
Weight (kg)
A
y=0.42x+2.80
r
=0.440,
P
<0.01
12
9
6
3
0
Waist (cm)
Weight (kg)
C
y=0.52x+2.56
r
=0.480,
P
<0.01
12
9
6
3
0
03691215
Waist (cm)
Weight (kg)
B
y=0.66x+1.44
r
=0.730,
P
<0.01
12
9
6
3
0
0 3 6 9 12 1503691215
Figure 4. Effect of Oolong Tea Ingestion on the Correlation Coefficient
between Waist and Subcutaneous Fat (102 cases)
Fat thickness (mm)
Waist (cm)
25
20
15
10
5
0
02.55 7.5
10
C
y=
0.96x+2.38
r
=0.554,
P
<0.01
Fat thickness (mm)
Waist (cm)
25
20
15
10
5
0
0 2.5 5 7.5 10
A
y=
0.39x+5.24
r
=0.190,
P
<0.1
Fat thickness (mm)
Waist (cm)
25
20
15
10
5
0
0 2.5 5 7.5 10
B
y
=
0.12x+7.37
r
=0.050,
P
>0.05
Figure 5. Beneficial Effects of Oolong Tea
Ingestion for Diet-induced Overweight and
Obese Subjects (102 cases)
Degree of obesity
58
52
50
48
15
8
14
22
33
34
36
30
1% 50% 100% >3 kg
1-3 kg
<1 kg
severe
moderate
slight
total
39
Chin J Integr Med 2009 Feb;15(1):34-41
and energy expenditure(18). Therefore, promoting fat
metabolism should be considered as basic. It was
previously reported that oolong tea could accelerate fat
metabolism through activating the lipoprotein lipase(19),
and significantly increase energy expenditure and fat
oxidation(9). In general, the main active components of
oolong tea affecting lipid metabolism are thought to be
tea caffeine and tea polyphenols including EGCG, EGC,
ECG, GCG, GC, CG and EC(20, 21). Among these active
components, caffeine played a key role for oolong tea
to prevent or treat obesity because of its thermogenesis
and fat oxidation effects. Some evidence from the high-
fat diet-treated mice indicated that the caffeine isolated
from oolong tea could enhance noradrenaline-induced
lipolysis. As a non-specific antagonist of adenosine
receptors, caffeine modifies energy metabolism through
increasing intracellular free Ca2+ concentration and
promoting catecholamine release from noradrenergic
nerve terminal. Caffeine also elevates the metabolic
rate and fatty acid availability by means of lipolysis of
fat cells(22, 23). The effects of caffeine are ascribed to
the adenyl cyclase-cAMP phosphodiesterase cycle(24).
cAMP-dependent protein kinase A activates hormone-
sensitive lipase, and then this enzyme catalyzes the
hydrolysis of TG in fat cells so that eventually lipolysis
is enhanced(25, 8). Besides, catechins and EGCG were
also proven to reduce the total TG accumulation of
murine 3T3-L1 preadipocytes during their differentiation
into adipocytes induced by dexamethasone, 1-methyl-
3-isobutylxanthine and insulin(26). EGCG and ECG
inhibited acetyl-CoA carboxylase activity, a rate-
limiting step in the fatty acid biosynthesis pathway, in
3T3-L1 cells(27).Therefore, the
in vitro
effect of EGCG
on fat tissues may be mediated by the modulation of
hormone-stimulated cell proliferation and differentiation
or by the inhibition of fat cell functions(6).
Reducing glucose and fat absorption were known
as an important step to improve obesity(28). It was
Table 3. Inhibition of Pancreatic Lipase by
Oolong Tea Extract and Catechins
in vitro
Sample Lipase inhibitory activity (IC50, μg/mL)
Oolong tea extract 0.97
Catechin >10
EGCG 0.16
ECG 0.14
GCG 0.24
GC >10
CG 0.38
Note: The values are presented as the mean of four
samples
Inhibition of Pancreatic Lipase by Oolong Tea
Extract and Catechins
in vitro
The IC50 values of oolong tea extract and tea
polyphenols such as catechin, EGCG, ECG, GCG, GC and
CG were shown in Table 3, indicating that ECG and EGCG
caused more potent inhibition than the oolong tea extract
did. GCG and CG had weakly inhibitory effects. However,
catechin and GC were not effective at up to 10 μg/mL.
DISCUSSION
In the present study, 102 diet-induced overweight
and obese subjects were recruited to investigate the
anti-obesity effects of oolong tea. Each of the subjects
ingested 8 g per day of oolong tea for 6 weeks. The
results show that the correlation between height and
body weight was slightly improved, which was more
remarkable in women. Although the effect of oolong tea
was slight or moderate, it was interesting that oolong
tea led to the drop of body weight reduction without
significant changes in food consumption before and
after the ingestion of oolong tea.
Furthermore, the waist size in the obese subjects
was observed to appear slightly lower after 6-week
ingestion of oolong tea, and the correlation coefficient
between the decrease in waist size and the decrease
in subcutaneous fat thickness was more marked in
women (
r
=0.554) than in men (
r
=0.050), indicating the
decrease in waist size in men might be due to improved
internal adipose levels rather than subcutaneous ones.
Usually, the general obesity is defined as an
excessive amount of fat tissue in the body, which
results from an imbalance between energy intake
(
P
<0.05, Figure 6A). and the plasma TC level in the
subjects with hypercholesterolemia also significantly
decreased (
P
<0.01, Figure 6B).
