HDL – the “good” cholesterol, but it doesn’t always help

A heart attack can also happen in people who have high levels of the so-called good cholesterol. Find out why HDL does not always effectively protect us against atherosclerosis and what secrets it still hides from us.

1. In common parlance, cholesterol is divided into “good” and “bad”
2. In fact, one fraction is considered unfavorable, while the other is actually only spoken of in a positive context
3. However, this is not entirely true. “Good” cholesterol can also be harmful
4. More current information can be found on the Onet homepage.

Cholesterol has many names! One of the most famous forms of it occurring in the human body is the so-called HDL (short for high density lipoprotein), named by doctors as good cholesterol. Studies have shown that its high concentration in the blood has a protective effect, reducing the risk of developing atherosclerosis, which is a serious disease of the arteries that can lead to a heart attack or stroke.

Unfortunately, this does not mean that everyone who has a lot of HDL particles in their blood can rest easy and forget about the risk of atherosclerosis altogether.

Good cholesterol and the risk of a heart attack

Although modern scientists and doctors already know quite a lot about HDL cholesterol, they admit that its molecules still hide many secrets.

– On the one hand, epidemiological and population studies always show that people with high HDL cholesterol have fewer cases of coronary heart disease (lower risk), and people who have low HDL levels have coronary heart disease more often (higher risk) . On the other hand, we know from practice that a heart attack can also occur in people with high levels of HDL. This is a paradox, because the aforementioned epidemiological studies show something else – says prof. Barbara Cybulska, a doctor who has been dealing with the prevention of cardiovascular diseases for many years, researcher at the Institute of Food and Nutrition (IŻŻ).

1. Symptoms of high cholesterol

So ultimately, it all depends on the specific case.

– And really on the condition of HDL particles in a given patient. In some people, HDL will be high and thanks to this they will avoid a heart attack, because the structure of HDL particles will guarantee their proper functioning, and in others, despite high HDL, the risk of a heart attack will be high, due to the incorrect structure of the HDL molecule – explains Prof. Barbara Cybulska.

Are There Drugs That Increase Good Cholesterol?

Currently, medicine has at its disposal drugs that effectively reduce the concentration of LDL in the blood, which reduces the risk of coronary heart disease, and therefore also its clinical complication, which is a heart attack.

However, after developing LDL-lowering drugs, scientists did not rest on their laurels. They have also been trying for a long time to develop drugs that will increase the levels of good cholesterol.

– These drugs have been developed, but despite the increase in HDL cholesterol levels, their use has not reduced the risk of coronary heart disease. It turns out that the HDL fraction is very heterogeneous, i.e. it consists of very different molecules: smaller and larger, containing more or less protein, cholesterol or phospholipids. So there is not one HDL. Unfortunately, we still do not know which specific HDL variant has antiatherosclerotic properties and how to increase its concentration in the blood, admits Prof. Barbara Cybulska.

At this point, it is worth explaining what exactly is the antiatherosclerotic effect of HDL.

– HDL particles also penetrate the arterial wall, but their effect is completely different to that of LDL. They have the ability to take cholesterol from the artery wall and carry it back to the liver, where it is converted into bile acids. HDL is therefore an important element of the feedback mechanism in the body’s cholesterol balance. Besides, HDL has many other antiatherosclerotic effects. But the most important thing is the reverse transport of cholesterol from the artery wall to the liver – emphasizes prof. Barbara Cybulska.

As you can see, the liver plays an important role in this process.

– LDLs are made in the circulation from lipoproteins called VLDL which are made in the liver, while HDLs are made directly in the liver. Therefore, they do not pass into the blood directly from the consumed food, as many people mistakenly think – says the IŻŻ expert.

Good cholesterol: why doesn’t it always help?

Unfortunately, there are quite a few possible reasons for HDL’s ineffectiveness in the fight against atherosclerosis.

– Various diseases and even age make HDL particles dysfunctional and defective. They lose their antiatherosclerotic properties, incl. this is the case in people with diabetes, obesity or coronary heart disease. Some autoimmune diseases can also impair HDL activity, warns Prof. Barbara Cybulska.

Therefore, even when someone has high HDL, they cannot feel completely safe.

– HDL particles may not be able to receive cholesterol from the artery wall or may not have the antioxidant properties that prevent LDL cholesterol from oxidizing. As you know, its oxidized form is the most atherogenic (atherogenic) – says Prof. Barbara Cybulska.

