Neuron Mommy

I have been thinking about what tone I would like to set for this particular blog entry. Should I be witty, sarcastic, humorous, serious, dogmatic…you get the idea. Those that know me would not call me a delicate flower. I am an opinionated person. I used to hate that word because it seemed to have a negative connotation. But now that I am in my 30’s I realize that it is so not a bad thing. Although I have my opinions, I respect and encourage a diversity of thoughts, beliefs, viewpoints, etc. Life would be utterly boring if everyone thought like me. All that I ask is that you put some reality, research, FACTS and good consideration behind your convictions. I also believe that sometimes your beliefs can contradict each other. I am, by nature, an over-analytical scientist. I love the scientific process of forming a hypothesis, testing it, and presenting your findings. So I really believe in the “if I can see it, prove it, I will believe in it” ideology. But, I believe in God. I can’t prove there is a God, but I believe it and I am willing to go toe to toe with anyone who belittles me for believing in God. So…what the hell did this little nugget of “what does Amber believe” (not that you asked) have to do with Neuroscience, child development, etc…well I am getting there :) I recently was having a conversation with my fabulous mother-in-law about some research suggesting that infant soy formula correlates with homosexuality. So going back to my preface, I would like to say that while I navigate you through this topic, the tone will be a complex variety, total “Amber” style. First, if you honestly believe that homosexuality is a choice, you might as well stop reading this blog entry. And in your spare time, I challenge you to find me actual SCIENTIFIC proof that it is a choice. And if you do, I promise to wear a hula skirt and do a Hawaiian dance while singing “It’s a Small World After All”.

There are 2 reasons the “infant soy formula correlates to homosexuality” gets my feathers all ruffled. First, the “articles” (and I use that term extremely loosely) just say “researchers say” without EVER giving actual citations to their, um, ahem, claims. Second, I get quite surly when people misrepresent science. We see it all of the time. Vitamin D does this, then does that, then they find actually does nothing, then can cause harm. The truth is science is pretty complex. Findings are usually not 100% absolute and straightforward. There are always exceptions. But one main point I must stress here, as I have in other entries, is this: CORRELATION DOES NOT MEAN CAUSATION!

Now for the fun to begin…

Here is some basic Neuroscience on sexual differentiation (oversimplified). All humans, regardless of whether you have XX (girl) or XY (boy) chromosomes start out as “girls”. The absence of testosterone, and some other hormones, makes for a girl. The presence of testosterone, makes for a boy. I found this on a website so I am paraphrasing it:

Sexual differentiation of the mammalian brain is dependent on the presence or absence of estradiol, which is formed from testosterone. If you are a boy, some of your secreted testosterone is converted to estradiol, which masculinizes the male fetus’ brain. "Masculinizing" means giving it characteristics of a male brain, like being bigger, having a different metabolic pattern, and some larger structures (INAH-3, SDN-POA) compared with female brains. If you are a girl, there is no testosterone to be converted to estradiol. The Estradiol you get from Mom, you rely on alpha-fetoprotein to bind and disable estradiol.
http://homepage.psy.utexas.edu/homepage/class/psy308/Humm/ReviewofSexualDifferentiation

Now, there are 2 critical periods for sexual differentiation. The first occurs in utero, the second at puberty. However, this is not to say that between these two times there are sensitivities to hormones. But this is the very simplified intro.

There is a website I found that basically calls soy products poison. The main reason it lists is that it is causing kids to be homosexual if they were exposed to infant soy milk. I won’t even list the website because it is spurious and egregious (in my opinion). But the “research” that this idiot (oops did I say that?), I mean author was using he never actually listed so who knows. Damn who knew that a soybean could open the magical world of gayness! So off I went to do my own research and here is what I found.

The basis of the soy=homo premise is based on a book by Dr. Doris Rapp who wrote “Is This Your Child’s World? (Bantam Books; 1996), p. 501. I have not read this book but what I know about her is that she is a pediatric allergist. Two websites have used her alleged claim that:
“Male children fed soy formulas and soy products may not ever get to like girls. Doris Rapp, MD, the world’s leading pediatric allergist, asserts that environmental and food estrogens are responsible for the increase in male homosexuality and the worldwide reduction in male fertility.” http://www.altpowerhealth.com/stephen_byrnes_archives/homosexualdebunking.htm
Now I have not idea if Dr. Rapp actually believes this, or if this is just a distorted view taken from her book. Regardless, I could NOT find any actual scientific articles linking isoflavones/soy/phytoestrogens to homosexuality. Homosexuality and sexual orientation is a HUGE topic. But since this is a blog (mostly) about child development and neuroscience, I will present a few scientific articles relevant to this topic.

A study by Storm et al. (2001) investigated different measures in men and women like onset of menarche, weight, height, sexual orientation, etc. These participants were in their 20’s and 30’s and were fed either “cow milk” formula or “soy milk” formula. They found no significant difference in sexual orientation. Period. Here is the studies’ actual conclusion “Exposure to soy formula does not appear to lead to different general health or reproductive outcomes than exposure to cow milk formula” (Storm et al., 2001). Now they do admit that they didn’t have the population numbers required to really draw a more definitive conclusion, which in layman’s terms means it happened too infrequently to be evaluated.