TG (mg/dL)
350
250
150
Before treatment After treatment
280
260
240
220
TC (mg/dL)
Before treatment After treatment
Figure 6. Effects of Oolong Tea Ingestion on
Plasma TG and TC Levels
Notes: A: 22 subjects with high plasma TG level; B: 51
subjects with high plasma TC level;
P
<0.05,
P
<0.01
AB
40 Chin J Integr Med 2009 Feb;15(1):34-41
found that polyphenols, including catechins, in oolong
tea could inhibit some digestive enzymes such as
α-glucosidase, which may be related to the inhibitory
effect of oolong tea on the absorption of glucose and
sucrose(28). However, it is not likely that the suppressive
effect of oolong tea on body weight is completely
dependent on a reduction in carbohydrate absorption.
Other studies displayed that oolong tea suppressed
the intestinal absorption of dietary fat by inhibiting
pancreatic lipase(7, 29). Our results also proved that
oolong tea extract and catechins inhibited pancreatic
lipase
in vitro
, in which ECG and EGCG caused more
potent inhibition than the oolong tea extract did. Thus,
the anti-obesity effects of oolong tea were not due to
diarrhea or anorexia, but to promoting lipid utilization
induced by caffeine, the suppression for fat tissue
function induced by catechins as mentioned above,
and the control of lipid absorption from the intestine.
A correlation between obesity and
hyperlipidemia crisis has been previously confirmed
and excessive cholesterol in obese subjects causes
arteriosclerosis(30-32). Therefore, it is important to
keep plasma TG and cholesterol at normal levels for
the prevention of diseases such as arteriosclerosis,
cerebral apoplexy and myocardial infarction. In
the present study, it was observed that oolong tea
decreased the plasma TG level to 20% in 22 subjects
with obesity and improved the plasma TC level
in 51 obesity subjects. However, the mechanism
responsible for the antihyperlipidemic effects of
oolong tea remains unclear. Many studies on the
reduction of cholesterol levels induced by tea have
been conducted in Japan since the 1980s. It has been
proved that tea catechins not only inhibit cholesterol
absorption by intestinal epithelium cells(33) and
decrease the solubility of cholesterol in bile acid(34, 35)
but also activate lipoprotein lipase to reduce the levels
of cholesterol and TG in the blood via the hydrolysis
of TG in TG-rich lipoprotein(19). Tea catechins also
improve the balance between high density lipoprotein
cholesterol (HDL) and low density lipoprotein
cholesterol (LDL)(36). TC, LDL and TG levels in the
plasma are decreased in healthy subjects, whereas
HDL levels in hyperlipidemia subjects are increased
by the ingestion of oolong tea(37). These data suggest
that the mechanism for oolong tea to prevent
hyperlipidemia may be related to the regulative action
of oolong tea catechins including EGCG, EGC, ECG,
GCG, GC, CG and EC in lipoprotein metabolism.
Although we are unable to describe the mechanism
responsible for plasma TC metabolism, it was
previously noted that this effect is due to inhibition of
the synthesis of cholesterol in the liver(38).
The increased risk of life-style related diseases
in obese individuals has been known since the ancient
times(39). The present study shows that oolong tea has
beneficial effects on health such as anti-obesity activity
and the improvement of lipid metabolism, in which its
consumption moderately reduces body weight and
decreases body fat contents. As a result, continuous
consumption of oolong tea may prevent many diseases
related to obesity from occurring without adversely
suppressing a person's appetite or physical fitness.
REFERENCES
Abelson P, Kennedy D. The obesity epidemic. Science
2004;304:1413.
Hill JO, Melanson EL, Wyatt HT. Dietary fat intake and
regulation of energy balance: Implications for obesity. J
Nutr 2000; 130: 284S-288S.
Manson JE, Colditz GA, Stampfer MJ, Willett WC, Rosner
B, Monson RR, et al. A prospective study of obesity and
risk of coronary heart disease in women. N Engl J Med
1990;322:882-889.
Astrup A, Buemann B, Western P, Toubro S, Raben A,
Christensen NJ. Obesity as an adaptation to a high-fat
diet: evidence from a cross-sectional study. Am J Clin Nutri
1994;59:350-355.
Campfield LA, Smith FJ, Burn P. Strategies and potential
molecular targets for obesity treatment. Science 1998;
280:1383-1387.
Bray GA, Greenway FL. Current and potential drugs for
treatment of obesity. Endocr Rev 1999;20:805-875.
Han LK, Takaku T, Li J, Kimura Y, Okuda H. Anti-obesity
action of oolong tea. Int J Obes 1999;23:98-105.
Kuo KL, Weng MS, Chiang CT, Tsai YJ, Lin-Shiau SY, Lin
JK. Comparative studies on the hypolipidemic and growth
suppressive effects of oolong, black, pu-erh, and green tea
leaves in rats. J Agric Food Chem 2005; 53:489-489.
Rumpler W, Seale J, Clevidence B, Judd J, Wiley E,
Yamamoto S, et al. Oolong tea increases metabolic rate
and fat oxidation in men. J Nutr 2001;131:2848-2852.
Okuda H, Han LK. Medicinal plant and its related metabolic
modulators. Nippon Yakurigaku Zasshi 2001;118:347-351.
