Endometrial, breast and liver safety of soy isoflavones plus Lactobacillus sporogenes in post-menopausal women

Abstract

Objective:
To assess the safety of a nutraceutical compound containing soy isoflavones and Lactobacillus sporogenes on endometrium, breast and liver function.

Setting:
Outpatient Menopausal Clinic.

Study design:
130 healthy postmenopausal women suffering from menopausal symptoms were randomized to receive soy isoflavones 60 mg and Lactobacillus sporogenes 1 billion spores (group E: 65 women) or calcium and vitamin D₃ (group C: 65 women). Safety of the treatment was assessed at baseline and after 1 year taking into account endometrial thickness, mammographic density, serum levels of transaminases, γ-GT and bilirubin. Efficacy of the treatment was evaluated rating the score of menopausal symptoms at baseline and every 3 months. The statistical analysis was carried out with χ², Fisher exact's test and ANOVA.

Results:
After 12 months of treatment mammographic density, endometrial thickness and hepatic function did not show significant differences between groups, while menopausal symptoms were progressively and significantly reduced in severity and frequency during treatment with soy isoflavones plus Lactobacillus sporogenes versus calcium plus vitamin D₃.

Conclusion:
A 12 months treatment with a nutraceutical compound based on isoflavones and Lactobacillus sporogenes at the recommended doses is safe for endometrium, mammary glands and liver function in postmenopausal women.

