Eggs, LDL VS HDL, the common comeback.

[bobo0100]

Whenever the healthfulness of eggs is brought up it is always argued that they contain HDL. Although I'm let to believe that they contain both LDL and HDL. I have heard eggs brought up in conversations about the healthfulness of cholesterol, and in these conversations no one bothered to differentiate between the two (LDL and HDL).

Why is LDL harmful and HDL not harmful?
Does absorption of HDL effect your ability to absorb LDL?
In regards to eggs, how much of each type of lipoprotein is present?

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Sorry if something similar has been asked before.

[Mr. Purple]

That's a really good question that I would be interested in knowing myself. It would be pretty important to the health argument if the HDL actually was enough to offset the LDL and make for an overall healthy food.

EDIT: This seems to somewhat answer things if accurate: http://nutritionfacts.org/video/does-ch ... ze-matter/

[DiscreteElite_]

Lipoproteins carry cholesterol to the liver to be processed via particles; cholesterol cannot dissolve in blood. HDL cholesterol can "clean up" the LDL cholesterol. LDL lipoproteins are not as dense as HDL lipoproteins. As a result, it can stay in your blood and you can possibly get a heart attack or stroke in the future.

http://www.heart.org/HEARTORG/Condition ... jASnrerS00

[bobo0100]

http://www.heart.org/HEARTORG/Condition ... jASnrerS00

so LDL and HDL are carriers of Cholesterol, and not Cholesterol itself, but Cholesterol itself isn't a worry because it cannot be dissolve in blood, and therefore does not contribute to blood clotting. very interesting!

What roll does saturated fat have to play in this? And does anyone know the LDL/HDL ratio for eggs?

[garrethdsouza]

AFAIK the major player is saturated fat which when consumed increases your serum LDL-cholesterol levels ("bad cholesterol") which is causal in CVD. This is called the lipid hypothesis. Check out my comment on page2 of this thread and watch plant positive's video: https://theveganatheist.com/forum/viewt ... t+positive

Its NOT that egg possesses these LDL or HDL cholesterol complexes that when consumed affect your serum cholesterol. Because LDL or HDL are proteins which bind cholesterol and when you ingest proteins they are anyways broken up in your stomach because of proteases and acidic pH and its the amino acids that would be absorbed. So the question isnt what type of lipoprotein complex does egg contain but what happens to your serum LDL,HDL levels and their ratio after consumption of egg. This would be affected by egg's saturated fat content and to a smaller degree by egg's total cholesterol content. Correct me if I'm wrong.

[brimstoneSalad]

Its NOT that egg possesses these LDL or HDL cholesterol complexes that when consumed affect your serum cholesterol. Because LDL or HDL are proteins which bind cholesterol and when you ingest proteins they are anyways broken up in your stomach because of proteases and acidic pH and its the amino acids that would be absorbed. So the question isnt what type of lipoprotein complex does egg contain but what happens to your serum LDL,HDL levels and their ratio after consumption of egg. This would be affected by egg's saturated fat content and to a smaller degree by egg's total cholesterol content. Correct me if I'm wrong.

For what it's worth, this is also my understanding.

I don't believe that LDL or HDL actually enter the body from the diet, but rather the cholesterol itself, which is picked up and transported by the carrier molecules already present in the body. The proteins would be digested AFAIK.

[bobo0100]

Nothing can be simple in nutrition Correct me if I am misunderstanding anything.

Low Density Lipoprotein (LDL) and High Density Lipoprotein (HDL) are not cholesterol, but rather the protein that transports cholesterol through the blood.

LDL is considered bad as it tends to clot, but HDL may reverse these effects.

Was Brimstone trying to suggest that the consumption of cholesterol is "bad" due to the fact the the body will need to transport it via LDL or HDL so it doesn't matter if its LDL or HDL because that is not necessarily how the body will transport it in the end?

Is dietary LDL and HDL levels worth differentiating between at all? why?

So saturated fat is more important than cholesterol, but especially when combined with cholesterol?

can someone better explain what role saturated fat has to play in this. Why does it effect LDL levels?

