What is ApoB?
ApoB (apolipoprotein B) is a protein found on the surface of every lipoprotein particle that can contribute to plaque buildup in your arteries. That includes LDL particles, VLDL particles, and a few others. Each of these particles carries exactly one ApoB molecule — so measuring ApoB effectively counts the total number of potentially harmful particles in your blood.
Here's why that matters: your standard lipid panel reports LDL-C, which tells you how much cholesterol is carried inside LDL particles. But it doesn't tell you how many particles there are. Two people can have the same LDL-C but very different particle counts. The person with more particles has more chances for cholesterol to enter artery walls and form plaque. ApoB captures that difference.
Why it matters for longevity
A growing body of evidence — championed by longevity physicians like Peter Attia — shows that ApoB is the single best blood marker for predicting cardiovascular disease risk. It's more accurate than LDL-C, more accurate than total cholesterol, and more accurate than most other lipid markers.
The logic is straightforward: atherosclerosis is driven by atherogenic particles penetrating artery walls. ApoB tells you how many of those particles are circulating. The fewer particles, the lower your cumulative risk over a lifetime.
Despite this, most standard checkups don't include ApoB. It's one of the most important tests that's not routinely ordered. If you're serious about long-term cardiovascular health, this is a test worth requesting.
For women: ApoB is equally important regardless of sex. However, women often have their cardiovascular risk underestimated — partly because their LDL-C may look "fine" while their actual particle count (ApoB) tells a different story. This is especially relevant after menopause, when lipid profiles shift.
What the numbers mean
Conventional ApoB reference ranges are typically:
- Desirable: below 130 mg/dL
- Moderate risk: 130–160 mg/dL
- High risk: above 160 mg/dL
Longevity-focused physicians aim much lower. An ApoB below 80 mg/dL is a common target, and some push for below 60 mg/dL in people with additional risk factors. Peter Attia has argued that getting ApoB as low as possible early in life is one of the highest-leverage moves you can make for cardiovascular longevity — because the damage from atherogenic particles accumulates over decades.
What affects it
- Diet: Saturated fat and trans fat increase ApoB particle production. Replacing them with unsaturated fats (olive oil, nuts, avocados) and increasing fiber tends to reduce particle count.
- Insulin resistance: When your body doesn't handle insulin well, the liver produces more VLDL particles (which carry ApoB), driving the count up. Elevated , , and often travel together with high ApoB.
- Body weight: Excess visceral fat is associated with higher ApoB. Reducing body fat typically lowers particle count.
- Genetics: ApoB is significantly influenced by genetics. Some people will have elevated ApoB despite excellent lifestyle habits — and they may benefit from medication (like statins) to bring it down.
- Thyroid function: Hypothyroidism reduces the liver's ability to clear ApoB-carrying particles, leading to higher levels. Check your if your ApoB is elevated without an obvious cause.
How to get tested
ApoB is a simple blood test that does not require fasting (though it can be drawn alongside a fasting lipid panel). The challenge is that most doctors don't order it by default — you'll likely need to ask specifically. Say something like: "I'd like an ApoB test added to my lipid panel." You can also order it directly through online lab services like Quest or Ulta Lab Tests. It's inexpensive — usually $20–40 out of pocket. Testing once a year is reasonable; every six months if you're actively making changes.
How to improve it
- Address insulin resistance first. If your triglycerides are elevated and your HDL is low, improving metabolic health is the highest-impact step. Reduce sugar, exercise regularly, and lose excess body fat.
- Reduce saturated fat. Replacing saturated fat with unsaturated fat lowers ApoB particle production. Olive oil, nuts, avocados, and fatty fish are excellent swaps.
- Eat more soluble fiber. Oats, beans, lentils, and flaxseeds help your body excrete cholesterol and reduce ApoB levels.
- Exercise consistently. Regular aerobic and strength training both improve lipid particle profiles. Use our Heart Rate Zone Calculator to find your optimal cardio zones.
- Talk to your doctor about medication. For some people — especially those with genetic predisposition — lifestyle alone may not bring ApoB low enough. Statins and other lipid-lowering medications are well-studied and can dramatically reduce ApoB. This is a conversation worth having, particularly if your ApoB stays above 100 mg/dL despite lifestyle changes.
- Track it over time. ApoB responds well to interventions. Retest every 6–12 months to see how your changes are working. It's one of the most actionable and informative biomarkers you can follow.