LDL cholesterol: Everything you need to know

Cholesterol is an essential fat substance that the body needs for building cells and producing hormones. Cholesterol is divided into two main types: LDL cholesterol and HDL cholesterol. However, LDL cholesterol plays a significant role in the development of cardiovascular diseases, and high levels can pose a serious health risk. This article comprehensively discusses what LDL cholesterol is, why it is harmful, how it is measured, and what factors can raise its levels. Additionally, treatment options will be examined, including both medications and lifestyle changes.

LDL cholesterol (Low-Density Lipoprotein) is a type of lipoprotein that carries cholesterol in the blood.LDL is commonly known as "bad cholesterol" because it can accumulate in the walls of blood vessels and cause plaque formation, leading to the narrowing and stiffening of arteries. The primary function of LDL cholesterol is to transport cholesterol from the liver to other parts of the body, where it is used as a building block for cells and to maintain other important processes.

High LDL cholesterol is a significant risk factor for cardiovascular diseases. When there is too much LDL cholesterol in the blood, it begins to accumulate in the walls of arteries, forming plaques. Over time, these plaques harden and narrow the arteries, restricting blood flow and making the blood vessels less flexible – this condition is called atherosclerosis.

• Heart attack:  If plaque ruptures, it can form a blood clot that blocks blood flow to the heart, potentially causing a heart attack.
•  Stroke: If a blood clot blocks blood flow to the brain, it can result in a stroke.
• Peripheral artery disease: The accumulation of plaque can also affect blood circulation in the limbs, causing pain and weakness.

High levels of LDL cholesterol are therefore directly related to the development of cardiovascular diseases, which is why managing it is an important part of maintaining health.

LDL cholesterol measurement is typically done through a blood test that measures the levels of various lipoproteins and fats in the blood. This blood test is known as a lipid panel or cholesterol test, and it measures the following values:

• Total cholesterol: The total amount of all types of cholesterol in the blood.
•  LDL cholesterol: The amount of "bad cholesterol," which is the greatest risk factor for the development of atherosclerosis.
•  HDL cholesterol:  The amount of "good cholesterol," which helps remove excess cholesterol from the bloodstream.
• Triglycerides: Blood fats that can also affect the risk of cardiovascular diseases.

The target level of LDL cholesterol depends on the individual's overall health status and other risk factors. Generally, the aim is to keep LDL cholesterol below 3.0 mmol/l, but for individuals at high risk of cardiovascular diseases, the target level may be even lower, such as below 2.0 mmol/l.

A blood test is usually performed after fasting, as food can temporarily raise blood fat levels, which may distort the results. Based on the results, the doctor may recommend lifestyle changes or medication to manage LDL cholesterol.

The increase in LDL cholesterol is due to various factors, such as genetics, diet, lifestyle, and even certain diseases. This section will focus specifically on the process in which fat accumulates in the liver, affecting the conversion of cholesterol from food into harmful LDL cholesterol.

Fatty liver is a condition where excess fat accumulates in the liver. This can be caused by excessive alcohol consumption (alcoholic fatty liver) or other reasons, such as obesity, excessive intake of sugar and fat, and insulin resistance (non-alcoholic fatty liver). Today, a high intake of saturated fats is one of the major causes of fatty liver.Especially meat and dairy products contain a high amount of saturated fat.

When fat accumulates in the liver, its normal function is disrupted. The liver produces cholesterol, but with fatty liver, this process can become unbalanced. Normally, both LDL and HDL cholesterol are produced in the liver, but in fatty liver, the production of LDL cholesterol can significantly increase, while the production of HDL cholesterol decreases. This leads to higher levels of LDL cholesterol circulating in the blood, which increases the risk of plaque formation in blood vessels.

Due to fatty liver, the liver's ability to process and remove cholesterol is impaired, which further exacerbates the problem. This condition can become more dangerous if it is associated with other risk factors such as high blood pressure, diabetes, or smoking.

Diet is a key factor that affects LDL cholesterol levels. Certain foods, such as those high in saturated fats (for example, fatty meats, butter, and cheese) and products containing trans fats (such as commercially baked goods and fast food), can significantly raise LDL cholesterol.

Saturated fats and trans fats contribute to the increase in LDL cholesterol because they increase the amount of cholesterol produced by the liver and reduce HDL cholesterol levels, which impairs the removal of cholesterol from the bloodstream. This combination leads to the accumulation of cholesterol in the walls of the arteries, increasing the risk of atherosclerosis.

High LDL cholesterol can be caused by various factors, which may be either hereditary or related to lifestyle and environment. Here are the most common risk factors for high LDL cholesterol:

Some individuals have a genetic predisposition to high LDL cholesterol. Familial hypercholesterolemia (FH) is an inherited condition where LDL cholesterol is exceptionally high from a young age. FH significantly increases the risk of cardiovascular diseases and often requires strict treatment.

A diet that is high in saturated fats, trans fats, and cholesterol can raise LDL cholesterol levels. For example, fatty meats, full-fat dairy products, foods containing butter, and baked goods are known to increase LDL cholesterol.

