Ok, lets talk about cholesterol. I suspect that it's to do with someones susceptibility for heart disease (atherosclerosis).
If cholesterol and especially LDL cholesterol was the cause of heart disease then we would see cholesterol damage throughout the entire circulatory system within the body but that isn't what's happening. There's not one case, not one, of atherosclerosis on the venus (veins) side of our circulatory system and atherosclerosis only happens on the arterial side. Basically that simple truth should and scientifically be the end the conversation of whether cholesterol causes heart disease by infiltrating the entire circulatory system and causing plaque build up.
The real question is why then does atherosclerosis only happen on the arterial side of the heart and predominantly at the Y junctions where the arteries branch off and not the venus side?
The blood that's pumped out of our left ventricle is under pressure every time the heart take a beat as I'm sure most are aware but the blood flow on the venus side is low pressure and just steady forward motion on it's journey back to the heart with additional valves that make sure the flow is strictly regulated for that flow which also gets reoxygenated by the respiratory system because it gets used mostly in the arterial side of the heart for function.
Ok so, I'll try to keep this as basic as I can
The heart take a beat, the oxygenated blood pumps out under a certain pressure, which can be and is measured. This action or pressure can damage the arterial walls and when someone's blood pressure is also high this adds to that result and why high blood pressure is one of the many a symptoms for atherosclerosis. Now we get into these Y junctions in those arteries that are close to the heart and think of them like you would a river where a tributary or a deviation is made from the main artery which normally ventures in another direction as well. So the main flow is not interrupted and continues on it's main path but the blood flow in the other vein which has deviated somewhat is disturbed and the flow creates these eddies and swirls around causing the blood to hang around longer which then create a turbulence which then also reduces the nitric oxide which helps keep vessels dilated and reduces inflammation basically causing some degree of
Endothelial Dysfunction.
So now we have the beginning of an inflammatory process where the immune system will try and fix it but that can also exacerbate the situation. Anyway I'll just talk about diet here because there's many other factors that effect inflammation, see my above post. Sugar and UPF that are also high in refined carbs and sugar are the 900lb gorilla. High blood sugar increases the production of reactive oxygen species (ROS) which attach the endothelial lining as well in forming advanced glycation end-products (AGEs) which actually stiffen and contribute to inflammation.
Basically what happens is all this preliminary inflammation causes dysfunction of our artery lining and create a problem for what are called "tight junctions" which basically are the spaces between each cell in our arterial lining. Tight junctions are crucial for maintaining the integrity of the endothelial barrier, which regulates the passage of molecules and cells between the bloodstream and surrounding tissues. Understanding the role of tight junctions and the impact of their compromise is crucial for developing treatments for various inflammatory and autoimmune diseases which include IBS, IBD and in the brain it can effect our blood brain barrier (BBB) and effect neurological function like dementia and Alzheimer's. Like I said previously inflammation is basically the cause of most western non communicable diseases including heart disease.
Anyway back to cholesterol in this process. After these tight junctions have been compromised by many different factors then the lipoproteins that carry cholesterol can and do get lodged in these tight junctions causing more inflammation.
Now we get to the the different sizes of these LDL lipoproteins, and there's basically for this arguement 2 different sizes. One being large and buoyant that actually are more floatable hense buoyant that are not seen as atherogenic as the small dense particles, dense meaning they sink and become less mobile and are more than likely to end up in our artery walls.
Like CD mentioned, everyone will be different and it really has to do with a persons life history and their own genetics, but one thing is certain someones cholesterol levels in the body is exactly where your particular metabolism needs it to be in order to deal with the dysfunction. As far as keeping these more prone LDL to circulate less then my advice would be again, only speaking dietarily is to consume whole foods and to keep refined carbs and added sugar to a bare minimum and again this also pertains to vegetarians and vegans as long as they understand that supplementation will be required, but a whole food diet is the least we can do for our heart health if you ask me, the 80/20 rule works pretty good. sorry I rambled on but i suspect some might have found this interesting.
Cholesterol is essential for maintaining these tight junctions and in try to help repair the problem they get lodged and increase that inflammation just by the accumulation that is encountered by that dysfunction, double edged sword kind of deal. But because cholesterol is always found in these circumstances they have been misinterpret as the cause of atherosclerosis, it made a great story fifty years ago and the cure was to consume 7-11 portions of grain a day and sugar has no cholesterol, so eat that too, how has that worked out so far.