|Image 1: I guess the feed of those boars does not contain any corn oil and is spiked with both bisphenol A and soy bean extract - I mean, how else could you possibly explain those balls? (img dirtybutton.com)|
Chose your poison: BPA, soy, or maybe just some governmentally subsidized corn oil?
The preceding paragraph was an ironic, yet as far as the underlying facts and figures are concerned 100% accurate introduction to today's post which revolves around a study Evanski from the Mind&Muscle forum has brought to my attention (Norazit. 2012). The authors, a group of scientists from the University of Malaya in Kuala Lumpur, Malaysia, had set out to investigate the purportedly negative effects of what they call "soya bean extract" (interestingly this spelling of "soy", which is identical to the German version is probably the reason the study did not appear on my "interesting stuff for the SuppVersity radar", before ;-), bisphenol A, 17β-estradiol and "harmless" corn oil on the testis and endocrine system of juvenile rats.
|Figure 1: Phytoestrogen content (µg/g dry weight; mind the logarithmic scale!) of soy bean extract an standard rat chow measured by LCMS (data adapted from Norazit. 2012)|
Note: It is (at least in my view) a lucky coincidence that contrary to the soy extract and the bisphenol, the estradiol did not solve in the Tween 80, so that the scientists had to come up with Mazola corn oil as a "positive control". I mean, if you take a look at the effects this supposedly neutral "solvent" had on the endocrine milieu of the peripubertal rats, it is no wonder that with the average testosterone levels of the male inhabitants of the #1 corn producer of the world, the Unites States of America, is on a constant decline.At the end of the study period the rats were sacrificed, the testis were excised and their testosterone and estrogen levels were assessed using standardized enzyme immunoessay (EIA) kits from Caymen Chemical.
|Figure 2: Section of seminiferous tubules from control Tween 80 group, BPA group and soy bean extract group; (1) maturing spermatids, (2) lumen filled with cellular debris, (3) vacuaolation, (4) interruption of spermatogenesis (data adapted from Norazit. 2012)|
The "harmless" corn oil shifts the testosterone to estrogen ratio from ~1/1 to 1/2pg/ng
Reckless, as I am I decided to discard Norazit et al.'s distinction into the BPA and soy groups with the Tween 80 group as a control and the estradiol group with their corn oil control and just plotted the total body and total and relative testis weight gain, estrogen and testosterone levels relative to the Tween 80 group. In other words, I treated the corn oil group as if it was just another treatment group. This is obviously somewhat fishy, but if no scientist appears to be willing to investigate the potential negative effects of corn oil on the endocrine system of adolescent rodents (let alone humans), this is the only way for us to get respective data ;-)
|Figure 3: Body weight gain, total and relative right testis weight, estradiol and testosterone levels in peri-pubertal rats after 21 days on diets containing 100mg/kg bisphenol A, soy bean extract, corn oil or 17b-estradiol (in soy bean oil); data expressed relative to Tweenn 80 (polysorbate + oleic acid) control (data calculated based on Norazit. 2012)|
BPA and soy compete for the title of "most potent endocrine disruptor"
Following the bro-scientific "the more the better" type of reasoning, bisphenol A and soy bean extract are two potential candidates for the "testosterone booster of the year"-award. After all both, the organic solvent bisphenol A, as well as the "natural toxin" (sorry, I just had to write that ;-) soy, exert potent (8x) and ueber-potent (100x) effects on the testosterone to estrogen ratio, which is 8.2pg/ng for BPA and 100.1pg/ng for soy!
Note: Neither I, nor the scientists have any clue as to why the results of this study are diametrically opposed to those of previous studies in which extracts from soy products reduced, not increased, testosterone levels in male rodents and monkeys(!), across-the-board (eg. Sharpe. 2002; Cline. 2004) - and that although Sharpe et al. observed an increase in the testosterone producing Leydig cells in their soy-formula fed monkeys. Whether the rats in the study at hand were in a state where similar effects temporarily increase testosterone output until the Leydig cells literally "burn out", or whether other effects were responsible for the temporary increase in testosterone, would have to be elucidated in future studies, the results of which you will obviously read here at the SuppVersity, first ;-)So, even if we assume that the data is correct and there were no cross-reactions between components in the soy bean extract and the testosterone anti-body test, I would strongly caution against the use of either of this compounds to boost your testosterone levels - I mean what's the use of a wickedly skewed testosterone to estrogen ratio (which in and out of itself will probably mess up your health and can potentially hinder your gains, cf. "Are You Serming Away Your Gains?"), when, at the same time, your testicles turn into dysfunctional balloons?