Causes of low / high cholesterol

About specific vitamines, minerals or fiber, for example
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RRM
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Re: Cholesterol

Post by RRM »

dime wrote: Here are the blood levels, in my opinion they prove quite well that there's no or low protection from too much cholesterol from diet (in rabbits at least..)
Why do you say "protection"?
If it were any other nutrient, you wouldnt say that.
All serum nutrients vary within certain margins, which is sometimes 900% (some amino acids).
So, why should the body stop taking in cholesterol when more is supplied by diet?
To match our thinking about cholesterol?
What it proves, is that the body will increase cholesterol when more is supplied.
It does not prove that cholesterol is absorbed 'beyond what the body deems healthy'.
What is a healthy cholesterol level???
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Re: causes of low / high cholesterol

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In the context of the above study, I guess it should stop taking in cholesterol because higher levels seem to lead to a significant DMA increase and higher risk of atherosclerosis (or at least that was the conclusion of the authors)?
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Re: causes of low / high cholesterol

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dime wrote:In the context of the above study, I guess it should stop taking in cholesterol because higher levels seem to lead to a significant DMA increase and higher risk of atherosclerosis (or at least that was the conclusion of the authors)?
Did it actually result in an arterial plague being formed?
Or to an increased risk (based on assumptions)?
And if so, is that the result of a lack of proper dietary cholesterol regulation in animals that normally dont ingest cholesterol?
"rats are less susceptible than are rabbits to the atherogenic effect of a cholesterol-rich diet because of differences in lipid peroxidation products as well as antioxidant enzymes activities in their livers" Mahfouz MM et al
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Re: causes of low / high cholesterol

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RRM wrote: And if so, is that the result of a lack of proper dietary cholesterol regulation in animals that normally dont ingest cholesterol?
Very good point, didn't think at all about the fact that rabbits are herbivores.
They checked about plaque
Morphological studies. To confirm formation of atherosclerosis, morphological
examination was made. In the aortas from normal animals, no pathomorphological change was
found. However, there were many ubiquitous fatty streaks on the intima of aortae from animals
fed with a high cholesterol diet. Light microscopy revealed that intimal thickening constituted by
an agglomerate of cells separated by a negligible amount of interstitial material such as collagen
fibrils. Large roundish cells with a foamy cytoplasm and round nucleus constituted the main cell
type in the intima.
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Re: causes of low / high cholesterol

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"DHA did not induce ER stress but was the most potent inhibitor of apoB100 secretion, acting via stimulation of autophagy" Caviglia et al.
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Re: causes of low / high cholesterol

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Cholesterol Levels Rise, Fall With Changing Seasons
(around 8% higher in winter)
http://www.sciencedaily.com/releases/20 ... 124235.htm
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Re: causes of low / high cholesterol

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Interesting. That may be to compensate for less daylight exposure in winter,
as both daylight exposure and cholesterol stimulate serotonin activity.
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Re: causes of low / high cholesterol

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"oxysterols are known to be potent inhibitors of 3-hydroxy-3-methylglutaryl CoA reductase, a key regulatory enzyme in the biosynthesis of sterols".Parish AJ et al
dime wrote:"DHA ... was the most potent inhibitor of apoB100 secretion Caviglia et al.
A meta-analysis shows that in people without coronary heart disease, DHA (from algal oil) increases (HDL and LDL) cholesterol,
and reduces triglycerides. Bernstein AM et al
dime wrote:I'm puzzled at the 1495 calories (vegan) vs 1947 (omnivore).. how do they survive on 25% less energy?
Im guessing autophagy; hence the health benefits of a vegan diet. (hard to consume enough energy/protein)
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My diet

Post by fred »

There is no study that show that dietary raw cholesterol/fat put you or nor at risk to atherosclerosis and heart disease, so how can you conclude that eating high cholesterol/fat raw food everyday is healthy? there is no doubt that fat/cholesterol is better raw than oxidized, but that does not make a high consumption of raw egg yolk safe. Especially when we look at the evidences linking cholesterol/saturated fat to atherosclerosis and heart disease.
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Re: Dietary (good) cholesterol essential?

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fred wrote:that does not make a high consumption of raw egg yolk safe. Especially when we look at the evidences linking cholesterol/saturated fat to atherosclerosis and heart disease.
Fred, i tried to tell you that science has come a long way since that finding, regarding both saturated fats and 'cholesterol'.
First you find an association.
Then you find the culprit and the mechanism.
You keep on clinging to the 1st phase; the association, but you need to move on beyond that.
Its too simplistic to label cholesterol / saturated fatty acids as (possibly) bad based on mere associations.
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Re: causes of low / high cholesterol

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RRM wrote:
dime wrote:"DHA ... was the most potent inhibitor of apoB100 secretion Caviglia et al.
A meta-analysis shows that in people without coronary heart disease, DHA (from algal oil) increases (HDL and LDL) cholesterol,
and reduces triglycerides. Bernstein AM et al
So which one is correct then? :)

It isn't contradicting, they confirm each other I think.
From wikipedia: "ApoB100 reflects lipoprotein particle number (independent of their cholesterol content)."