Davies MJ, Judd JT, Baer DJ, Clevidence BA, Paul DR,
Edwards AJ, et al. Black tea consumption reduces total and
LDL cholesterol in mildly hypercholesterolemic adults. J
Nutr 2003;133:3298-3302.
Khosla T, Lowe CR. Indices of obesity derived from body
weight and height. Br J Prev Soc Med 1967;21:122-128.
WHO Physical Status: The use and interpretation of
anthropometry. Report of a WHO expert committee
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
41
Chin J Integr Med 2009 Feb;15(1):34-41
Geneva: World Health Organization Technical Report
Seriels; 1995:854.
WHO. Obesity: preventing and managing the global
epidemic. Report of a WHO Consultation on obesity,
Geneva 3-5, June 1997. World Health Organization
Techinical Report Series. Vol. 210. Geneva: World Health
Organization;1997:1-276.
Xie B, Shi H, Chen Q, Ho CT. Antioxidant properties of
fractions and polyphenol constituents from green, oolong
and black teas. Proc Natl Sci Counc Repub China (B)
1993;17:77-84.
Bitou N, Ninomiya M, Tsujita T, Okuda H. Screening of
lipase inhibitors from marine algae. Lipids 1999;34:441-445.
Golor G, Yamashita K, Koner W, Hagenmaier H, Neubert
D. Kinetics and inductive potency of 1, 2, 3, 4, 6, 7,
8-heptachlorodibenzo-p-dioxin (H7CDD) in rats. Life Sci
2001;69:493-508.
Saris W. Sugars, energy metabolism, and body weight
control. Am J Clini Nutri 2003;78:850-857.
Iwata K, Inayama T, Miw S, Kawaguchi K, Koike G. Effect of
oolong tea on plasma lipids and lipoprotein lipase activity in
young women. J Jpn Soc Nutr Food Sci 1991;44:251-259.
Lin YS, Tsai YJ, Tsay JS, Lin JK. Factors affecting the
levels of tea polyphenols and caffeine in tea leaves. J Agric
Food Chem 2003;51:1864-1873.
Dulloo AG, Dure C, Rohrer D, Girardier L, Mensi N, Fathi M.
Efficacy of a green tea extract rich in catechin polyphenols
and caffeine in increasing 24-h energy expenditure and fat
oxidation in humans. Am J Clin Nutri 1999;70:1040-1045.
Bianchi CP. Cellular pharmacology of contraction
of skeletal muscle. In: Narahashi T, ed. Cellular
pharmacology of excitable tissues. Charles C: Thomas
Publisher;1975:485-519.
Arciero PJ, Gardner AW, Calles-Escandon J, Benowitz NL,
Poehlman ET. Effects of caffeine ingestion on NE kinetics,
fat oxidation, and energy expenditure in younger and older
men. Am J Physiol 1995;268:E1192-E1198.
Couturier C, Janvier B, Girlich D, Bereziat G, Andreani-
Mangeney M. Effects of caffeine on lipoprotein lipase gene
expression during the adipocyte differentiation process.
Lipids 1998;33:455-460.
Mulder H, Holst LS, Svensson H, Degerman E, Sundler
F, Ahren B. Hormone-sensitive lipase, the rate-limiting
enzyme in triglyceride hydrolysis, is expressed and active
in beta-cells. Diabetes 1999;48: 228-232.
Kao YH, Hiipakka RA, Liao S. Modulation of obesity by
green tea catechins. Am J Clin Nutr 2000;72:1232-1233.
Watanabe J, Kawabata J, Niki R. Isolation and
identification of acetyl-CoA carboxylase inhibitors from
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
green tea (Camellia sinensis). Biosci Biotechnol Biochem
1998;62:532-534.
Nakahara K, Izumi R, Kodama T, Kiso Y, Tanaka T.
Inhibition of postprandial hyperglycaemia by oolong tea
extract (OTE). Phytother Res 1994;8:433-435.
Han LK, Kimura Y, Kawashima M, Takaku T, Taniyama
T, Hayashi T, et al. Anti-obesity effects in rodents
of dietary teasaponin, a lipase inhibitor. Int J Obes
2001;25:1459-1464.
Inui Y, Kawata S, Matsuzawa Y, Tokunaga K, Fujioka A,
Tamura S, et al. Increased level of apolipoprotein B mRNA
in the liver of ventromedial hypothalamus lesioned obese
rats. Biochim Biophys Res Commun 1989;163:1107-1112.
Wang SR, Infante J, Catala D, Petit D, Bonnefis MT, Infante
R. Lipid and lipoprotein synthesis in isolated and cultured
hepatocytes from lean and obese Zucker rats. Biochim Acta
1989;1002:302-311.
Garrison RJ, Wilson PW, Castelli WP, Feinleib M,
Kannel WB, McNamara PM. Obesity and lipoprotein
cholesterol in the Framingham offspring study. Metabolism
1980;29:1053-1060.
Chisaka T, Matsuda H, Kubomura Y, Mochizuki M,
Yamahara J, Fujimura H. The effect of crude drugs on
experimental hypercholesteremia: Mode of action of
(-)-epigallocatechin gallate in tea leaves. Chem Pharm Bull
1988;36:227-233.
Ikeda I, Imasato Y, Sasaki E, Nakayama M, Nagao T,
Takeo T, et al. Tea catechins decrease micellar solubility
and intestinal absorption of cholesterol in rats. Biochim
Biophys Acta 1992;1127:141-146.
Okuda T, Kimura Y, Yoshida T, Hatano T, Okuda H, Arichi S.
