Cholesterol
Cholesterol
Understanding Its Role, Risks, and How to Manage It
TL;DR
- Cholesterol is vital for hormone production, cell membranes, and vitamin D.
- Around 80% is made by the body, not food — genetics and liver function matter most.
- Extremely high or low levels both increase mortality risk.
- Aim for LDL below 130 mg/dL and HDL above 50 mg/dL for optimal heart health.
- Lifestyle changes such as diet, exercise, and weight control are the first line of action before medication.
What Cholesterol Does
Cholesterol is a waxy, fat-like molecule essential to every cell.
The body uses it to build cell membranes, produce hormones such as oestrogen and testosterone, and synthesise vitamin D.
About three-quarters of cholesterol is produced internally by the liver and intestines, while the rest comes from food.
For most people, cholesterol levels depend more on genetics, metabolism, and inflammation than on diet alone.
(Harvard Health, 2024)
| Source | Contribution | Notes |
|---|---|---|
| Liver and intestines | 75–85 % | Around 800–900 mg/day synthesised |
| Diet | 15–25 % | About 300 mg/day absorbed |
| Total | Around 1,000 mg/day | Excess removed via bile and stool |
HDL vs LDL: The Balance That Matters
HDL (high-density lipoprotein) removes excess cholesterol from tissues and returns it to the liver for disposal.
LDL (low-density lipoprotein) delivers cholesterol to cells but can deposit it in artery walls, forming plaques.
Typical ranges linked with the lowest all-cause mortality:
| Marker | Optimal Range | Unit |
|---|---|---|
| HDL | 50–80 mg/dL (men) / 60–95 mg/dL (women) | 1.29–2.46 mmol/L |
| LDL | 100–130 mg/dL | 2.59–3.36 mmol/L |
| Total cholesterol | 180–220 mg/dL | 4.65–5.69 mmol/L |
| Triglycerides | 70–100 mg/dL | 0.79–1.13 mmol/L |
Why Elevated Cholesterol Can Be Harmful
High LDL contributes to atherosclerosis — the gradual buildup of fatty plaques that stiffen arteries and restrict blood flow.
Over time, this increases the risk of heart attack, stroke, and other cardiovascular diseases, which remain leading causes of death worldwide.
However, not everyone with high LDL develops disease. The effect depends on other factors such as inflammation, blood pressure, blood sugar, physical activity, and smoking status — all of which interact with lipid metabolism.
How Often to Test
- Children: once between ages 9 and 11
- Adults: every 4–6 years, or more often if at risk (for example, family history, diabetes, obesity)
A standard lipid profile includes total cholesterol, LDL, HDL, and triglycerides.
(CDC Testing Guidelines, 2023)
Other Important Markers
| Marker | Description | Why It Matters |
|---|---|---|
| Triglycerides | Fat molecules for energy storage | Levels above 150 mg/dL (>1.7 mmol/L) raise CVD risk |
| ApoB | Protein counting LDL particles | Strong predictor of cardiovascular events |
| ApoA-I | Main protein in HDL | Linked to vascular protection |
Evidence-Based Ways to Lower LDL
| Action | Typical LDL Change | Why It Helps |
|---|---|---|
| Statins (prescribed) | ↓ 20–50 % | Block liver cholesterol synthesis |
| Weight loss (5–10 %) | ↓ 5–20 % | Improves metabolism and reduces liver fat |
| Diet (less saturated fat, more fibre) | ↓ 10–15 % | Improves bile excretion and gut lipid clearance |
| Exercise 150 minutes per week | ↓ 5–10 % | Raises HDL and lowers triglycerides |
| Quit smoking | ↑ HDL by about 10 % | Improves vessel function |
Food Choices That Matter Most
- Eggs: neutral for most people; up to one per day is safe.
- Red and processed meat: raises LDL — choose lean or plant alternatives.
- Butter and coconut oil: increase LDL; replace with olive or avocado oil.
- Olive, avocado, and canola oils: improve HDL and lower LDL.
- Nuts and seeds: provide plant sterols and healthy fats.
- Avocado: rich in monounsaturated fats; improves lipid ratios.
- Low-fat, fermented dairy: neutral or slightly positive for HDL.
- Filtered coffee: minimal effect; unfiltered raises LDL.
- Alcohol: small HDL rise, but excess elevates triglycerides.
- Fibre-rich foods (oats, beans, flax, apples): bind cholesterol in the gut, reducing absorption.
Key Insights
- Most cholesterol is produced by the body, not absorbed from food.
- Focus on fat quality, not cholesterol content — replace saturated with unsaturated fats.
- Lifestyle measures often achieve meaningful LDL reductions within 3–6 months.
- Track your own lipid trends rather than relying on one measurement.
- Both very low and very high cholesterol levels are linked to higher mortality.
References
- Harvard Health (2024). How it’s made: Cholesterol production in your body. Link
- American Heart Association (2024). HDL vs LDL Cholesterol. Link
- CDC (2023). Cholesterol Testing and Treatment Guidelines. Link
- Circulation (2023). Systematic Review and Updated Meta-Analysis. DOI
- Cleveland Clinic (2024). High-Cholesterol Foods: What to Eat and Avoid. Link
- UT Southwestern (2024). ApoB Testing Accuracy. Link
Disclaimer: This article is for informational purposes only and not a substitute for medical advice.
Scientific summaries were compiled and synthesised using the AI models and peer-reviewed research.