Cholesterol 101: Your Guide to Understanding A Lipid Panel
Your Guide to Understanding Cholesterol
Cholesterol often gets a bad rap in the media, but it’s actually a vital player in our bodies. This waxy molecule is essential for building cell membranes and is the starting material for important hormones.
And it is also a main culprit of cardiovascular disease. High cholesterol can increase the risk of cardiovascular disease (CVD) by causing plaque to build up in the arteries. Heart disease has been the leading cause of death in the United States for over 100 years. According to the AHA, in 2024 we can expect nearly 1 million cardiovascular-related deaths. Stroke is the second leading cause of death.
In this article, I will explain what cholesterol is, how it is measured, and when and how to lower your cholesterol. Ultimately, this is a key step in lowering your risk of cardiovascular disease and unlocking a longer, healthier life.
Cholesterol is an Essential Molecule
Cholesterol is critical for several key functions in the body:
Building Cell Membranes
Cholesterol helps construct and maintain cell membranes, providing them with the necessary structure and fluidity to function properly.
Hormone Synthesis
It acts as a precursor for steroid hormones like cortisol, aldosterone, testosterone, and estrogen, which are essential for various bodily functions.
Intracellular Transport
Cholesterol plays a role in transporting substances within cells.
Modulating Membrane Fluidity
It affects how easily molecules can move through cell membranes, which is vital for maintaining cell integrity and function.
Eye Health
Cholesterol is important in the eye lens, helping to maintain its transparency and proper function.
The Great Cholesterol Food Fallacy
A major misconception is that eating foods high in cholesterol has a significant impact on your blood cholesterol levels. In reality, your liver is the main producer of cholesterol, churning out about 80% of what your body needs. So, while that eggs Benedict might feel like a guilty pleasure, it’s not the cholesterol villain you might think it is.
Sources of Cholesterol
Cholesterol in your body comes from two primary sources:
Endogenous Production
About 80% of your body’s cholesterol is produced by the liver. Every cell in the body can synthesize cholesterol, starting from a molecule called acetyl-CoA. The liver carefully regulates cholesterol production, increasing or decreasing it based on the body’s needs.
Dietary Intake
The remaining 20% comes from the food you eat, particularly animal-based products like meat, dairy, and eggs. While dietary cholesterol has less impact on blood cholesterol levels than previously thought, foods high in saturated and trans fats can still raise blood cholesterol levels significantly.
What Dietary Culprits Really Raise Cholesterol Levels?
When it comes to raising blood cholesterol levels, not all foods are created equal. Let’s look at the main offenders:
Saturated Fats: The Primary Culprit
Saturated fats are the main dietary factor that raises LDL (low-density lipoprotein) cholesterol levels. Some of the worst offenders in this category include:
Processed and Cured Meats
Hot dogs, sausages, bacon, and pepperoni are not only high in saturated fats but also have been linked to increased cardiovascular risk. They often contain preservatives and additives that can also contribute to heart disease.
Fatty Cuts of Meat
Delicious as they may be, cuts like ribeye steaks and lamb chops are packed with saturated fat. Leaner cuts like sirloin or tenderloin are better options. Leaner cuts like sirloin or tenderloin are better options, offering lower saturated fat content while still providing protein and nutrients.
High-Fat Dairy Products
Whole milk, full-fat cheeses, and creamy ice creams are high in saturated fat and can significantly impact your cholesterol levels. These can be enjoyed in moderation, and for those at particularly high risk, low-fat dairy products may be a better option.
Trans Fats: The Double Whammy
Trans fats are particularly harmful because they not only raise LDL cholesterol but also lower HDL (high-density lipoprotein) cholesterol, the “good” cholesterol. While many countries have banned artificial trans fats, they can still be found in some processed and packaged foods, certain types of margarine, and some fried foods.
Surprising Offenders
Coconut Oil
Despite its trendy reputation, coconut oil is high in saturated fat and can raise LDL cholesterol levels. It may have some benefits, but use it sparingly.
Organ Meats
While nutrient-dense, organ meats like liver and heart are also high in cholesterol and saturated fat. Enjoy them in moderation if you’re watching your cholesterol levels.