Studies on the activities of tannins and related compounds
from medicinal plants and drugs. I. Inhibitory effects on lipid
peroxdation in mitochondria and microsomes of liver. Chem
Pharm Bull 1983;31:1625-1631.
Muramatsu K, Fukuyo M, Hara Y. Effect of green tea
catechins on plasma cholesterol level in cholesterol-fed
rats. J Nutr Sci Vitaminol 1986;32:613-622.
Matsuda H, Chisaka T, Kubomura Y, Yamahara J, Sawada
T, Fujimura H. Effects of crude drugs on experimental
hypercholesterolemia. I. Tea and its active principles. J
Ethnopharmacol 1986;17:213-224.
Hasegawa N, Yamda N, Mori M. Powdered green tea
has antilipogenic effect on Zucker rats fed a high-fat diet.
Phytother Res 2003;17:477-480.
Matsuzawa Y. Life style-related disease. Nippon Rinsho
2001;59:188-194.
(Received September 17, 2008)
Edited by WANG Wei-xia
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
... The oolong tea used in this study was commercially available Himalayan oolong tea (Udyan tea, Siliguri, West Bengal, India; FSSL 12813006001028; Grade-SFTGFOP1; Family-Theaceae and species-C sinensis). About 2 g of tea leaves (sealed in one-time use pre-weighed sachets) were steeped in 300 mL of hot water (90 to 95ºC) for 5 minutes (13). The subjects were asked to bring the water to a boil and then cool it down for about 2 minutes so that the ideal temperature was reached. ...
... In the present study, the test subjects ingested 2 g of oolong tea in 300 mL of hot water in one serving per day. Studies have shown that this may result in total caffeine and polyphenol concentrations of 23.5 mg and 99.32 mg, respectively, per 100 mL of tea consumed, which was slightly more than green tea (13,25,26). As there are no direct studies relating oolong tea consumption with periodontal health, twice daily administration was advised to ensure minimum caffeine exposure and patient compliance. ...
Article
Introduction: Oolong tea, a functional food, has numerous therapeutic benefits owing to the presence of bioactive polyphenols, theasinensins (TS) and catechins. The present study aimed to evaluate the influence of systemic administration of oolong tea as an adjunct to nonsurgical periodontal therapy (NSPT) in the management of chronic periodontitis (CP).Methods: A total of 60 subjects with mild to moderate CP were randomly divided into two groups of tests (n = 30) and the controls (n = 30). They underwent NSPT with adjunctive oolong tea supplementation in the test group only. At baseline, 1, and 3 months, their gingival index (GI), plaque index (PI), probing pocket depth (PPD), clinical attachment loss (CAL), percentage of sites with bleeding on probing (BOP), and lobene stain index (LSI) were recorded. Furthermore, the levels of glutathione peroxidase (GPx), total antioxidants (TAO), and malondialdehyde (MDA) were also estimated in gingival crevicular fluid (GCF), saliva and serum. Additionally, colony-forming units (CFUs) of selective supra and subgingival plaque bacteria were estimated in the plaque samples.Results: In both groups, at 1 month, the GI, PI, BOP, GPx, and TAO levels were improved with a reduction in the levels of MDA and CFU’s and no staining of teeth (P < 0.05). The results were maintained in the test group at 3-month recall visit.Conclusion: Adjunctive administration of oolong tea with NSPT reduced the local and systemic oxidative burden and rapidly resolved the inflammation in CP. This would be specifically beneficial in CP subjects with systemic conditions.
... For example, one RCT study found that the intake of black Chinese tea extract (BTE) (333 mg/day) before meals for 12 weeks induced a decrease in both BMI and weight (Kubota et al., 2011). Another study found that drinking 8 g of oolong tea per day could decrease body fat content (He et al., 2009). In addition, one cohort study published in 2021 [relative risk (RR) = 0.767, 95% CI = 0.738 to 0.796, p < 0.05] and two meta-analyses published in 2020 came up with the positive results of the effect of tea on obesity (Li X. et al., 2020;Lin et al., 2020;Zhang et al., 2021c). ...
... Traditional epidemiological studies, consisting of case-control studies and cohort studies, provide representative findings on the relationship between exposures and outcomes. However, these studies are usually biased by confounding factors and adverse causal effects (He et al., 2009;Vernarelli and Lambert, 2013;Cai et al., 2021). MR analysis can control the biases by introducing instrumental variables (Gage et al., 2018;Choi et al., 2020). ...
Article
Full-text available
Evidence from observational studies for the effect of tea consumption on obesity is inconclusive. This study aimed to verify the causal association between tea consumption and obesity through a two-sample Mendelian randomization (MR) analysis in general population-based datasets. The genetic instruments, single nucleotide polymorphisms (SNPs) associated with tea consumption habits, were obtained from genome-wide association studies (GWAS): UK Biobank, Nurses’ Health Study, Health Professionals Follow-up Study, and Women’s Genome Health Study. The effect of the genetic instruments on obesity was analyzed using the UK Biobank dataset (among ∼500,000 participants). The causal relationship between tea consumption and obesity was analyzed by five methods of MR analyses: inverse variance weighted (IVW) method, MR-Egger regression method, weighted median estimator (WME), weighted mode, and simple mode. Ninety-one SNPs were identified as genetic instruments in our study. A mild causation was found by IVW (odds ratio [OR] = 0.998, 95% confidence interval [CI] = 0.996 to 1.000, p = 0.049]), which is commonly used in two-sample MR analysis, indicating that tea consumption has a statistically significant but medically weak effect on obesity control. However, the other four approaches did not show significance. Since there was no heterogeneity and pleiotropy in this study, the IVW approach has the priority of recommendation. Further studies are needed to clarify the effects of tea consumption on obesity-related health problems in detail.
