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Abbreviations:
LFO, licorice flavonoid oil
MCT, medium-chain triglycerides
AE, adverse event
BMI, body mass index
BMR, basal metabolic rate
CT, computed tomography
AbstractAbdominal obesity, or accumulation of visceral fat,
is mainly associated with the onset of metabolic
syndrome. Licorice flavonoid oil (LFO) consisting
of licorice hydrophobic polyphenols in medium-
chain triglycerides (MCT) is a new functional food
ingredient effective in preventing metabolic syn-
drome. We have demonstrated significant effects
of LFO on reduction of total body fat and visceral
fat together with body weight in overweight Japan-
ese subjects. Obesity is a more serious problem in
Western countries such as Europe and the United
States compared to Japan. We hypothesized that
LFO could also work for abdominally obese people
in Western countries. We therefore tested the effects
of 300 mg LFO concentrate solution taken once
daily with evening meals for up to 12 weeks in
obese adult male and female subjects in the United
States. Results showed that visceral fat, as measured
by an abdominal CT scan, waist circumference
measurements and waist-to-hip ratio significantly
decreased in subjects in the LFO group compared
to the placebo group at Week 12. The side-effect
profile of LFO was indistinguishable from placebo.
Moreover, no adverse trends or toxicologically
meaningful differences in haematology and chem-
istry test results, vital signs or physical examina-
tions were observed that were attributable to LFO.
These results indicate that LFO is a safe food ingre-
dient for preventing metabolic syndrome not only
in Japan but also in Western countries such as Eu-
rope and the United States.
IntroductionMetabolic syndrome represents a combination of
medical disorders consisting of abdominal obesity
with clustering of high blood glucose, dyslipidaemia
Yuji Tominaga, Mitsuaki KitanoPharmacology & Toxicology LaboratoryFrontier Biochemical and Medical Research LaboratoriesKaneka Corporation1-8 Miyamae-machi, Takasago-cho, TakasagoHyogo 676-8688, Japan
Tatsumasa Mae, Sachie Kakimoto, Kaku Nakagawa (•)QOL DivisionKaneka Corporation2-3-18, Nakanoshima, Kita-kuOsaka 530-8288, [email protected]
Original Research 35
Effect of licorice flavonoid oil on visceral fat in obese subjects in the United States
A randomized, double-blind, placebo-controlled study Yuji Tominaga, Mitsuaki Kitano, Tatsumasa Mae, Sachie Kakimoto, Kaku Nakagawa
Received: 25 September 2013 / Accepted: 13 January 2014
© Springer – CEC Editore 2014
Correspondence to:
Kaku Nakagawa
Keywords: licorice flavonoid, Glycyrrhiza glabra L., metabolic syndrome, visceral fat, total body fat, abdominal fat
Nutrafoods (2014) 13:35-43DOI 10.1007/s13749-014-0002-9
36
Despite the fact that an enormous number of people
suffer from obesity in Europe and the United States,
this promising anti-obesity effect of LFO had not
been tested in obese subjects in Western countries.
In the present study, we hypothesised that LFO
could also work for obese people with a BMI of over
30 kg/m2 in Europe and the United States. If effec-
tive, LFO may be useful in human nutrition world-
wide for the prevention of metabolic syndrome by
reducing visceral fat accumulation in overweight
and obese people. Here, we conducted a ran-
domised, double-blind, placebo-controlled study to
evaluate the efficacy of LFO in obese Americans
with a BMI between 30 and 40 kg/m2.
Methods and materialsSubjectsSubjects eligible for the study consisted of adult
males and females aged 18–65 years inclusive, who
were obese, with a BMI of ≥30 to <40 kg/m2 and a
waist-to-hip ratio of ≥0.9 for men and ≥0.8 for
women. Subjects needed to be in generally good
health (with mild stable conditions such as hyper-
tension, dyslipidaemia, gastroesophageal reflux,
controlled diabetes or asthma allowable at the in-
vestigator’s discretion). Subjects had to be willing
to maintain a daily diet of calories equivalent to
their basal metabolic rate (BMR)×1.375 for the du-
ration of the study. BMR was calculated according
to the Harris-Benedict equation [16]. Subjects
needed to be compliant with study procedures and
understand and provide written informed consent.
A total of 310 subjects were screened and 120 eligi-
ble subjects (60 male, 60 female) were enrolled.