Remember, cholesterol itself isn't inherently bad—it's essential for life. It only becomes problematic when there's too much in the bloodstream, leading to potential health risks. As the saying goes, "Too much of a good thing can be bad for you," and that includes cholesterol.
Traditional and Emerging Cholesterol Markers
When it comes to assessing cholesterol, traditional markers like LDL and HDL are still important, but new players like ApoB and Lp(a) are also worth paying attention to.
Traditional Markers
LDL (Low-Density Lipoprotein)
Often referred to as “bad” cholesterol, LDL is responsible for transporting cholesterol to cells throughout the body. However, too much LDL in the bloodstream can lead to plaque buildup in artery walls, increasing the risk of heart disease, stroke, and peripheral artery disease.
HDL (High-Density Lipoprotein)
Known as the “good” cholesterol, HDL helps remove excess cholesterol from the bloodstream by transporting it back to the liver for disposal. Higher levels of HDL are associated with a lower risk of heart disease, but maintaining healthy LDL levels remains crucial as HDL only removes a fraction of blood cholesterol.
Triglycerides
While not technically cholesterol, triglycerides are often measured alongside it. These are the most common type of fat in your body, storing excess energy from your diet. High triglyceride levels, especially when combined with high LDL or low HDL, are linked to fatty buildups in artery walls and an increased risk of heart attack and stroke.
Emerging Markers
ApoB (Apolipoprotein B)
This protein is a key component of all atherogenic lipoproteins, including LDL, VLDL, and Lp(a). Measuring ApoB provides a more accurate count of potentially problematic particles and is considered a more accurate predictor of cardiovascular risk than LDL cholesterol alone. High ApoB levels indicate a greater number of atherogenic particles, which can increase the risk of developing cardiovascular disease.
Lp(a) (Lipoprotein(a))
Lp(a) is a lipoprotein particle that is genetically determined and associated with increased cardiovascular risk. Unlike other lipid markers, Lp(a) levels are not significantly affected by diet or lifestyle changes, making it a unique risk factor. High levels of Lp(a) are linked to an increased risk of heart disease, stroke, and aortic valve stenosis.
High-sensitivity C-reactive protein (hs-CRP)
Hs-CRP is a more sensitive test for detecting low levels of inflammation associated with cardiovascular risk. Hs-CRP can help predict the risk of first-time heart attacks, strokes, and sudden cardiac death in apparently healthy individuals. I high level is > 3.0 mg/L.
NMR (Nuclear Magnetic Resonance) Lipoprofile
The NMR lipoprofile provides more detailed information about lipoprotein particles than standard lipid tests. It measures the number and size of LDL, HDL, and VLDL particles, rather than just their cholesterol content. It's particularly useful in patients with metabolic syndrome, diabetes, or those with discordance between LDL cholesterol and apoB levels.
Cholesterol Ratios and What They Mean
Cholesterol ratios can provide more insight into cardiovascular risk than looking at lipid levels in isolation:
Total Cholesterol to HDL Ratio
Calculated by dividing total cholesterol by HDL cholesterol, this ratio includes triglyceride-rich lipoproteins. An optimal ratio is below 3.5:1, while ratios above 5:1 indicate increased cardiovascular risk.
LDL to HDL Ratio
Calculated by dividing LDL cholesterol by HDL cholesterol. An optimal ratio is below 2:1, with ratios above 5:1 indicating increased risk.
Non-HDL Cholesterol
This is calculated by subtracting HDL from total cholesterol and captures all atherogenic lipoproteins. Some experts believe it may be more useful than ratios for predicting risk.
Target Numbers for Healthy Cholesterol Levels
Managing cholesterol involves targeting these key components:
LDL
Aim for low levels, generally below 100 mg/dL for most adults. For those with a history of cardiovascular disease, the target may be even lower.
HDL
Strive for high levels, at least 40 mg/dL for men and 50 mg/dL for women. Higher HDL levels are generally better for cardiovascular health.
Triglycerides
Keep them in check, with normal levels below 150 mg/dL. I target under 100 mg/dL for my patients. Elevated triglycerides can increase the risk of heart disease, especially when accompanied by other risk factors like high blood pressure and obesity.
