Posted by tealady on September 27, 2003, at 9:38:40
In reply to Re: Soy » tealady, posted by Larry Hoover on September 19, 2003, at 20:00:59
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>> A quick look at the soy/thyroid connection was rather revealing. One of the isoflavones, genistein, alters thryoid function in two distinct and deleterious ways. First, it is an alternate substrate for the iodinating enzyme, so it consumes iodine without contributing to the formation of T4 (that's called competitive enzyme inhibition), leading to functional iodine deficiency. Second, under conditions of oxidative stress (e.g. high peroxide levels), the genistein binds permanently to the reactive site of the iodinating enzyme, inactivating it entirely. That's irreversible non-competitive enzyme inhibition.
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> For anyone whose thyroid hormone production is already impaired or marginal, genistein could simply be the straw that broke the camel's...uhhh....neck, I guess.
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> Both forms of enzyme inhibition are associated with goiter formation.
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> LarLar,
A new study on genisten from Larrian's newsletter
~ GENISTEIN LOWERS PSA LEVELS-
While menopausal women want to avoid soy because of the increased incidence of hypothyroidism, men may benefit from an isoflavone, genistein, which can slow down prostate cell growth. Now the study was touting a supplement which used megadoses ( 5gm a day), and diarrhea was a side effect. Genistein did not affect testosterone or estradiol levels in men, which is a GOOD thing. A wider study is planned.
AUA 2003 Annual MeetingHugs, Jan
poster:tealady
thread:259853
URL: http://www.dr-bob.org/babble/alter/20030903/msgs/263708.html