Good Cholesterol Myth Shifting Understanding Risk
New evidence suggests HDL levels alone may not predict cardiovascular risk, shifting focus toward function and LDL reduction
HDL cholesterol, long viewed as protective, shows a U-shaped relationship with cardiovascular risk, with both low and very high levels linked to harm, emphasizing function over quantity.
Study Details
For decades, high-density lipoprotein cholesterol (HDL-C) has been labeled “good cholesterol” because of its association with lower cardiovascular (CV) risk. This perspective shaped both clinical thinking and public health messaging.
However, emerging large cohort studies and updated clinical insights now challenge this simplified model. Researchers are observing that the relationship between HDL-C and cardiovascular outcomes is nonlinear, meaning both low and very high levels may be associated with increased risk.
At the same time, clinical guidelines increasingly emphasize that low-density lipoprotein cholesterol (LDL-C) remains the primary causal factor in atherosclerotic cardiovascular disease.
Methodology
The evolving understanding comes from large observational cohort studies and guideline reviews rather than a single randomized trial. These studies analyzed population-level data linking HDL-C levels with cardiovascular outcomes across diverse groups.
Researchers assessed HDL-C ranges, tracked cardiovascular events over time, and examined how risk changed at both low and extremely high HDL levels. Additional mechanistic studies explored HDL functionality, including its ability to remove cholesterol and regulate inflammation.
Key Findings
Low HDL-C remains a risk factor for cardiovascular disease
Moderate levels (40–60 mg/dL) are associated with lower risk
Very high HDL-C (>90 mg/dL) may increase cardiovascular risk
U-shaped risk pattern identified, challenging traditional assumptions
Raising HDL-C pharmacologically has not improved outcomes
HDL function (not just level) may better reflect cardiovascular protection
Implications for Practice
For patients, this research suggests that simply having “high HDL” does not guarantee protection. Balanced lipid management matters more than chasing a single number. Lifestyle factors such as diet, exercise, and metabolic health remain critical in maintaining healthy cholesterol function.
For clinicians, the shift is more significant. LDL-C reduction continues to be the primary therapeutic target, supported by strong causal evidence. HDL-C should no longer be used in isolation to estimate cardiovascular risk, especially at very high levels.
There is also growing interest in HDL functionality, including cholesterol efflux capacity and anti-inflammatory activity. While not yet part of routine clinical practice, these measures may eventually refine risk assessment and guide treatment decisions.
Importantly, conditions such as chronic inflammation, diabetes, and autoimmune disease can lead to dysfunctional HDL, which may lose protective effects or even contribute to atherosclerosis. This reinforces the need for a broader, systems-level approach to cardiovascular risk.