Full text

Gynecological Endocrinology, 2012; Early Online: 1–4
© 2012 Informa UK, Ltd.
ISSN 0951-3590 print/ISSN 1473-0766 online
DOI: 10.3109/09513590.2012.738724
Objective: To assess the safety of a nutraceutical compound
containing soy isoflavones and Lactobacillus sporogenes on
endometrium, breast and liver function. Setting: Outpatient
Menopausal Clinic. Study Design: 130 healthy postmenopausal
women suffering from menopausal symptoms were randomized
to receive soy isoflavones 60 mg and Lactobacillus sporogenes
1 billion spores (group E: 65 women) or calcium and vitamin D3
(group C: 65 women). Safety of the treatment was assessed at
baseline and after 1 year taking into account endometrial thick-
ness, mammographic density, serum levels of transaminases,
γ-GT and bilirubin. Efficacy of the treatment was evaluated
rating the score of menopausal symptoms at baseline and every
3 months. The statistical analysis was carried out with χ2
, Fisher
exact’s test and ANOVA. Results: After 12 months of treatment
mammographic density, endometrial thickness and hepatic
function did not show significant differences between groups,
while menopausal symptoms were progressively and signifi-
cantly reduced in severity and frequency during treatment with
soy isoflavones plus Lactobacillus sporogenes versus calcium
plus vitamin D3. Conclusion: A 12 months treatment with a
nutraceutical compound based on isoflavones and Lactobacillus
sporogenes at the recommended doses is safe for endometrium,
mammary glands and liver function in postmenopausal women.
Keywords: Endometrial thickness, isoflavones, lactobacillus,
menopausal symptoms, mammographic density
Introduction
Vasomotor menopausal symptoms impair women’s daily quality
of life. Appropriate treatment includes an early administration
of hormonal replacement therapy (HRT) [1]. Customisation of
the dose, routes of administration, types of combination, annual
controls and treatment duration less than 5 years are guarantees
of a good risk/benet ratio [2]. Nevertheless, HRT use is usually
restricted to moderate or severe symptoms, and is limited by
contraindications and warnings such as mammary cancer or
advanced menopausal age. Moreover, many women simply refuse
HRT for a variety of reasons concerning fear of cancer and weight
gain [3] and request a “natural” approach [4]. In this scenario,
nutraceuticals classied as food supplements have a role in the
management of symptomatic menopausal women. Particularly,
soy isoavones (SI) are natural substances as genistein and daid-
zein with agonist-antagonist oestrogen action that have been
demonstrated to alleviate climacteric symptoms at the dose
between 40 and 80 mg/day [5,6].
SI exert elective stimulation of β-oestrogen receptors (βERs)
with less anity and lower potency than oestrogens [7], moreover
stimulate the synthesis of SHBG [8], therefore, safety in long-
term use could be expected. While epidemiological, experimental
and clinical studies suggest the ecacy of the phytoestrogens in
reducing the risks of endometrium and breast cancer [9,10], the
long-term results are not completely consistent [11–14].
It is well known that the absorption of the SI depends on the
presence of the intestinal ora that is capable to produce glyco-
sidases and therefore to hydrolyze genistin and daidzin to the
active aglycons [15,16]. Taken this consideration, it has been
appeared quite rational to combine SI with lactic acid bacteria in
the form of spores, resistant to the gastric and biliary secretion,
to assure the bioavailability of SI [17,18]. To date, clinical data
on long-term eects of nutraceuticals with SI and Lactobacillus
sporogenes on endometrium, mammary glands and liver func-
tion in postmenopausal women are lacking. e aim of the study
was to assess the eects of a nutraceutical compound containing
isoavones and Lactobacillus sporogenes compared to calcium
and vitamin D alone on endometrium, breast and liver function.
Material and methods
In a prospective randomised study 130 healthy postmenopausal
women suering from menopausal symptoms were enrolled.
Inclusion criteria were: age 45–65 years, amenorrhoea > 12
months, FSH > 30 mIU/mL, E2 < 20 pg/mL. Exclusion criteria
were: use of antibiotic in the last 6 months, HRT or treat-
ments for climacteric symptoms, dietetic regimens such as
strict vegetarian, high bre or high soy diet, regular consump-
tion of vitamin and mineral supplementation greater than the
Recommended Dietary Allowances, chronic disorders, benign
breast disease, endometrial thickness > 5 mm and BMI > 30. e
study was approved by the Local Ethic Committee. An informed
consent was obtained and the subject’s right to withdraw from
the study was clearly allowed. Using the randomization list
balanced in blocks of 10 provided for each centre, the patients
received one tablet per day (apart from meals) containing
ORIGINAL ARTICLE