From your article I think this is important
The 8% increase in LDL-C and 5% increase in HDL-C we observed with algal oil is similar to that observed with 4 g/d of purified DHA, the latter which was also associated with a transition to larger, possibly less-atherogenic LDL particles (52). DHA is thought to decrease TG levels by reducing hepatic VLDL synthesis (53). Reduced synthesis in turn leads to reduced secretion and smaller VLDL particles, which are more readily converted to LDL than are large VLDL particles and which also compete with LDL for uptake by LDL receptors (52). Both of these actions lead to higher serum LDL-C. The mechanism by which DHA increases HDL-C is not known but may be through decreased lipid transfer protein activity (54).
So basically, DHA lowers number of lipoprotein particles (by inhibiting ApoB100), resulting in bigger particles with more cholesterol in them. Which should be a good thing, wiki: "It is well established that ApoB100 levels are associated with coronary heart disease, and are even a better predictor of it than is LDL level."

This explanation makes sense to me
wiki wrote:One way to explain the above is to consider that large numbers of lipoprotein particles, and, in particular large numbers of LDL particles, lead to competition at the ApoB100 receptor (i.e. LDL receptor) of peripheral cells. Since such a competition will prolong the residence time of LDL particles in the circulation, it may lead to greater opportunity for them to undergo oxidation and/or other chemical modifications. Such modifications may lessen the particles' ability to be cleared by the classic LDL receptor and/or increase their ability to interact with so-called "scavenger" receptors. The net result is shunting of LDL particles to these scavenger receptors. Scavenger receptors typically are found on macrophages, with cholesterol laden macrophages being better known as "foam cells". Foam cells characterize atherosclerotic lesions. In addition to this possible mechanism of foam cell generation, an increase in the levels of chemically modified LDL particles may also lead to an increase in endothelial damage. This occurs as a result of modified-LDL's toxic effect on vascular endothelium as well its ability both to recruit immune effector cells and to promote platelet activation.
Supose this theory is correct, then having low cholesterol but distributed in a lot of lipoproteins would be worse than higher cholesterol but in much less lipoproteins.
Testing for apoB100 levels would be far more useful than LDL-C..
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Re: Causes of low / high cholesterol

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Interesting.
Lets see if there's a connection with oxidized cholesterol.
(though ive run out of time now)
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Re: Causes of low / high cholesterol

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This is an interesting association, as HDL gets above 50-60, irrelevant of LDL and other levels, incidence of various "issues" goes to very low.

Image
Figure 4. Incidence of coronary events in men according to HDL-cholesterol and other risk factors in the PROCAM study. Hypertriglyceridemia: triglycerides > 2.1 mmol/L; hypercholesterolemia: LDL cholesterol > 4.1 mmol/L; IFG: impaired fasting glucose (glucose 6.1–7.0 mmol/L) (modified from Ref. [5]).

Source: http://www.sciencedirect.com/science/ar ... 6508000709
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Re: Causes of low / high cholesterol

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That does not contribute the bad effects to the LDL carrier that transports the (oxidized or not) cholesterol.
The risk getting lower when the HDL transporter becomes more dominant, has an underlying cause,
probably related to what it predominantly transports (non-oxidized).
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Re: Causes of low / high cholesterol

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In the light that HDL mediates (oxy)cholesterol efflux from macrophages, protects against oxidized LDL (oxLDL),
and oxLDL initiates the formation of arterial plaque (see this post) ,
HDL may rather represent the (individual) strength of our defense against elevated (oxy)cholesterol,
(much like anti-oxidants vs radicals) and oxidized LDL the influence of (bad) diet and poor defense.

I think your graph actually supports this, as without risk factors, the lowest-HDL risk is 'only' 3- to 4-fold higher (5-fold with hypercholesteremia) than the highest-HDL risk,
meaning that with the highest HDL level in the world, your risk is still substantial,
so that HDL represents the strength of our defense, and not 'the cause'.
And, similarly as too much antioxidants vs radicals is not good, too much HDL is not good either:
One study shows that eventually the risk may go up again, when HDL levels are very high...
"When apoA-I and apoB are kept constant, HDL-C and HDL particle size may confer risk at very high values." van der Steeg WA et al
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