Cholesterol has long been a topic of concern. In order to keep cholesterol within normal range, we often examine food carefully like a magnifying glass, trying to find out which foods can help lower cholesterol and which may make cholesterol out of control. Eggs, seafood, and offal are often the first to be examined. Every day, we have to be careful when facing the food in front of us. If we are not careful, we will start to worry about our cholesterol level. Such a life is really too hard!
"You may have misunderstood cholesterol! Cholesterol is a necessity for the body, the lower the better!"
70% of the body's cholesterol is produced in the liver and then transported throughout the body by different lipoproteins (like cars) or sent back to the liver for processing.
HDL (like a cleaning vehicle):
Send excess cholesterol in the blood back to the liver for processing. If the concentration is too low, too much cholesterol will accumulate in the blood, affecting blood flow.
LDL (like a large truck):
The liver's cholesterol is sent to the whole body for the organs and tissues that need it to use as raw materials (as shown below). If the concentration is too low, it will affect the production of hormones and the development of nerve cells.
In fact, cholesterol is not as scary as you think.
As long as it is within the normal standard value, it is actually a good friend of the body.
It helps repair cell membranes, produce important hormones and vitamin D, and even protects your nerve cells.
"Then why do people keep saying that LDL is a risk factor for cardiovascular disease?"
To be precise, what we should worry about is small, dense and oxidized LDL (Oxidized LDL), which is likened to a broken car. Simply put, when the blood vessels are blocked by many broken cars, blood flow cannot be maintained smoothly, and the vascular endothelium is damaged.
Thrombosis is a long process. The earliest indicator that can be detected to represent endothelial damage and inflammation is oxidized low-density lipoprotein (oxLDL), which is also the earliest risk indicator of atherosclerosis [1]. Low-density lipoprotein (LDL) is responsible for transporting cholesterol in the body, but when it is oxidized by free radicals and oxidative stress, it will trigger an inflammatory response and cause greater damage to the endothelium. Because of this variation, oxidized low-density lipoprotein plays the role of the culprit in atherosclerosis. In addition, low-density lipoprotein (sdLDL) with a smaller density is also closely related to the risk of cardiovascular disease, and is likened to a small car . Compared with the LDL we talk about, the small car is more likely to penetrate the blood vessel wall, promote the formation of atherosclerosis, and increase the risk of heart disease and stroke.
"OxLDL represents the main culprit in current theories of atherosclerosis" [2]
The link between oxidized low-density lipoprotein (oxLDL) and cardiovascular disease has been confirmed in a large number of studies. The presence of oxLDL is closely related to the formation of atherosclerosis, especially in the formation of plaques in the blood vessel walls and hardening of the arteries. When oxLDL accumulates on the blood vessel walls, it causes an inflammatory response, attracting white blood cells (macrophages) to enter the blood vessel walls and form plaques. These plaques gradually grow larger, block blood vessels, and eventually lead to cardiovascular diseases such as heart disease and stroke.
At this point, everyone must be very curious, which one is more dangerous, sdLDL or oxLDL?
In fact, the two play different roles in the development of cardiovascular disease, but both are lipoproteins closely related to cardiovascular health. However, they differ in biological functions and ways of influence. The following is a brief introduction:
- Definition: sdLDL is a type of low-density lipoprotein with a smaller particle size and higher density
- Impact: sdLDL can more easily penetrate the blood vessel wall, enter the blood vessel wall, and be more easily oxidized
- Risks: sdLDL is considered an important factor in atherosclerosis and cardiovascular disease, which can easily trigger inflammation and plaque formation in the arterial wall.
- Definition: oxLDL is a product of LDL oxidation, usually caused by oxidative stress or inflammation in the body.
- Impact: Oxidation makes LDL more inflammatory and capable of damaging endothelial cells, promoting the progression of atherosclerosis
- Risk: oxLDL is considered a major component of atherosclerotic plaques and an independent risk factor for cardiovascular disease.
Main differences:
- sdLDL is a subtype of LDL with specific biochemical characteristics (smaller particle size, higher density), which makes it easy to accumulate in blood vessels and participate in the development of atherosclerosis.
- OxLDL is an oxidized product of LDL, which has enhanced inflammatory and damaging properties and is an important component of atherosclerotic plaque formation.
In addition, some studies have found that glycated low-density lipoprotein in diabetics, also known as glycated LDL , is also a dangerous substance that causes cardiovascular damage [ 3].
Therefore, we should pay attention to refined sugars and foods that easily cause inflammation in our diet, which are the real reasons for the accumulation of low-density lipoprotein (LDL) in blood vessels. After understanding this cause and effect relationship, we will find that the existence of cholesterol is actually to repair inflamed vascular cells. Therefore, accumulated cholesterol is the "result" rather than the "cause".
In other words, we should rethink cholesterol. It is not our enemy, but our body's good friend. What we really need to worry about is oxidized low-density lipoprotein (oxLDL), because it damages blood vessels and causes inflammation. Therefore, instead of worrying too much about why cholesterol stays in our body, we should focus on controlling blood sugar, reducing inflammation, and increasing the liver's antioxidant capacity. Only in this way can oxidized low-density lipoprotein (oxLDL) disappear from our body.
"Protect your blood vessels, protect your health!"
References
[1] Overview of OxLDL and Its Impact on Cardiovascular Health: Focus on Atherosclerosis Front Pharmacol. 2020; 11: 613780.
[2] REVIEW article Front. Cardiovasc. Med., 01 June 2022 Sec. Cardiovascular Therapeutics Volume 9 - 2022
[3] Lipoprotein lipase mediates the uptake of glycated LDL in fibroblasts, endothelial cells, and macrophages. PMID: 1423487
