What is Cholesterol? (HDL and LDL Cholesterol)

Cholesterol is a waxy substance that is necessary for the body but can negatively affect vascular health at high levels. It is produced in the liver and can be obtained through food. It supports the flexibility and permeability of cell membranes and plays a role in important functions such as hormone production and vitamin D synthesis. There are two main types: HDL (good cholesterol) and LDL (bad cholesterol).

HDL collects cholesterol from vessel walls and carries it to the liver for elimination, which protects heart health. LDL, on the other hand, can increase the risk of heart disease when it accumulates in excess amounts and blocks blood vessels. Cholesterol levels should be kept in balance for a healthy life.

What is Cholesterol?

Cholesterol is a substance that plays a role in our body’s cell structure and hormone production, and is both beneficial and an element that needs to be controlled. Cholesterol, which is produced by the liver, is also obtained from animal foods such as meat, dairy products, and eggs. Since it does not dissolve in water, it circulates in the blood bound to carrier proteins. Cholesterol has important functions such as maintaining the structure of cell membranes and producing vitamin D and certain hormones. However, excess amounts in the blood can impair vascular health and increase the risk of cardiovascular diseases.

What Are the Types of Cholesterol (HDL and LDL Cholesterol)?

Cholesterol is transported in the blood through proteins called lipoproteins. There are two main types:

What is HDL Cholesterol?

HDL cholesterol (High-Density Lipoprotein) is a type of lipoprotein known as “good cholesterol” among the public and has protective effects in the body. HDL is a protein synthesized in the liver and small intestine, which undertakes the task of collecting excess cholesterol accumulated in vessels and tissues and transporting it to the liver. Cholesterol transported to the liver is either converted into bile acids and eliminated from the body or reused.

HDL cholesterol, unlike LDL cholesterol (“bad cholesterol”), helps prevent cholesterol accumulation in vessel walls. Therefore, high HDL cholesterol levels are considered an important factor in reducing the risk of cardiovascular diseases. HDL cholesterol not only transports cholesterol but also has antioxidant and anti-inflammatory properties, which provides protection against the atherosclerosis process by reducing inflammation and oxidative damage in vessels.

Low HDL cholesterol refers to HDL cholesterol levels in the blood circulation being below normal, indicating values below 40 mg/dL in men and 50 mg/dL in women. It is a condition that increases the risk of cardiovascular disease. Optimal HDL is 60 mg/dL and above. Additionally, it should be kept in mind that very high HDL cholesterol levels (above 90-100 mg/dL) may indicate impairment in HDL function in some cases and may not be beneficial.

What is LDL Cholesterol?

LDL cholesterol (low-density lipoprotein) is a fat carrier protein found in the blood and is known as “bad cholesterol” among the public. LDL undertakes the task of transporting cholesterol produced in the liver to other tissues and cells in the body.

In general, it is recommended that the LDL cholesterol value be below 100 mg/dL, while values of 70 mg/dL or lower may be targeted in individuals with a high risk of cardiovascular disease.

High LDL cholesterol (hypercholesterolemia) refers to the elevation of LDL levels in the blood circulation above normal values, generally expressed as values above 130 mg/dL. High LDL cholesterol can lead to arterial stiffness, known as atherosclerosis. In this process, plaques form on the vessel walls, narrowing the vessels and restricting blood flow. Over time, these plaques can rupture and cause blood clots, which can lead to serious health problems such as heart attacks and strokes.

High LDL can result from fatty foods (fried foods, processed meats), inactivity, and genetic factors. Sometimes, underlying diseases such as diabetes can also cause this. Lifestyle changes such as healthy eating, regular physical activity, weight control, quitting smoking, and limiting alcohol consumption are recommended to lower LDL cholesterol. Additionally, statins and other cholesterol-lowering medications can be used in treatment when necessary.

What Should Cholesterol Levels Be?

For a healthy life, total cholesterol values are recommended to be below 200 mg/dL. While HDL cholesterol above 60 mg/dL shows a protective effect, falling below 40 mg/dL is considered a risk factor. The goal is to keep LDL cholesterol below 100 and triglyceride values below 150 mg/dL. These values may vary depending on a person’s age, gender, and general health condition.

