Atherosclerosis is the slow buildup of cholesterol-carrying plaque inside the walls of arteries, which narrows and stiffens them and can eventually choke off blood flow to the heart, brain or legs. It begins decades before any symptom, often in early adulthood, and stays silent for most of that time. Heart attacks and most ischemic strokes are the late, visible events of a process that had been running for years. A fuller clinical reference for the disease process is the Atherosclerosis entry in the Smart Longevity glossary.
What it measures
Atherosclerosis is a condition, not a single lab value, so what gets measured is either the plaque itself or the forces that build it. Plaque is imaged: a coronary artery calcium (CAC) scan quantifies calcified plaque in the heart’s own arteries, carotid ultrasound looks for focal thickening of the neck arteries, and CT angiography shows how much a vessel is narrowed. The drivers come from a blood draw and a blood pressure cuff, chiefly the apoB-carrying particles, of which LDL (LDL, “bad” cholesterol) is by far the most abundant, together with blood pressure, blood glucose and smoking status.
The process starts in the Endothelium, the single-cell lining of the artery. When that lining is injured and leaky, apoB particles cross into the wall and are retained there, get oxidized, and draw in immune cells that swallow them and turn into the foam cells of the earliest fatty streak. Over years the lesion accumulates lipid, fibrous tissue and calcium. Whether it causes an event depends less on its size than on whether its cap tears and triggers a clot.
Typical values
The closest thing to a number is the coronary calcium score, reported in Agatston units and usually grouped like this:
| CAC score | Usual interpretation |
|---|---|
| 0 | No calcified plaque detected |
| 1-99 | Mild calcified plaque burden |
| 100-399 | Moderate burden |
| 400 or higher | Extensive burden |
Guidelines label these bands slightly differently, and the same score means more at 45 than at 75, so it is often read as an age- and sex-adjusted percentile. A score of zero is reassuring but not proof of clean arteries: the scan sees calcium, and young, soft, non-calcified plaque does not show up on it.
Why it matters for longevity
Atherosclerotic disease is the leading cause of death worldwide, so most attempts to extend healthy years run through it. Cohort studies and human genetics point the same way: risk tracks cumulative lifetime exposure to apoB particles, not just today’s reading, which is why an average level held for decades matters more than one good result. Imaging adds independent information, with a higher plaque burden associated with more events in the following years.
Randomized trials are unusually consistent here. Lowering LDL cholesterol with statins, and with ezetimibe or PCSK9 inhibitors added on top, reduced heart attacks and strokes, and the benefit scaled with how much the LDL actually fell and for how long. Lowering blood pressure and stopping smoking reduced events too. Few areas of longevity have evidence this direct.
What changes it
Established plaque rarely disappears, but progression can be slowed and lesions can stabilize, which is the outcome that matters. Stopping smoking is the single largest lever for anyone who smokes. A pattern built on vegetables, legumes, whole grains, nuts, fish and olive oil, trading much of the saturated fat for unsaturated fat and adding real fiber, moves lipids in the right direction. Aerobic exercise and strength training help through blood pressure, glucose and body composition; sleep and stress mostly work through those same channels.
When measured risk is high, drugs do the heavy lifting: lipid-lowering therapy, blood pressure treatment and glucose control. What you cannot change is age, sex, family history and inherited lipoprotein(a) – which is exactly why some people need earlier treatment of the parts that are modifiable. Any decision about medication belongs with your own clinician.
Related reading
- Heart Health: A Prevention Guide for Longevity
- Which Blood Tests Reflect Aging and How to Read Them
- The Mediterranean Diet and Longevity: The Evidence
- Chronic Inflammation and Aging: Inflammaging
Disclaimer. This article is for information only and does not replace medical advice. Talk to a qualified clinician before changing anything about your health.