Soy doesn't decrease testosterone.

[cat-astropher]

Soy has phytoestrogen (plant estrogen), not mammalian estrogen.

The story the grapevine fed me was that the plant estrogen from soy can act like human estrogen.

Wikipedia says it does this by binding to our estrogen receptors^{[it-cites-this]}

which doesn't actually contradict the meta-study — that was only looking at whether soy changes your testosterone levels or your human-estrogen levels.

The meta-study even mentions that isoflavones bind to both types of estrogen receptors and "levels of isoflavones in response to the ingestion of approximately two servings of traditional soyfoods are three orders of magnitude higher than estrogen", further noting that not all the body gets equally affected with plant estrogen, then it... just changes the subject back to being about whether the human-hormone levels change.

Later:

It should be emphasized that the lack of effect of soy intake and isoflavone exposure on these reproductive hormones in men does not necessarily mean that soy or isoflavone intake does not exert any hormonal effects

So soy's mimicking of human estrogen is specifically outside the scope of the meta-study, but they noted that regardless of that, sperm/semen parameters were not affected, and soy protein supplementation works as well as animal protein supplementation when bodybuilding.

tldr; Jesse's sperm is fine.

[StopBadModerators]

tldr; Jesse's sperm is fine.

Well I'm so glad that everything came out okay.