LFO test substanceTo prepare the LFO test material, an ethanol extract
of licorice (G. glabra) root was obtained. After filtra-
tion and concentration, the ethanolic layer was
mixed with medium-chain triglycerides (MCT) with
a fatty acid composition of C8:C10=99:1. The con-
centration of glabridin, the major component of the
solution, was adjusted to 3% (w/w). This solution
and high blood pressure [1,2]. Those with metabolic
syndrome are twice as likely to suffer death from
all causes and three times as likely to have a heart
attack or stroke compared to those without [3]. Ac-
cording to findings from the Third National Health
and Nutrition Examination Survey, about 47 million
US residents have metabolic syndrome [4].
One of the primary causes of metabolic syndrome
is accumulation of visceral fat, which drives pro-
gression of multiple risk factors directly through ex-
cessive secretion of free fatty acids and inflammatory
adipocytokines, and suppression of adiponectin se-
cretion [5,6]. Considerable evidence supports the
association between insulin resistance and athero-
sclerosis and cardiovascular diseases. Insulin resist-
ance in particular could accelerate atherosclerosis
via the direct entry of atherogenic VLDL-derived
particles into the vasculature [7]. Therefore, reducing
excessive visceral fat is very important for preventing
such fatal vascular diseases.
Licorice flavonoid oil (LFO), derived from licorice,
Glycyrrhiza glabra L., is a new functional food in-
gredient consisting of licorice hydrophobic polyphe-
nols in medium-chain triglycerides (MCT). LFO was
developed by Kaneka Corporation under the brand
name Kaneka Glavonoid™. We previously demon-
strated that LFO can ameliorate abdominal obesity
and diabetes in metabolic syndrome mouse models
[8,9].
A number of studies have confirmed the preclinical
safety of LFO in vitro and in vivo including a 90-day
subchronic toxicity study in rats [10], genotoxicity
studies [11] and a medium-term liver bioassay for
carcinogenesis [12]. Subsequently, human safety
studies that included single and continuous-dose
studies [13] also confirmed the ingredient’s safety,
with no adverse events (AEs), accumulation in the
blood or carcinogenicity observed. Thereafter, stud-
ies with human subjects have shown LFO to be ef-
fective in reducing total body fat and visceral fat
together with body weight in Japanese overweight
subjects with a body mass index (BMI) of up to 30
kg/m2 [14,15].
Nutrafoods (2014) 13:35-43
1 3
37
to-hip ratio, BMI, sitting blood pressure, pulse rate,
temperature, and clinical laboratory tests. A physi-
cal examination was performed, AEs were assessed
and concomitant medication usage was recorded.
Abdominal computed tomography (CT) scans were
performed at baseline and at the end of the Week
12 visit. Females of childbearing age needed to test
negative for urine pregnancy tests to be eligible for
the study and to have abdominal CT scans at spec-
ified time points during the study.
Efficacy and safety measurementsBody weight, height, waist and hip circumference,waist-to-hip ratio measurementsBody weight was measured in kilograms with the
subject wearing light clothing such as a hospital
gown, and no shoes. Subjects were instructed to wear
the same type and amount of clothing at each study
visit and the same weight scale was used to the extent
possible. Height was measured in centimetres, with
subjects instructed to remove their shoes and socks
(i.e., subjects were measured barefoot).
Waist circumference was measured according to
the NHANES III protocol [17]. Specifically, to define
the level at which waist circumference was meas-
ured, a bony landmark was first located and
marked. The subject stood and the examiner pal-
pated the upper hip bone to locate the right iliac
crest. Just above the uppermost lateral border of
the right iliac crest, a horizontal mark was drawn
and then crossed with a vertical mark on the mid -
axillary line. A measuring tape was placed in a hor-
izontal plane around the abdomen at the level of
this marked point on the right side of the trunk.
The plane of the tape was set parallel to the floor,
with the tape pulled snugly but not compressing
the skin. The measurement was made during nor-
mal minimal respiration. Hip circumference was
measured by comfortably determining the distance
around the largest extension of the buttocks. The
waist-to-hip ratio was calculated by dividing the
waist circumference measurement by the hip cir-
cumference measurement.
was named “LFO concentrate solution”, which car-
ries the brand name Kaneka Glavonoid™. In the
present study, an LFO concentrate solution contain-
ing 3.0% glabridin was used as the LFO test sub-
stance. Each test capsule contained 100 mg LFO con-
centrate solution, 200 mg MCT and 33 mg beeswax
in a vegetable soft gel (Vegicap Soft®; Catalent Japan,
Tokyo, Japan), while placebo capsules contained 300
mg of MCT and 33 mg beeswax alone.