Endometrial, breast and liver safety of soy isoflavones plus Lactobacillus
sporogenes in post-menopausal women
Nicola Colacurci1, Pasquale De Franciscis1, Marco Atlante2, Pasquale Mancino3, Marco Monti3, Giuseppe Volpini4
& Claudio Benvenuti5
1Department of Obstetrics, Gynaecology and Reproductive Sciences – Second University of Naples – Largo Madonna delle Grazie 1,
Naples, Italy, 2Menopausal Outpatient Clinic, Regina Apostolorum Hospital, Albano Laziale, Rome, Italy, 3Department of Gynaecology,
Obstetrics and Urologic Sciences – La Sapienza University of Rome, Italy, 4ASL RMA Woman Health Centre S. Anna, Rome, Italy, and
5Medical Department, Rottapharm Madaus, Monza, Italy
Correspondence: Pasquale De Franciscis, Department of Obstetrics, Gynaecology and Reproductive Sciences – Second University of Naples – Largo
Madonna delle Grazie 1, Via Tasso 133, 80127 Naples, Italy. Tel: +390815665603. Fax +390815665610. E-mail: pasquale.defranciscis@unina2.it
Gynecological Endocrinology
2012
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© 2012 Informa UK, Ltd.
10.3109/09513590.2012.738724
0951-3590
1473-0766
Long-term safety of isoavones
N. Colacurci et al.
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2 N. Colacurci et al.
Gynecological Endocrinology
the active compound or placebo for 12 months. e active
compound contained a nutraceutical combination of SI 60 mg
(30 mg of genistin, 30 mg of daidzin), Lactobacillus sporogenes 1
billion spores, calcium 240 mg, vitamin D3 5 µg and glucosamine
250 mg (group E: 65 women); the placebo tablets contained
calcium 240 mg and vitamin D3 5 µg (group C: 65 women). Both
tablet types were supplied by the same manufacturing company
(Rottapharm Madaus, Italy), and were identical in appearance
and packaging. All subjects received a list of foods to avoid
containing soy and phytoestrogen. During the study the women
were encouraged to lead normal lives with no changes in dietary
habits, alcohol consumption, or physical activity.
Safety of the treatment was assessed at baseline and aer 1
year, and was based on endometrial thickness, mammographic
density, hepatic function, report of adverse events. Endometrial
thickness was measured with a 5.9-MHz transvaginal transducer
(Voluson 730 expert-GE) in the anteroposterior direction from
the echogenic interface of the endometrial-myometrial junc-
tion. Mammographic density was classied according to the
criteria set out by Wolfe as previously described [19]. Moreover,
mastodynia and mammary tension reported by the patients
were classied as mild, moderate and severe. Hepatic func-
tion was assessed by means of serum levels of transaminases,
γ-GT and bilirubin. Ecacy of the treatment was evaluated
rating the score of menopausal symptoms (ushing, nocturnal
sweating, palpitations, libido loss, vaginal dryness, dyspa-
reunia) at baseline and every 3 months. A standardized deni-
tion of severity was used to record the symptoms: 0= absent;
1= mild; 2= moderate; 3= severe; 4= very severe. Compliance
with use of the medication was conrmed by checking diaries
and obtaining unused tablets back at the end of the study. e
statistical analysis was carried out with χ2
, Fisher exact’s test
and ANOVA when appropriate.
Results
Baseline clinical characteristics were homogeneous between group
E (55.3 ± 7.6 years, BMI 24.9 ± 2.9, amenorrhoea 3.2 ± 2.8 years)
and group C (5.7 ± 7.7 years, 25.0 ± 2.9, amenorrhoea 2.8 ± 2.6
years). In group E the treatment was withdrawn in two cases for
cautionary reasons and in one case for diarrhoea, in group C one
patient discontinued the treatment for mammary tension and two
patients were lost to follow-up. Finally, data of sixty-two patients
for each group were available: aer 12 months of treatment
mammographic density and endometrial thickness decreased in
both study groups with no signicant dierence, hepatic func-
tion did not show signicant dierences between groups (Table
I); menopausal symptoms were progressively and signicantly
improved in terms of severity and frequency during active versus
placebo treatment (Figure1). No dierence in mastodynia and
mammary tension was observed between the groups.
Discussion
Altogether, our data show that a combination of nutraceuticals
based on SI and Lactobacillus sporogenes administered for 1
year at the recommended daily dose is safe for endometrium,
mammary tissue and hepatic function. e clinical outcome
also conrms the previously documented eectiveness on
menopausal symptoms of the combination favoured by the
improved bioavailability of the SI guaranteed by Lactobacillus
sporogenes [20–22].
It is well known that SI selectively bind to βERs, that are poorly
represented in the organs susceptible to estrogen-dependent
tumors [23], with less anity and milder action than oestrogens
[7]; moreover, they stimulate the synthesis of SHBG subtracting
estradiol from the circulation [8]. erefore, it could be expected
