Role of Cholesterol: Its Not Bad After All

A friend of mine sent us through a WhatsApp group this video about cholesterol as something bad for health and for the heart. It is an interview by Esha Chopra, an Indian actress and screenwriter to her father Dr Alok Chopra who is a cardiologist. He spoke about the functions of cholesterol in the body here:

https://www.instagram.com/taseer60/reel/DCsk_0yNxqJ/

After hearing what Dr Alok Chopra said, I decided to add more to what he explained, more than just the role of cholesterol in the body. It is always associated with something bad for health that causes cardiovascular diseases.

Let me first of all put the record straight. Cardiovascular is not about heart attack only. The nature of cardiovascular diseases is multifactorial. It is a group of diseases involving the heart and its blood vessels. They include coronary heart disease – a disease of the blood vessels supplying the heart muscle, cerebrovascular disease – a disease of the blood vessels supplying the brain, peripheral arterial disease – a disease of blood vessels supplying the arms and legs, rheumatic heart disease – damage to the heart muscle and heart valves from rheumatic fever, caused by streptococcal bacteria, congenital heart disease – birth defects that affect the normal development and functioning of the heart caused by malformations of the heart structure from birth, and deep vein thrombosis and pulmonary embolism – blood clots in the leg veins, which can dislodge and move to the heart and lungs.

Neither is cardiovascular disease caused solely by high blood cholesterol. In fact, cholesterol is needed and has a functional role in the body such as it helps build the structure of cell membranes that control what enters and leaves cells.

Cholesterol has its structural, hormonal, and metabolic functions such as it supports tissue repair, serves as a precursor for hormones such as oestrogen, testosterone, and adrenal hormones, and plays a critical role in synthesizing vitamin D

Cholesterol also helps produce bile acids, which in turn helps the body digest fat and absorb nutrients. It helps create bile in the liver as Dr Chopra explained

Cholesterol also helps the body's metabolism work efficiently.

 Low -density lipoproteins (LDLs) although always dubbed as the “bad cholesterol” too have its function in the body. LDLs are the primary carriers of cholesterol in blood because their main role is to deliver cholesterol to both peripheral and liver cells.

Low- and High-Density Cholesterol:

Let me explain a little bit more about Low-Density Lipoprotein (LDL) Cholesterol. 

LDL cholesterol is often termed "bad cholesterol" because high levels can lead to harmful health consequences. Some of the reasons are:

1.      Transport Function and Plaque Formation:

LDL's primary function is to transport cholesterol from the liver to tissues for cell membrane formation, hormone production, and other needs.

When there is excess LDL in the bloodstream, it can deposit cholesterol in the walls of arteries. This leads to the formation of atherosclerotic plaques, which narrow and harden the arteries (atherosclerosis).

2.      Inflammatory Response:

The cholesterol deposits trigger an immune response, leading to inflammation in the arterial walls. This exacerbates the damage and contributes to the progression of cardiovascular diseases.

3.      Oxidation of LDL:

Oxidized LDL is particularly harmful. It attracts white blood cells, which engulf the cholesterol to form foam cells. These cells accumulate and contribute to plaque formation, further increasing the risk of blockage.

Health Risks:

Elevated LDL levels are strongly associated with an increased risk of

1. Coronary artery disease (CAD) 

2. Heart attacks 

3. Strokes 

4. Peripheral artery disease

High-Density Lipoprotein (HDL) Cholesterol - The "Good" Cholesterol:

HDL is considered "good cholesterol" due to its protective effects on the cardiovascular system. Here are some of the reasons:

Reverse Cholesterol Transport:

HDL plays a crucial role in removing excess cholesterol from tissues and arterial walls. It transports this cholesterol back to the liver for processing and excretion via bile.

Anti-Inflammatory Properties:

HDL has anti-inflammatory effects, reducing the risk of inflammation in the arterial walls and protecting against atherosclerosis.

Antioxidant Effects:

HDL prevents the oxidation of LDL, reducing the formation of oxidized LDL, which is a major contributor to plaque development.

Cardiovascular Protection:

Higher levels of HDL are associated with a reduced risk of cardiovascular diseases because it helps maintain arterial health and prevents cholesterol build-up.

The Balance Between LDL and HDL:

The ratio of LDL to HDL is critical in assessing cardiovascular health here:

1.      High LDL and low HDL: Increased risk of plaque formation, heart disease, and strokes.

2. Low LDL and high HDL: Protective against these conditions.

Key Takeaways are:

1. LDL cholesterol becomes harmful when its levels are high, leading to cholesterol deposits, arterial damage, and cardiovascular disease.

2.HDL cholesterol is beneficial because it removes excess cholesterol from the bloodstream, has anti-inflammatory and antioxidant effects, and protects the arteries.

Plaque formation due to oxidative stress and free radical oxidizing LDL-cholesterol is taken up by macrophages and deposited in atheromatous plaques that develop into atherosclerotic lesions.

LDLs have apoB-100 as their sole protein constituent, which interacts with LDL receptors on target cell surfaces. The LDL-receptor complex is then taken up into the cell where LDLs are degraded, and cholesterol is released. This, in turn, regulates the amount of cholesterol produced by the cell. Cholesterol taken up by peripheral cells redistributes to various cell membranes and in this way, becomes involved in metabolic reactions.