Chase away atherosclerosis: the importance of physical activity

Fortunately, there are also optimistic news from the world of science regarding HDL, such as the fact that increased physical activity generates active, anti-atherosclerotic HDL particles.

– To achieve this effect, all you need is at least 30 minutes of aerobic exercise a day, such as swimming, brisk walking or cycling. This is very important news, because so far no medicine can do it. HDL concentration should be increased especially in people with cardiovascular diseases – says Prof. Barbara Cybulska.

The expert suggests that in order to increase HDL concentration, in addition to increasing physical activity, the European Society of Cardiology also recommends: reducing the consumption of trans fatty acids, quitting smoking, reducing the consumption of monosaccharides and disaccharides (simple sugars) and weight reduction.

But according to prof. Cybulska One cannot be under the illusion that even a well-functioning HDL is able to repair all the damage caused by the elevated LDL cholesterol level that has persisted for many years.

– Therefore, it is important to prevent the increase in LDL cholesterol from childhood (through proper nutrition), and if it is increased, it is necessary to reduce it (through dietary management and medication). Drugs can even cause partial regression, i.e. a reduction in the volume of the atherosclerotic plaque, but only its lipid (cholesterol) part is affected. Then the cholesterol from the plaque decreases – says prof. Barbara Cybulska.

This is especially important in relation to young atherosclerotic plaques, because they most often break and cause dangerous clots (which can block blood flow and lead to a heart attack or stroke).

“This is because the young plaques have a lot of cholesterol in them, but do not yet have a fibrous cover to protect them from the bloodstream. As for the old, calcified, fibrous plaques, they can also decrease, but only in the cholesterol part – says the IŻŻ expert.

Inevitably, in young people, atherosclerotic plaques are usually also young. But there are exceptions to this rule. Unfortunately, they may also have advanced atherosclerotic plaques.

– Premature heart attack in people at a young age may be a consequence of familial hypercholesterolaemia. In such people, atherosclerosis develops practically from childhood, because the arteries are constantly under the influence of high cholesterol levels. This is why everyone, especially people with a family history of premature cardiovascular disease, should have their blood cholesterol tested, recommends prof. Barbara Cybulska.

1. Symptoms of familial hypercholesterolaemia that everyone should know [EXPLAINED]

Good and bad cholesterol: what are the standards?

When you are aware of the risks associated with inadequate cholesterol levels, it is important to know the alarm thresholds associated with it.

– It is considered that the level of LDL cholesterol in the blood is safe for health is below 100 mg / dL, i.e. below 2,5 mmol / L. Probably, however, the optimal level for health is even lower, below 70 mg / dL. In the case of cardiovascular diseases, including coronary heart disease (a history of myocardial infarction or stroke), diabetes or chronic kidney disease, it is desirable to keep LDL cholesterol levels below 70 mg / dL – advises prof. Barbara Cybulska.

The requirements are therefore the greater, the higher the risk of these serious diseases or their complications by the patient.

– When it comes to HDL cholesterol, a value below 40 mg / dL, i.e. below 1 mmol / L in men and below 45 mg / dL, i.e. below 1,2 mmol / L in women, is considered to be bad, insufficient its concentration – reminds prof. Barbara Cybulska.

Do you have bad cholesterol? Change your lifestyle and diet

If you want to avoid lipid disorders and atherosclerosis, use as many of the following recommendations as possible in your daily life:

1. physical activity (at least 30 minutes 5 days a week),
2. a diet rich in vegetables (200 g or more per day) and fruit (200 g or more)
3. limit the consumption of saturated fats (which are mainly rich in animal fats) – preferably below 10% the daily amount of energy consumed with food,
4. replace saturated fats with polyunsaturated fatty acids (their source is mainly vegetable oils, but also fatty fish),
5. minimize the consumption of trans fats (they include ready-made confectionery, instant ready meals and fast food),
6. keep your salt consumption below 5 g per day (one level teaspoon),
7. eat 30-45 g of fiber a day, preferably from whole grain cereal products,
8. eat fish 1-2 times a week, including a fatty one (e.g. mackerel, herring, halibut),
9. eat 30 g of unsalted nuts a day (e.g. walnuts)
10. limit alcohol consumption (if you drink at all), men: up to 20 g of pure alcohol per day, and women to 10 g,
11. It is also best to do without sugary drinks altogether.