more reasons to eat your tomatoes and carrots!(and avoid soy)

[Lani]

ABSTRACT: Lycopene and other carotenoids inhibit estrogenic activity of 17?-estradiol and genistein in cancer cells [Breast Cancer Research and Treatment]
Epidemiological evidence suggests that carotenoids prevent several types of cancer, including mammary and endometrial cancers. On the other hand, such studies have also shown that estrogens are the most important risk factors for these cancer types. Genistein, the phytoestrogen mainly found in soy, also shows significant estrogenic activity when tested at concentrations found in human blood. The aim of this study was to determine whether carotenoids inhibit signaling of steroidal estrogen and phytoestrogen which could explain their cancer preventive activity. Similar to the known effect of 17?-estradiol (E2), treatment of breast (T47D and MCF-7) and endometrial (ECC-1) cancer cells with phytoestrogens induced cell proliferation, cell-cycle progression and transactivation of the estrogen response element (ERE). However, each of the tested carotenoids (lycopene, phytoene, phytofluene, and ?-carotene) inhibited cancer cell proliferation induced by either E2 or genistein. The inhibition of cell growth by lycopene was accompanied by slow down of cell-cycle progression from G1 to S phase. Moreover, the carotenoids inhibited estrogen-induced transactivation of ERE that was mediated by both estrogen receptors (ERs) ER? and ER?. The possibility that this inhibition results from competition of carotenoid-activated transcription systems on a limited pool of shared coactivators with the ERE transcription system was tested. Although cotransfection of breast and endometrial cancer cells with four different coactivators (SRC-1, SRC-2, SRC-3, and DRIP) strongly stimulated ERE reporter gene activity, it did not oppose the inhibitory effect of carotenoids. These results suggest that dietary carotenoids inhibit estrogen signaling of both 17?-estradiol and genistein, and attenuate their deleterious effect in hormone-dependent malignancies.

PLEASE don't ask me if this means it is OK to eat soy oil, flour if they are in carrot cake, because it JUST IS NOT KNOWN YET!

This is just FOOD FOR THOUGHT.

Only thing I understood was title, but I had just finished a tomato sandwich (Jersey tomato) on whole wheat, and feel very self righteous. I love these posts, Lani. Thanks.

[suzan w]

thanks, Lani! From everything my 'instincts' tell me...we who are ER+ should avoid soy in any shape or form. If it does convert to estrogen, then it would just make my estrogen blocker, Arimidex, have to work even harder!!???

[SoCalGal]

was feeling that I should have stopped at half, but after reading your post, Lani, I am glad I ate the whole thing

[hutchibk]

haha Flori! Me too! Chips and salsa are my only known addiction...

good post Lani!

It seems 99% of all food available to me contains Soy. Even my bread is now made from Soy flour, And nowhere on the net can I find alternative food to eat. WHY. Is there a conspiracy to turn all males into women? Some body please ell me what CAN I eat, not what I should avoid.

[BonnieR]

I find this discouraging. I am trying to replace the meat in our diet with soy products, tofu, etc.
I know my onc told me that soy was permissible in moderation. I just dont know what that means anymore.

[ElaineM]

I agree. All natural foods have something benefical otherwise they wouldn't be on the planet. The key here is to eat things in their most natural state whenever possible. That doesn't mean we have to eat everything raw, just not altered to look and function like something else whenever possible. Everything in moderation is the key to good health. For example edamane are soy beans. They may have soy which may or may not affect estrogen levels in the body, but they are also very high in protein and have some other nutrients which are good for us. If we want soy milk we can cook some edamane and then throw them in a blender instead of buying commercially prepared soymilk which may or may not have additives that may change the way the soy affects our bodies.

[BonnieR]

What about tofu, do you suppose?

[ElaineM]

I eat a little tofu occassionally, but I stick to edamane most of the time whenever I want soy. I get them fresh or frozen and do whatever I want with them. I started off extremely ER positve, but after extensive testing I now know all my ER levels are totally normal, so soy did not affect me in a negative way. Also women in Asia eat alot of soy and have less breast cancer than Western women do, so I don't think soy is as bad it is supposed to be. Other things affect breast cancer more than soy does. That is my personal belief.

[BonnieR]

It's not that I want soy so much as I want a meat substitute to use in curry sauces and etc.

[Jackie07]

Here's a new report on soy consumption:

Cancer Epidemiol Biomarkers Prev. 2011 Feb 25. [Epub ahead of print]
Soy Food Consumption and Breast Cancer Prognosis.