Remember, these numbers are part of a bigger picture of cardiovascular health, which includes factors like blood pressure, smoking status, and family history.
Who Should Be Treated?
The decision to treat high cholesterol is based on overall cardiovascular risk, not just cholesterol numbers. Factors to consider include LDL levels, the presence of cardiovascular disease or diabetes, age, 10-year cardiovascular risk score, and other risk factors like family history or smoking.
Guidelines recommend considering statin therapy for adults with cardiovascular disease, those with very high LDL (>190 mg/dL), diabetics aged 40-75, and adults 40-75 with elevated 10-year risk and LDL >70 mg/dL.
Advanced Testing with a Coronary Artery Calcium Score
In my practice, I use additional testing such as the Coronary Artery Calcium (CAC) score to help determine who might benefit most from statin therapy. This specialized CT scan of the heart identifies calcified plaque in the arteries, which can guide treatment decisions based on the level of risk.
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CAC Score of 1-99
Generally favors starting statin therapy, especially in individuals aged 55 and older.
CAC Score of 100-300
Indicates moderate coronary artery calcification, suggesting a relatively high risk of heart disease in the next 3-5 years.
CAC Score Above 300
Suggests extensive coronary artery calcification and a higher risk of cardiovascular events. Statin therapy is often recommended in these cases, unless contraindicated.
The decision to start statin therapy should not be based solely on the CAC score but should be considered in the context of overall cardiovascular risk and other risk-enhancing factors.
Building a Holistic Treatment Plan
When it comes to treatment, it’s not just about prescribing statins for every elevated number. The decision is based on a comprehensive risk assessment that includes overall cardiovascular risk, family history, other risk factors, and patient preferences.
The foundation of cholesterol management includes a heart-healthy diet, regular physical activity, weight management, and smoking cessation.
Heart-Healthy Diet
Focus on foods rich in omega-3 fatty acids, fiber, and unsaturated fats while limiting saturated and trans fats (ie processed food). This can help lower LDL cholesterol and raise HDL cholesterol.
Regular Physical Activity
Aim for at least 30 minutes of moderate exercise most days of the week to help improve cholesterol levels and overall cardiovascular health. This is of course just a starting point.
Weight Management
Losing excess weight can help lower LDL cholesterol and triglycerides while raising HDL cholesterol.
Smoking Cessation
Quitting smoking improves HDL cholesterol and reduces the risk of cardiovascular disease.
Medications
If lifestyle changes aren’t enough, medications may be necessary. Options include statins (the first-line treatment), ezetimibe (which decreases cholesterol absorption), PCSK9 inhibitors (for dramatically lowering LDL), bile acid sequestrants, bempedoic acid, and fibrates.
Treating High Lp(a)
Lipoprotein(a), or Lp(a), is a genetically determined risk factor for cardiovascular disease with limited treatment options. Management focuses on aggressively controlling other cardiovascular risk factors, as statins don’t significantly impact Lp(a) levels.
Niacin: Can modestly lower Lp(a), but its use has declined due to side effects and lack of cardiovascular benefit in trials.
PCSK9 Inhibitors: May lower Lp(a) by 20-30%, though they’re not specifically approved for this purpose.
Antisense Oligonucleotides: Targeting Lp(a) are in development and show promise in clinical trials.
Personalized Cholesterol Management
Managing cholesterol is more art than science. It’s about finding the right balance for each individual, considering their unique risk factors and life circumstances. Our goal isn’t just to lower numbers on a lab report but to help patients lead longer, healthier lives by reducing their risk for cardiovascular disease.
If you have questions about your cholesterol levels or want to learn more about reducing your risk for cardiovascular disease, consider scheduling a call to learn more about how to work with us. At our clinic, we provide personalized, comprehensive care to help you achieve your health goals. Together, we can chart the best course for your health and ensure you're on the path to a heart-healthy future.
Contact us today to set up an appointment and take the first step toward better heart health.
And the next time someone says, "Cholesterol is bad," you can confidently reply, "Well, actually, it's complicated." Because in medicine, as in life, it usually is.
