Kenneth H. Cooper, MD, MPH, Founder and Chairman of Cooper Aerobics, knows a thing or two about heart health and the conditions that impact it, including the importance of maintaining healthy cholesterol levels. The internationally recognized “father of aerobics” first published Controlling Cholesterol the Natural Way in 1999, which features a step-by-step plan for lowering cholesterol without the use of prescription drugs. In this article, we will take a look at how well those recommendations have stood the test of time.
Over the last 25 years, robust clinical data demonstrate the benefits of a number of classes of cholesterol-lowering prescription medications (moderate and high-intensity statins as well as non-statin medications such as PCSK-9 inhibitors) in reducing the risk of fatal and non-fatal heart attack and stroke in moderate and high-risk patients. However, improving health habits is still an important recommendation for patients with high cholesterol at any risk level, particularly lower-risk patients who don’t need to take prescription medication.
Components of a Lipid Panel
In order to understand how to improve your cholesterol profile, it’s helpful to review the different components measured in a lipid panel:
- Total Cholesterol (the sum of LDL plus HDL plus VLDL)
- LDL (low-density lipoprotein) cholesterol
- HDL (high-density lipoprotein) cholesterol
- VLDL (very-low-density lipoprotein)
- Triglyceride level
Depending on how the lipid profile is ordered by your health care provider, the middle three components (LDL, HDL and VLDL) may be measured individually and summed to determine the total cholesterol level. Alternatively, the HDL and triglyceride levels may be directly measured and then the LDL and VLDL levels are calculated using a validated formula. Thus, you may see the LDL value on a lab result described as “calculated” or “direct.” Typically, it is less time-consuming and less expensive to directly measure only two components and calculate the others.
What is LDL cholesterol?
LDL, referred to as “bad cholesterol,” can enter the inner lining of artery walls and trigger an inflammatory response that leads to the buildup of plaque or atherosclerosis. High levels of LDL increase the risk of atherosclerotic cardiovascular disease (ASCVD) which includes heart attack, stroke, aortic aneurysm and peripheral arterial disease (atherosclerosis in the arteries in the lower extremities). Furthermore, numerous clinical trials using different medications have shown a reduction in ASCVD risk that increases with increasing LDL reduction. Thus, high LDL is a common target for cardiovascular risk reduction recommendations.
An optimal LDL level for an individual patient depends on their cardiovascular risk profile. For example, a patient with a history of coronary bypass surgery and diabetes has an LDL treatment goal of < 55 mg/dL. A patient with multiple cardiovascular risk factors but no history of clinical cardiovascular events has an LDL treatment goal of <70 mg/dL. For a younger patient with no risk factors for heart disease and no evidence of calcified plaque in their arteries, an LDL level of 100-130 may be acceptable.
What is HDL cholesterol?
HDL is commonly referred to as “good cholesterol. This is because epidemiologic studies like the Framingham Heart Study have shown an inverse relationship between HDL and the risk of atherosclerotic cardiovascular disease. HDL has been shown to have cardioprotective functions such as preventing inflammation and oxidative stress in arterial walls, as well as promoting cholesterol removal from the arterial wall to reduce atherosclerotic plaque formation. However, the cardioprotective role of a high HDL level has been called into question by more recent studies that have shown (1) people who are born with genetically driven high levels of HDL do not have a lower risk of developing atherosclerotic cardiovascular disease, and (2) clinical trials of medications used to increase HDL have not been shown to reduce cardiovascular risk. Ongoing studies now suggest that absolute HDL levels do not necessarily reflect the level of cardioprotective functioning of HDL.
Genetics and Lifestyle Choices Affect HDL
Genetics appear to play the biggest role in determining HDL levels, but lifestyle choices can also affect HDL. Reductions in HDL are also associated with smoking, being overweight, being sedentary, insulin resistance, high triglyceride levels, having a diet high in refined carbohydrates (added sugars) and transfats. At this point, improving unhealthy lifestyle habits is the best way to increase HDL. There is no optimal level or target for HDL given the complex relationship between level and function. The general approach is “the higher, the better” because higher values imply achievement of optimal cardiovascular health habits.
What are Triglycerides?
Triglycerides are the most common type of fat in the blood and are used by the body for energy. Triglycerides are found in higher-fat foods such as butter, oils, eggs, cheese, red meat, fried foods and creamy sauces and dressings—foods that deliver calories the body may not need right away. Individuals with elevated triglyceride levels are at increased risk for cardiovascular complications, particularly atherosclerosis; the mechanism of this increased risk is a topic of active research.
A healthy level of triglyceride is < 150 mg/dL. Prescription drug treatment is often not recommended unless the triglyceride level is >500 mg/dL due to an increased risk of pancreatitis. Older trials of drug therapy aimed at reducing cardiovascular risk by reducing triglyceride levels have not demonstrated a benefit. The impact of triglyceride reduction on cardiovascular risk using commercial omega 3 fatty acids is a current topic of considerable debate.
Finally, because total cholesterol is comprised of multiple components that have different levels of cardiovascular risk associated with them (high LDL with high risk and high HDL with low risk), it is difficult to define ideal total cholesterol values. For example, a patient with a low LDL and high HDL may have the same total cholesterol value as a patient with a high LDL and low HDL level but these patients would have different cardiovascular risks.