that SI have very slight eects on the endometrium and breasts,
much smaller than exogenous oestrogens, and the mixed
oestrogen agonist-antagonist properties showed by SI [24] can
explain the weak oestrogenic eects.
Epidemiological studies indicate a relatively low inci-
dence of hormone-dependent tumours both endometrial
[25,26] and breast [27,28] in populations that consume
high amounts of soy, although there is no general consensus
concerning the real daily quantity of soy intake in those
populations [29] and the effect may be restricted to soy food
consumption in the same amount commonly consumed in
Asian populations [30].
Experimental data on endometrial eects of SI are generally
reassuring [31–33], while those on breast eects are contrasting:
a large body of evidence suggests that SI protect against breast
cancer [34,35], but other reported that they may induce prolifera-
tion of cultured human MCF-7 breast cancer cells [36] and harm-
fully interact with selective estrogen receptor modulators such as
tamoxifen and aromatase inhibitors [13,14].
More than 15 RCTs show no evidence of estrogenic or prolifera-
tive endometrial eects of SI [37] with the exception of a 5-year study
[11] that found no cases of endometrial hyperplasia aer 30-month
treatment but a small increase in the number of women that devel-
oped simple hyperplasia aer 5 years. e weaknesses of this study
have been highlighted [6] regarding the high dose of SI that was 2 to
2.5 times higher than the limit xed by the Italian Ministry for food
supplements containing isoavones (80 mg/day) [38].
Information on the relation between soy intake and breast
risk is limited and is focused on mammographic density as a
biomarker for cancer risk [39]. A systematic review of the few
available RCTs showed that SI intake does not alter breast density
in post-menopausal women, but may cause a small increase in
breast density in pre-menopausal women [40]. Larger long-term
trials are therefore required.
A very recent meta-analysis including 174 randomized clinical
trials with a total of 9629 women, 5502 of whom were treated with
phytoestrogens, reported a similar rate of adverse events with
Table I. Mammographic density score, endometrial thickness and liver function values before and aer the treatments.
Isoavones + lactobacillus (62 patients) Calcium + vitamin D3 (62 patients)
Baseline 1 Ye ar Baseline 1 Ye ar
Mammographic density score 1.89 ± 0.96 1.80 ± 0.95 1.75 ± 0.85 1.58 ± 0.84
Endometrial thickness 3.35 ± 0.95 3.08 ± 0.62 3.47 ± 1.07 3.12 ± 0.73
Alanine transaminase 19.9 ± 6.4 21.9 ± 6.5 20.2 ± 6.7 22.5 ± 7.2
Aspartate transaminase 20.6 ± 5.8 21.8 ± 5.4 20.5 ± 6.2 21.8 ± 5.6
Gamma-glutamyl transferase 24.3 ± 22.3 25.1 ± 24.6 25.6 ± 23.2 26.0 ± 25.5
Bilirubin 0.46 ± 0.25 0.42 ± 0.25 0.49 ± 0.29 0.41 ± 0.26
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Long-term safety of isoavones 3
©  Informa UK, Ltd.
phytoestrogens and controls (36.7% vs. 38.0%) being gastrointes-
tinal eects statistically more frequent in phytoestrogens group
than in controls and no dierence in the incidence of gynaeco-
logical, neurological, or skeletal muscle eects between treat-
ment groups. In particular, there was no increased incidence of
side eects related to hormonal activity, such as risk of bleeding,
endometrial hyperplasia, endometrial cancer and breast cancer
among women taking phytoestrogens compared with the control
group [41].
In agreement with the international literature [42] our ndings
are reassuring: in a homogeneous large sample of postmenopausal
patients treated for 12 months with 60 mg/day of SI enriched with
Lactobacillus sporogenes, neither endometrial stimulation nor
increase of breast density was observed. Moreover, enterohepatic
function does not appear impaired. In conclusion, SI plus lactoba-
cillus can eectively and safely be used at the recommended dose
in post-menopausal symptomatic women for whom HRT is not
indicated, is refused or discontinued.
Figure 1. Severity score of menopausal symptoms: percentage changes during the treatment. White bar: group E taking soy isoavones + lactobacillus
sporogenes. Grey bar: group C taking calcium + vitamin D3. (***p < 0.001 comparing group E vs. group C).
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4 N. Colacurci et al.
Gynecological Endocrinology
Acknowledgement
e authors have no nancial aliation (e.g. employment, direct
payments, stock holdings, retainers, consultantship, patient-
licensing arrangements, or honoraria) or involvement with any
commercial organization with direct nancial interest in the
subject or material discussed in this manuscript. e authors have
no nancial interest in any aspect of the work and did not receive
any nancial support. Any other potential conict of interest also
is disclosed.
Declaration of Interest: C. Benvenuti MD, ScD is consultant
for Rottapharm Madaus.
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