... Cellular studies showed that black tea extract suppressed pancreatic lipase activity and reduced fat digestion, and the in vivo study indicated that black tea extract inhibited the body weight gain and reduced the parametrial adipose tissue mass, which was attributed to the decreased intestinal lipid absorption (Uchiyama et al. 2011;Oi et al. 2012). Another in vitro assay showed that oolong tea extract and catechins exerted an inhibitory effect on pancreatic lipase, which might contribute to decreasing body weight and preventing hyperlipidemia (He et al. 2009). Besides, green tea extract reduced the lipid accumulation in mice fed with HFD by downregulating mRNA expression of hepatic lipid uptake genes, such as cluster of differentiation 36 (CD36) (Li, Kek, et al. 2016). ...
... The intake of catechin reduced the total abdominal fat area, abdominal subcutaneous fat area and the concentrations of TG and FFA in serum, which improved the body composition and fat distribution in overweight adults (Maki et al. 2009). Furthermore, a total of 102 overweight or obese subjects daily ingested 8 g oolong tea for 6 weeks, and their body weight and plasma levels of TG and total cholesterol (TC) were decreased, indicating that the chronic consumption of oolong tea might prevent obesity and hyperlipidemia (He et al. 2009). Although some clinical trials show that tea and its components could improve obesity-related indicators, such as fat oxidation, energy expenditure, serum lipid parameters and hormones, they exerted no significant change in the body weight. ...
Article
Obesity has become a global health concern. It increases the risk of several diseases, such as type 2 diabetes mellitus, nonalcoholic fatty liver disease, and certain cancers, which threatens human health and increases social economic burden. As one of the most consumed beverages, tea contains various phytochemicals with potent bioactive properties and health-promoting effects, such as antioxidant, immune-regulation, cardiovascular protection and anticancer. Tea and its components are also considered as potential candidates for anti-obesity. Epidemiological studies indicate that regular consumption of tea is beneficial for reducing body fat. In addition, the experimental studies demonstrate that the potential anti-obesity mechanisms of tea are mainly involved in increasing energy expenditure and lipid catabolism, decreasing nutrient digestion and absorption as well as lipid synthesis, and regulating adipocytes, neuroendocrine system and gut microbiota. Moreover, most of clinical studies illustrate that the intake of green tea could reduce body weight and alleviate the obesity. In this review, we focus on the effect of tea and its components on obesity from epidemiological, experimental, and clinical studies, and discuss their potential mechanisms.
... For its purported health advantages [61], green tea, an aqueous extract prepared from the leaves of the Camellia sinensis plant, has long been treasured throughout Asia. Century-old anecdotal evidence has been experimentally validated by showing that Camellia sinensis has antioxidant [62], anti-inflammatory [63], antimicrobial [64] activities, and that it also has anti-carcinogenic [65] activities, as well as antiobesity [66][67][68] activities, as well as cardioprotective [69] and neuroprotective [70] activities. Catechins, the polyphenolic chemicals derived from the Camellia sinensis plant, are thought to be the primary catalysts for these pharmacological effects [71]. ...
Article
Full-text available
Wounds on the skin can heal on their own through a process known as cutaneous wound healing. Haemostasis, inflammation, proliferation, and remodelling are the four stages of wound healing that are usually recognised. To close the wound and restore homeostasis in humans and animals, keratinocytes create a functional epidermis (reepithelialisation) as quickly as feasible. "Granulation tissue" is formed when dermal fibroblasts move into the wound bed and multiply, allowing for the formation of new blood vessels. In the end, the wounded tissue is returned to its pre-injury form over an extended period. Various skin diseases, such as nonhealing or chronic ulceration, can result from wound healing cascade dysfunction. For more than half of all medicines used today, indigenous, and traditional treatments rely heavily on natural ingredients and their derivatives. A detailed literature review has been carried out recognising the importance of traditional medicine and the use of medicinal plants and plant-based products to treat cutaneous wounds. Curcuma longa, Aloe vera and Camellia sinesis are some of the most often utilised wound healing products throughout a wide range of countries and ethnicities. Traditional techniques still have a lot to teach us, as seen by their continuous use and popularity. Natural products and derivatives from natural products are full of unknown combinations, reagents, and adjunct chemicals that potentially have a position in today's therapeutic arsenal.
