Understanding cholesterol

Cholesterol is not the simple villain it is often made out to be, but one form of it, over enough time, does quiet and cumulative damage.

Cholesterol is essential. Every cell membrane depends on it, and the body uses it to build hormones and vitamin D. The question is not whether you have cholesterol, but how it travels through the blood, and in what quantity, for how long.

The role of LDL

The clearest villain of the story is low-density lipoprotein, or LDL. Atherosclerosis, the narrowing and hardening of arteries, is driven primarily by cumulative exposure to LDL cholesterol, which is the major cause of atherosclerotic cardiovascular disease.¹ At high levels, LDL delivers cholesterol into the wall of the artery, where it is taken up by immune cells and begins the slow formation of plaque.¹

It is not a single reading that matters most. It is exposure, how much LDL, over how many years.

The HDL story is more complicated

High-density lipoprotein, or HDL, has long been called the “good” cholesterol, and it is broadly associated with lower cardiovascular risk. But the picture is more nuanced than a simple “higher is better”: research now shows that very high HDL can also be linked to increased risk, and that how well HDL functions may matter more than the level alone.²

Why the long view matters

Because the damage is cumulative, cholesterol is best understood over a lifetime rather than a single test. That is also why it is one of the areas where earlier attention (to diet, activity, and, where needed, treatment) can change the trajectory.