What is High Cholesterol?

High cholesterol is the elevation of LDL (“bad” cholesterol) or total cholesterol levels in the blood above normal. This condition can lead to the accumulation of atherosclerotic plaques on vessel walls. Over time, these plaques can lead to the development of arterial stiffness (atherosclerosis), paving the way for serious health problems such as heart attacks and strokes.

What Causes High Cholesterol?

High cholesterol occurs due to reasons such as unhealthy diet, sedentary lifestyle, genetic factors, excess weight, and smoking. In particular, a diet containing saturated fats (red meat, butter) and trans fats (processed foods) can increase LDL levels. The risk is higher if there is a family history of cholesterol or heart disease. Apart from this, health conditions such as diabetes, thyroid problems, or liver diseases can also affect cholesterol. This problem can be seen more frequently as age advances and stress increases.

Causes of high cholesterol:

• High-Fat Diet: Especially saturated fats (red meat, full-fat dairy products, processed foods) and trans fats (ready-made foods, fast food) can increase cholesterol levels. These types of fats encourage the body to produce LDL (bad cholesterol).
• Excess Weight and Obesity: Being overweight can cause HDL (good cholesterol) levels to decrease and LDL levels to increase. Obesity can also trigger insulin resistance and other metabolic problems, which can lead to imbalances in cholesterol levels.
• Low Physical Activity: Not exercising regularly can cause HDL (good cholesterol) levels to decrease and LDL (bad cholesterol) levels to increase. Regular exercise helps keep cholesterol levels balanced.
• Smoking: Smoking lowers HDL (good cholesterol) levels and weakens vessel walls, causing cholesterol to adhere to the inner surface of the vessel. This can lead to vessel blockage.
• Alcohol Consumption: Excessive alcohol consumption can lead to an increase in cholesterol levels. Especially excessive alcohol can cause elevated triglyceride levels.
• Genetic Factors: Individuals with a family history of high cholesterol or heart disease may have a genetic predisposition. Hereditary conditions such as familial hypercholesterolemia can cause the body to be unable to process cholesterol properly.
• Age and Gender: As age advances, cholesterol levels tend to rise. Post-menopausal women may have higher LDL cholesterol levels than men.
• Health Conditions: Certain health problems such as diabetes, hypertension, kidney diseases, and hypothyroidism can cause cholesterol levels to rise.

What are the Symptoms of High Cholesterol?

High cholesterol typically does not produce symptoms and progresses silently, but as vessel blockage advances to an advanced stage, signs such as chest pain, shortness of breath, fatigue, leg pain or cramps, and yellowish nodules around the eyes may appear. In some cases, the first symptom may be a heart attack. Most often, this condition is detected incidentally with a routine blood test.

Symptoms of high cholesterol:

• Chest Pain (Angina): High cholesterol can lead to vessel blockages and heart diseases. This can result in insufficient oxygen reaching the heart muscle, which can cause chest pain (angina).
• Shortness of Breath: High cholesterol can cause blockages in the blood vessels of the heart and lungs, which can lead to shortness of breath.
• Leg Pain or Cramps: High cholesterol levels can make blood circulation in the legs difficult, which can cause pain or cramping sensations, especially while moving.
• Yellowish Patches on the Skin (Xanthomas): Yellowish nodules (xanthomas) can form on the skin, especially on the elbows, knees, upper parts of the hands, and around the eyes. This can be a sign of high cholesterol levels in the body.
• Symptoms Related to Stroke: High cholesterol can increase the risk of stroke by narrowing vessels. Symptoms related to stroke can include difficulty speaking, drooping on one side of the face, and weakness or numbness in the arms.

What are the Risks of High Cholesterol?

High cholesterol carries serious risks such as arterial stiffness (atherosclerosis), heart attack, stroke, and peripheral arterial disease. When LDL cholesterol accumulates in the vessels and blocks blood flow, sufficient oxygen may not reach vital organs such as the heart and brain. This condition leads to life-threatening complications over time.

The risk increases, especially when combined with additional factors such as smoking, high blood pressure, or diabetes. If not intervened early, vessel blockage can cause permanent damage.

