Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Component in soy products causes reproductive problems in laboratory mice

12.01.2006


Genistein, a major component of soy, was found to disrupt the development of the ovaries in newborn female mice that were given the product. This study adds to a growing body of literature demonstrating the potentially adverse consequences of genistein on the reproductive system.


This illustration depicts normal egg cell development in mice as schown in the top: the bottom image shows the genistein-treated animals where the abnormal egg clustering occurs.



"Although we are not entirely certain about how these animal studies on genistein translate to the human population, there is some reason to be cautious," said Dr. David A. Schwartz, Director of the National Institute of Environmental Health Sciences (NIEHS). "More clinical studies are needed to determine how exposure during critical windows of development can impact human health."

Genistein is the primary naturally occurring estrogen in plants (called phytoestrogens) and can mimic the effects of estrogen in the body. Genistein can be found in foods containing soy such as soy-based infant formulas as well as over-the-counter dietary supplements.


The results of this study conducted by researchers at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health, in collaboration with an investigator at Syracuse University, are published in the January issue of Biology of Reproduction.

The NIEHS researchers previously showed that mice given genistein immediately after birth had irregular menstrual cycles, problems with ovulation, and problems with fertility as they reached adulthood. The new study looks at the direct effects of genistein on the ovaries during early development.

"We knew genistein was linked to reproductive problems later in life, but we wanted to find out when the damage occurs," said Retha R. Newbold, MS, a developmental endocrinologist at NIEHS and an author on the study. "The study showed that genistein caused alterations to the ovaries during early development, which is partly responsible for the reproductive problems found in adult mice."

Female mice were injected with three different doses of genistein during their first five days of life. The genistein given to the mice was comparable to what human infants might receive in a soy-based formula, which is approximately 6-9 mg/kg per day. The researchers examined the effects on days 2 through 6.

The researchers found effects at all levels. Mice treated with the high dose (Gen 50 mg/kg) were infertile and mice treated with lower doses were subfertile, meaning they had fewer pups in each litter, and fewer pregnancies. Mice receiving the highest level of genistein, 50 mg/kg per day, had a high percentage of egg cells that remain in clusters, unable to separate and therefore develop abnormally. The researchers explain that oocytes that remain in clusters are less likely to become fertilized based on previous research. The largest difference between the genistein treated and normal mice was found at six days of age where 57 percent of the egg cells in the non-treated ovaries were single or unclustered; and only 36 percent in the genistein treated group were single

We think genistein inhibits the oocytes or egg cells from separating apart," said Wendy Jefferson, Ph.D. of NIEHS and lead researcher on the paper. "Since there are many egg cells in the same follicle instead of just one, the resources from the surrounding cells are spread too thin and they can’t get the support they need to become a mature functioning egg cell."

"You need at least one good healthy single oocyte that is ovulated and fertilized by a sperm to get a healthy baby. Genistein seems to have a way of making this task very difficult," said Newbold.

"I don’t think we can dismiss the possibility that these phytoestrogens are having an effect on the human population," said Dr. Jefferson. "They may not show their effects or be detected until later in life, but chances are they are having an effect."

Robin Mackar | EurekAlert!
Further information:
http://www.niehs.nih.gov
http://www.niehs.nih.gov/home.htm

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>