Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plant Estrogens in Soy Do Not Increase Breast Cancer Risk

07.07.2004


Research in monkeys suggests that a diet high in the natural plant estrogens found in soy does not increase the risk of breast or uterine cancer in postmenopausal women.

“This is convincing evidence that at dietary levels, the estrogens found in soy do not stimulate cell growth and other markers for cancer risk,” said Charles E. Wood, D.V.M., lead researcher, from Wake Forest University Baptist Medical Center. “The findings should be especially interesting to women at high risk for breast cancer who take soy products.”

The research is reported in the current issue of The Journal of Clinical Endocrinology & Metabolism.



Wood said there has been much debate about whether high levels of dietary soy are safe for postmenopausal women. Soy products are sold as a natural alternative to traditional hormone therapy. The most common form of hormone therapy, estrogen plus a progestin, has been shown to increase risk of breast cancer.

Soy and some other plants contain estrogen-like compounds called isoflavones or phytoestrogens. These plant estrogens are thousands of times weaker than the estrogen produced by the body, but may be present in much higher concentrations in the blood. Evidence about their safety has been mixed. It is known that populations that typically consume diets high in soy have lower rates of breast cancer. On the other hand, some studies have shown that soy isoflavones can stimulate breast cancer cells grown in the laboratory.

“Evidence from observational studies in women indicates that soy intake may help prevent breast cancer,” said Wood. “But there has still been reluctance to conduct research studies in women because of concerns that isoflavones may stimulate breast cell growth and increase the risk of breast cancer.”

Wood and colleagues measured how a diet high in soy isofllavones affected markers for breast and uterine cancer risk in postmenopausal monkeys. The monkeys ate one of three diets for three years: soy that didn’t contain isoflavones, soy with the isoflavones intact, or soy without isoflavones, but with Premarin, or estrogen therapy, added.

The isoflavone group consumed the human equivalent of about 129 milligrams a day, more than most people would get in a soy-rich diet.

The researchers measured breast density, numbers of dividing breast and uterine cells, and levels of the estrogen produced by the body – all markers for cancer risk. Monkeys on the soy plus estrogen diet had increased levels of all markers, while monkeys that ate soy with isoflavones did not.

In fact, the monkeys eating soy with isoflavones had lower levels of the estrogen produced by the body. High levels of this estrogen are considered an important predictor of breast cancer risk in postmenopausal women.

“These findings suggest that high dietary levels of soy isoflavones do not increase markers for breast and uterine cancer risk in postmenopausal monkeys and may contribute to an estrogen profile associated with reduced breast cancer risk,” said the researchers.
Wood said it is important to note that the research addressed the effects of plant estrogens on normal breast tissue, and not in breast cancer.

“A big unanswered question is whether it is safe for breast cancer survivors to turn to soy,” he said.

Researchers are not certain how plant estrogens and the estrogen produced by the body, or given in pills, act together. One theory is that the plant estrogens bind to cells that have estrogen receptors, such as breast tissue, and block the effects of the other types of estrogen. Isoflavones may also help reduce the amount of active estrogen in the body.

To investigate these ideas, Wood and colleagues are currently looking at whether soy may block breast cell proliferation induced by estrogen therapy.

Other researchers involved the study included J. Mark Cline, Ph.D., D.V.M., Mary S. Anthony, Ph.D., Thomas C. Register, Ph.D., and Nancy D. Kock, Ph.D., D.V.M., all from Wake Forest Baptist.

The research was funded by grants from the National Institutes of Health.

| newswise
Further information:
http://www.wfubmc.edu

More articles from Health and Medicine:

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

nachricht The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

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...

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

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>