Soya-noia could Destroy-ya!

From Mark Sisson's Weekend Link Love this past weekend comes this:  Soy protein present in egg yolks and chicken tissues.  Ruh roh!!  Mark writes:

It’s confirmed: meat and eggs from soy-fed chickens contain soy isoflavones. The title of the article – “Soy protein present in egg yolks and chicken tissues” – isn’t quite accurate, but soy isoflavones are often phytoestrogens and thus somewhat concerning.

Boys are reaching puberty younger than ever before, a new study shows, but “it’s unclear why.” Perhaps the phytoestrogens from soy-fed chicken products are involved?

I'm sorry but this sort of thing really grates on me leading to unnecessary dietary angst.     It is one thing to avoid things where soy is directly added or direct soy products such as soy milk, tofu soy protein in processed foods, and even the beans themselves.  If that's an issue for you, that's between you and your body.  It's also fine by me to avoid commercially raised chickens/eggs for various reasons from questioning of the treatment of the chickens, to sustainability, to the use of unnatural diets, antibiotics, and hormones.  Again, to each their own.

I just don't think it's helpful to needlessly demonize two of the most economical protein sources out there: eggs and chicken.  Doing so is, frankly, irresponsible!  Dare I say especially so for someone who purportedly is trying to help people improve their health while making a living doing so.  Or is it only those who can afford and have access to pricey non-commercial alternatives that we care about?  Remember too, that Mark's Sample Menu cited eating "chicken (with the skin on!)" as a "regular" for dinner, and thus leftovers often topping off his Big Ass Salad.  Do we really need to burden those struggling to make ends meet that at least opt to buy chicken and cook it at home with more stressors?  Heck, I am far from struggling and I just, gasp!, purchased a butt ton (well a whopping $10 worth) of chicken legs from Stew Leonards for $0.69/lb.  I am not worried over this chicken harming my health, and if I had young boys, I'd not worry in the least feeding it to them either.  I hope after reading this blog post, any who might be wary and worried, will no longer be either.

First off, let's look past the past the scare-mongering headline at the link.  First I note it's to Health Impact News Daily, subtitled:  News that Impacts Your Health that Other Media Sources May Censor! Oooooohhhhhh.  Such claims have me switching to the browser in which I've installed my new AMH (Anti-Mercolaesque Hyperbole) plug-in.  Who puts out Health Impact News Daily?   Tropical Traditions, an outfit dedicated to over-hyping the miracles of the coconut.  Atop this "news" article we see this is a cleverly disguised advertisement for their soy-free eggs.   These eggs come from chickens:

"raised by family farmers [that] eat a coconut-based soy-free feed mixture that is certified organic, with no genetically modified grains (no GMOs!). 

Yeah, because as we all know, soy may well be an unnatural food for the chicken, but chickens have a long evolutionary history of consuming coconuts.  C'mon!!  From the egg link:

Almost all commercial eggs, including those that are organic or marketed as "Omega 3" eggs, are from chickens fed high concentrations of soy. So if eggs are a part of your diet today, so is soy protein, whether you realize it or not. 

Now when one thinks of soy proteins, as Mark rightly points out, isoflavones are not really what comes to mind.  The Tropical Traditions use of this renders this "health news" scientifically bankrupt from the get-go.  

Alright, so maybe they are just suffering from Mercolaperbole, but we shouldn't disregard the good underlying science out of hand because of this.  These cases, however, tend to counter the old adage about smoke and fire.

But, I look into it a bit because I know a thing or two about soy isoflavone doses, because I took max strength Estroven when I went through menopause.  And this soya-noia almost kept me from even trying this inexpensive (especially getting it from Costco)  remedy.  Either the isoflavones or something else in there, or the synergistic mix really did help me, particularly with my most severe symptom of night sweats.  What is the concentration in this max strength Estroven?  A "mere" eighty milligrams, 80 mg.  Let's keep that number in mind.  For a 100 to 200 lb woman, this works out to a dose of 0.8 to 0.4 mg/lb/day.

So let's look at the HIND cited study:  QUANTIFICATION OF SOY ISOFLAVONES IN COMMERCIAL EGGS AND THEIR TRANSFER FROM POULTRY FEED INTO EGGS AND TISSUES.  First, they looked at the soy isoflavone  (from hereout, SI) content of commercial eggs.  The graph at right shows their results (you can click to view full size).  

