Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Eating soy during adolescence may reduce breast cancer

29.08.2002


University of Southern California study shows link between diet and cancer in Asian-American women



Eating soy foods on a regular basis-especially during adolescence-might lower the risk of breast cancer, according to preventive medicine researchers at the Keck School of Medicine of USC and colleagues.

Asian-American women who consumed soy foods on a weekly basis during their teen years and adulthood had about half the risk of developing breast cancer compared to similar women who ate little soy during the same time periods, according to a study in the September issue of Carcinogenesis.


Risk also was somewhat lowered for women who ate soy regularly during the teen years but consumed little during adulthood. However, preliminary data suggest little added benefit for women who ate little soy during adolescence but a high amount of soy during adulthood.

"There has been a lot of talk and controversy about the Asian diet and connections between soy food intake and breast cancer. We wanted to look at soy very carefully, to better understand if soy by itself is protective or if the level of soy consumption is just a marker for acculturation," says Anna H. Wu, Ph.D. professor of preventive medicine at the Keck School of Medicine.

Wu and colleagues conducted a case-control study of breast cancer among Chinese, Japanese and Filipino women in Los Angeles County, specifically looking at the importance of soy. From 1995 to 1998, they interviewed 501 Asian-American breast cancer patients and compared them to 594 healthy Asian-American women.

The researchers asked about eating habits, including how many times each week during adolescence they ate tofu. They also asked about the frequency and amounts of whole soy foods, such as tofu, soymilk, miso and fresh soybeans, usually eaten during adulthood.

Intake was highest among Chinese (26.8 milligrams of isoflavones a day), intermediate among Japanese (18.4 mg of isoflavones a day) and lowest among Filipinas (9.3 mg of isoflavones a day). Migrants ate a little more soy than American-born women did. Most of the Chinese and Filipino women in this study-more than 90 percent-were born in Asia, compared to less than 30 percent of the Japanese women.

When women were grouped by how often they ate soy during adolescence and adult life, researchers found that women who were high consumers during both time periods had a 47 percent reduction in risk. Those who ate little soy during adult life but were regular soy consumers during adolescence showed a 23 percent reduction in risk Women who were low consumers during adolescence and high consumers during adulthood showed little reduction in risk. However, the number of such women was small, and researchers note that larger studies must be conducted to confirm this result.

So how does soy work? Scientists are not sure, but they have some ideas.

Animal studies indicate that early life exposure to genistein-the main isoflavone in soybeans-seems to help protect against chemically induced breast tumors. Getting genistein early in life may help the mammary glands develop in a favorable way.

Eating soy might also lead to lower levels of estrogen circulating within the body, some theorize. And some studies show that genistein seems to inhibit some enzymes that are important in metabolizing estrogen.

Regardless of the protective mechanism, Wu notes that if the mounting soy research shows promise, many may ask, "How much soy is enough?" There may be a point at which eating more soy does not further reduce risk, she says. Researchers are still seeking to understand the relationship between soy food dose and risk reduction, though in this study the greatest risk reduction was seen among women with the highest level of consumption: 12.68 mg or more of isoflavones per 1000 kilocalories during adulthood and eating soy foods four or more times a week during adolescence.

Isoflavone levels in soy foods vary considerably, but a serving of store-bought tofu-a quarter of a box-contains about 10 mg of isoflavones, Wu says.

Wu notes that a much larger study is needed to sort out the benefits of adult soy food intake and what levels of soy intake are most helpful. Her study looked only at traditional soy foods, not at genistein or other isoflavones that may be contained in pills and supplements.

Jon Weiner | USC Health Sciences
Weitere Informationen:
http://uscnews3.usc.edu/experts/index.html

Weitere Nachrichten aus der Kategorie Medizin Gesundheit:

nachricht Stammzell-Transplantation: Aktivierung von Signalwegen schützt vor gefährlicher Immunreaktion
20.04.2017 | Technische Universität München

nachricht Was Bauchspeicheldrüsenkrebs so aggressiv macht
18.04.2017 | Friedrich-Alexander-Universität Erlangen-Nürnberg

Alle Nachrichten aus der Kategorie: Medizin Gesundheit >>>

Die aktuellsten Pressemeldungen zum Suchbegriff Innovation >>>

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

Im Focus: Immunzellen helfen bei elektrischer Reizleitung im Herzen

Erstmals elektrische Kopplung von Muskelzellen und Makrophagen im Herzen nachgewiesen / Erkenntnisse könnten neue Therapieansätze bei Herzinfarkt und Herzrhythmus-Störungen ermöglichen / Publikation am 20. April 2017 in Cell

Makrophagen, auch Fresszellen genannt, sind Teil des Immunsystems und spielen eine wesentliche Rolle in der Abwehr von Krankheitserregern und bei der...

Im Focus: Tief im Inneren von M87

Die Galaxie M87 enthält ein supermassereiches Schwarzes Loch von sechs Milliarden Sonnenmassen im Zentrum. Ihr leuchtkräftiger Jet dominiert das beobachtete Spektrum über einen Frequenzbereich von 10 Größenordnungen. Aufgrund ihrer Nähe, des ausgeprägten Jets und des sehr massereichen Schwarzen Lochs stellt M87 ein ideales Laboratorium dar, um die Entstehung, Beschleunigung und Bündelung der Materie in relativistischen Jets zu erforschen. Ein Forscherteam unter der Leitung von Silke Britzen vom MPIfR Bonn liefert Hinweise für die Verbindung von Akkretionsscheibe und Jet von M87 durch turbulente Prozesse und damit neue Erkenntnisse für das Problem des Ursprungs von astrophysikalischen Jets.

Supermassereiche Schwarze Löcher in den Zentren von Galaxien sind eines der rätselhaftesten Phänomene in der modernen Astrophysik. Ihr gewaltiger...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: Neu entdeckter Exoplanet könnte bester Kandidat für die Suche nach Leben sein

Supererde in bewohnbarer Zone um aktivitätsschwachen roten Zwergstern gefunden

Ein Exoplanet, der 40 Lichtjahre von der Erde entfernt einen roten Zwergstern umkreist, könnte in naher Zukunft der beste Ort sein, um außerhalb des...

Im Focus: Resistiver Schaltmechanismus aufgeklärt

Sie erlauben energiesparendes Schalten innerhalb von Nanosekunden, und die gespeicherten Informationen bleiben auf Dauer erhalten: ReRAM-Speicher gelten als Hoffnungsträger für die Datenspeicher der Zukunft.

Wie ReRAM-Zellen genau funktionieren, ist jedoch bisher nicht vollständig verstanden. Insbesondere die Details der ablaufenden chemischen Reaktionen geben den...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Smart-Data-Forschung auf dem Weg in die wirtschaftliche Praxis

21.04.2017 | Veranstaltungen

Baukultur: Mehr Qualität durch Gestaltungsbeiräte

21.04.2017 | Veranstaltungen

Licht - ein Werkzeug für die Laborbranche

20.04.2017 | Veranstaltungen

 
VideoLinks
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Intelligenter Werkstattwagen unterstützt Mensch in der Produktion

21.04.2017 | HANNOVER MESSE

Forschungszentrum Jülich auf der Hannover Messe 2017

21.04.2017 | HANNOVER MESSE

Smart-Data-Forschung auf dem Weg in die wirtschaftliche Praxis

21.04.2017 | Veranstaltungsnachrichten