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 Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center

nachricht Study advances gene therapy for glaucoma
17.01.2018 | University of Wisconsin-Madison

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: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Polymers Based on Boron?

18.01.2018 | Life Sciences

Bioengineered soft microfibers improve T-cell production

18.01.2018 | Life Sciences

World’s oldest known oxygen oasis discovered

18.01.2018 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>