Phytoestrogens and
Menopause
Just another con?
If you've read anything about
soy phytoestrogens it's most likely that you've read that they
help women through tmenopause. Spend five minutes on the
internet and you can find claims, such as the following, being
made:
Encore-soy: Some
Isoflavones convert into weak phytoestrogens in the body and
have been found to ease the difficulties of hot flushes, tension
and mood swings experienced by many menopausal women.
Promensil (by Novogen):
Scientific research suggests that diets high in all
four isoflavone phytoestrogens, or naturally occurring dietary
oestrogens, found in red clover, can be effective in relieving
the symptoms of menopause.
Phytolife (by Blackmores):
Blackmores has formulated a therapeutic dose of soy
in a concentrated nutritional supplement for women approaching
and experiencing menopause.
Phytosource (by
Herron): As women, we're aware that menopause brings
about changes to our bodies. But these changes can vary
greatly from one individual to another. today the most
common form of therapy is HRT. However may women aren't
prepared to take this. For those who prefer a more natural
form of treatment, Herron has developed two complimentary supplements
from their Body Optimum range.
Sad to say if you believe these
claims you've
been conned. And not only conned about the benefits
of isoflavones, but manufacturers of isoflavone supplements
have failed in their duty to inform you that taking isoflavone
supplements places consumers at increased risk of thyroid
disease and cancer. Read
more here
http://www.mercola.com/2002/jan/12/menopause.htm. Also
read our Big Ugly Bull Award
for Novogen.
The Office On Womens Health,
US Department Of Health And Human Services have also released
a press
statement urging caution on soy-based menopause remedies.
To quote Dr Whitehead of St Georges Hospital Medical School,
London, "We really don't know how phyto-estrogens
act in the human body". The safety issues
of phytoestrogens in breast cancer patients have also been raised
in correspondence to the Journal
of Clinical Oncology.
The Federal Institute for Risk Assessment (BfR) Germany, has
undertaken a health assessment of isoflavone supplements. BfR
found that there is a lack of evidence to confirm the safety
of such supplements, yet there is some evidence to suggest that
there may be health risks. Long term studies of these extracts
are needed to evaluate the health implications. Read
more here.
Lewis JE, Nickell LA, Thompson LU,
Szalai JP, Kiss A, Hilditch JR.
Department of Family Medicine, University of Calgary, Calgary,
Alberta, Canada. lewisj@ucalgary.ca
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16837885&query_hl=2&itool=pubmed_docsum
OBJECTIVE: To
compare the effects of daily ingestion of soy flour (S), ground
flaxseed (F), or wheat flour (W) muffins, on quality of life
and hot flash frequency and severity in postmenopausal women.
DESIGN: This was a double-blind, randomized, controlled, intention-to-treat
trial. Ninety-nine women, 1 to 8 years after menopause, ingested
muffins with 25 g of flaxseed (50 mg of lignans), 25 g of soy
(42 mg of isoflavones), or wheat (control) daily for 16 weeks.
Subjects completed the Menopause-specific Quality of Life instrument
monthly along with daily hot flash frequency and severity diaries.
Compliance measures included a 3-day food diary and urinary
isoflavone and lignan analyses at weeks 0 and 16 and returned
muffin counts monthly.
RESULTS: Eighty-seven women (28, ground flaxseed
muffins; 31, soy flour muffins; and 28, wheat flour muffins)
completed the trial. Multivariate analysis of variance of all
quality-of-life domains yielded an insignificant treatment x
time interaction (F46,122 = 0.92, P = 0.62) but a significant
time main effect (P <.0001). Repeated-measures analyses of
covariance controlling for body mass index showed no significant
group x time interaction nor time nor group differences on all
quality-of-life domains and hot flash measures except severity.
Hot flashes were less severe with flaxseed (P = 0.001) compared
to placebo; however, the group x by time interaction was not
significant. Phytoestrogen excretion analysis showed treatment
group exposure as allocated and no contamination.
CONCLUSION: Neither dietary flaxseed nor soy
flour significantly affected menopause-specific quality of life
or hot flash symptoms in this study. PMID: 16837885 [PubMed
- in process]
For Menopause Symptoms, Soy & Other Alternatives Appear
to Provide Little Relief, Says Consumer Reports' Survey
Dietary soy protein and isoflavones
have no significant effect on bone and a potentially negative
effect on the uterus of sexually mature intact Sprague-Dawley
female rats.
Nakai M, Cook, L, Pyter, LM,
Black M, Sibona, J, Turner RT, Jeffery EH, Bahr JM.
Menopause. 2005 May-Jun;12(3):291-8.
Histologically, uteri and vaginae
were normal in all groups except that 1 of 10 rats in the high-soy
group and 2 of 10 rats in the high-extract group showed extensive
squamous metaplasia in the uterine gland. CONCLUSION: These
results suggest that dietary isolated soy protein and isoflavones
have no effect on bone and the vagina during premenopausal period,
but may have an adverse effect on the uterus.
