What is the main difference between good (HDL) and bad (LDL) cholesterol?

Cholesterol is a waxy, fat-like substance that is essential for body cells, the production of hormones, vitamin D, and digestive materials. The body produces all the cholesterol it needs, and it is also found in animal-based foods. Cholesterol is transported in the blood by particles called lipoproteins, which are mainly divided into two types: high-density lipoprotein (HDL) and low-density lipoprotein (LDL), each having a different role in the body.

Bad Cholesterol (LDL): The Risk of Plaque Accumulation

Low-density lipoprotein (LDL) is often known as "bad cholesterol" because it is associated with the accumulation of fatty deposits in the arteries. When LDL levels are too high in the blood, it can combine with other substances to form plaque that sticks to the walls of the arteries. This accumulation, known as atherosclerosis, leads to narrowing or even blockage of the arteries, which can cause coronary artery disease, heart attacks, strokes, and other blood vessel problems [1].

Healthcare providers focus heavily on LDL levels; a lower level is desirable. If the LDL level rises significantly, medical intervention becomes necessary [2].

Good Cholesterol (HDL): The Protective Agent

In contrast, high-density lipoprotein (HDL) is often referred to as "good cholesterol" for its protective role. HDL helps the body get rid of excess cholesterol by transporting it from different parts of the body back to the liver. The liver then removes this cholesterol from the body [1]. Higher levels of HDL may reduce the risk of health problems associated with cholesterol accumulation [3].

Therefore, the goal is to have high HDL levels. Exercise can help raise its levels, even by a small amount [2].

Factors Affecting Cholesterol Levels

Cholesterol levels in the body are affected by several factors, most notably lifestyle. Unhealthy habits that raise bad cholesterol (LDL) and lower good cholesterol (HDL) include:

• Unhealthy diet: Consuming too much saturated fat, found in red meat, full-fat dairy products, some baked goods, and fried and processed foods. These fats can raise bad cholesterol (LDL) [1].
• Lack of physical activity: Sitting for long periods and lack of exercise can lower good cholesterol (HDL) [1].
• Smoking: It lowers good cholesterol (HDL) and raises bad cholesterol (LDL) [1].
• Obesity and being overweight: These raise total cholesterol levels [1].

In addition to lifestyle, genetics also play a role. For example, familial hypercholesterolemia is a genetic condition that causes very high levels of cholesterol in the blood. Also, certain medical conditions such as diabetes and chronic kidney disease, as well as some medications, can affect cholesterol levels [1].

Practical Steps to Manage Cholesterol

To maintain cholesterol levels in a healthy range, it is recommended to follow lifestyle changes that promote heart health, even if cholesterol levels are within the normal range, to help prevent future health problems [2]:

• Healthy diet: Eating foods rich in fiber such as oats, legumes, and brown rice; limiting foods rich in saturated and trans fats; and choosing lean proteins such as fish and skinless poultry [2].
• Regular physical activity: Exercising regularly helps raise good cholesterol (HDL) [2].
• Weight management: Maintaining a healthy weight contributes to improving cholesterol levels [1].

If lifestyle changes are not sufficient to lower cholesterol, the doctor may recommend medication, such as statins [1]. It is important to continue following lifestyle changes even when taking medication. For more information on managing cholesterol levels, you can visit Cholesterol Levels: Risks and Management (Arabic).

When Should Cholesterol Be Checked?

There are usually no signs or symptoms of high cholesterol, and it is diagnosed through a blood test [1]. Screening recommendations depend on age, risk factors, and family history:

• For people aged 19 or younger: The first screening is recommended between ages 9-11, then every 5 years. Screening may begin as early as age 2 if there is a family history of high cholesterol or heart disease [1].
• For adults (20-65 years old): Screening is recommended every 5 years for younger adults, and every 1-2 years for men between 45-65 and women between 55-65 [1].
• For people over 65 years old: Annual screening is recommended [1].

Consult a doctor to determine the most appropriate screening schedule based on individual circumstances.

Medical references

• Cholesterol
• Cholesterol and lifestyle
• Blood Cholesterol What is Blood Cholesterol?