Why cholesterol is not just cholesterol
Cholesterol is a fat-like substance that the body needs for many vital functions: it is a component of every cell membrane, a precursor for hormones such as oestrogen, testosterone and cortisol, and indispensable for the formation of vitamin D and bile acids. About three-quarters of cholesterol is produced by the body itself – mainly in the liver. Only a smaller portion is taken in through food.
As cholesterol is not water-soluble, it is transported in the blood bound to proteins. These transport particles are known as lipoproteins. Depending on their density and function, several forms are distinguished – the best known are LDL and HDL. Anyone who wants to understand their cholesterol levels cannot avoid these two terms.
LDL vs HDL: The most important forms of cholesterol
LDL cholesterol – the "unfavourable" cholesterol
LDL stands for Low Density Lipoprotein. It transports cholesterol from the liver to the body's cells. If too much LDL is present in the blood, excess cholesterol can be deposited in the vessel walls. Over time, so-called plaques form, which can narrow the arteries – a process referred to as atherosclerosis. Elevated LDL levels are therefore considered a key risk factor for heart attack and stroke.
HDL cholesterol – the "favourable" cholesterol
HDL stands for High Density Lipoprotein. HDL performs an opposing task: it takes up excess cholesterol from tissues and vessel walls and transports it back to the liver, where it is broken down. Higher HDL levels are associated with a lower risk of vascular calcification.
The difference between LDL and HDL can therefore be summarised in simple terms as follows: LDL carries cholesterol into the vessels, HDL removes it again. For risk assessment, not only each individual value is important, but also their ratio to one another.
Total cholesterol and triglycerides
Total cholesterol comprises LDL, HDL and other lipoproteins. It provides an initial overview but, on its own, says little about an individual's risk. Triglycerides are usually determined in addition – blood fats that, when elevated, can likewise be associated with an increased risk of cardiovascular disease.
Which cholesterol levels are considered desirable?
The target values for cholesterol are not rigid thresholds but depend on the individual risk profile. Factors taken into account include age, sex, blood pressure, smoking habits, diabetes and family history.
The following reference values are often used as a general orientation for adults without particular risk factors:
- Total cholesterol: below 200 mg/dl
- LDL cholesterol: below 116 mg/dl (lower in case of increased risk)
- HDL cholesterol: women above 45 mg/dl, men above 40 mg/dl
- Triglycerides: below 150 mg/dl
For people with existing cardiovascular disease, diabetes mellitus or familial hypercholesterolaemia, considerably stricter target values may be appropriate. Individual interpretation should always be carried out by a doctor.
What influences cholesterol levels?
Cholesterol levels are the result of various factors – some can be influenced, others cannot.
Non-modifiable factors
- Genetic predisposition (e.g. familial hypercholesterolaemia)
- Age and sex
- Hormonal changes, such as after the menopause
Modifiable factors
- Diet
- Physical activity
- Body weight
- Smoking
- Alcohol consumption
- Concomitant conditions such as diabetes or an underactive thyroid
Lowering cholesterol: What can lifestyle achieve?
Anyone who wants to lower their cholesterol can often make a noticeable contribution through everyday adjustments. The following measures have been well researched scientifically and form one of the cornerstones of any treatment – also when medication is used in addition.
Adjusting the diet
- Reduce saturated fats: such as fatty meat, sausages, butter, lard and high-fat dairy products.
- Prefer unsaturated fats: olive, rapeseed and linseed oil, nuts, avocado.
- Include omega-3 fatty acids: oily sea fish such as salmon, mackerel or herring, ideally once or twice a week.
- Increase dietary fibre: wholegrain products, pulses, oats, fruit and vegetables.
- Avoid trans fats: often found in fried foods, ready-made baked goods and industrially processed snacks.
- Limit sugar and highly processed carbohydrates, as they can also affect triglycerides.
A Mediterranean-style diet with plenty of plant foods, high-quality oils and fish has been shown in many studies to be favourable for blood lipid levels.
Integrating exercise into everyday life
Regular physical activity can help to raise HDL cholesterol and lower triglycerides. As a rule, at least 150 minutes of moderate endurance activity per week is recommended – such as brisk walking, cycling, swimming or Nordic walking. Strength training is a useful addition.
Other lifestyle factors
- Stopping smoking: not only reduces cardiovascular risk but can also have a favourable effect on HDL.
- Weight reduction if overweight: even a moderate loss can improve blood lipid levels.
- Consume alcohol only in moderation.
- Reduce stress and ensure sufficient sleep.
When is lifestyle not enough?
For some people – particularly those with familial hypercholesterolaemia or a high overall risk – target values cannot be reached through lifestyle measures alone. In such cases, drug therapy may be appropriate. Several classes of active substances are available, including statins, cholesterol absorption inhibitors or newer agents that specifically intervene in cholesterol metabolism. Selection, dosage and monitoring are always carried out by a doctor.
How often should levels be checked?
An initial determination of blood lipids is usefully carried out in adulthood as part of a check-up. How often subsequent checks are performed depends on the individual risk:
- if values are unremarkable and risk is low: usually every few years
- if values are elevated or risk factors are present: more frequently, as advised by a doctor
- during ongoing therapy: at regular intervals determined by a doctor
Conclusion
Cholesterol is a necessary building block of the body – it only becomes problematic when there is an unfavourable ratio of LDL to HDL over a longer period. Those who know their values can work together with their doctor to assess their individual risk and take targeted action. A balanced diet, regular exercise, refraining from smoking and a healthy body weight form the most important basis – and complement drug treatment if needed.
This article does not replace medical advice.