Cholesterol myth: we clear it up
The word “cholesterol” makes many people uncomfortable because it is associated with fat, obesity and disease. But what exactly is cholesterol? Is cholesterol really as bad as we think? And why do we actually distinguish between “good” and “bad” cholesterol?
Not much time, but you don’t want to miss anything? You can find the facts at a glance at the bottom!
What is cholesterol?
Cholesterol is a fat-like substance (lipid) and is present in every cell of the body. It is not only an essential component of the cell membranes of our cells, but also participates in the synthesis of vitamin D and is the starting compound for bile acids as well as various hormones (e.g. oestrogen, testosterone and cortisol, the stress hormone).
The human body can produce about 90 percent of the daily required cholesterol amount of 0.5 to 1 gram: about three quarters of the cholesterol is produced by the body itself, mainly in the liver. Only a quarter of the total cholesterol is taken in with food. Since the body can thus cover its need for cholesterol almost entirely through its own production, any further cholesterol intake through food is actually superfluous. While foods of animal origin are rich in cholesterol, plant foods contain absolutely no cholesterol. Additional cholesterol intake through food does not stop the body’s own production, but continues normally. Cholesterol accumulates in the body, which manifests itself as high cholesterol levels in the blood and is the cause of cardiovascular diseases in old age.
A distinction is made between LDL and HDL cholesterol.
Cholesterol is not water-soluble and needs special packaging to be transported in the blood so that it can pass from the liver to other tissues. For this purpose, the body forms certain proteins (lipoproteins, “fat-protein globules”), which carry free fatty acids and the cholesterol inside. In medicine, a distinction is made between two classes of these transport forms, depending on the amount of fat: the “good” high-density lipoproteins (HDL) and the “bad” low-density lipoproteins (LDL). Normally, the lipoproteins are present in the blood in a certain ratio to each other. HDL is “good” because it transports excess cholesterol from the tissues back to the liver, where it is excreted. LDL, on the other hand, distributes cholesterol and fats from the liver throughout the body and — if there is excess — deposits itself in blood vessels and organs. To avoid these deposits and their consequences such as heart attacks or strokes, the LDL cholesterol level should therefore be kept low.
In whom is LDL cholesterol elevated?
A high total cholesterol level is not necessarily dependent on body weight, as both normal-weight and overweight people can have elevated LDL cholesterol levels. Elevated cholesterol levels are “not visible from the outside” and do not always have to be associated with obesity or excessive fat consumption. Other risk factors, such as lack of exercise, high blood pressure, diabetes and tobacco consumption also play a major role. In addition, cholesterol-containing foods such as eggs and butter play a smaller role in raising cholesterol levels than thought. Similarly, the assumption that butter is generally bad for your health and margarine is the better alternative is not entirely true. While butter consists of saturated fatty acids, margarine also contains so-called trans fatty acids, which can lower the “good” HDL cholesterol.
The German Nutrition Society (DGE) recommends a diet with a moderate fat content of 30 percent. This is based on results of a Lancet study in which people who ate a 35% fat diet had a lower mortality risk than those who consumed only 11% fat. However, the DGE also stresses that the percentage figure is not the main focus: “It is much more about improving the quality of fat and carbohydrates in our Western diet.” It is particularly important to pay attention not only to the visible fats, but also to the so-called “hidden” fats, which can be found, for example, in cheese, sausage, sauces, baked goods or confectionery and also convenience foods. For patients with risk factors, a lifestyle change towards a healthy and balanced diet is advisable in addition to exercise. The lowest risk of death was found in those who ate three to four portions of fruit, vegetables or legumes per day. This corresponds to at least 375 to 500 grams. Larger amounts had only a slight additional health benefit. In general, the motto is: “too much” is always bad for our health — no matter what is consumed.
The facts at a glance:
1. Cholesterol is present in every cell of the body and is an essential component of the cell membranes of our cells. It is involved in the formation of vitamin D and is even the starting compound for digestive juices and sex hormones.
2. The human body can produce 90 percent of the daily cholesterol it needs: three quarters is produced by the body itself, only one quarter of the total cholesterol is ingested with food.
3. Since the body can cover its cholesterol requirements almost entirely through its own production, any further cholesterol intake through food is superfluous.
4. Plant foods — in contrast to animal foods — contain absolutely no cholesterol.
5. Elevated cholesterol levels are “not visible from the outside” and do not always have to be associated with obesity or excessive fat consumption. Lack of exercise, high blood pressure, diabetes and tobacco consumption can raise cholesterol levels, even if body weight remains constant.
6. The German Nutrition Society (DGE) recommends a diet with a moderate fat content of 30 per cent
Text sources:
(1) https://de.wikipedia.org/wiki/Cholesterin
(2) https://www.dge.de/wissenschaft/referenzwerte/fett/
(3) https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(17)32252-3/fulltext
Image sources:
(4) Designed by rawpixel.com / Freepik