Overweight, particularly abdominal obesity, is one of the most significant risk factors for high LDL cholesterol. The accumulation of fat tissue can alter the body's ability to process fats and cholesterol, leading to higher LDL levels.

A lack of exercise can lead to higher LDL cholesterol levels and lower HDL cholesterol levels. Regular physical activity helps improve cholesterol profiles and reduce the risk of cardiovascular diseases.

Smoking damages the walls of blood vessels and lowers HDL cholesterol levels, which increases the risk of atherosclerosis. Smoking can also increase the oxidation of LDL cholesterol, making it even more dangerous for blood vessels.

As one ages, LDL cholesterol levels may rise, and in women, LDL cholesterol often increases more after menopause than in men. This is partly due to the reduction of estrogen's protective effect, which helps keep cholesterol levels in check.

Certain diseases, such as diabetes and hypothyroidism, can affect cholesterol levels and increase the amount of LDL cholesterol in the blood. Managing these diseases is also important for controlling cholesterol levels.

When lifestyle changes are not enough to lower LDL cholesterol levels, medication may be necessary. There are several different medications available for the treatment of high LDL cholesterol that affect cholesterol production, absorption, and removal from the body.

Statins are the most commonly used medications for the treatment of high LDL cholesterol. They inhibit the action of an enzyme that is key to cholesterol production in the liver.Statins effectively lower LDL cholesterol levels and simultaneously reduce the risk of cardiovascular diseases. The most common statins are simvastatin, atorvastatin, and rosuvastatin.

Ezetimibe is a medication that inhibits the absorption of cholesterol in the intestines. This medication can lower LDL cholesterol, especially when combined with statin therapy. Ezetimibe is also suitable for individuals who cannot tolerate statins.

PCSK9 inhibitors are a newer class of medications that act on the PCSK9 protein in the liver. This protein destroys LDL receptors that remove LDL cholesterol from the bloodstream. By inhibiting the action of the PCSK9 protein, PCSK9 inhibitors increase the number of LDL receptors and thus effectively lower LDL cholesterol levels.

Fibrates are medications that lower triglyceride levels and may slightly raise HDL cholesterol at the same time. Fibrates are often used in conjunction with statins, especially if the patient has high triglyceride levels.

Bile acid sequestrants, such as cholestyramine, bind bile acids in the intestine, forcing the liver to use more cholesterol for bile acid production. This process reduces the amount of LDL cholesterol in the blood.

In addition to medication, lifestyle changes are an essential part of managing high LDL cholesterol.Many changes, such as improving diet, increasing exercise, and quitting smoking, can significantly lower LDL cholesterol levels and improve overall heart health.

The diet is a key factor in managing LDL cholesterol. A healthy diet that is low in fat and high in fiber can significantly help reduce LDL cholesterol levels. The following diet-related tips can help manage cholesterol:

•  Avoid saturated fats:  Limit the consumption of fatty meats, butter, cheese, and other high-fat dairy products.

•  Prefer healthy fats: Use vegetable oils, such as olive oil, and eat nuts and fatty fish like salmon and sardines, which contain healthy omega-3 fatty acids.

•  Add fiber: Eat plenty of fiber-rich foods, such as oats, barley, legumes, fruits, and vegetables. Fiber helps bind cholesterol in the intestines and remove it from the body.

•  Avoid trans fats:  Foods containing trans fats, such as margarines and industrial baked goods, raise LDL cholesterol and should therefore be avoided.

Regular exercise is an effective way to improve cholesterol levels.Aerobic exercise, such as walking, running, cycling, or swimming, can raise HDL cholesterol while also helping to reduce LDL cholesterol. The goal should be to engage in at least 150 minutes of moderate-intensity exercise per week.

Quitting smoking is one of the most important changes you can make to improve your cholesterol profile and reduce the risk of cardiovascular diseases. Quitting smoking raises HDL cholesterol levels and reduces the oxidation of LDL cholesterol, which decreases the risk of plaque formation in the arteries.

Reducing overweight and especially abdominal obesity is important for managing LDL cholesterol. Losing weight helps improve cholesterol levels and reduce the risk of cardiovascular diseases. 

Moderate alcohol consumption, especially red wine, can raise HDL cholesterol levels, but excessive alcohol use can lead to many health issues, such as elevated triglyceride levels and liver damage. The general recommendation is a maximum of one drink per day for women and two drinks for men.

LDL cholesterol is one of the most important risk factors for cardiovascular diseases, and its management is an essential part of maintaining health. High LDL cholesterol can lead to serious health problems, such as heart attacks and strokes, but its levels can be managed through lifestyle changes and medication.Based on the results obtained from the blood test, you can work with your doctor to plan the best possible treatment strategy that helps you reduce risks and improve heart health. Remember that a healthy diet, regular exercise, quitting smoking, and weight management are key factors in controlling LDL cholesterol and improving overall health.