... Previous research indicated that teas exhibit plenty pro-health properties including reducing obesity and blood glucose levels (Jigisha et al., 2012;Shi and Schlegel, 2012;Hosoda et al., 2003;He et al., 2009;Panagiotakos et al., 2009;Oba et al., 2010), concentration and immunity (Hammer, 2007), lowers total cholesterol levels (Sinija and Mishra, 2008), preventing several types of cancer (Huang et al., 2014;Michalak-Majewska, 2011;Seow et al., 2020;Sinija and Mishra, 2008;Jigisha et al., 2012;Shi and Schlegel, 2012), brain strokes (Arab et al., 2013), furthermore make possible more efficient heart muscle (Stańczyk, 2010;Jigisha et al., 2012;Shi and Schlegel, 2012), expansion of coronary and brain vessels and of bronchi, increasing body temperature (Stańczyk, 2010), diarrhea prevention (Doustfatemeh et al., 2016), contraction (Einöther and Martens, 2013), anti-inflammation (Sanliera et al., 2018;Sinija and Mishra, 2008;Shi and Schlegel, 2012), bactericidal and bacteriostatic effects, alleviation of burning and itching (Stańczyk, 2010;Jigisha et al., 2012), protects against solar radiation (Michalak-Majewska, 2011), antiviral and anticaries effects (Michalak-Majewska, 2011;Sanliera et al., 2018;Sinija and Mishra 2008;Jigisha et al., 2012), protection of the nervous system (Steptoe et al., 2007;Unno et al., 2017), slowing down the aging process (Stańczyk, 2010;Sanliera et al., 2018;Jigisha et al., 2012), lessening the symptoms of depression. ...
... 14,16) Reportedly, daily consumption of 8 g oolong tea leaves, which is rich in polymerized polyphenols, reduced body weight and subcutaneous fat. 17) Our pilot study showed that Kosen-cha significantly reduced the body weight and BMI of overweight patients. 15) However, in the present study, body weight, BMI, waist circumference, blood glucose, LDL-C, and TG remained unchanged between the two groups. ...
Article
Full-text available
Green tea contains catechins, possessing anti-obesity and anti-oxidative effects, and has been consumed for hundreds of years. Our previous pilot study reported that Kosen-cha improves obesity and the parameters of metabolic syndromes in obese patients, however, the effect of Kosen-cha on obesity is still unclear in pre-obese subjects. The aim of this study was to investigate the effect of Kosen-cha on obesity and related clinical parameters including blood lipid and liver functions in a randomized placebo-controlled, double-blinded study. In total, 54 subjects with body mass index (BMI) of 25–30 were enrolled and randomized to receive either Kosen-cha or a placebo. The subjects drank Kosen-cha or the placebo thrice-daily for 12 weeks. Thereafter, we examined the effect of Kosen-cha on obesity (body weight, BMI, body fat, waist circumference, and visceral fat), lipid metabolism (triglyceride and high- and low-density lipoprotein cholesterol), and serum liver enzymes (aspartate aminotransferase, alanine aminotransferase (ALT), and γ-glutamyl transpeptidase). None of the subjects reported adverse effects from drinking Kosen-cha. Body weight, BMI, body fat, waist circumference, and visceral fat area remained unchanged in both groups. However, the change ratio of ALT significantly reduced between placebo and Kosen-cha groups after 12 weeks (Kosen-cha: −11.1 ± 32.7% vs. placebo: 8.46 ± 23.4%, p = 0.019). These results show that the consumption of Kosen-cha did not significantly improve obesity and may reduce liver enzyme levels in pre-obese Japanese subjects.
... Green tea contains carbohydrates, proteins, amino acids, chlorophyll, minerals and minor elements (Lien et al., 2003), Green tea is a highly effective antioxidant because it contains high levels of polyphenols known as cation (Apak et al., 2006) which has multiple properties with positive effects as it inhibits free radicals (Lien et al., 2008) and contributes to lower cholesterol level. (He et al., 2009) and used as antimicrobial (Friedman, 2007) antiviral (Isaaca et al., 2008). ...
Conference Paper
Full-text available
This study was conducted in Department of Animal Production in the college of Agriculture, University of Diyala during the period 25/10/2017 to 7/12/2017, the study aimed to investigate the effect of adding green tea as an antioxidant to the diet on the carcass characteristics, parts in broiler Rose 308. The experimental units consist of 225 one day chicks which distributed randomly on four groups(45 chick for each treatment) and three replicates and an initial weight of 38 grams chick , where the number of birds in each replicate 15 chick and the treatments as following: standard diet without additions as a control (T1); standard diet with 1 kg/ton green tea Powder (T2); Add 2 kg/ton green tea powder (T3); Add 3 kg/ ton green tea powder (T4); Add 4kg/ ton green tea powder (T5).
Chapter
Noncommunicable diseases (NCDs) are one of the major public health concerns globally. Most of the NCDs including insulin resistance, metabolic syndrome, type 2 diabetes mellitus, fatty liver disease, and coronary heart disease are related to obesity and are called obesity-related NCDs (OR-NCDs). However, adipocytes can reduce OR-NCDs by secreting adiponectin. Adiponectin has an inverse relationship with body fat. Obese people have impairment in differentiating pre-adipocytes to adipocytes, the process facilitated by adiponectin. Adiponectin directly increases insulin sensitivity and reduces obesity-related insulin resistance by down-regulating hepatic glucose production and increasing fatty acid (FA) oxidation in skeletal muscle. Considering the various beneficial effects of adiponectin on health, increasing adiponectin might be a promising approach to prevent and treat OR-NCDs. Recent studies have shown that nutraceuticals and medicinal compounds isolated from plants could prevent and treat various diseases, particularly cardiovascular diseases (CVDs), diabetes mellitus, obesity, and non-alcoholic fatty liver disease. However, to our knowledge, the effect of these natural products, including herbal supplements and functional foods on adiponectin, has not yet been fully reviewed. The main aim of this review is to summarize the effects of nutraceuticals and herbal bioactive compounds on plasma adiponectin concentrations based on clinical studies. It can be concluded that medicinal plants, and herbal bioactive compounds, particularly curcumin, anthocyanins, resveratrol, soy, walnut, and dihydromyricetin can be used as adjunct or complementary therapeutic agents to increase plasma adiponectin, which could potentially prevent and treat NCDs.
