Risk Factor: Cholesterol

What it is

Cholesterol is a complex organic compound that is vital for the body’s functioning. Present in the blood and all tissues, it contributes to the production of the hormone cortisol, sex hormones, vitamin D, acids involved in fat digestion, and also plays an important role in the structure and regeneration of animal cells

Although most cholesterol in humans is produced by the body itself, it can also be obtained from foods such as eggs, meat, and whole milk. Its presence is essential for the balanced functioning of vital processes; however, when present in excess in the bloodstream, it can lead to complications

The most common of these is the formation of fatty plaques in the arteries, which leads to the hardening and blockage of blood vessels—a condition known as atherosclerosis. When vessels are obstructed, the heart receives less oxygen and nutrients, impairing its function and potentially leading to conditions such as angina, myocardial infarction, heart failure, and even sudden death. When it affects the carotid and cerebral arteries, it can result in strokes

The causal relationship between elevated blood cholesterol and cardiovascular diseases has been demonstrated in robust studies involving more than 800,000 individuals followed for up to five decades. This undeniable link is recognized by reputable academic institutions, medical societies, the World Health Organization, and regulatory agencies such as the U.S. FDA and the European Medicines Agency (EMA)

Types and Causes

What determines whether cholesterol is healthy or harmful to health is the type of lipoprotein (a small structure made of lipids and proteins) that carries lipids through the bloodstream. There are, therefore, two types of cholesterol: good and bad. HDL (High-Density Lipoprotein) collects cholesterol that has accumulated in blood vessels and transports it to the liver for elimination. On the other hand, LDL (Low-Density Lipoprotein), when accumulated, can lead to artery blockage

LDL carries cholesterol from the liver to the arteries. Thus, the higher the LDL cholesterol (i.e., the cholesterol carried by LDL) and the lower the HDL cholesterol (carried by HDL), the greater the risk of cardiovascular diseases. The opposite is also true, with very few exceptions

Causes of elevated LDL-C include an unbalanced diet, excess weight, use of certain medications such as corticosteroids and HIV treatments, and genetic factors. Among the genetic causes, familial hypercholesterolemia (FH) stands out. It affects 1 in every 260 people in Brazil and is inherited in an autosomal dominant pattern—meaning it affects 1 in 2 individuals in the same family—and, if untreated, advances the risk of cardiovascular problems by 10 to 15 years

Naturally, the role of LDL cholesterol as a cause of cardiovascular diseases is intensified by the presence of other risk factors such as diabetes, smoking, and high blood pressure

Risk Factors

A diet high in saturated fat, excess weight, physical inactivity, excessive alcohol consumption, stress, heredity, age, and sex. Women tend to experience an increase in bad cholesterol levels after the onset of menopause

Signs, Symptoms, and Diagnosis

High cholesterol does not necessarily present symptoms. In rare cases, excess cholesterol in the blood can lead to the formation of nodules in the tendons (xanthomas) and yellowish patches around the eyes (xanthelasmas). Most of the time, signs only appear as a consequence of fatty plaque buildup in the arteries, when the condition may already be advanced

When it affects the coronary arteries, leading to angina and myocardial infarction, the most common symptoms are chest pain (pressure, tightness, burning, or even stabbing pain), shortness of breath, sweating, palpitations, and fatigue. In the cerebral arteries, neurological symptoms that may indicate a stroke include tingling, paralysis, speech loss, and drowsiness

It is essential to regularly assess cholesterol levels. For individuals with a family history of early cardiovascular disease—that is, in first-degree male relatives (father and brothers) who experienced a cardiovascular event before age 55, and female relatives (mother and sisters) before age 65—or a family history of high cholesterol, monitoring should begin in childhood. From age 20 onward, cholesterol should be measured every five years. If levels are abnormal, more frequent testing may be required, as determined by a physician

Diagnosis and monitoring are done through a blood test that measures total cholesterol, HDL cholesterol, and LDL cholesterol levels. Another type of cholesterol-rich lipoprotein, called lipoprotein(a) or [Lp(a)], may be measured in individuals with a family history of early cardiovascular disease, in cases of familial hypercholesterolemia, or when LDL cholesterol is not effectively reduced by statin treatment

Treatment and Cardiovascular Risk Reduction

The intensity of cholesterol control through diet and/or medication depends on an individual's cardiovascular risk. In high-risk individuals—especially those who have already experienced a cardiovascular event, those with diabetes, individuals with multiple associated risk factors, those with extensive subclinical atherosclerosis (presence of coronary plaques detected by tests such as coronary CT angiography or calcium scoring), or those with familial hypercholesterolemia—intensive LDL cholesterol control is recommended (reductions greater than 50% from the individual's baseline levels)

In individuals with lower risk, control may be less intensive, aiming for reductions of 30–50%. In addition to a diet low in saturated fats and increased intake of mono- and polyunsaturated fats (such as olive, canola, and soybean oils), lifestyle changes are recommended, including smoking cessation, regular physical activity, and weight loss in cases of obesity

There are medications that help lower LDL cholesterol (the "bad" cholesterol) and may also slightly increase levels of HDL cholesterol (the "good" cholesterol). In addition to statins and ezetimibe (a medication that reduces cholesterol absorption in the intestine), powerful biological agents are now available in Brazil to help reduce cholesterol. These are known as PCSK9 inhibitors
It is important to emphasize that, when properly prescribed and used in at-risk individuals, these medications significantly reduce the risk of heart attacks, strokes, the need for cardiac surgeries and angioplasties, and even the risk of death. The benefit is proportional to the individual's risk level, the duration of treatment, and the degree of LDL cholesterol reduction

The benefits of treatment far outweigh the potential adverse effects, such as muscle problems or the risk of developing diabetes (the latter observed only with statins and only in predisposed individuals)

Prevention of High Cholesterol

The best way to prevent an increase in bad cholesterol is to combine physical exercise with a healthy diet, avoiding excessive consumption of saturated fats, coconut and palm oils, too much red meat, egg yolks, butter, dairy products, mortadella, salami, yellow cheeses, and processed foods

Reducing alcohol intake and quitting smoking are also essential for maintaining health and cholesterol levels (smoking lowers HDL cholesterol). However, it is important to remember that in individuals with a genetic predisposition to high cholesterol, diet alone—while helpful—will be insufficient in most cases

By the Einstein Editorial Board