Study designThis was a single-centre, randomised, double-blind,
placebo-controlled study, which was performed at
the Advanced Biomedical Research, Inc. (Hacken-
sack, NJ), in accordance with the applicable good
clinical practice and ICH guidelines. The study pro-
tocol was approved by a properly constituted insti-
tutional board, the Essex Institutional Review
Board, Lebanon, NJ. Subjects received investiga-
tional food product, including 59 subjects who re-
ceived LFO and 61 subjects who received placebo.
At a screening visit (Visit 1, performed within 21
days of the baseline or randomisation visit), sub-
jects who provided written informed consent un-
dertook screening procedures, including a complete
medical history; medication history; physical ex-
amination including height, weight, waist and hip
circumference, waist-to-hip ratio, BMI, sitting blood
pressure, pulse rate and temperature; and clinical
laboratory tests. Subjects taking dietary supple-
ments containing licorice products were required
to discontinue their use at least 2 weeks prior to
randomisation. Eligible subjects who returned for
a baseline visit (Visit 2) were randomised to active
treatment consisting of LFO concentrate solution
300 mg/day or matching placebo (three capsules
once daily). The subjects took the LFO or placebo
capsules with their evening meal for up to 12 weeks
of double-blind treatment. Subjects returned to the
research clinic every 4 weeks (28±2 days) at the
end of Weeks 4, 8 and 12 (Visits 3, 4 and 5). At
each visit, the following measurements were per-
formed: weight, waist and hip circumference, waist-
Nutrafoods (2014) 13:35-43
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38
to the product, was assessed by the principal doctor.
All AEs reported by the subject or observed by the
principal investigator were individually listed. Signs
and symptoms, time of onset (24-h clock), dura-
tion, seriousness, action taken, relationship to in-
vestigational food product and follow-up proce-
dures were recorded.
Data sets analysedFor the safety analysis, all 120 subjects who were
enrolled and randomised, including 59 subjects in
the LFO group and 61 subjects in the placebo
group, were included. For the efficacy analysis, sub-
jects who dropped out of the study were excluded
from the 120 subjects analysed. Thus, 110 subjects
were included in the efficacy analysis, including
54 subjects in the LFO group and 56 subjects in
the placebo group.
Statistical analysisData are presented as mean±standard deviation
(SD). For efficacy analyses, a Student’s t-test was
conducted to compare placebo and LFO groups. A
p-value of less than 0.05 was considered significant.
ResultsDemographicsA total of 120 subjects were enrolled and ran-
domised, with 59 receiving LFO and 61 receiving
placebo. A total of 110 (91.7%) subjects completed
the study and 10 (8.3%) subjects, 5 from each
group, discontinued prior to study completion due
to request by the subject to be withdrawn, subject
non-compliance or being lost to follow-up. No sub-
ject discontinued study participation due to the
occurrence of an AE.
Table 1 shows subject demographics and baseline
characteristics. Mean (SD) age was 41.23 (11.41) years
(range 20–65 years), with 50% males and 50% fe-
males; 57.5% were Caucasian, 20.8% were Hispanic,
17.5% were Black and 4.2% were of other races. Mean
(SD) body weight was 99.51 (14.76) kg, BMI was
34.78 (2.70) kg/m2, waist circumference was 108.35
CT scan procedureAbdominal CT scans were performed at a diagnostic
imaging centre in close proximity to the ABR Clin-
ical Research Center, in accordance with the man-
ufacturer’s instructions and the imaging centre’s
standard procedures.
The abdominal CT scan procedure was performed
at Visit 2 (baseline) and Visit 5 (end of Week 12) in
the fasting state. The baseline abdominal CT scan
was obtained within 48 h prior to randomisation,
and the abdominal CT scan at the end of Week 12
was obtained within 48 h of the final visit.
