I received a PM from orbitalboner on the Mercola reference and I figured I would include my response here.
[quote]Orbitalboner wrote:
http://www.mercola.com/nutritionplan/intermediate_proteins.htm
Hi, since you’re a chemist, I was wondering if I could get your opinion on this whole cholesterol oxidation thing. Apparently Dr. Mercola is considered a bit of a quack on this site, but I haven’t read anything by him that sounded totally out there…yet. Just wondering if the cholesterol could be oxidized as he says, by the iron in the egg whites. It sounds entirely plausible on the surface. Anyway, I’ll keep looking into it, as I was planning on upping my egg intake. It would be great if you could post your response on the ‘too many eggs?’ thread, as I’m sure this subject is extremely pertinent for everyone on this site. Thx for you opinion.[/quote]
Hi Orbital,
I think there are two important questions about this topic. 1) Can Iron oxidize cholesterol? 2) Is this oxidized product harmful? Maybe we can add a third - just how harmful is it?
2 and 3) I think these questions are best answered by medical trials. Have these been done? I am not sure. If they have, Dr. Mercola does not provide those sources. I do not know if he corresponds to email, but I would seek sound literature evidence that oxidized cholesterol leads to arterial hardening. Also, the extent of the harm is important, which is not so much a research fact but a conclusion that is open for interpretation. My chemical intuition is clueless to an opinion here.
back to 1) The structure of cholesterol contains a hydroxy group, which could potentially be oxidized to a ketone group (this is a common reaction performed in test tubes in research labs). In the laboratory, this is typically performed with Chromium (VI). I can’t seem to find the oxidation potential for Cr(VI) off hand. In general, I am not so informed on inorganic (ie. non-carbon) chemistry so I am not even sure if the iron in egg is Iron (II), Iron (III) or Iron solid. Iron solid would not do this transformation because it has a low oxidizing potential. I would imagine the others have lower potentials than Cr(VI) but that is a guess (because labs would opt to use Iron if it were better…)
Could either of the irons still do the transformation? Perhaps there is literature evidence, but again Dr. Mercola does not give a citation.
I think the human body is capable of such oxidations as well. Could cholesterol be oxidized within the human body anyway?
I also want to point out that Dr. Mercola’s personal research citation list did not have any paper(s) that would have seemingly studied any of the questions we are seeking answers to here. Likely, there has to be some research done somewhere to lead him to these conclusions, I would seek that research.
Should you stop cooking eggs? I can’t answer that, but if you are concerned, see if you can find any sound literature support to the two claims made by Mercola.
As an aside, Mercola mentions that many people have egg allergies, myself included. If I eat eggs (in any form, except raw which I have never tried) I get stomach pains and general indegestion problems. He says that eating raw eggs will not have the same allergic response, so that might be an alternative for those like me. I am not totally sure about eating raw eggs, but I might try it to see if I have the same problems or not.
Good luck.
Steve