WHAT IS CHOLESTEROL AND WHY IS IT IMPORTANT FOR THE BODY?

Cholesterol is a fat-like (waxy) substance found in your blood and in every cell of your body. It is essential for life, but too much of certain types can increase the risk of heart disease and stroke.

Why cholesterol is important

Your body needs cholesterol to:

• Build cell membranes
• Produce hormones (e.g. estrogen, testosterone, cortisol)
• Make vitamin D
• Help form bile acids for digestion of fats

Your liver produces most of the cholesterol you need. The rest comes from food.

Types of cholesterol (simplified)

Cholesterol travels in the blood attached to proteins called lipoproteins.

1. LDL – “Bad” cholesterol

• Low-Density Lipoprotein
• Can deposit cholesterol in artery walls
• Leads to plaque buildup, narrowing arteries
• High LDL → higher risk of heart attack & stroke

2. HDL – “Good” cholesterol

• High-Density Lipoprotein
• Helps remove excess cholesterol from arteries and return it to the liver
• Higher HDL → protective for the heart

3. Triglycerides (often measured together)

• A type of fat used for energy
• High levels increase cardiovascular risk, especially when combined with high LDL or low HDL

Where cholesterol comes from

Your body (major source)

• Liver makes ~70–80% of cholesterol

Food (minor but important)

• Animal-based foods:
• Egg yolks
• Red meat
• Organ meats
• Full-fat dairy
• Saturated and trans fats raise LDL more than cholesterol itself

What happens when cholesterol is too high?

• Fatty plaques form in arteries (atherosclerosis)
• Reduced blood flow
• Can lead to:
• Heart attack
• Stroke
• Peripheral artery disease

Often there are no symptoms until serious disease develops.

Healthy cholesterol levels (general guide)

Type	Desirable Level
Total cholesterol	< 5.2 mmol/L
LDL	< 2.6 mmol/L (lower if high risk)
HDL	> 1.0 (men), > 1.3 (women)
Triglycerides	< 1.7 mmol/L

(Targets may differ based on individual risk)

Key takeaway

👉 Cholesterol is necessary, but balance matters.
👉 Focus on lowering LDL, raising HDL, and managing overall cardiovascular risk through diet, exercise, and lifestyle.