It is very important to note that "isoflavones were found in the egg yolk of all commercial egg samples analyzed in concentrations ranging from 33 to 120 μg of isoflavones/ 100g of egg yolk."  Note:  MICROgrams of SI per 100g of egg yolk, where a large egg yolk is 17g.  Let's round up to 20g per yolk, and use the maximum SI content of commercial eggs and do the calculation: 

In commercial eggs currently available at your run-of-the-mill, plebeian-frequented, addict-patronized grocery store, soy isoflavone content is at most 0.024 milligrams per large egg yolk.  

(I'm presuming there wasn't much to be alarmed over in the whites).  Let's put that in context with maximum strength Estroven at 80 mg, you'd have to consume 3333 commercial eggs of Brand 8.  Even presuming anything would happen at 1/1000th of that dose, we're still talking 3 eggs to reach just that!

A little more math for context.  

• On the "In" Side:  In the study (thesis) they then fed chickens for 28 days, regular feed, soy enhanced diet and a SI-enhanced feed that included 500 mg SI/100g.  I Googled a bit and found that your average American egg-layer weighs around 6 lbs and consumes around 100g feed per day.  Therefore, in order to produce the "alarming" levels in this study, they fed these chickens over 6X the dose of concentrated SI that menopausal women might consume as a supplement (max strength!).  On a pound for pound basis?  These chickens received over 80 mg/lb/day ... compared with a 150 lb menopausal woman taking maximum strength Estroven getting around 0.5 mg/lb/day.  
• On the "Out" Side:  For now just meaning the SI content of eggs produced, they found roughly 1000 micrograms = 1 milligram (1 mg) per 100g egg yolk.  So, this is up from 33 to 120 μg per 100g egg yolk.

Thus, expose egg-laying chickens to 160X the dose of soy isoflavones a menopausal woman might take in a supplement and their eggs will contain, in the yolk, a level roughly 10X the maximum level currently present in commercially available eggs.  This thesis did indeed demonstrate that high levels of SI in the diet can impact egg/tissue levels.   Anyone wanna go in on my Menovum (copyright, trademark and all those dibbs laid here!) egg project?!  LOL.  Beyond that, however, was this at all significant in the global scheme of things?  No.

Let's look at eggs vs. chicken muscle -- aka "chicken".  In the mega SI dosed chix, the eggs were found to have about 1000 μg/100g yolk while the muscle was found to have roughly one-tenth that, at 100 μg/100g.  For those not in the metric groove, if you ate one full pound of Estrovenofied chicken meat, you would get 450 μg SI or less than half a milligram "exposure".  But -- investors, are you hearing me??!! -- you can achieve that with just 2 jumbo Menovums!!!  Whoa boy, I'm probably giving some opportunistic shyster ideas here :(:(  Here's a better idea, I suppose, foie gras from these chix!  A whopping just over 7000 μg = 7 mg per 100g liver was found in those chickens.  Woo hoo!! Stop me before I kick off the next scam (folks omega-3 eggs are a scam, just check the numbers, just eat the fish oil yourself!).

But ... but ... what about cumulative effects?   There appear to be none ... at least not on what we consider a truly long term.  In the study they fed the chickens this diet for 28 days, the isoflavones peaked at around 10 days.  Further, isoflavones in eggs of the high SI chickens became undetectable after 10 days of switching the chix to a soy-free diet.   This would argue strongly against any claims that consuming these eggs or chicken meat may lead to an accumulation of SI to deleterious effect.

OK, now time to take Mark Sisson to task here for his rank speculation about the role of soy chicken feed as possible culprit in early puberty in boys.  There's a saying that with great power comes great responsibility.  I'm told this is biblical in origin, but I think one can be of any religious persuasion or none at all and agree with that adage.  Through the sheer volume of his website traffic, Sisson wields great influence and is about as powerful a figurehead in the community as any.  With that power does come great responsibility, whether he wants it or not, and such episodes of flippant speculation are not helpful here.

One doesn't even need to be scientific about this, just apply some common sense.  Whole egg consumption is down, and while chicken consumption is up (quite a lot), a goodly portion of that is the dreaded skinless/boneless chicken breast and fast food mangle-ations thereof.  Trace isoflavones in the diets of boys these days?  Highly unlikely.  About as unlikely as a chicken eating coconut.