Cholesterol in the body plays a fundamental role, and it is important to understand the difference between its forms and states.
Normal (native) cholesterol
Cholesterol is found in cell membranes, participates in the synthesis of steroid hormones (cortisol, estrogens, testosterone), bile acids, and vitamin D.
The body produces up to 80% of cholesterol in the liver, while the remaining part is obtained from food.
Cholesterol coming from natural products (meat, eggs, dairy products, butter) is not inherently "harmful." Moreover, in most people, when consuming cholesterol from food, its level in the blood is regulated through feedback: the liver decreases or increases its own synthesis.
Oxidized cholesterol
When cholesterol molecules undergo oxidation (due to free radicals, high temperatures, trans fats, or chronic inflammation), they are converted into so-called oxysterols. These compounds damage the endothelial cells of blood vessels, trigger an inflammatory response, and become a key factor in the formation of atherosclerotic plaques.
Mechanism:
- Low-density lipoproteins (LDL, "bad cholesterol") are oxidized.
- Macrophages engulf oxidized LDL particles → "foam cells" are formed.
- They accumulate in the vessel wall → inflammation and plaque growth begin.
- Over time, this leads to narrowing of the vessels and the risk of heart attack/stroke.
Trans fats and cholesterol oxidation
Trans fats (artificially hydrogenated oils, margarine, fast food, repeatedly fried dishes) enhance cholesterol oxidation and disrupt lipid metabolism. They:
- increase LDL levels,
- decrease HDL levels ("good cholesterol"),
- create conditions for free radical stress.
In contrast, cholesterol from natural products (eggs, meat, cheese, oils) typically retains its structure under normal conditions and does not trigger pathological processes.
Therefore, it is healthier to eat whole foods (eggs, meat, natural oils), avoid industrial trans fats, and minimize excessive frying to prevent the formation of oxysterols.
