Cholesterol & Cardiovascular Risk
Cholesterol blood tests are among the most frequently ordered laboratory tests. But what do the numbers really tell us about our risk of heart attack or stroke?
For decades, much of the attention has focused on LDL cholesterol, often called "bad cholesterol." Yet cardiovascular risk is more complicated than any single number.
Other measurements—including HDL cholesterol, triglycerides, non-HDL cholesterol, apolipoprotein B (ApoB), and lipoprotein(a)—can provide additional information.
An important distinction: Cholesterol is essential for life. It helps form cell membranes and is used to produce hormones and bile acids. The concern is not cholesterol itself, but the role of cholesterol-carrying particles in the development of atherosclerosis, the buildup of plaque in artery walls.
In this article, we'll examine what the major cholesterol tests measure, what they may tell us about cardiovascular risk, and why interpreting the results can be particularly important for people in their 70s and 80s.
What Changed in the 2026 Cholesterol Guidelines?
Updated guidelines from the American Heart Association and American College of Cardiology emphasize that LDL cholesterol alone may not provide a complete picture of cardiovascular risk.
They recommend measuring lipoprotein(a), or Lp(a), at least once in adulthood and using ApoB and coronary artery calcium (CAC) testing selectively when additional information could help guide treatment decisions.
The guidelines continue to emphasize lowering LDL cholesterol while considering overall cardiovascular risk and individual circumstances.
LDL Cholesterol: How Important Is It?
LDL stands for low-density lipoprotein. These particles transport cholesterol through the bloodstream.
LDL cholesterol (LDL-C) measures the amount of cholesterol carried by LDL particles, not the number of particles themselves.
Is LDL Cholesterol Actually Measured?
In most routine cholesterol panels, LDL-C is calculated rather than measured directly. The calculation uses total cholesterol, HDL cholesterol, and triglycerides. Several formulas are available, including the traditional Friedewald equation.
Calculated LDL-C can be less accurate when triglycerides are very high or LDL cholesterol is very low. Some laboratories offer direct LDL-C measurement, although these methods also have limitations.
This is one reason why ApoB, which measures the number of atherogenic lipoprotein particles more directly, can sometimes provide useful additional information.
What Is a Normal LDL Level?
Traditionally, LDL cholesterol below 100 mg/dL has been considered desirable for many adults. However, the appropriate level depends on individual cardiovascular risk.
People with established cardiovascular disease may benefit from substantially lower LDL levels.
Why Is LDL Cholesterol Controversial?
Higher LDL cholesterol is associated with increased cardiovascular risk, and extensive genetic, clinical, and treatment evidence supports a causal role for LDL particles in atherosclerosis.
However, some researchers emphasize that LDL cholesterol alone does not adequately predict cardiovascular risk.
For example, people with insulin resistance may have relatively normal LDL cholesterol but elevated triglycerides, low HDL, and increased numbers of cholesterol-carrying particles.
Conversely, some people following low-carbohydrate diets experience substantial increases in LDL cholesterol despite improvements in triglycerides, HDL, weight, and blood glucose.
These metabolic improvements are encouraging, but they do not establish that markedly elevated LDL is harmless.
The important point: LDL cholesterol matters, but it should be interpreted alongside other risk factors and, when appropriate, more informative measurements such as ApoB.
HDL Cholesterol and Triglycerides: Clues to Metabolic Health
HDL Cholesterol
HDL is often called "good cholesterol" because higher HDL levels are generally associated with lower cardiovascular risk.
However, simply raising HDL cholesterol with medication has not consistently reduced heart attacks or strokes. HDL appears to be more useful as a marker of metabolic health than as a treatment target by itself.
Low HDL is commonly associated with insulin resistance.
Triglycerides
Triglycerides are a form of fat circulating in the blood. They rise after meals and can also be elevated with insulin resistance, excess refined carbohydrates, alcohol consumption, and certain medical conditions.
Fasting triglyceride levels are generally classified as:
Below 150 mg/dL — Normal
150–199 mg/dL — Borderline high
200–499 mg/dL — High
500 mg/dL or higher — Very high
Very high triglycerides can increase the risk of pancreatitis.
Is Below 150 Really Optimal?
Although triglycerides below 150 mg/dL are generally classified as normal, some metabolic health physicians recommend substantially lower levels.
Dr. William Davis favors triglycerides below 60 mg/dL, particularly as part of his approach to reducing insulin resistance and improving metabolic health.
Lower triglycerides are generally associated with a healthier metabolic profile. However, the specific target of 60 mg/dL has not been established through clinical trials as a universal goal for preventing cardiovascular disease.
