The bottom line is there is no
problem having a glass of soy
milk or eating tofu as part of a
healthy diet with variation while
trying to get pregnant or being
pregnant. Soy is an excellent
source of protein, especially for
vegetarians and people with lactose
intolerance or intolerances to
dairy products. In fact, a review
reported in The American Journal
of Clinical Nutrition states that
reproductive and developmental
toxicity studies did not find
significant variations in fertility from
soy phytoestrogens consumption
in healthy couples, indicating that
normal intake of soy is basically
harmless to your fertility and hence
your chances of becoming pregnant
or maintaining a pregnancy.
No Impact on
Menstrual Cycle
Researchers looked at the effect
of soy supplementation on the
menstrual cycles of a group of 96
premenopausal female monkeys over
the course of a year. Researchers
say monkeys have menstrual
cycles similar to those found
in women. Half of the
monkeys ate a diet
high in soy protein
that contained 1.88
milligrams of
isoflavones (the
human equivalent
of about 129
milligrams per
day), and the
other half got all
their protein from
animal sources.
The study
showed that soy
supplementation
did not appear to
change the monkey’s
menstrual cycle or affect
their hormone levels. In both
monkeys and humans, lowerthan-normal levels of estrogen
can make menstrual cycles more
variable and negatively affect fertility.
Soy treatment did not change any
characteristics of the menstrual
cycle, including length, amount of
bleeding, or hormone levels.
The Benefits of Soy
A diet high in phytoestrogens has
been shown to contribute to a
lower rate of breast cancer found
in Asian women compared with
those in Western countries. One
explanation for that is that the
plant estrogens found in soy, called
isoflavones, are in part protective
and can increase a woman’s
menstrual cycle length or reduce
ovarian hormones. The protective
effects of phytoestrogens could
also reduce women’s exposure
to estrogen and may reduce the
risk of breast cancer. But changes
in the menstrual cycle may also
impair women’s fertility. In some
cases, when low estrogen levels
are a cause of infertility, soy and
soy supplements can be used as
treatment, even in high doses, Dr.
Rideo Alonso says. “This diagnosis
of estrogen deficiency of course
needs to be confirmed by your
doctor with a blood test or with
an ultrasound (showing that your
uterus lining around ovulation
time is too thin or that you are
not ovulating),” she says and then
soy becomes a first choice natural
medication. H
Best Sources
According to David Jenkins,
Professor and Chairman of
Nutrition and Metabolism
at the University of Toronto
and St. Michael’s Hospital in
Toronto, the richest in soy
benefits are soy milk and tofu.
He also categorized as being very
effective, the soy from meatless
burgers and hot dogs. As far
as soy sauce is concerned, it is
on the other side of the scale
because of the scant quantities
of active soy within it. So how
much soy should an individual
consume to benefit from it? One
third of a cup a day will give
good protective levels in terms of
heart disease.
Mar/Apr 2016
67