Subjects were instructed not to wear tightly binding
clothes such as girdles or clothes that excessively
constrict the abdomen. In scanning the umbilical
region, individual CT image slices of three regions
were taken, including 1 cm above the umbilicus,
at the umbilicus level and 1 cm below the umbili-
cus. This umbilical region was scanned while the
subject held his or her breath at the expiratory
phase (after exhaling). Total fat area, visceral fat
area and subcutaneous fat area were calculated for
each abdominal CT image slice, and the average of
the three slices was also calculated.
Clinical laboratory testsBlood and urine samples for the clinical laboratory
tests described were obtained for each subject at
each study visit (Visits 1–5) after a 10-h (minimum)
fast, and included those for serum chemistry, liver
and kidney tests, lipid profiling, other metabolic
tests (glucose, haemoglobin A1c and insulin) and
haematology.
Vital signsSitting vital signs (blood pressure, pulse rate and
body temperature) were measured at the screening
visit and at each treatment visit (Visits 2–5).
AE reportingAny AE (clinical sign, symptom or disease) tempo-
rally associated with the use of the investigational
food product, whether or not considered related
Nutrafoods (2014) 13:35-43
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39
(9.61) cm and waist-to-hip ratio was 0.93 (0.06). En-
rolled subjects were representative of an overweight
to obese adult male or female population.
Body fat measurement from abdominal CT scanTable 2 shows results of the visceral fat area, sub-
cutaneous fat area and total fat area (abdominal
fat area), which is the sum of visceral and subcuta-
neous fat areas, on an abdominal CT scan.
The mean percent and absolute change from base-
line for visceral fat area were –3.318% and –6.412
Nutrafoods (2014) 13:35-43
1 3
Table 1 Subject demographics and baseline characteristics
Parameter LFO Placebo TotalN=59 N=61 N=120
Age (years)Mean (SD) 43.02 (11.17) 39.49 (11.47) 41.23 (11.41)Range 21–65 20–62 20–65
Gender (N)Male (%) 30 (50.85%) 30 (49.18%) 60 (50.0%)Female (%) 29 (49.15%) 31 (50.82%) 60 (50.0%)
Race (N)White, non-Hispanic (Caucasian) (%) 37 (62.71%) 32 (52.46%) 69 (57.50%)Black, non-Hispanic (%) 9 (15.25%) 12 (19.67%) 21 (17.50%)Latino/Hispanic (%) 11 (18.64%) 14 (22.95%) 25 (20.83%)American Indian or Alaskan Native (%) 0 (0.00%) 1 (1.64%) 1 (0.83%)Asian or Pacific Islander (%) 2 (3.39%) 1 (1.64%) 3 (2.50%)Other (%) 0 (0.00%) 1 (1.64%) 1 (0.83%)
Weight (kg)Mean (SD) 97.84 (13.75) 101.12 (15.63) 99.51 (14.76)Range 70.30–136.50 68.90–133.30 68.90–136.50
Height (cm)Mean (SD) 167.51 (9.63) 169.96 (9.68) 168.76 (9.69)Range 148.10–188.00 151.10–189.20 148.10–189.20
BMI (kg/m2)Mean (SD) 34.74 (2.56) 34.82 (2.86) 34.78 (2.70)Range 30.36–39.29 30.12–40.09 30.12–40.09
Hip circumference (cm)Mean (SD) 116.37 (6.86) 117.37 (8.22) 116.88 (7.56)Range 100–132 103–142 100–142
Waist circumference (cm)Mean (SD) 108.47 (9.69) 108.23 (9.62) 108.35 (9.61)Range 92–133 84–139 84–139
Waist-to-hip ratioMean (SD) 0.93 (0.07) 0.92 (0.06) 0.93 (0.06)Range 0.81–1.07 0.79–1.14 0.79–1.14
Parameter LFO Placebo TotalN=59 N=61 N=120
Fasting glucose (mg/dl)Mean (SD) 96.90 (8.63) 96.79 (10.22) –Range 78.0–126.0 76.0–121.0 –
Haemoglobin A1c (%)Mean (SD) 5.53 (0.37) 5.53 (0.36) –Range 4.4–6.5 5.0–6.5 –
Insulin (UIU/ml)Mean (SD) 8.25 (6.34) 12.07 (14.46) –Median 7.10 8.00 –Range 1.0–36.2 1.0–102.0 –
TSH (mIU/l)Mean (SD) 1.65 (0.78) 1.88 (1.05) –Median 1.43 1.55 –Range 0.48–4.06 0.35–5.12 –
Sitting SBP (mmHg)Mean (SD) 121.53 (13.90) 123.15 (12.60) 122.35 (13.23)Range 80–153 94–149 80–153