Article
Full-text available
The replacement of consumed with foods containing high carbohydrates, fats and proteins exceed that the daily needs of body, causes many health problems, especially obesity. Complicated health problems have been trying to be solved with drugs, but it is not possible to control diseases if obesity is not resolved. Obesity causes inflammation, insulin resistance, vascular endoth elial dysfunction, and Low-Density Lipoprotein (LDL) increase. There are very few weight loss drugs with acceptable side effects, and these drugs are not given to people who are not considered obese according to their body mass index. For this reason, people seek the remedy in over the counter (OTC) (mostly products with active ingredients derived from plants) products or herbal teas. These products, which do not have direct effects, have mechanisms that can help and can be supportive with diet and sports. However, these products and teas that cannot be dosed by a knowledgeable healthcare professional can disrupt the balance of the body and cause various diseases. In this study, the effect levels with the mechanisms supporting weight loss on the biochemical parame ters of the active substances in the herbal forms sold and consumed as diet tea, were evaluated.
Article
Ethnopharmacological relevance Phyto-preparations and phyto-compounds, by their natural origin, easy availability, cost-effectiveness, and fruitful traditional uses based on accumulated experiences, have been extensively explored to mitigate the global burden of obesity. Aim of this review The review aimed to analyse and critically summarize the prospect of future anti-obesity drug leads from the extant array of phytochemicals for mitigation of obesity, using adipose related targets (adipocyte formation, lipid metabolism, and thermogenesis) and non-adipose targets (hepatic lipid metabolism, appetite, satiety, and pancreatic lipase activity). Phytochemicals as inhibitors of adipocyte differentiation, modulators of lipid metabolism, and thermogenic activators of adipocytes are specifically discussed with their non-adipose anti-obesogenic targets. Materials and methods PubMed, Google Scholar, Scopus, and SciFinder were accessed to collect data on traditional medicinal plants, compounds derived from plants, their reported anti-obesity mechanisms, and therapeutic targets. The taxonomically accepted name of each plant in this review has been vetted from “The Plant List” (www.theplantlist.org) or MPNS (http://mpns.kew.org). Results Available knowledge of a large number of phytochemicals, across a range of adipose and non-adipose targets, has been critically analysed and delineated by graphical and tabular depictions, towards mitigation of obesity. Neuro-endocrinal modulation in non-adipose targets brought into sharp dual focus, both non-adipose and adipose targets as the future of anti-obesity research. Numerous phytochemicals (Berberine, Xanthohumol, Ursolic acid, Guggulsterone, Tannic acid, etc.) have been found to be effectively reducing weight through lowered adipocyte formation, increased lipolysis, decreased lipogenesis, and enhanced thermogenesis. They have been affirmed as potential anti-obesity drugs of future because of their effectiveness yet having no threat to adipose or systemic insulin sensitivity. Conclusion Due to high molecular diversity and a greater ratio of benefit to risk, plant derived compounds hold high therapeutic potential to tackle obesity and associated risks. This review has been able to generate fresh perspectives on the anti-diabetic/anti-hyperglycemic/anti-obesity effect of phytochemicals. It has also brought into the focus that many phytochemicals demonstrating in vitro anti-obesogenic effects are yet to undergo in vivo investigation which could lead to potential phyto-molecules for dedicated anti-obesity action.
Conference Paper
Obesity represents a major threat to health and quality of life. Although obesity has strong genetic determinants, it is generally accepted that it results from an imbalance between food intake and daily physical activity. Health guidelines have been focused on 3 particular lifestyle factors: increased levels of physical activity and reductions in the intakes of fat and sugars. The dietary guidelines, especially, are under debate. This review covers evidence from carefully controlled laboratory studies, clinical trials, studies in populations at high risk of developing obesity, and epidemiologic studies on the role of sugars, particularly sucrose, in the development of obesity. Although many environmental factors promote a positive energy balance, it is clear that the consumption of a low-carbohydrate, high-fat diet increases the likelihood of weight gain. The evidence related to carbohydrate, particularly sugars, and the type of food (solid or liquid) is less clear because the number of long-term ad libitum dietary intervention trials is very small. Data on sucrose intake in relation to metabolism and weight gain do not associate high consumption of sucrose with the prevalence of obesity. The evidence supports the current dietary guidelines for reducing fat intake. However, the effect of the carbohydrate source and class and of the form in which carbohydrate is consumed (solid or liquid) on body weight control requires further consideration.
