Maybe you've seen Denise Minger's blog posts (If not check out "The China Study, Wheat, and Heart Disease; Oh My!" where she discusses the strong correlation she found between wheat and heart disease in the raw china study data. Yes, ultimately it only shows correlation and not causation, but the correlation appears strong. She also brings up a few studies, including this one in which wheat germ raised LDL a little and flax seed lowered it. This study was very similar (but longer and only involving women) and reported the same result; wheat germ raised LDL. And I found a few more studies with the same results.
I also recently posted a question about this study, in which whole wheat increased LDL relative to white bread but, interestingly enough, this effect varied depending on ApoE genotype. This made me wonder if perhaps something in wheat germ raises LDL and does so in part through interactions with ApoE.
I researched physiological differences between the various ApoE phenotypes and found that one prominent trait is varying quantities of sialic acid in the ApoE protein. Why is sialic acid important? Wheat Germ Agglutinin (WGA), the infamous lectin in wheat, binds to sialic acid.
(From here I get more speculative...) Apolipoproteins such as ApoE and ApoB100 are proteins that help form LDL, HDL, and so on. They all contain sialic acid which WGA can bind to. These apolipoproteins are what is recognized by several receptors of the LDL receptor family. So perhaps when WGA binds to the sialic acid on these proteins it changes their structure and reduces or eliminates the ability of some LDL receptors to recognize them (such a process seems to happen when AGE's modify LDL)
There is some conflicting evidence that wheat or wheat germ increases LDL. My hypothesis is that this is at partly due to WGA entering the blood stream, binding to sialic acid on apolipoproteins and changing their structure, impairing their recognition by LDL receptors and potentially leading to increased LDL levels. Whether this implies wheat increases heart disease is too difficult to determine.
I'm aware this is total mechanistic speculation, but I'd really like to hear what people think, even if that means explaining why none of this makes any sense.
asked byMscott (12682)
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on July 02, 2012
at 01:01 PM
A common thought/theory is that WGA that makes it past the gut defenses causes an immune response by the body. Antibodies are created that target WGA. It so happens that these anti-WGA antibodies also cross-react with other human tissues leading to autoimmunity symptoms (that's the popular theory). Should WGA make it into general circulation, it should be targeted and eliminated by immune response. I doubt that it would have the effect on LDL that you propose.
I wouldn't call any of the studies you cite as a slam-dunk inditing wheat. The studies comparing wheat and flax only show an advantage for flax, not a disadvantage for wheat. Whole-wheat vs white bread study shows a very limited effect.
Now if you could find a study comparing blood lipids and the presence of antibodies against various antigens, that might be useful.
on July 02, 2012
at 05:15 AM
Your post is above my level of competence but I have a general feeling that nothing good can come out of wheat. Why?
It is not even about gluten. It is about that wheat is a cheap source of ... pretty much everything that you eat, apply, brush with, feed, add and consume. If you do not believe me, check out a list of items that have wheat-derived products with gluten in it. Anything from facial cream and toothpaste to anti-clumping additives in your spices and peanuts. It is a cheaper alternative to more expensive stuff. So to produce cheap wheat, you have to modify it, not only genetically but chemically and on a molecular level. All those fields of gold need tons of insecticides, herbicides, and any other... cides you can imagine.
Do you know why kale has the most nutrients out of all cabbages? Because it underwent the least amount of domestication. It is as wild as a domesticated plant can be.
Do you know why berries have the most antioxidants? Because they were not as inbred as other agricultural fruit.
So wheat is no longer in its form it was 1,000 years ago. It is a mutant. And you are what you eat.
Two more things. One: I was reading a study from some Chinese scientists that suggested that they could trace unaltered chains of genetic material in rice in humans who consumed that rice. I wish I could put it in more scientific terms, but the idea was that we carry the genes of what we eat (in that particular research it was rice).
Second: one of the guys I know used to work as a doctor in Vietnam. I don't like the guy and think he is not a good doctor, but he claims that liver cancer is more common in Vietnam due to rice consumption and apparently that's what all doctors who worked in Vietnam came to believe. Take it with a grain of salt because I do not know anything about it.
Thanks for your post. I also would love to know if you are a researcher.
on July 02, 2012
at 06:29 AM
I like your train of thought. I asked a question here about whether or not the WGA survives the cooking process, I'm not sure if it does...