What is the real story on HDL — is high HDL actually protective?

HDL (high-density lipoprotein) cholesterol has long been promoted as "good cholesterol" because high HDL is associated with lower cardiovascular risk in observational studies, but Mendelian randomization studies (which test genetic variants that raise HDL without changing other factors) have found that genetically elevated HDL does not reduce cardiovascular events, suggesting HDL-C is a marker of cardiovascular health rather than a cause of it, and raising HDL pharmacologically (niacin, CETP inhibitors) has consistently failed to reduce cardiovascular events in RCTs (Voight et al., Lancet, 201260312-2)).

This is a striking reversal of a 40-year clinical belief. HDL-C remains a useful risk marker, low HDL (below 40 mg/dL in men) indicates metabolic dysfunction, insulin resistance, and is associated with elevated cardiovascular risk. But spending clinical energy trying to raise HDL is not evidence-based. The patient who asks "how do I raise my HDL?" should be told: improve insulin sensitivity, exercise consistently, and reduce visceral fat, not because these raise HDL, but because they address the metabolic dysfunction that the low HDL reflects.

Honesty Scale: Solid (1) for HDL as a cardiovascular risk marker rather than a modifiable treatment target. Solid (1) for the Mendelian randomization evidence against pharmacological HDL raising.

What to do: Stop pursuing interventions specifically to raise your HDL number. Use low HDL as a marker of insulin resistance and metabolic dysfunction requiring lifestyle intervention, not a treatment target in itself. Focus on ApoB and hs-CRP as the concrete cardiovascular risk markers.

For the full picture, read The ApoB/Lp(a)/Lipids Deep Dive