Study in Korea published in J Nutrition and Cancer shows a protective effect of soy on the risk of developing breast cancer.
The study’s conclusion supports that of previous research concerning soy’s effect on breast cancer risk
Benefits seem to be shown for premenopausal women but not for postmenopausal women but here is a (as yet unpublished) study July 2008:
"Soy intake and breast cancer risk in Singapore Chinese Health Study," Wu AH, Yu MC, et al, Br J Cancer, 2008; 99(1): 196-200.
(Address: Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA 90089, USA. E-mail: firstname.lastname@example.org ).
Summary: In a prospective study involving 35,303 Singapore Chinese women, results indicate that higher soy intake may be associated with a reduced risk of breast cancer in postmenopausal women. Diet was assessed using a validated semiquantitative food frequency questionnaire.
During 12 years of follow-up, 629 cases of breast cancer were recorded. Using Cox regression adjusted for potential confounders, soy intake was found to be inversely associated with risk of breast cancer in postmenopausal women, where the higher intake of soy (above median) was associated with a 26% reduced risk of breast cancer, compared with lower intake of soy (below median; less than 10.6 mg isoflavone per 1000 Kcal). Additionally, higher soy intake was associated with a 33% reduced risk of breast cancer in postmenopausal women with a BMI above the median, and a 17% reduced risk in leaner postmenopausal women.
Thus, the authors of this study conclude, "These prospective findings sugg est that approximately 10 mg of isoflavones per day, obtained in a standard serving of tofu, may have lasting beneficial effects against breast cancer development."
SOY is often Genetically Modified, so Always look for Non-GMO (or ORGANIC). Additionally soy is NOT the same as its individual elements. Looking at powders and 'active' elements may well be very different from eating whole soy. After all, Asians, to whom we look at our epidemiologic evidence do NOT eat soy powders. They eat the whole food as miso, tofu, tempeh, edamame, etc.
In another boost to the reputation of soy, researchers claim to have found a link between higher soy intake and reduced breast cancer risk.
Women without breast cancer have roughly 60 percent higher levels of isoflavones -- compounds found primarily in soy -- than do women with the disease, say scientists at Vanderbilt University and the Cancer Research Center of Hawaii.
This translates statistically into a reduction of breast cancer risk by as much as 50 percent among those with the highest levels of isoflavones, says study co-author Dr. Wei Zheng, a Vanderbilt professor.
"This is one of the first studies in humans that involves an association [between soy intake and reduced breast cancer risk]," Zheng says. "It is too early to say whether it's causal, however. You have to be cautious."
For their study, the researchers measured isoflavone levels in the urine of 120 women from Shanghai, China, to determine how much soy they consumed. Half of the women had been diagnosed with breast cancer and half were cancer free.
"The average level of isoflavones was on average 60 percent lower [in those women with a cancer diagnosis]," Zheng says.
The women's isoflavone levels were consistent with what they reported they ate, he says. Those with higher levels said they consumed more soy products, like tofu and beans.
Lee-Jane Lu, a University of Texas professor who also studies the effects of isoflavones on breast cancer, says "it's conceivable" that differences exist in isoflavone levels among those with and without breast cancer.
"It is an area a lot of us are pursuing, trying to find if this is going to prevent cancer or not," Lu says.
Soy has been touted in recent years as a healthy food source that reduces risk for a variety of diseases. The American Heart Association, for instance, last month recommended adding soy protein to daily diets as a way to help reduce high cholesterol levels.
Some studies have indicated that to best enjoy the benefits of soy, you must start taking it at puberty and that waiting to start in middle age is too late. But Zheng disagrees.
"I don't think the evidence is strong enough to say you have to start at puberty, but certainly it would be good to start as early as possible," he says.
Zheng presented his findings yesterday in Hawaii at the International Chemical Congress of the Pacific Basin Societies, which meets every five years. Results also appeared earlier this year in the journal Cancer Epidemiology, Biomarkers and Prevention.
By Janice Billingsley
Study shows cancer-free women tend to consume more
Cancer Epidemiology, Biomarkers and Prevention,
Cancer Epidemiology, Biomarkers,
& Prevention, May, 2001
Eating Soy During Adolescence
Euro J Cancer, 3/05
J Clinical Endocrinology and Metabolism, 8/01
Phytoestrogens w/ Estrogen Receptors
Long-Term Soy Consumption Does Not Effect Hormones in Post-meno
Role of Isoflavones on Estrogen Metabolism (Premenopausal)
Soy Isoflavone as Estrogen Replacement
Diet Rich in Soy Protein Lowers Estrogen
Highly Purified Soy Not Good
Soybean Products & Rdctn Bca Risk: Japan
Soy's protective effect against breast ca varies by receptor status
British J of Cancer, 8/01
Dietary Soy & Risk of Bladder Ca
Breast Cancer Res Treat 1997
Chemoprevention in Rats by Dietary Soy
Preventive Effects of Soy Isoflavones (Endometrial Ca-Mice)
Soy Protein Isolate Protects in Male Rats
Chemopreventive Soybean Peptide
Reduced Risk with 'high' Soy Food Intake
Soy & Mammographic Breast Density:High Risk Women
J Clin Endocrinol Metab, 4/05
Bca prevention:a rat study
Some Good News on Soy
Oral Lesions Respond To Soy Factor
Soy Protein Suppresses Bca Hormones
Dietary Genistin Stimulates Growth of Estrogen Dependent Bca
Differences between Human Breast Cell Lines & Susceptibility
Effects of Genistein & EPA
Combined Soy & Tea is Antiangiogenic
Soy Protein & Endogenous Hormones:Postmeno
Cancer Res, 5/02
Int J Cancer, 7/02
J Nutr, 10/02
LINK to book with
NEGATIVES on Soy
Intl J Cancer, 10/04
Nutrition and Cancer (volume 60, issue 5)
Posted October 2008
J of Nutrition, 1999
Abstract from Review
See more here
Intro to Review & Biological Actions
Sources of Isoflavones & Absorption/Metabolism
Clinical Effects of Isoflavones
Phyto-estrogens & Osteoporosis: Safe Dose?
J Free Radical Biology & Med,
Article in Press, May 2011
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