Caan BJ, Natarajan L, Parker BA, Gold EB, Thomson CA, Newman VA, Rock CL, Pu M, Al-Delaimy WK, Pierce JP.
1Division of Research, Kaiser Permanente.
Abstract

BACKGROUND: Contrary to earlier clinical studies suggesting soy may promote breast tumor growth, two recent studies demonstrate that soy-containing foods are not adversely related to breast cancer prognosis. Using data from the Women's Healthy Eating and Living (WHEL) study, we examined the effect of soy intake on breast cancer prognosis.
METHODS: 3088 breast cancer survivors, diagnosed between 1991 and 2000 with early stage breast cancer and participating in WHEL were followed for a median of 7.3 years. Isoflavone intakes were measured post-diagnosis using a food frequency questionnaire (FFQ). Women self-reported new outcome events semi-annually which were then verified by medical records and/or death certificates. Hazard ratios (HR) and 95% confidence intervals (CI) representing the association between either a second breast cancer event or death and soy intake were computed, adjusting for study group and other covariates using the delayed entry Cox proportional hazards model.
RESULTS: As isoflavone intake increased, risk of death decreased (p for trend=0.02). Women at the highest levels of isoflavone intake (>16.3 mg isoflavones) - had a non-significant 54% reduction in risk of death.
CONCLUSIONS: Our study is the third epidemiological study to report no adverse effects of soy foods on breast cancer prognosis. Impact: These studies, taken together, which vary in ethnic composition (two from the US and one from China) and by level and type of soy consumption, provide the necessary epidemiological evidence that clinicians no longer need to advise against soy consumption for women diagnosed with breast cancer.

[ElaineM]

I cook and blend other beans for sauces and soups. Gabanzo, white beans and other lightly colored beans work well for that kind of thing.

[BonnieR]

Jackie, thanks for the article.

[ElaineM]

Please see another post about soy and the latest research at
http://her2support.org/vbulletin/showthread.php?t=49641

[pibikay]

Carrots Tomatoes Fine.What about bertroot,Tofu is from soy extract and we have benadvised to avoid it

[BonnieR]

PBK, the studies included above say that it is no longer necessary to avoid soy. So tofu is okay to eat.

[Rich66]

Considering most of the studies don't seem to control for her2/Er+ BC (and that can change across treatment), might be wise to avoid:

Carcinogenesis. 2010 Jan 12. [Epub ahead of print]
Genistein Induces Enhanced Growth Promotion in ER Positive/erbB-2 Overexpressing Breast Cancers by ER-erbB-2 crosstalk and p27/kip1 Downregulation.

Yang X, Yang S, McKimmey C, Liu B, Edgerton S, Bales W, Archer L, Thor AD.
Department of Pathology, University of Oklahoma Health Sciences Center.
Genistein is a major isoflavone with known hormonal and tyrosine kinase modulating activities. Genistein has been shown to promote the growth of estrogen receptor (ER) positive MCF-7 cells. In ER negative/erbB-2 overexpressing cells, genistein has been shown to inhibit cell growth through its tyrosine kinase inhibitor activity. The effects of genistein on cell growth and tamoxifen response in ER positive/erbB-2 altered breast cancers (known as luminal type B and noted in approximately 10-20% of breast cancers) have not been well explored. Using erbB-2 transfected ER+ MCF-7 cells, we found that genistein induced enhanced cellular proliferation and tamoxifen resistance when compared to control MCF-7 cells. These responses were accompanied by increased phosphorylation of ERalpha and ER signaling, without increase in ER protein levels. Genistein treated MCF-7/erbB-2 cells also showed enhanced activation/phosphorylation of erbB-2, Akt and MAPK/Erk. Blockade of the PI3K and/or MAPK pathways abrogated genistein induced growth promotion, suggesting that genistein effects involve both critical signaling pathways. We also found that p27/kip1 was markedly downregulated in genistein treated MCF-7/erbB-2 cells. Overexpression of p27/kip1 attenuated genistein mediated growth promotion.



In aggregate, our data suggest that the concomitant co-expression of ER and erbB-2 makes breast cancers particularly susceptible to the growth promoting effects of genistein across a wide range of doses. The underlying mechanisms involve enhanced ER-erbB-2 crosstalk and p27/kip1 downregulation.

PMID: 20067990 [PubMed - as supplied by publisher]