How to Lower Cholesterol?

To lower cholesterol, it is important to adopt a healthy lifestyle first. A diet low in saturated and trans fats and rich in fiber should be created. Healthy fats such as olive oil, fish, and nuts should be preferred. Regular physical activity can lower bad cholesterol (LDL) levels while increasing good cholesterol (HDL). Avoiding smoking and alcohol consumption also helps control cholesterol levels. If lifestyle changes are not sufficient, cholesterol-lowering medications recommended by your doctor can be used. Additionally, treating any underlying health problems is also important.

• Balanced Diet: Avoid foods containing saturated fat and trans fat. Consume vegetables, fruits, whole grains, and healthy fats.
• Regular Exercise: Exercise at moderate intensity for at least 150 minutes per week.
• Healthy Weight: Maintain your ideal weight.
• Quitting Smoking: Smoking lowers HDL cholesterol levels and negatively affects vascular health.
• Reducing Alcohol Consumption: Avoid excessive alcohol consumption.

Medication Use in Cholesterol Treatment

In cases where lifestyle changes are not sufficient, your doctor may prescribe cholesterol-lowering medications. Medications such as statins, fibrates, and niacin are used to lower cholesterol levels. Medication therapy is determined according to a person’s health condition and risk factors.

Frequently Asked Questions (FAQ) About Cholesterol

How are cholesterol levels measured?

Cholesterol levels are measured with a blood test. This test evaluates total cholesterol, LDL, HDL, and triglyceride levels. Ideal levels should be as follows:

• Total Cholesterol: Below 200 mg/dL
• LDL Cholesterol: Below 100 mg/dL
• HDL Cholesterol: 60 mg/dL and above
• Triglycerides: Below 150 mg/dL

How to increase good cholesterol (HDL)?

Regular physical activity is important to increase HDL cholesterol. Aerobic exercises such as walking, cycling, or swimming for at least 30-45 minutes 5 days a week positively affect HDL levels. In terms of diet, consumption of fatty fish such as olive oil, avocado, walnuts, and salmon, which are rich in omega-3 fatty acids, can increase HDL. Since smoking lowers HDL levels, quitting smoking is an important step. Limiting refined sugar and processed carbohydrates also has a positive effect on HDL. Moderate alcohol consumption (for example, one glass of red wine per day) can increase HDL, but caution should be exercised as excessive consumption can negatively affect liver health.

Can high cholesterol be hereditary?

Yes, high cholesterol can occur for genetic reasons. Familial hypercholesterolemia (FH) is a genetic disorder that prevents the liver from clearing LDL cholesterol. In this case, individuals have high LDL levels from birth, and the risk of vascular diseases increases at an early age. Diagnosis can be made with symptoms such as a family history of early heart attacks, fat deposits in tendons (xanthomas), or yellow spots around the eyes (xanthelasma). In this condition, which is diagnosed with genetic tests and blood analyses, lifestyle changes and medication therapy should be initiated early.

What is the difference between triglyceride and cholesterol?

Cholesterol and triglyceride are different types of fats found in the blood circulation. While cholesterol is involved in the structure of cell membranes and plays a role in hormone production, triglyceride is the body’s stored energy source. While cholesterol is divided into two as “LDL” (bad) and “HDL” (good), high triglyceride levels increase the risk of pancreatitis (pancreatic inflammation) and heart diseases. Especially triglyceride levels above 200 mg/dL are considered dangerous and should be controlled with diet, exercise, or medications.

Does vegetarian diet lower cholesterol?

Vegetarian diet can help lower LDL cholesterol due to the lack of consumption of animal products containing saturated fat. Fiber-rich vegetables, whole grains, legumes, and plant oil sources such as walnuts reduce cholesterol absorption and support vascular health. However, care should be taken in selection as ready-made vegetarian products (packaged burgers, processed soy products) may contain trans fat or high salt. A significant decrease in LDL levels can be achieved with a balanced plant-based diet plan.

What are the side effects of cholesterol-lowering medications?

