Apolipoprotein A1

What it is

Apolipoprotein A1 (ApoA1) is the main protein in HDL ("good") cholesterol particles. It helps carry cholesterol away from artery walls back to the liver.

Why it matters

Because every HDL particle carries one ApoA1, it is a direct read on your protective, cholesterol-clearing capacity and a useful complement to the standard HDL number.

What high values can mean

A higher value usually reflects more protective HDL particles, which is generally considered favourable for heart health.

What low values can mean

A lower value can mean fewer protective particles and is sometimes linked with higher cardiovascular risk.

How to improve it

Regular aerobic activity, not smoking, and a diet rich in unsaturated fats are most associated with healthier ApoA1; discuss your own targets with a clinician.

Food & lifestyle

Olive oil, nuts and oily fish plus regular exercise tend to support ApoA1/HDL; trans fats and smoking work against it.

Preparing for the testFasting required

Usually drawn as part of a lipid panel. Fasting is often requested, though many labs now accept non-fasting samples — follow your lab's instructions.

When to talk to a doctor

Review it with a doctor as part of your overall cardiovascular risk, especially if your HDL or ApoA1 is persistently low.

Related markers

• Apolipoprotein B
• HDL Cholesterol

Sources

• MedlinePlus (NIH)
• Testing.com (AACC)

Content reviewed on June 26, 2026