Full
Abstract Here
The effect of soy protein
isolate on bone metabolism.
Gallagher JC, Satpathy R, Rafferty
K, Haynatzka V.;
Menopause. 2004 May-Jun;11(3):290-8.
The present study did not find
a significant positive effect of soy protein isolate supplemented
with isoflavones on BMD and the serum lipid profile in early
postmenopausal women.
Full
Abstract Here
Endometrial effects of long-term
treatment with phytoestrogens: a randomized, double-blind, placebo-controlled
study.
Unfer V, Casini ML, Costabile
L, Mignosa M, Gerli S, Di Renzo GC.;
Fertil Steril. 2004 Jul;82(1):145-8.
Long-term treatment (up to 5
years) with soy phytoestrogens was associated with an increased
occurrence of endometrial hyperplasia. These findings call into
question the long-term safety of phytoestrogens with regard
to the endometrium.
Full
Abstract Here,
More Here
Estrogen Linked to Insulin
Resistance
Postmenopausal women taking oral
estrogen, with or without progesterone, show increased insulin
resistance, even when allowing for being overweight.
Read
More Here
A pilot study of the effects
of phytoestrogen supplementation on postmenopausal endometrium.
Balk JL, Whiteside DA, Naus G,
DeFerrari E, Roberts JM.
J Soc Gynecol Investig 2002 Jul-Aug;9(4):238-42
We performed a prospective, double-blinded,
randomized, placebo-controlled trial comparing the effects of
6 months of dietary phytoestrogen supplementation versus placebo
in postmenopausal women.
Hot flushes, night sweats, and
vaginal dryness were significantly less severe at the final
week of the study compared with baseline in the placebo group.
Insomnia was more common in the treated group. There were no
other statistically significant differences in symptoms or side
effects. CONCLUSION: Phytoestrogens did not cause stimulation
of the endometrium. Insomnia was more frequent over the 6-month
study in the soy group, whereas hot flushes, night sweats, and
vaginal dryness improved from baseline in the placebo group
but not in the soy group.
Full
Abstract Here
Effect of soy-derived isoflavones
on hot flushes, endometrial thickness, and the pulsatility index
of the uterine and cerebral arteries.
Penotti M, Fabio E, Modena AB,
Rinaldi M, Omodei U, Vigano P.
Fertil Steril 2003 May;79(5):1112-1117
The patients were administered
72 mg of soy-derived isoflavones or placebo under double-blind
conditions. The daily number of hot flushes was recorded in
a diary.
Both treatments led to a 40%
reduction in the number of hot flushes. Soy-derived isoflavones
had no effect on endometrial thickness or the PI of the uterine
and cerebral arteries. The daily administration of 72 mg of
soy-derived isoflavones is no more effective than placebo in
reducing hot flushes in postmenopausal women. It also has no
effect on endometrial thickness or the PI of the uterine and
cerebral arteries.
Full
Abstract Here
Phytoestrogen supplements
for the treatment of hot flashes: the Isoflavone Clover Extract
(ICE) study: a randomized controlled trial.
Tice JA, Ettinger B, Ensrud K,
Wallace R, Blackwell T, Cummings SR.
JAMA. 2003 Jul 9;290(2):207-14.
Clinical trials demonstrating
increased risk of cardiovascular disease and breast cancer among
women randomized to hormone replacement therapy have increased
interest in other therapies for menopausal symptoms.
Although the study provides some
evidence for a biological effect of Promensil, neither supplement
had a clinically important effect on hot flashes or other symptoms
of menopause.
Full
Abstract Here
Hot flushes and other menopausal
symptoms in relation to soy product intake in Japanese women.
Climacteric 1999 Mar;2(1):6-12
Nagata C, Shimizu H, Takami R,
Hayashi M, Takeda N, Yasuda K.
Department of Public Health,
Gifu University School of Medicine, 40 Tsukasa-machi, Gifu 500-8705,
Japan.
OBJECTIVE: To examine the relationships
between dietary intake of soy products and hot flushes and other
menopausal symptoms. METHODS: Subjects were 284 women aged 40-59
years who attended a health check-up program provided by a general
hospital in Gifu, Japan. They completed a health questionnaire
including the Kupperman test of menopausal distress. Diet was
assessed by a semiquantitative food frequency questionnaire.
RESULTS: Fermented soy product intake but not total soy product
intake was significantly negatively correlated with hot flush
severity (r = -0.16, p = 0.01) after controlling for age and
menopausal status. Neither total soy product intake nor fermented
soy product intake was significantly correlated with menopausal
index score. Estimated isoflavone intake from total and fermented
soy products was significantly lower by 15% (p = 0.02) and 19%
(p = 0.01), respectively, in women with hot flushes, compared
to those without hot flushes after controlling for covariates.
CONCLUSION: The data support a hypothesis that intake of fermented
soy products alleviates the severity of hot flushes.
HOME