Having explained the above, however, the longitudinal cohort Framingham Heart Study (FHS) that started in 1948 initially found that high cholesterol was a risk factor in cardiovascular disease. But later as the study continued longitudinally among the cohort population, it was shown that other factors are also the precipitating factors, not just high cholesterol. They include high blood pressure, unhealthy eating patterns, smoking, physical inactivity, or unhealthy weight. Researchers also know that these conditions can affect people differently depending on a patient’s sex or race. These findings are important because they are behavioural risk factors of heart disease and stroke.

Hence, we also need to consider behavioural patterns of individuals at risk such as unhealthy diet, physical inactivity, tobacco use and harmful use of alcohol. Amongst environmental risk factors, air pollution is an important factor. The effects of behavioural risk factors may show up in individuals as raised blood pressure, raised blood glucose, raised blood lipids, and overweight and obesity. These “intermediate risk factors” can be measured in primary care facilities such as in any government or private health clinics in Malaysia. An elevated HDL-cholesterol level indicates an increased risk of heart attack, stroke, heart failure and other complications. Cessation of tobacco use, reduction of salt in the diet, eating more fruit and vegetables, regular physical activity and avoiding harmful use of alcohol have been shown to reduce the risk of cardiovascular disease. A variety of coloured fruits and vegetables not only are rich in a variety of antioxidants, but some of them are very salicylates or salicylic acid (aspirin) that thins the blood and lowers the risk of heart attacks.

Vegetables rich in salicylates include broccoli, cauliflower, cucumber, mushrooms, radishes, spinach, and zucchini. Vegetables from the nightshade family, like brinjals, and peppers, also contain salicylates. So are tomatoes, apples, grapes, oranges, avocado, berries, cherries, grapes, peaches and plums including most tropical fruits  that are very high in salicylates

Many herbs and spices contain salicylates. Examples of salicylate-rich spices include thyme, rosemary, curry powder, paprika (a spice made from dried and ground red peppers), chilli and garam masala.

Not only salicylates or aspirin is cardio-protective, but studies have shown that salicylates in curry powder colon cancer protective. 

In Malaysia, the Chinese have the highest incidence of colon cancer, followed by the Malays, lest are the Indians whose diet is mainly curries that contain a lot of salicylates.

Most cardiologists would prescribe low doses (100 mg) of aspirin as a prophylactic against heart disease. A standard tablet aspirin contains 300 mg of acetyl salicylic acid. 

 Health policies that create conducive environments for making healthy dietary choices affordable and available, as well as improving air quality and reducing pollution, are essential for motivating people to adopt and sustain are also important. 

 Unfortunately, doctors concentrate only on cholesterol, such that they rampantly continue to prescribe all these statin drugs to reduce blood cholesterol ignoring the patient lifestyle and other more important factors such as free radicals damage. There is over-reliance on statins and the pharmaceutical industry's influence

Despite the availability of high-quality research, there remains a concerning reliance on pharmaceutical materials provided by drug companies, which may inadvertently bias clinical decisions. Often doctors are highly influenced by the pharmaceutical companies to prescribe out-of-date remedies that have nothing to do with their patients’ disease, such as using statins rampantly given for high cholesterol whether or not their patients are at any risk of any cardiovascular disease.

It is concerning that some clinicians may overlook the wealth of knowledge available in peer-reviewed medical journals, potentially limiting the integration of the latest research into clinical practice. The root causes such as lifestyles are never addressed. Clinicians should revisit their approach through published research papers.

Research papers published in medical and scientific journals do not come cheap. Each study can cost anything between RM 100,000 in Malaysia to several hundreds of thousands or millions of US dollars in the United States or elsewhere and they take the combined efforts of multidisciplinary medical and scientific teams many, many years to study especially in longitudinal studies, lesser time in cross-sectional studies.

Maintaining a healthy balance involves lifestyle choices such as a balanced diet (rich in fruits, vegetables, and healthy fats), regular exercise, and avoiding smoking. If needed, medications like statins or other lipid-lowering drugs may be prescribed by healthcare professionals.

Instead, they are highly influenced by the pharmaceutical companies to prescribe out-of-date remedies that have nothing to do with their patients’ disease, such as using statins rampantly given for high cholesterol whether their patients are at any risk of any cardiovascular disease. The root causes such as lifestyles are never addressed.

References for further reading:

Saturday, December 16, 2023

Does Cholesterol cause coronary heart disease?

References on Cholesterol, LDL/HDL, CVD, and the Framingham Heart Study

Here’s an overview and suggested resources:

Cholesterol Functions and Types (LDL & HDL):

Cholesterol is essential for:

Cell membrane structure: It maintains fluidity and integrity.

Hormone production: Precursor for steroid hormones like oestrogen, testosterone, and cortisol.

Bile acids: Helps digest fats.

Vitamin D synthesis: Crucial for calcium metabolism.

LDL ("Bad" Cholesterol): Transports cholesterol to tissues. High levels can lead to plaque buildup in arteries, increasing the risk of cardiovascular disease (CVD).

HDL ("Good" Cholesterol): Removes excess cholesterol from tissues and arteries, transporting it back to the liver for excretion. Higher HDL levels are generally protective against CVD.

Framingham Heart Study:
This landmark study, begun in 1948, explored risk factors for CVD, identifying key contributors like high cholesterol, hypertension, smoking, and obesity.

Framingham Heart Study Website: 

https://www.framinghamheartstudy.org

Article: “LDL vs. HDL Cholesterol in Cardiovascular Risk” (PubMed: 10.1016/j.amjmed.2020.06.020)

NIH on Cholesterol:

 https://www.nhlbi.nih.gov