There is some evidence that soy can interfere with reproduction. I found this article which just about sums it up:
Isoflavone (IF), a type of phytoestrogen, has multiple beneficial effects, but too much phytoestrogen can have adverse effects on offspring. To examine whether chronic exposure to high IF has adverse effects on reproductive development, mice offspring were exposed to IF through dietary administration to dams during pregnancy and lactation and to the offspring directly after weaning until sacrifice. In male offspring, there was no difference between the IF group and controls; however, in female offspring in the IF group, remarkably earlier puberty and induction of multioocyte follicles on postnatal day (PND) 21 were observed. Gene expression levels of estrogen receptor beta decreased in the ovary and vagina on PND 21. These results suggest that chronic exposure to higher than normal levels of IF induces alterations in the reproductive development of female mice through an estrogenic effect.
Effect of exposure to high isoflavone-containing diets on prenatal and postnatal offspring mice.Takashima-Sasaki K, Komiyama M, Adachi T, Sakurai K, Kato H, Iguchi T, Mori C. Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University. Biosci Biotechnol Biochem. 2006 Dec;70(12):2874-82. Epub 2006 Dec 7.

Then I found this article:
The goal of this study was to determine if exposure to genistein, an isoflavone found in soy, during early periods of sex differentiation alters reproductive development and behavior in male mice. Female C57BL/6 mice were fed a phytoestrogen-free diet supplemented with 0, 5 or 300 mg/kg of genistein throughout gestation and lactation. Anogenital distance (AGD) and body mass of male offspring was measured weekly from postnatal days 2-21, timing of preputial separation was assessed at puberty, and in adulthood, reproductive organ masses, sperm and testosterone production, and reproductive and aggressive behaviors were assessed. Exposure to genistein resulted in smaller AGD are reduced body mass, with the low-dose diet exerting a greater effect. Timing of preputial separation, adult reproductive behavior, sperm concentrations and testosterone production were not influenced by genistein treatment at either dose. Aggressive behaviors were decreased, whereas defensive behaviors were increased, in males that received the low-dose genistein diet. Exposure to genistein during critical periods of sex differentiation results in concurrent and persistent demasculinization in male mice.
Perinatal exposure to genistein alters reproductive development and aggressive behavior in male mice. Wisniewski AB, Cernetich A, Gearhart JP, Klein SL. Department of Pediatrics, Division of Pediatric Endocrinology, The Johns Hopkins School of Medicine, USA. Physiol Behav. 2005 Feb 15;84(2):327-34. Epub 2005 Jan 12


Well doesn’t that just take the wind out of my sails…not so fast, though. Demasculinization and lower testosterone don’t mean homosexual. Mainly this article mentions affects to aggressive versus defensive behaviors. Let me repeat its statement “Timing of preputial separation, adult reproductive behavior, sperm concentrations and testosterone production were not influenced by genistein treatment at either dose”. So there you have it. Another example of how some studies find effects, and subsequent ones do not. But even if soy products lower sperm count and testosterone, there are plenty of heterosexual men that have low testosterone and you don’t see them running for the gay hills, right?! There is a laundry list of articles that state that soy-based phytoestrogens don’t interfere with all reproductive functions and/or behavior:

W.A. Fritz, M.S. Cotroneo, J. Wang, I.E. Eltoum and C.A. Lamartiniere, Dietary diethylstilbestrol but not genistein adversely affects rat testicular development, J. Nutr. 133 (2003) (7), pp. 2287–2293.

N Atanassova, C McKinnell, K.J. Turner, M. Walker, J.S. Fisher and M. Morley et al., Comparative effects of neonatal exposure of male rats to potent and weak (environmental) estrogens on spermatogenesis at puberty and the relationship to adult testis size and fertility: evidence for stimulatory effects of low estrogen levels, Endocrinology 141 (2000) (10), pp. 3898–38907.

Nagao, S. Yoshimura, Y. Saito, M. Nakagomi, K. Usumi and H. Ono, Reproductive effects in male and female rats of neonatal exposure to genistein, Reprod. Toxicol. 15 (2001) (4), pp. 399–411

N. Masutomi, M. Shibutani, H. Takagi, C. Uneyama, N. Takahashi and M. Hirose, Impact of dietary exposure to methoxychlor, genistein, or diisononyl phthalate during the perinatal period on the development of the rat endocrine/reproductive systems in later life, Toxicology 192 (2003) (2–3), pp. 149–170.

So, to sum this all up, I would say that there really isn’t any concrete evidence that infant soy formula has anything to do with homosexuality. While soy products may decrease fertility, and affect certain reproductive aspects, or lower testosterone, this is WAAAAYYYY different than saying it causes our boys to like other boys. All in all, I don’t think cow’s milk is the golden ticket either. Cow’s milk is laden with growth and other hormones, and antibiotics, and you really wanna tell me that isn’t affecting out kidlets? In addition, while I am not expert in food anthropology, wouldn’t countries that consume a lot of soy products, like oh I don’t know, China, Japan, Vietnam, to name a few, have higher instances of homosexuality? Maybe we consume more soy products here? Dunno?

Ok, I am ready…bring it! No really, I would love to get feedback, your viewpoints, or, dare I say…evidence counter to what I presented!