Safe protein sources for ER+ ?

WC3

I'm looking for a safe protein I can safely consume a lot of to help get my strength back. Dairy can contain high levels of estrogen and EGF and I hear animal proteins increase IGF-1 levels which could be bad for cancer, while plant proteins don't. But most plant proteins that are readily available seem to have phytoestrogens in them.

edj3

This website has been invaluable to me. What I especially love is that every recommendation to eat or to avoid is backed up with reputable scientific studies.

WC3

edj3:

Thanks for the link!

Gudrun

Dear edj3, here's another thank you so much for your link.

WC3

Well I've just found this article implicating leucine in anti-hormone therapy resistance.

Dietary link found to drug-resistant breast cancer

I know it's been mentioned before here. I'm just kind of bummed because it seems that there isn't really a safe source of protein for people with hormone receptor positive cancers.

DorothyB

Re: phytoestrogens:

https://www.medicalnewstoday.com/articles/320630.p... says "However, phytoestrogens do not bind to estrogen receptors as firmly as estrogen produced by the body, so their effects may be weaker."

https://ascopubs.org/doi/10.1200/JCO.2006.06.0244 says "By competing for estrogen receptors, phytoestrogens possibly inhibit binding of the more potent endogenous estrogens and decrease their potential effects on breast cancer risk."

https://www.ascopost.com/issues/july-15-2012/soy-p... is from 2012 and says "there is a growing body of research in humans that supports soy consumption as safe. Three large epidemiologic studies published over the past few years, two in U.S. breast cancer survivors and one in Chinese survivors,found no adverse affects of soy consumption on outcome. Furthermore, they suggest that soy consumption at levels comparable to those among Asian populations does not detract from the benefits of tamoxifen therapy, and may even offer some protection against recurrence and cancer-related death."

https://www.bcpp.org/resource/phytoestrogens/ says "In general, isoflavone intake appears to have a greater protective impact on later breast cancer recurrence and mortality among postmenopausal breast cancer patients, compared to premenopausal breast cancer patients." and "Since highly processed and concentrated phytoestrogens may have different effects on breast tumor cells, it is best to avoid highly processed soy." and

"Who should be cautious about soy consumption?

While evidence is still growing, some data suggest women with HER-2-positive tumors and pre-menopausal women at high risk for breast cancer should avoid phytoestrogens."

WC3

DorothyB:

Thank you for the links to the studies. My cancer was HER2 positive.

There seems to be a lot of conflicting studies on soy and phytoestrogens. I guess the question is, do phytoestrogens work against the purpose of the tamoxifen/AIs, or work with them?