Article
I. Introduction II. Criteria for Evaluating the Efficacy of Antiobesity Treatment III. Physiological and Pharmacological Mechanisms to Reduce Food Intake A. Peripherally acting agents B. Centrally acting agents IV. Drugs That Alter Metabolism A. Preabsorptive agents B. Postabsorptive modifiers of nutrient metabolism V. Drugs That Increase Energy Expenditure A. Thyroid hormone B. Adrenergic thermogenic drugs VI. Conclusion
Article
Overweight and obesity represent a rapidly growing threat to the health of populations in an increasing number of countries. Indeed they are now so common that they are replacing more traditional problems such as undernutrition and infectious diseases as the most significant causes of ill-health. Obesity comorbidities include coronary heart disease, hypertension and stroke, certain types of cancer, non-insulin-dependent diabetes mellitus, gallbladder disease, dyslipidaemia, osteoarthritis and gout, and pulmonary diseases, including sleep apnoea. In addition, the obese suffer from social bias, prejudice and discrimination, on the part not only of the general public but also of health professionals, and this may make them reluctant to seek medical assistance. WHO therefore convened a Consultation on obesity to review current epidemiological information, contributing factors and associated consequences, and this report presents its conclusions and recommendations. In particular, the Consultation considered the system for classifying overweight and obesity based on the body mass index, and concluded that a coherent system is now available and should be adopted internationally. The Consultation also concluded that the fundamental causes of the obesity epidemic are sedentary lifestyles and high-fat energy-dense diets, both resulting from the profound changes taking place in society and the behavioural patterns of communities as a consequence of increased urbanization and industrialization and the disappearance of traditional lifestyles. A reduction in fat intake to around 20-25% of energy is necessary to minimize energy imbalance and weight gain in sedentary individuals. While there is strong evidence that certain genes have an influence on body mass and body fat, most do not qualify as necessary genes, i.e. genes that cause obesity whenever two copies of the defective allele are present; it is likely to be many years before the results of genetic research can be applied to the problem. Methods for the treatment of obesity are described, including dietary management, physical activity and exercise, and antiobesity drugs, with gastrointestinal surgery being reserved for extreme cases.
Article
実験1健康な成人女子を被験者とし, 日常飲用する濃度の3または5倍量の茶葉を浸出させた濃い濃度の烏龍茶を負荷したときの血漿脂質の経時変化を, 空腹時ならびに脂肪食経口負荷時において観察した。1) 血漿中の総コレステロール, HDLコレステロール, 中性脂肪およびリン脂質は, 空腹時および脂肪食負荷時ともに烏龍茶負荷の影響はみられなかった。2) 空腹時において血漿中のFFA量は時間の経過とともに上昇するが, 鳥龍茶負荷によりFFAはさらに高値を示し, 血中への放出が有意に増加した。脂肪食経口負荷時においても烏龍茶負荷によりFFAの放出が明らかに増加した。実験2健康な成人女子を被験者とし, 日常飲用する普通濃度の鳥龍茶を1日7杯, 6週間飲用させ血漿脂質ならびに血中LPL, H-TGL活性の変化を観察した。1) 烏龍茶の飲用により中性脂肪ならびにリン脂質は低値を示した。総コレステロールに変化はみられなかったが, 飲用後6週の時点において動脈硬化指数が改善された。2) 血中のH-TGL活性には有意な変化は認められなかったが, LPL活性は烏龍茶の飲用により高い活性値を示し, その傾向は烏龍茶の飲用終了後も引き続き観察された。
Article
An aqueous methanol extract from green tea showed potent acetyl-CoA carboxylase inhibitory activity. An active compound was isolated from the extract and identified as (-)-epigallocatechin gallate by instrumental analyses, The IC50 value of (-)-epigallocatechin gallate was 3.1 x 10(-4) M. Among tea catechins and related compounds, nearly equal activity was found in(-)-epigallocatechin gallate and (-)epicatechin gallate, whereas (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, gallic acid and methyl gallate each had no inhibitory activity. These results indicate that the 3-O-gallate group of the catechin structure was necessary for this activity. (-)-Epigallocatechin gallate inhibited triglyceride accumulation in 3T3-L1 cells at a concentration of 1.0 x 10(-7) M or higher.
Article
Oolong tea extract (OTE) was found to inhibit sucrase from the small intestine and α-amylase. The IC50 values were 0.25 mg/mL and 5.0 mg/mL respectively. The effect of OTE on postprandial hyperglycaemia was investigated in vivo in rats loaded with sucrose, maltose, soluble starch or glucose. OTE suppressed the increase of blood glucose levels in sucrose-, maltose- and glucose-loaded rats, but not in soluble starch-loaded rats. From these results it was assumed that orally administered OTE inhibits intestinal glycosidases, especially sucrase, thereby deterring the digestion of certain amounts of sucrose or maltose, and also inhibits glucose absorption partially, leading eventually to a reduction in blood glucose levels.
Article
A(−)-epicatechin (EC) and (−)-epigallocatechin (EGC) mixture and a mixture of their gallates (ECG and EGCG, respectively) markedly lowered lymphatic cholesterol absorption in rats with a cannulated thoracic duct. A mixture of ECG and EGCG was more effective in reducing cholesterol absorption than the EC and EGC mixture. These catechins also tended to decrease lymphatic absorption of triacylglycerols, although not so pronounced as in cholesterol absorption. An in vitro study on micellar solubility of cholesterol showed that these catechin mixtures precipitated cholesterol solubilized in mixed bile salt micelles in a dose-dependent manner. A mixture of ECG and EGCG more effectively precipitated micellar cholesterol than a mixture of EC and EGC. When purified EC, EGC, ECG and EGCG were used, EGCG was more effective in precipitating micellar cholesterol than ECG. The effect of EC and EGC was comparable and weaker than their gallate esters. The bile acid concentration in the micelles was not affected by these catechins. A positive correlation was observed between the amount of coprecipitated EGCG and cholesterol. These results clearly show that tea catechins, in particular their gallate esters, effectively reduce cholesterol absorption from the intestine by reducing solubility of cholesterol in mixed micelles. The observation accounts for the hypocholesterolemic effect of tea catechins.