When it comes to cholesterol, most people immediately associate it with the culprit behind cardiovascular diseases, high blood lipids, and coronary artery issues. This notion isn’t entirely wrong, as cholesterol is a common factor contributing to these conditions. However, what many fail to realize is that cholesterol is present in all organs of the body. So, what exactly is this compound? What roles does it play within the body? Why is it both a friend and a foe?
What is Cholesterol?
Cholesterol is a type of steroid fat that resembles wax and is primarily synthesized from Acetyl CoA, appearing in a pale yellow color. Despite its vilified reputation, cholesterol is an essential component for all organisms. It is found in blood lipids and within every cell of the body, participating in the structural composition of cell membranes.
Approximately 75% of this steroid fat is produced daily in the liver (1-2g), with additional quantities produced in other locations such as the intestines, adrenal glands, and reproductive organs. Some cholesterol also originates from dietary sources and other metabolic processes. In an average 68kg individual, around 35g (35000mg) can be produced, with intrinsic production accounting for about 1000mg and dietary intake contributing 200-300g.
Despite being an indispensable substance, cholesterol is sometimes dubbed an adversary due to the existence of two types:
LDL Cholesterol – The ‘Enemy’
This is often referred to as the ‘carrier’ of cholesterol from the liver to the blood. When the levels of this compound increase in the blood, it poses a high risk of fat accumulation and deposition within arteries. This is a primary cause of atherosclerosis. The growing plaques of atherosclerosis can narrow or block blood vessels, and in severe cases, they can lead to dangerous heart conditions such as coronary artery disease or even result in strokes. Due to the potential hazards, this compound is termed the ‘enemy’ of the body.
HDL Cholesterol – The ‘Friend’
Constituting about 20-30% of the blood’s cholesterol content, HDL cholesterol plays a crucial role in transporting steroid lipids from the blood back to the liver, helping remove atherosclerotic plaques from the arteries. This facilitates smooth blood circulation and limits the potential for hazardous complications. Hence, they are the ‘good companions’ that individuals consistently strive to increase.
Unhealthy habits such as smoking, sedentary lifestyles, lack of exercise, and unbalanced diets leading to overweight or obesity can cause an increase in the ‘enemy’ while diminishing the number of ‘good friends’ within the body.
The Role of Cholesterol in the Body
Despite its potential to contribute to various dangerous conditions, cholesterol is an essential substance with crucial roles:
Production of Steroid Hormones
Steroid hormones are indispensable for both development and the maintenance of normal bodily functions. These hormones include the gender-specific estrogen and progesterone in females and testosterone in males. They play a pivotal role in shaping the distinctive characteristics of both genders during adulthood and facilitate reproductive functions. Cholesterol serves as the precursor for the production of these hormones.
Additionally, cholesterol contributes to the synthesis of cortisol, which regulates blood sugar levels and shields the body from infectious agents. Moreover, the hormone aldosterone, responsible for maintaining water and salt balance, is also derived from these steroid fats.
Supporting Immune System Functions
The proper functioning of the immune system owes much to cholesterol. Immune cells gain the ability to combat infections and recover after encounters with harmful agents in the body, thanks to cholesterol. LDL cholesterol directly interacts with dangerous bacteria and viruses, rendering them inactive and preventing their harmful effects on the body.
In cases of bodily injuries, cholesterol is rapidly synthesized and transported to the site of injury for healing purposes. It also prevents the occurrence of potential infections. These diverse roles highlight that while cholesterol can pose risks, it’s an integral part of the body’s functioning, contributing significantly to hormone production and immune system regulation.
Cholesterol serves as a crucial antioxidant in the body, aiding in the swift healing of wounds through the utilization of free radicals present in lipids. In the event of an injury, immune cells employ highly active molecules, including free radicals, to eliminate bacteria and toxins. Any excess free radicals are efficiently managed by cholesterol.
Notably, after surgical procedures that involve cutting arteries, veins, tissues, or cells, the liver swiftly produces this essential fat to distribute throughout the body. This process clears and heals the injuries, leading to a rapid recovery post-surgery.
This is why, when the levels of this compound are low in the blood, particularly after surgery, wounds tend to heal slowly and are susceptible to infection. In severe cases, this could lead to life-threatening infections.
Cell Membrane Formation
Cholesterol is likened to the bricks that construct the foundation of every cell in the body. These steroid fats, in conjunction with polar lipids, participate in the structure of cell membranes, forming a sturdy protective barrier. Any alteration, whether an increase or decrease in this compound, can impact cells, disrupt metabolic and energy production processes, ultimately affecting various functions such as digestion and absorption.
Furthermore, for nerve cells, this compound plays a pivotal role in the formation of the Myelin sheath, which separates nerve impulses.
Supporting Bile Production
In addition to these vital functions, this compound also takes part in the production of bile in the liver. Bile, a greenish fluid, is secreted by the liver and stored in the gallbladder. It contributes to the digestion of lipid-containing foods. After the digestion of fats, bile aids the body in absorption, simultaneously facilitating the absorption of vitamins like A, D, E, and K obtained from food or other sources.
In conclusion, cholesterol, often labeled as a health villain, presents a complex and multifaceted role within the human body. Despite its association with cardiovascular risks, it remains an indispensable component for various essential functions.
From serving as a precursor for vital hormones like estrogen, progesterone, and testosterone, to contributing to antioxidant defenses and supporting immune responses, cholesterol plays a significant role in maintaining overall health. Its involvement in cell membrane formation ensures cellular integrity and function, while its contribution to bile production aids in efficient digestion and nutrient absorption.
John Alen was born in 1971 and is a doctor in the healthcare and psychology fields with many years of experience. He is currently working at easyhealthylive.com, a leading health and psychology blog. Having studied at Y1 National Medical University named after IM Sechenov, John Alen is using his knowledge and experience to help improve the physical and mental health of people in the United States.