03-09-2011, 11:42
Eve M wrote soy was in her program for the isoflavones, not for the protein:
http://www.breastnexus.com/showthread.php?tid=5599&pid=35702#pid35702
That makes her program the only one to recommend mixing a strong phyto-estrogen, hops, with a weaker one, soy. There is a lot of caution against doing that on this forum, and the reasoning is this: you only have so many receptors, why fill them with weak estrogens, if you can have stronger ones there instead?
I don't really buy that. A receptor is a protein that receives the estrogen signal at the cellular level. If there's a phyto-estrogen on it, the signal is received, and the protein will do what needs to be done. A "stronger" or "more potent" phyto-estrogen just means the chemical bond it builds with the receptor is stronger. In my understanding of dynamic chemical equilibrium, that just means that at equal concentrations of strong and weak estrogens, most of the receptors will be occupied by the stronger estrogen. So in practice, there is no objection at the receptor level against mixing strong and weak phyto-estrogens.
There is an objection at the level of digestion of phyto-estrogens to the bioactive estrogens. In post #49 of this thread, I linked this publication:
http://jn.nutrition.org/content/139/12/2293.short
http://jn.nutrition.org/content/139/12/2293.full
The phyto-estrogens from hops, flax, and soy, are digested to the bioactive 17β-estradiol. When the phyto-estrogens are taken together, less 17β-estradiol becomes available.
The same research group later found that soy is not really a weak phyto-estrogen:
http://www.ajcn.org/content/91/4/976.abstract
http://www.ajcn.org/content/91/4/976.full
At the receptor level, there is 21 and 10 times more 17β-estradiol than in adipose and glandular breast tissue. The authors conclude that this level is high enough to cause health effects. So far, conventional wisdom expected no effect at all unless people eat soy products all day.
http://www.breastnexus.com/showthread.php?tid=5599&pid=35702#pid35702
That makes her program the only one to recommend mixing a strong phyto-estrogen, hops, with a weaker one, soy. There is a lot of caution against doing that on this forum, and the reasoning is this: you only have so many receptors, why fill them with weak estrogens, if you can have stronger ones there instead?
I don't really buy that. A receptor is a protein that receives the estrogen signal at the cellular level. If there's a phyto-estrogen on it, the signal is received, and the protein will do what needs to be done. A "stronger" or "more potent" phyto-estrogen just means the chemical bond it builds with the receptor is stronger. In my understanding of dynamic chemical equilibrium, that just means that at equal concentrations of strong and weak estrogens, most of the receptors will be occupied by the stronger estrogen. So in practice, there is no objection at the receptor level against mixing strong and weak phyto-estrogens.
There is an objection at the level of digestion of phyto-estrogens to the bioactive estrogens. In post #49 of this thread, I linked this publication:
http://jn.nutrition.org/content/139/12/2293.short
http://jn.nutrition.org/content/139/12/2293.full
The phyto-estrogens from hops, flax, and soy, are digested to the bioactive 17β-estradiol. When the phyto-estrogens are taken together, less 17β-estradiol becomes available.
The same research group later found that soy is not really a weak phyto-estrogen:
http://www.ajcn.org/content/91/4/976.abstract
http://www.ajcn.org/content/91/4/976.full
At the receptor level, there is 21 and 10 times more 17β-estradiol than in adipose and glandular breast tissue. The authors conclude that this level is high enough to cause health effects. So far, conventional wisdom expected no effect at all unless people eat soy products all day.