Sitting DBP (mmHg)Mean (SD) 80.02 (9.98) 80.25 (9.07) 80.13 (9.49)Range 45–100 63–98 45–100
Sitting pulse rate (bpm)Mean (SD) 71.42 (10.34) 70.30 (9.77) 70.85 (10.03)Range 52–100 53–100 52–100
Visceral fat area measured by CT (cm2)Mean (SD) 150.31 (64.65)* 147.47 (65.86)* –Range 47.10–313.33* 33.73–314.87* –
Subcutaneous fat area measured by CT (cm2)Mean (SD) 438.81 (107.59)* 443.65 (112.46)* –Range 241.30–694.00* 234.63–664.87* –
Total (abdominal) fat area measured by CT (cm2)Mean (SD) 589.22 (120.96)* 590.92 (113.69)* –Range 317.60–837.17* 386.00–851.90* –
*N=58
Table 2 Visceral, subcutaneous and total (abdominal) fat areameasured by CT at Week 12
N Visceral Subcutaneous Total (abdominal) fat area fat area fat area
Percent change from baseline (%)Placebo 56 7.066±23.544 –0.982±11.288 0.599±12.120LFO 54 –3.318±13.585** –3.707±10.819 –4.024±9.406*
Absolute change from baseline (cm2)Placebo 56 7.800±35.857 –5.376±49.146 2.286±69.041LFO 54 –6.412±20.526* –17.619±45.889 –24.359±57.165*
Values are mean±SDSignificant differences between the LFO and placebo groups by the Student’s t-test:**p<0.01, *p<0.05
40
(p=0.0352) and absolute change (p=0.0273) in waist
circumference at the same point in time.
Table 4 shows the results of waist-to-hip ratio, which
is calculated by dividing the waist circumference
measurement by the hip circumference measure-
ment. The mean percent change and absolute change
from baseline in waist-to-hip ratio were –3.190% and
–0.031, respectively, in the LFO group, and –1.119%
and –0.010, respectively, in the placebo group at
Week 12, with statistically significant differences be-
tween the two groups seen in percent change
(p=0.0273) and absolute change (p=0.0155) in waist-
to-hip ratio at the same point in time.
Body weight measurementsTable 5 shows the results of body weight measure-
ments for the two groups. The mean percent
changes from baseline in body weight in the LFO
group were –0.956 at Week 4, –1.363 at Week 8,
and –1.147 at Week 12. Those in the placebo group
were –0.776 at Week 4, –0.951 at Week 8 and –1.239
at Week 12. There were no statistically significant
differences between the two groups at Week 4, Week
8 and Week 12.
cm2, respectively, in the LFO group, and 7.066%
and 7.800 cm2, respectively, in the placebo group at
Week 12. There were statistically significant differ-
ences observed between the two groups in both per-
cent change (p=0.0057) and absolute change
(p=0.0125) in visceral fat area at the same point in
time. The mean percent and absolute change from
baseline in subcutaneous fat area was –3.707% and
–17.619 cm2, respectively, in the LFO group,
and –0.982% and –5.376 cm2, respectively, in the
placebo group at Week 12. There was no statistical
difference between the two groups regarding percent
change (p=0.1991) and absolute change (p=0.1801)
in subcutaneous fat area at the same point in time.
The mean percent and absolute change from base-
line in total fat area was –4.024% and –24.359 cm2,
respectively, in the LFO group, and 0.599% and
2.286 cm2, respectively, in the placebo group at Week
12, with statistically significant differences between
the two groups seen in total fat area for percent
change (p=0.0279) and for the absolute change
(p=0.0299) at the same point in time.
Waist circumference measurementsTable 3 shows the results of waist circumference
measurements for the two groups. The mean per-
cent and absolute change from baseline in waist
circumference were –5.634% and –6.269 cm, respec-
tively, in the LFO group, and –3.355% and –3.734
cm, respectively, in the placebo group at Week 12.