This illustrates an important distinction between a laboratory's normal range and the more ambitious targets advocated by some physicians.
Dr. William Davis explores why triglycerides deserve greater attention in evaluating metabolic and cardiovascular health, challenging the traditional emphasis on cholesterol alone.
The Triglyceride-to-HDL Ratio
Dividing triglycerides by HDL cholesterol (both in mg/dL) produces the triglyceride-to-HDL ratio.
For example, triglycerides of 100 and HDL of 50 produce a ratio of 2.0.
A higher ratio is often associated with insulin resistance and an unfavorable metabolic profile. However, there is no universally accepted diagnostic cutoff, and the ratio should not replace established cardiovascular risk assessments.
The important point: Triglycerides and HDL provide useful clues about metabolic health, particularly when interpreted together with glucose, insulin, blood pressure, and waist circumference.
ApoB and LDL Particle Size: Two Different Perspectives
What Is ApoB?
Apolipoprotein B (ApoB) is a protein found on LDL and several other cholesterol-carrying particles that can contribute to plaque buildup in arteries.
Each of these particles contains one ApoB molecule. Measuring ApoB therefore provides an estimate of the total number of potentially atherogenic particles in the bloodstream.
Two people can have the same LDL cholesterol level but different ApoB levels because their particles carry different amounts of cholesterol.
ApoB can be particularly informative when triglycerides are elevated, insulin resistance is present, or LDL cholesterol and other risk markers disagree.
What About LDL Particle Size?
LDL particles vary in size and density. People with insulin resistance often have more small, dense LDL particles, along with elevated triglycerides and low HDL.
Small LDL particles are associated with increased cardiovascular risk. However, evidence suggests that the number of atherogenic particles is generally more important for predicting risk than particle size alone.
William Davis's Perspective
Dr. William Davis emphasizes small LDL particles, triglycerides, HDL cholesterol, and insulin resistance. He argues that advanced lipoprotein testing, particularly NMR testing that measures small LDL particles, can reveal metabolic abnormalities that conventional cholesterol panels miss.
Davis is skeptical of relying on ApoB alone because it does not distinguish between large and small LDL particles.
A practical guide to understanding an NMR lipoprotein report, including which measurements deserve attention and how to interpret the results.
What Does the Broader Evidence Show?
Major cardiovascular guidelines increasingly recognize ApoB as a useful measure of cardiovascular risk, especially when conventional cholesterol results may be misleading.
Although small LDL particles are associated with metabolic dysfunction, current evidence does not establish that measuring particle size improves cardiovascular outcomes beyond established risk assessment and particle-number measurements.
The important point: ApoB and LDL particle size answer different questions. ApoB estimates how many potentially harmful particles are circulating, while particle-size testing describes their characteristics. Neither replaces consideration of overall cardiovascular risk.
Lipoprotein(a): An Inherited Cardiovascular Risk Factor
Lipoprotein(a), usually abbreviated Lp(a), is a cholesterol-carrying particle similar to LDL but with an additional protein attached.
High Lp(a) levels are associated with increased risk of heart attack, stroke, and aortic valve stenosis (narrowing of the heart's aortic valve).
Why Is Lp(a) Different?
Unlike triglycerides and many other cardiovascular risk markers, Lp(a) levels are determined largely by genetics.
Diet, exercise, and weight loss generally have little effect on Lp(a).
What Is Considered High?
Lp(a) may be reported in either mg/dL or nmol/L.
Below 30 mg/dL — Generally considered lower risk
30–49 mg/dL — Intermediate range
50 mg/dL or higher — A commonly used threshold for increased risk
A level of approximately 125 nmol/L is also commonly used to identify elevated risk, although the two measurement units cannot be converted precisely using a single formula.
Should Everyone Have Lp(a) Measured?
Many cardiovascular organizations now recommend measuring Lp(a) at least once in adulthood.
Because levels are largely inherited and relatively stable, repeated testing is usually unnecessary.
An elevated result may lead to more careful management of other cardiovascular risk factors, particularly LDL cholesterol and blood pressure.
Can High Lp(a) Be Treated?
Several treatments specifically designed to lower Lp(a) are being studied. However, lowering the laboratory number is not the same as proving that treatment prevents heart attacks or strokes.
The important point: Lp(a) can reveal inherited cardiovascular risk that may not be apparent from a standard cholesterol panel.
Non-HDL Cholesterol: A Useful Number Already in Your Blood Test
Non-HDL cholesterol is calculated by subtracting HDL cholesterol from total cholesterol.