Apart from the ethical implications of animals product's, is there any reason to avoid cholesterol when not accompanied by saturated fat?

[brimstoneSalad]

Was Brimstone trying to suggest that the consumption of cholesterol is "bad" due to the fact the the body will need to transport it via LDL or HDL so it doesn't matter if its LDL or HDL because that is not necessarily how the body will transport it in the end?

Yes, that is my understanding.

Saying that consuming HDL cholesterol will raise your HDL levels would be like saying eating hair would help your hair grow -- or even that eat blonde hair would make you grow blonde hair, eating black hair would make you grow our black hair, etc.

Take that with a grain of salt, though. I can't reference anything to back that up, and I'm not certain on that one.

Is dietary LDL and HDL levels worth differentiating between at all? why?

I don't think so, no. It would be like differentiating between dietary rotini and penne pasta. AFAIK.

So saturated fat is more important than cholesterol, but especially when combined with cholesterol?

Saturated fat is more important, yes. With or without cholesterol.

Cholesterol is bad too, with or without saturated fat.

Because cholesterol is of low solubility, and your body needs to transport it with HDL or LDL, if you eat a huge amount of cholesterol compared to eating just a little bit, it doesn't make a lot of difference.
At least, that is my understanding.

You are limited in your ability to uptake cholesterol from your diet. Eating a little is about the same as eating a lot. But eating none is better.
It's kind of like there's a uptake cap.

Saturated fat is more important because there is no limit (or, at least, the cap is much higher) to how much harm it can do to you. Eating more is just worse and worse for you.

can someone better explain what role saturated fat has to play in this. Why does it effect LDL levels?

Your body produces more cholesterol, and possibly metabolizes cholesterol more poorly too, when you consume higher amounts of saturated fats.
"Why?" is kind of the question of the hour.
It comes down to, as I understand it, a mix of gene expression (which involves another "why" that is evolutionary, and varies a lot between people), good old metabolism, and other factors.

Here's an interesting answer given on research gate which broke it down:
http://www.researchgate.net/post/How_do ... holesterol

1. Oxidation of saturated fatty acids can provide acetylcoA for cholesterol biosynthesis. Also check during VLDL packing which fatty acids are preferred for cholesterol esterification (sat or unsat).
2. Saturated fatty acids can alter cell signaling by changing membrane fluidity that can result in change in cholesterol metabolism (synthesis and lipoprotein distribution).
3. Fatty acids can regulate cholesterol metabolism by providing signaling molecules like arachidonic acids, prostaglandins, cyclins, anandamides, etc. Generally these are synthesized from unsaturated fatty acids. But saturated fatty acids can competitively inhibit the enzymes involved in synthesis of these molecules (I think). Look for this connection in literature.
4. Fatty acids can directly regulate gene expression by acting as ligands for PPARs. PPARs role in cholesterol metabolism is well known. Here also unsaturated fatty acids are better ligands than saturated fatty acids. Look in this angle.

That seems credible to me. Again, though, grain of salt.
Why more LDL rather than HDL? Probably the same kind of answer. Gene expression and all of that.

These are certainly important questions, but they're ones that medical science needs to answer. They're unimportant for us to merely explain that saturated fat is unhealthy because is raises total and LDL levels. This is a well documented cause and effect.

We don't need to know why being shot with bullets causes death, for example, to say that it overwhelmingly does. It's a causative link, and knowing the mechanism of action isn't essential to establishing beyond a reasonable doubt that point.

[bobo0100]

These are certainly important questions, but they're ones that medical science needs to answer. They're unimportant for us to merely explain that saturated fat is unhealthy because is raises total and LDL levels. This is a well documented cause and effect.

We don't need to know why being shot with bullets causes death, for example, to say that it overwhelmingly does. It's a causative link, and knowing the mechanism of action isn't essential to establishing beyond a reasonable doubt that point.

This is true, and I understand how it is applicable to egg's and health, but the answers do have useful implications. As the topic title suggest's this is about how to deal with those who argue that eggs are made up of HDL. The answer to this being that its irrelevant given the prevalence of Saturated fat.

Thank you guys for your help, I believe that I have a far sounder understanding of the topic.