What the value means
LDL cholesterol reflects the amount of cholesterol carried in particles that can lodge in artery walls. Genetic studies and large clinical trials show that a long-term higher LDL causally increases the risk of atherosclerosis. HDL is far less clear-cut: drugs that raised HDL did not reduce heart attacks, and very high HDL has not been linked with extra benefit in some studies. Laboratory LDL ranges vary and the “normal” range often reflects the population average – from a prevention standpoint the target is lower, and the lower the higher your overall risk.
Possible causes
- Genetics – with LDL above roughly 4.9 mmol/L, familial hypercholesterolaemia should be considered.
- Diet – plenty of saturated fat (fatty meat, butter, coconut fat) and little fibre.
- Low-carbohydrate diet – in some lean people it markedly raises both LDL and HDL.
- Underactive thyroid – slows LDL clearance.
- Menopause – falling estrogen typically raises LDL.
What you can do
- Add ApoB and Lp(a) – ApoB better captures the number of risky particles; Lp(a) needs measuring only once in a lifetime.
- Rebalance fats – replace some saturated fat with olive oil, nuts and fish.
- Fibre – oats, legumes and psyllium provide soluble fibre that modestly lowers LDL.
- Exercise and not smoking – both reduce overall cardiovascular risk.
- Recheck in 2–3 months – after changing your diet, to see the real effect.
When to see a doctor
See a doctor if your LDL is repeatedly high, especially above 4.9 mmol/L, if a relative had a heart attack or stroke at a young age, or if you have diabetes, high blood pressure or kidney disease. Your doctor will assess your overall risk (for example with the SCORE2 tool) and decide whether lifestyle is enough or treatment is also appropriate.