There were statistically significant differences be-
tween the two groups regarding percent change
Nutrafoods (2014) 13:35-43
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Table 3 Waist circumference measurements
N Week 4 Week 8 Week 12
Percent change from baseline (%)Placebo 56 –2.129±6.191 –3.650±6.514 –3.355±5.691LFO 54 –3.392±5.878 –4.752±4.558 –5.634±5.507*
Absolute change from baseline (cm)Placebo 56 –2.450±6.409 –4.066±6.683 –3.734±5.712LFO 54 –3.796±6.322 –5.198±4.920 –6.269±6.167*
Values are mean±SDSignificant differences between the LFO and placebo groups by the Student’s t-test:*p<0.05
Table 5 Body weight measurements
Percent change from baseline (%)
N Week 4 Week 8 Week 12
Placebo 56 –0.776±2.279 –0.951±3.225 –1.239±4.198LFO 54 –0.956±2.160 –1.363±2.682 –1.147±3.198
Values are mean±SD
Table 4 Waist-to-hip ratio
N Week 4 Week 8 Week 12
Percent change from baseline (%)Placebo 56 –1.207±5.396 –2.234±5.731 –1.119±4.622LFO 54 –2.178±4.542 –2.665±4.436 –3.190±5.077*
Absolute change from baselinePlacebo 56 –0.012±0.048 –0.021±0.051 –0.010±0.040LFO 54 –0.021±0.043 –0.025±0.041 –0.031±0.048*
Values are mean±SDSignificant differences between the LFO and placebo groups by the Student’s t-test:*p<0.05
41
DiscussionObesity is a serious health concern due to its asso-
ciation with type 2 diabetes mellitus and cardio-
vascular disease. According to the World Health
Organization [18], being overweight is defined as
having a BMI of 25 kg/m2 or higher, while obesity
is defined as having a BMI of 30 kg/m2 or higher.
The prevalence of obesity is no more than 2–3% in
the Japanese population; however, Japanese people
are prone to developing visceral fat obesity even if
they remain within the defined limits of being
overweight [19]. It is notable that lifestyle-related
diseases such as diabetes, hypertension and hyper-
lipidaemia are relatively common in Japan since
the pathogenesis of lifestyle-related diseases is re-
lated to visceral fat obesity [19].
On the other hand, the prevalence of obesity is
30.5% in the United States, and 17% for men and
19.8% for women in EU countries participating in
the MONICA study [20]. Thus, obesity is a more se-
rious problem in Western countries than in Japan.
Therefore, in order to demonstrate that LFO is ef-
fective as a dietary supplement even in obese people
in Europe and the United States, this clinical study
was conducted entirely with obese adult male and
female subjects from the United States with a BMI
of 30 kg/m2 or higher. In this study, the LFO con-
centrate solution was ingested as capsules at a dose
of 300 mg once daily for up to 12 weeks. After 12
weeks of LFO ingestion: (1) Visceral fat, as measured
by abdominal CT scan, was significantly lower in
the LFO group than the placebo group. (2) the LFO
group also experienced a decrease in the mean value
of waist circumference during the 12-week ingestion
period. This was reflected in observed significant
decreases in waist circumference measurements and
waist-to-hip ratio compared to placebo. (3) No clin-
ically significant AEs were observed during the
12-week ingestion period.
Since it is known that visceral fat area measured by
CT scan correlates with waist circumference meas-
urements [21], we believe that the above-mentioned
results possess higher reliability. Remarkably, the
Results of safety evaluationLFO concentrate solution 300 mg administered
orally once daily with evening meals was safe and
well-tolerated in adult male and female subjects
between the ages of 20 and 65 years in this study.
As shown in Table 6, a total of 13 (22.0%) subjects
in the LFO group reported AEs compared to 26
(42.6%) subjects in the placebo group. The most
common AEs were headache, reported in 8 (13.1%)
subjects in the placebo group and no subjects in
the LFO group; abdominal distension, reported in
7 (11.5%) subjects in the placebo group and no
subjects in the LFO group; and diarrhoea, reported
in 7 (11.5%) subjects in the placebo group and 6
(10.2%) subjects in the LFO group. Most AEs were
considered mild or moderate in intensity. There
were no adverse trends or toxicologically mean-
ingful differences between both groups regarding
haematology, coagulation and chemistry test re-
sults. Additionally, there were no clinically signifi-
cant adverse changes in vital signs or physical ex-
aminations attributable to LFO observed during
the study.
