Before you start reading this blog, spoiler alert: there are many technical terms used in this article, something I did knowingly to help provide a better understanding. Unfortunately, there was no easier way!
When we hear the word “cholesterol”, our mind immediately starts thinking about LDL, HDL and the risk of “heart disease.” However, the relation between cholesterol, its metabolism and heart disease is very complex. As a result, heart associations of various countries keep reviewing the guidelines continually.
However, not all cholesterol is bad. In fact, it is a very important sterol (waxy substance) required for the structure and smooth functioning of the cell membranes as well as for synthesis of steroid hormones (such as Estrogen and Testosterone), Vitamin D and bile acid. Majority of our cholesterol is synthesized by the body and only some is obtained from the diet. The average recommended intake of dietary cholesterol is around 300 mg/day (equivalent to 2 eggs). However, the western diet is a high fat diet and increases the dietary cholesterol to about 600mg/day.
Let us begin to clear the confusion in our mind about cholesterol and its components.
A) What is the relation between cholesterol and lipoproteins?
The lipoprotein molecule is like a coconut. The outer shell of the coconut contains fat and cholesterol and the inner contains triglyceride and other cholesterol forms. This fat and cholesterol, being water repelling, cannot enter the blood. The function of these lipoproteins is to help with the transport and circulation of cholesterol and other fats in the blood and tissues of the body. There are four key types of lipoproteins:
Chylomicrons- think Mass transit railway (MTR)
VLDL- think Double Decker Bus
LDL- think Minibus
HDL- think Private Car
B) Why is HDL called good and LDL called bad cholesterol?
LDL circulates in our blood stream. It is majorly made up of cholesterol. When excessive amount of cholesterol builds up in the blood it tends to get deposited in the artery.
HDL acts as a scavenger of LDL. It helps in removing about 1/3 to 1/4 of cholesterol from the blood and recycle to the liver.
C) What is the role of VLDL and Chylomicron?
VLDL help in carrying the triglycerides from the liver to the fat tissue whereas Chylomicron transports the absorbed triglycerides from the intestine to the muscles and fat tissue.
D) What are triglycerides and why are they important?
They are the simplest form of fat stored in our body.
While they are not directly related to cholesterol, they are an important health indicator. A high level of triglyceride (body fat), low HDL (limited scavenger) and high LDL (excess cholesterol in blood) predisposes us to an increased risk of stroke and heart attacks.
E) What is Oxidized Cholesterol?
It is the cholesterol that is formed because of interaction with free radicals (highly reactive molecules). The research studies have proven that the oxidized cholesterol from diet (frying fatty food in high temperature oil- Fried chicken, French fries) increases the cholesterol level in the liver as well as the buildup of plaque around the arteries. Oxidized cholesterol is more problematic than the regular cholesterol.
F) Are there certain people who are predisposed to higher cholesterol levels?
Yes. The American Heart Association has guidelines which identify high risk categories. These guidelines were recently updated in 2018 and now include both a larger variety of high risk categories and revised risk assessment procedures. Apart from the regular cholesterol risk levels, the association has new guidelines which include an assessment of lifetime risk in children as young as 9 years old, people with South Asian ancestry, those with family history of heart disease, Metabolic Syndrome, premature menopause, kidney disease and Chronic inflammatory disorder (C- Reactive Protein).
G)Why is pre-menopause being considered as a part of the guidelines?
As women age, the receptors that bind with the LDL decrease in number. Imagine a broken-down minibus. As a result, the transport of LDL to the liver diminishes, leading to higher levels of LDL cholesterol in blood.
H)Are 3 eggs per day bad for you?
Eggs are rich in protein and micronutrients, low in
saturated fatty acids as well as an affordable food. However
different types of scientific studies across various populations
have shown different results. Thus, in this case, science cannot give a conclusive answer yet.
Managing Cholesterol Tips
1. Increasing the consumption of soluble fiber (for example fruits and vegetables) helps in absorption of cholesterol as well as excretion in the form of bile acid.
2. The consumption of insoluble fibre (for example oats, barley, mushroom, seaweed, psyllium) helps in decreasing the insulin response as well as release certain acids that decrease the cholesterol synthesis.
3. Decrease the consumption of red meat as it leads to greater cholesterol deposit in the arteries.
4. Avoid excessive consumption of deep fried food. Instead, go for healthy options like baking, steaming, sautéing and grilling.
5. A healthy regime of regular exercise, avoiding smoking and excessive alcohol all help in reducing cholesterol synthesis and risk of heart disease.
Treat cholesterol like criticism: You need some healthy quantities for the system to function properly but too much of it is unhealthy.