LDL cholesterol explained: targets, and what actually lowers it

Cholesterol is not the enemy. Your body needs it to build cell walls and make hormones, and your liver makes most of what you have. The problem is where it ends up. LDL, low density lipoprotein, carries cholesterol through the blood, and when there is too much of it for too long, some is deposited in the walls of your arteries. Over decades those deposits grow into plaque, which narrows arteries and can rupture, causing a heart attack or stroke.

The evidence that LDL causes this process is among the strongest in medicine. Genetic studies, population studies and many treatment trials all point the same way: the lower your LDL and the longer it stays low, the lower your risk.

Your target depends on your risk

There is no single “normal” LDL. The target is set by how likely you are to have a heart attack or stroke in the coming years, which depends on your age, blood pressure, smoking, diabetes, kidney function, family history and whether you already have heart disease.

The South African dyslipidaemia guideline from SA Heart and the Lipid and Atherosclerosis Society of Southern Africa (LASSA), updated in 2018, sets these LDL targets:

• Low to moderate risk: below 3.0 mmol/L.
• High risk: below 2.5 mmol/L.
• Very high risk, such as people who have already had a heart attack or stroke: below 1.8 mmol/L.

The European Society of Cardiology and European Atherosclerosis Society (ESC/EAS) 2019 guideline goes further for people at the highest risk, with a target below 1.4 mmol/L. Both guidelines agree on the principle. Your doctor sets your personal target once they have assessed your overall risk.

LifePrint's report uses the low to moderate risk target of 3.0 mmol/L, because it cannot know your full risk profile. An LDL of 3.0 to 3.4 mmol/L is shown in the grey zone: just above target, worth attention, but not alarming on its own. Higher results are graded in bands, with 4.1 and 4.9 mmol/L as the next steps up.

How LDL is measured

Many labs calculate LDL from your total cholesterol, HDL and triglycerides rather than measuring it directly. The calculation works well in most people but becomes less accurate when triglycerides are high or LDL is very low. In those situations non-HDL cholesterol or ApoB can give a clearer picture, and both are on the Heart and Metabolic panel.

What actually lowers LDL

Lifestyle changes can lower LDL meaningfully, although the effect varies a lot from person to person because genes play a big part. The changes with the best evidence are:

• Replacing saturated fat, found in fatty red meat, processed meat, butter, ghee, cream, hard cheese and coconut oil, with unsaturated fats from olive or canola oil, nuts, seeds, avocado and oily fish.
• Eating more soluble fibre, from oats, beans, lentils, chickpeas, barley and many fruits and vegetables.
• Losing excess weight, which helps LDL and, even more, triglycerides and HDL.
• Regular physical activity, which has a modest direct effect on LDL but large benefits for heart health overall.

Dietary cholesterol, such as from eggs, has a smaller effect on blood LDL in most people than saturated fat does. Stopping smoking does not lower LDL much, but it is one of the most powerful things you can do for your arteries.

When medicine is needed

For people at higher risk, or with a very high LDL, lifestyle alone is usually not enough to reach the target. Statins are the first choice. They are among the most studied medicines in the world and reliably reduce heart attacks and strokes. Other options, such as ezetimibe or injectable treatments, are used when statins are not enough or not tolerated. The choice of medicine and dose is a decision for you and your doctor.

Supplements marketed for cholesterol vary widely in quality and evidence. Speak to your doctor before relying on any of them, and never use one in place of a prescribed medicine.

Tracking your LDL

LDL changes slowly with diet and lifestyle. A repeat test after about three months of consistent change gives a fair picture of what those changes achieved. If you start a medicine, your doctor will usually check again after a few weeks to see whether the target has been reached.

If your LDL is above target, discuss it with a registered healthcare practitioner who can assess your full risk. Your LifePrint report is health information, not a diagnosis.