Statins, the most commonly used group of cholesterol-lowering drugs, can cause side effects such as muscle pain, elevated liver enzymes, or rarely a slight increase in blood sugar. Fibrates can generally increase the risk of stomach discomfort or gallstones. Flushing and itching in the face are common with niacin (vitamin B3) use. Since the side effects of medications vary from person to person, regular blood tests should be performed under doctor supervision, and treatment should be adjusted if necessary.

Can high cholesterol be seen in children?

High cholesterol in children can occur, especially in cases of obesity, genetic predisposition, or diabetes. Cholesterol testing is recommended for children between the ages of 2-10 who have a family history of high cholesterol or early heart disease. In this case, the risk can be reduced with healthy eating habits and regular physical activity from childhood. Although rarely, medication therapy may be necessary.

Do cholesterol levels change with age?

As we age, metabolism slows down, and changes in hormone levels (e.g., menopause) can affect cholesterol balance. Especially LDL cholesterol levels generally increase with age, while HDL cholesterol may slightly decrease. Changes in sedentary lifestyle and eating habits also contribute to this process. Therefore, regular cholesterol screenings are important in individuals over 40 years of age.

Does stress raise cholesterol?

While stress does not directly raise cholesterol, it has an indirect effect. Behaviors such as unhealthy eating, smoking, or inactivity may increase in people under chronic stress. Additionally, cortisol, the stress hormone, can cause LDL levels to rise by disrupting fat metabolism. Stress management techniques (meditation, yoga) and regular sleep help reduce these risks.

Does coffee consumption affect cholesterol?

Unfiltered coffee types (Turkish coffee, French press) can raise LDL cholesterol due to a compound called “cafestol” they contain. This compound is found in the oily part of coffee beans and is largely removed using filter paper. While consuming 2-3 cups of filter coffee per day is generally considered safe, excessive consumption should be avoided.

Which herbal supplements are effective for lowering cholesterol?

Herbal products such as psyllium (fiber supplement), garlic, and flaxseed show cholesterol-lowering effects. Especially psyllium helps lower LDL levels by reducing cholesterol absorption in the intestines. However, these supplements do not replace medication therapy and should not be used without consulting a doctor. It should also be remembered that some herbal products may interact with medications.

Is it necessary to give blood on an empty stomach for high cholesterol diagnosis?

Yes, a 9-12 hour fast is generally required for a cholesterol test. Especially since triglyceride levels can temporarily rise after eating, tests performed on an empty stomach give more accurate results. Water consumption is free, but sugary drinks or foods should not be consumed.

Which foods should be avoided in a cholesterol-lowering diet?

Products containing saturated fat such as red meat, butter, full-fat cheese, and milk should be limited. Trans fats (margarine, fast food, packaged snacks) and processed meat products (sausage, salami) should be completely removed from the diet. Additionally, sugary drinks and refined flour foods can indirectly disrupt the cholesterol balance by raising triglyceride levels.

Are there any harms of low cholesterol?

Extremely low total cholesterol (below 120 mg/dL) is a rare condition and is generally associated with genetic factors or nutritional disorders. Very low cholesterol levels can lead to disruptions in hormone production or impairments in cell membrane functions. However, if HDL and LDL values are in the normal range, low total cholesterol generally does not pose a problem.

How should athletes’ cholesterol levels be?

HDL cholesterol levels are generally high in athletes who exercise regularly. However, LDL cholesterol may remain high if there is a genetic predisposition. It is recommended that even athletes have their lipid profile checked at least once a year. Especially in those engaged in endurance sports, triglyceride levels may be low due to excessive energy consumption.

Is there a relationship between cholesterol and blood pressure?

High cholesterol causes plaque accumulation in vessel walls, leading to the development of arterial stiffness (atherosclerosis). This condition causes vessels to lose their elasticity and blood pressure to rise. Therefore, when high cholesterol and hypertension coexist, the risk of heart attack or stroke increases exponentially. Lifestyle changes are essential to control both conditions.

Conclusion

Although cholesterol is vital for the body, high levels can lead to serious health problems. You can keep your cholesterol levels under control by adopting a balanced lifestyle and having regular health check-ups. Remember, with early diagnosis and correct treatment, you can significantly reduce the risk of heart and vascular diseases.

Reference: High Cholesterol