Non-HDL Cholesterol = Total Cholesterol − HDL Cholesterol
For example, if total cholesterol is 220 mg/dL and HDL is 60 mg/dL, non-HDL cholesterol is 160 mg/dL.
Unlike LDL cholesterol, non-HDL cholesterol includes cholesterol carried by several types of potentially atherogenic particles, including LDL and triglyceride-rich remnants.
Why Is It Useful?
Non-HDL cholesterol provides a broader picture of cholesterol carried by particles associated with atherosclerosis.
It can be particularly helpful when triglycerides are elevated or LDL cholesterol may not fully reflect cardiovascular risk.
It also has practical advantages:
It requires no additional laboratory test.
It can be calculated from a standard cholesterol panel.
It generally remains useful even when the blood sample was collected without fasting.
What Is a Desirable Level?
For many adults, non-HDL cholesterol below 130 mg/dL has traditionally been considered desirable. Lower targets may be appropriate for people at higher cardiovascular risk.
As with LDL cholesterol, the appropriate target depends on individual circumstances.
The important point: Non-HDL cholesterol is an easily available measurement that may provide a more complete assessment of atherogenic cholesterol than LDL-C alone.
Putting the Cholesterol Numbers Together
No single cholesterol measurement tells the whole story about cardiovascular risk.
LDL cholesterol measures the cholesterol carried by LDL particles. It is usually calculated rather than directly measured.
HDL cholesterol is associated with cardiovascular risk, but raising HDL by itself has not consistently improved outcomes.
Triglycerides provide important clues about insulin resistance and metabolic health.
Non-HDL cholesterol measures cholesterol carried by all the major potentially atherogenic lipoproteins.
ApoB estimates the number of atherogenic particles and can be especially useful when LDL cholesterol and metabolic risk markers disagree.
LDL particle size provides additional information about metabolic abnormalities, although its value beyond particle-number measurements remains uncertain.
Lp(a) identifies an important inherited risk factor that may not be apparent from a routine cholesterol panel.
What Matters at Different Ages?
In Your 50s and 60s
This is an important time to identify cardiovascular risk factors before a heart attack or stroke occurs.
Cholesterol measurements, blood pressure, blood glucose, smoking history, family history, and sometimes coronary artery calcium (CAC) testing can help guide prevention decisions.
Because cardiovascular disease develops over decades, reducing risk factors during these years may provide substantial long-term benefits.
In Your 70s and 80s
Cardiovascular prevention remains important, but decisions become more individualized.
Previous heart attack or stroke, diabetes, kidney function, medications, physical function, and overall health all influence the potential benefits and risks of treatment.
For otherwise healthy older adults, preventive treatment may still offer meaningful benefits. However, the evidence for starting certain cholesterol-lowering medications after age 75 in people without established cardiovascular disease is less definitive.
Familial Hypercholesterolemia: When High Cholesterol Is Inherited
Some people inherit a condition called familial hypercholesterolemia (FH), which causes very high LDL cholesterol beginning in childhood.
FH increases the risk of premature cardiovascular disease because arteries are exposed to high concentrations of LDL particles over many decades.
In adults, an untreated LDL cholesterol level of 190 mg/dL or higher raises suspicion of FH, particularly when accompanied by a family history of very high cholesterol or early heart disease. However, not everyone with LDL at this level has FH.
FH is important to recognize because early identification and treatment can substantially reduce cardiovascular risk. Close relatives may also benefit from cholesterol testing.
The important point: Persistently very high LDL cholesterol, especially with a family history of premature heart disease, deserves further evaluation rather than being dismissed as an individual variation.
Looking Beyond Cholesterol
Cholesterol measurements are only part of cardiovascular risk assessment.
Blood pressure, insulin resistance, smoking, physical activity, family history, and evidence of existing atherosclerosis may substantially change how cholesterol results should be interpreted.
For some people, coronary artery calcium (CAC) testing can help clarify risk when the decision about preventive treatment remains uncertain. CAC measures calcified plaque in the coronary arteries, although a score of zero does not rule out noncalcified plaque.
The important point: Cholesterol tests are tools for understanding risk—not a competition to achieve the lowest possible number. The goal is to reduce the likelihood of cardiovascular disease while considering age, overall health, and personal preferences.
Learn More
Information about cholesterol, cardiovascular risk, and prevention.
Clinical research and guidelines on LDL cholesterol, ApoB, Lp(a), and cardiovascular risk.
Information about familial hypercholesterolemia, inherited high cholesterol, and lipoprotein(a).
A metabolic health perspective emphasizing triglycerides, HDL, insulin resistance, and LDL particle characteristics.
Resources on metabolic health, low-carbohydrate nutrition, and insulin resistance.