Cardiovascular disease (CVD) is the leading cause of death globally. For several decades, medicine has strived to understand the mechanisms of CVD. Over time, the blame for heart disease has settled on high blood cholesterol levels. Low-density lipoprotein (LDL) cholesterol has, particularly, earned a reputation as the “bad” cholesterol. LDL is widely considered to be responsible for the development of plaque and atherosclerosis. Today, cholesterol’s reputation persists in the general population and within the medical community.
However, new evidence has revealed the reality of cholesterol in cardiovascular health. The truth is out—high cholesterol levels cannot be linked independently to coronary heart disease. Nevertheless, cholesterol levels are integral to heart health. When it comes to your patients’ cardiovascular health, monitoring cholesterol remains vital.
Known as the “good” cholesterol, high-density lipoprotein transports excess cholesterol to the liver. High levels of HDL cholesterol—and the consequent low levels of LDL–were thought to reduce the risk of heart disease. Low levels of HDL correlated to risk of metabolic syndrome. Lifestyle changes associated with raised HDL levels include quitting smoking and increasing exercise. These changes reduce the risk of cardiovascular disease. The evidence seemed clear.
Yet, medications for specifically raising HDL have not reduced the risk of heart attacks. Furthermore, HDL contains a protein called apolipoprotein C3. Apolipoprotein C3 exerts certain atherogenic effects that ultimately contribute to heart disease. Those with extremely high levels of HDL are actually at a higher risk for heart attack and stroke.
These findings show the difference between HDL’s perceived and actual function. Likewise, LDL’s role in cardiovascular health has proven to be more complex.
Low-density lipoprotein cholesterol was considered to be the root of ischemic heart disease. For decades, high LDL-C levels were associated with plaque buildup in blood vessels and arteries and subsequent complications. However, as revealed in a comprehensive review, LDL and total cholesterol levels don’t contribute directly to coronary artery disease.
On the contrary, LDL cholesterol manages important facets of heart health. First, LDL allows steroids to be synthesized. It also creates vitamin K, which inhibits calcium formation, and creates vitamin D. Many medications exist to lower LDL levels. If LDL were responsible for atherosclerosis, these medications should reduce or eliminate CVD if LDL were responsible for atherosclerosis. Yet, LDL-lowering medications can stimulate atherosclerosis. Additional evidence against LDL’s negative effects continues to come to light. Though humans are not the only species with LDL and HDL, they remain the only species with coronary vascular disease.
Additionally, LDL particles are 20-22 nanometers in diameter. To result in even an average plaque build up, over 3.5 quadrillion particles of LDL must accumulate in one area. At an average rate of build up, it would take at least several decades for LDL, on its own, to generate atherosclerosis.
These discoveries have forced a reevaluation of cholesterol and CVD. Experts are beginning to understand that the mechanism of heart disease is more complicated and nuanced than previously believed. As a result, current practice stresses complete pictures of cardiovascular health. Individual readings beyond cholesterol have become necessary for patient care.
The relationship between cholesterol and cardiovascular disease remains undefined. Although additional research is necessary, current evidence highlights the positive effects of HDL and LDL cholesterol. Cholesterol increases the order of lipid packing. This reduces the permeability of lipid layers and mitigates damage from degrading chemicals. Cholesterol’s role in cell repair is essential to the cardiovascular system.
One of the essential connections held between cholesterol and CVD lies in diet. For years, diets high in cholesterol were thought to cause plaque buildup and atherosclerosis.
However, there may be an alternative explanation. Significantly, many of the same foods high in cholesterol are also rich in fatty acids, saturated fats, and trans fats. These substances, which have been shown to contribute to obesity and metabolic syndrome, may contribute more directly to the development of CVD than cholesterol. Diets high in cholesterol do not independently lead to plaque buildup and atherosclerosis. Foods that are cholesterol-dense but low in fatty acids, such as eggs, have no correlation to CVD. Alternative diet-related substances, such as triglycerides, may be more responsible for heart failure.
Similarly, regular physical activity reduces the risk of CVD while also lowering LDL cholesterol levels. Like diet, this connection is misleading. The healthy lifestyle that reduces LDL levels also reduces damaging substances in the bloodstream. In fact, additional evidence reveals that cholesterol plays an instrumental role in maintaining heart health. The Minnesota Cholesterol Experiment, thought to be the most comprehensive randomized control trial for cholesterol levels, shows cholesterol’s definitive cardiovascular benefit. The re-evaluated findings from this experiment, published in 2016, suggest that reduction in cholesterol levels was correlated with an increased mortality.
A healthy lifestyle remains central to heart health. Additional major risk factors such as family history, hypertension, and high blood pressure create potential cardiovascular issues. Cholesterol-lowering statins, however, have out-lived their usefulness.
Although cholesterol may not be responsible for CVD, it is a vital part of cardiovascular health. Tracking LDL, HDL, and other aspects of heart health is essential for patient health and wellness.
Regular in-depth cardiovascular screenings are essential for the best patient care. For a comprehensive look at your patients’ heart health, learn more about Access Medical Labs CardioPro panel. AML’s panel includes total cholesterol, HDL, LDL, triglycerides, and more. When our team of experts receives your sample, you’ll receive results in an industry-leading 24 hours. Explore our panels now.