Nutrafoods (2014) 13:35-43
1 3
Table 6 Treatment-emergent adverse events (AEs)
Subjects with any AEs
LFO N=59 Placebo N=61
All subjects with AEs 13 22.03 26 42.62
Gastrointestinal disorders 7 11.86 14 22.95
General disorders and administration 1 1.69 0 0.00site conditions
Infections and infestations 0 0.00 1 1.64
Injury, poisoning and procedural 0 0.00 3 4.92complications
Investigations 1 1.69 2 3.28
Metabolism and nutrition disorders 1 1.69 1 1.64
Musculoskeletal and connective tissue 1 1.69 1 1.64disorders
Nervous system disorders 1 1.69 9 14.75
Respiratory, thoracic and mediastinal 1 1.69 1 1.64disorders
Skin and subcutaneous tissue disorders 0 0.00 2 3.28
Surgical and medical procedures 1 1.69 0 0.00
42
synthesis [9]. We then conducted a similar experi-
ment in rats and found that in the liver, the enzy-
matic activities of acetyl-CoA carboxylase and fatty
acid synthase, involved in fatty acid synthesis, were
significantly decreased, whereas that of acyl-CoA
dehydrogenase, involved in beta-oxidation, was
significantly increased by LFO ingestion [24]. These
results suggest that LFO ingestion suppresses fatty
acid synthesis, while at the same time activating
fatty acid catabolism in the liver, which is quite a
unique mechanism that leads to the suppression
of fat accumulation. The significant reduction of
visceral fat observed in the LFO group in this study
may be due to the same mechanism that has been
elucidated from animal studies. We are currently
investigating this mechanism in humans.
Finally, taken together with previous results, we note
that LFO was effective in reducing visceral obesity
not only in overweight Japanese subjects [14,15],
but also in obese American subjects including non-
Hispanic Whites, non-Hispanic Blacks, Latinos/His-
panics, etc. Therefore, LFO added as an ingredient
to functional foods is safe and may yield substantial
health benefits with regards to reducing or prevent-
ing metabolic syndrome in people around the world.
Conflict of interest
Yuji Tominaga, Mitsuaki Kitano, Tatsumasa Mae, Sachie Kakimoto
and Kaku Nakagawa are employees of Kaneka Corporation.
Human and Animal Rights
All procedures followed were in accordance with the ethical
standards of the responsible committee on human experimen-
tation (institutional and national) and with the Helsinki Decla-
ration of 1975, as revised in 2008.
Informed Consent
Informed consent was obtained from all patients for being in-
cluded in the study.
References1. Alberti KGMM, Zimmet P, Shaw J (2006) Metabolic syn-
drome: a new world-wide definition. A consensus statement
mean percent change in visceral fat area from base-
line was –3.318% in the LFO group and 7.066% in
the placebo group at Week 12, indicating that the
difference of the mean percent change in visceral
fat area between LFO and placebo groups reached
up to around 10% of the whole visceral fat area.
It is known that caloric restriction and exercise can
reduce visceral fat more easily than subcutaneous
fat [22,23]. This was supported by a significant re-
duction of visceral fat in the short term over 12
weeks in this study. However, a corresponding sig-
nificant lowering of body weight was not observed
between the two groups in this study. This may be
because body weight is easily affected by food in-
gestion/egestion and amount of water in the body
at the time of measurement, which may have
caused wide variation in the data for change in
body weight. Thus, significant decreases in visceral
fat and total (abdominal) fat, but not body weight
measurements, could be detected by CT scans in
the LFO group compared to the placebo group.
In this study, significant improvements of the meta-
bolic parameters in the LFO and placebo groups
were not observed. The reason may be that the sub-
jects were recruited according to BMI and waist-to-
hip ratio, and the assessment of blood biochemistry
parameters relevant to the metabolic syndrome re-
vealed that baseline values of the subjects were
within normal range. However, in the recent study
with Japanese overweight subjects [15], significant
reduction of total and LDL-cholesterol levels was
observed by ingestion of 300 mg of LFO concentrate
solution 8 weeks after baseline because those levels
of subjects in the study were slightly high. In order
to confirm the effects of LFO in preventing meta-
bolic syndrome, further studies are needed with sub-
jects with higher levels of metabolic parameters.
To understand the mechanism of suppression of
fat accumulation, we used DNA microarray analysis
to identify changes in gene expression in the liver
of mice fed a high-fat diet and LFO for 8 weeks,
and found that LFO up-regulated genes for beta-
oxidation and down-regulated those for fatty acid
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