Cholesterol: What Are Its Types, Functions, Sources, Risks, and Global Impact?

Content Outline

• What Is Cholesterol?
• Types of Cholesterol
• Functions of Cholesterol
• Sources of Cholesterol
• Risks of Cholesterol
• Global Impact of Cholesterol

What Is Cholesterol and Why Does It Matter?

Cholesterol is a waxy, fat-like substance (lipid) that is essential for health. It helps build healthy cells, supports hormone production, and contributes to vitamin D synthesis. While your body needs cholesterol to survive, having too much cholesterol can increase the risk of serious cardiovascular diseases (CVD), including heart attacks and strokes.

How Does Cholesterol Travel in the Blood?

Cholesterol cannot move through the bloodstream on its own. Instead, it attaches to proteins, forming lipoproteins. These lipoproteins act as transport carriers, delivering cholesterol to different parts of the body or returning excess cholesterol to the liver for removal.

Cholesterol exists in all body cells but is most often measured in the blood through a lipid panel test, which helps healthcare providers assess heart disease risk and recommend treatment if necessary.

What Are the Different Types of Cholesterol?

• HDL (High-Density Lipoprotein): The “good cholesterol” that removes excess cholesterol from the bloodstream and protects arteries.
• LDL (Low-Density Lipoprotein): The “bad cholesterol” that can deposit plaque inside arteries, raising the risk of atherosclerosis.
• VLDL (Very Low-Density Lipoprotein): Another harmful cholesterol type that contributes to plaque buildup.
• Non-HDL Cholesterol: Includes LDL, VLDL, IDL, and chylomicrons.

What Does Cholesterol Do in the Body?

• Gives structure to cell membranes and controls what enters and exits cells.
• Helps the liver produce bile acids for digestion.
• Serves as a building block for steroid hormones and vitamin D.

How Much Cholesterol Does the Body Produce?

The liver produces about 80% of the body’s cholesterol, ensuring adequate supply for normal function.

What Foods Add Cholesterol to the Body?

• Foods high in saturated fat (red meat, butter, full-fat dairy).
• Foods containing trans fats (packaged snacks, fried foods, baked goods).

How Is Cholesterol Transported in the Body?

Because cholesterol cannot move through the bloodstream on its own, it binds with proteins and triglycerides to form lipoproteins. These lipoproteins act like boats, transporting cholesterol to where it’s needed.

Some lipoproteins deliver cholesterol to tissues, while others remove excess cholesterol and carry it back to the liver for breakdown and elimination. This process, called reverse cholesterol transport, helps maintain balance.

What Health Conditions Are Related to Cholesterol?

• High Cholesterol (Hyperlipidemia): Total cholesterol above 200 mg/dL.
• High LDL Cholesterol (Hypercholesterolemia): LDL above 100 mg/dL.
• Low HDL Cholesterol: A marker of metabolic syndrome.
• Atherosclerosis: Plaque buildup in arteries, which can lead to coronary artery disease, heart attack, or stroke.

⚠️ Note: High cholesterol often has no symptoms until complications occur.

How Common Is High Cholesterol and What Is Its Global Impact?

• Prevalence in the U.S.: From 2017–2020, 10% of adults 20+ had high cholesterol (≥240 mg/dL). About 86 million had cholesterol above 200 mg/dL.
• Global Deaths: High cholesterol causes 4.4 million deaths annually (7.8% of all deaths).
• LDL vs. HDL: LDL drives plaque buildup; HDL helps remove cholesterol.
• Unexpected Risk: 75% of heart attack patients had LDL within guideline targets.
• Differences by Sex/Ethnicity: High cholesterol ranged from 7%–13% among U.S. adults 20+, depending on group.

What Factors Influence Cholesterol Levels?

• Age: Levels rise with age.
• Diet: Saturated and trans fats raise LDL.
• Exercise: Regular activity increases HDL and lowers LDL.
• Genetics: Family history plays a role.
• Sex: Women usually have lower cholesterol before menopause; LDL rises after.

What Is the Key Takeaway About Cholesterol?

Cholesterol is vital for health but dangerous when imbalanced. Keeping LDL low and HDL high helps prevent cardiovascular diseases. Regular screening, a balanced diet, exercise, and medical care are the best ways to manage cholesterol.