High soy diet during pregnancy may cause hormonal changes in fetus

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>Link Between High Soy Diet During Pregnancy and Nursing and Eventual

>Developmental Changes in Children

>

>http://www.mercola.com/1999/nov/7/soy_and_children.htm

>

>Two separate studies – one in animals and the other in humans – that

>considered together suggest that a diet high in soybeans and other legumes

>during pregnancy and breastfeeding may have a subtle but long-term impact on

>the development of children.

>

>Soybeans and other food-source plants contain compounds, called

>phytoestrogens or isoflavones, which have been found to produce a variety of

>mild hormonal actions within the human body.

>

>Studies in recent years are confirming that the estrogenic effects of these

>compounds may be beneficial in preventing or treating a variety of

>conditions such as the unpleasant symptoms of menopause.

>

>We are a very different creature when we are an embryo or a fetus or a child

>or a teenager. We’re very different when we are a reproductive-age adult or

>an aging adult.

>

>At each stage, we have a different profile of risk or benefit. At the

>beginning of the life span, when tissues in our bodies are being organized

>in utero and in the first months of life, there is good reason to believe --

>based on animal studies and in some human observations -- that sex hormones

>are very important in getting things organized properly.

>

>These hormones influence the way the brain is organized, the way the

>reproductive organs and cells develop, even the way immune function

>develops. Therefore, if mom is eating something or has in her body fat

>something that can act like sex hormones, it is logical to wonder if that

>could change the baby’s development. If there is an impact, is it positive,

>negative or irrelevant?

>

>To determine if unborn babies are indeed exposed to phytoestrogens, the

>researchers analyzed amniotic fluid samples of 54 pregnant women from the

>Los Angeles area. No phytoestrogens were detected in 11 samples, extremely

>high levels were found in seven samples, and the remaining 36 contained

>modest levels.

>

>The study concluded that about 80 percent of the fetuses were exposed to

>estrogenic isoflavones at concentrations ranging from 20 to 180 times the

>levels of naturally occurring female sex hormones in the amniotic fluid of

>female fetuses.

>

>The amniotic fluid samples were taken during routine amniocentesis between

>16 and 20 weeks of gestation – after a baby’s organs have formed but during

>a critical stage of development.

>

>The researchers used an animal model to begin to determine whether this in

>utero phytoestrogen exposure might affect the organizational stage of the

>fetus and the future development of the child. In a controlled study, they

>fed pregnant female rats genistein, an isoflavone that is known to have

>significant estrogenic properties.

>

>The rat study was carefully designed to take into account the obvious

>differences that exist in the developmental and life cycles of rats and

>humans, and to correlate as closely as possible to the timing of the

>amniotic fluid sampling. The mother rats were given genistein from day 14 of

>gestation through post-natal day 21 when the rat pups were weaned.

>

>Developmentally, this time period is almost exactly the same time that the

>human amniotic fluid samples were obtained. The major steps of formation of

>organs in the body occur early on, in both rats and humans. Therefore, the

>treatment of the rats was intentionally delayed until major organ formation

>had occurred.

>

>The goal was to assess the effects of exposure on the developing organism,

>and this is about as close as one can get to being able to take measurable

>samples from humans and match them up with meaningful findings in an animal

>model.

>

>According to the results, the genistein fed to the mother rats had a

>“masculinizing” effect on both male and female pups, based on the accepted

>criterion of anogenital distance – the distance between the anus and

>genitals, adjusted for the animal’s overall size. The lengthening of the

>anogenital distance strongly suggests a relative masculinization of the

>pups.

>

>This may be caused by the anti-estrogenic properties of the genistein being

>transferred through the mother’s milk to the babies or it is possible that

>the mom’s intake of genistein changed the amount of her own steroids going

>into the milk. That’s a little more complicated but if these compounds are

>reducing the amount of hormones she’s producing, either from her ovaries or

>her adrenal glands, it could have the same effect.

>

>Male rat pups whose mothers received genistein also experienced early onset

>of puberty. Normal puberty in a rat life cycle begins about two weeks after

>weaning. Whatever the clocks are in the brain that control the timing of

>puberty appear to have been advanced by a couple of days, which is highly

>significant in this kind of animal model. It is known that sex hormones have

>important organizational effects in primates in the second and third

>trimesters of pregnancy through the first six months of life.

>

>Studies have shown that altered male or female hormone levels at this time

>of life in a rhesus macaque, for example, can change the timing of puberty

>in males. Concern is based on the expectation that animal models will be at

>least somewhat predictive of what occurs in humans. There is no reason to

>assume that there will be gross malformations of fetuses but there may be

>subtle changes, such as neurobehavioral attributes, immune function, and sex

>hormone levels.

>

>The researchers are seeking a grant to track outcomes of human babies for

>whom exposure assessments have been made. There are many long-term health

>questions that come about when the little clocks in our heads are changed.

>There may be subtle things occurring and we don’t know it. Or it could be

>that humans are much more resistant to these effects than are other animals,

>and this is not an issue.

>

>Researchers in the Center conducted the studies presented for Women’s Health

>and the Department of Obstetrics and Gynecology at Cedars-Sinai Medical

>Center, The Centre for Toxicology at the University of Calgary in Canada,

>and the Department of Obstetrics and Gynecology at Duke University in North

>Carolina. For media information and to arrange an interview, please e-mail

>sandy or call 1-800-396-1002.

>

>Third International Symposium on the Role of Soy in Preventing and Treating

>Chronic Disease sponsored by the American Oil Chemists’ Society in

>Washington, D.C. November 3, 1999. submitted by Michael Belkin

>

>

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>DR. MERCOLA'S COMMENT:

>

>More early research that soy is not all that is cracked up to be. If you

>have not read the soy article by Dr. Enig, I would strongly encourage you to

>do so as it provides a broad overview of this topic.

>

>It is also important to realize that soy formula should rarely if ever be

>used for the above concerns. It is a potent negative hormonal influence on

>developing children and may have significant adverse side effects. Soy

>formula also has well over ten times as much aluminum in it as conventional

>formula.

>

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