Cholesterol is produced by the liver from certain fats in the diet, with a small amount derived from animal-based foods like meat and egg yolk. People are becoming increasingly aware of the risks of "high cholesterol” and its impact on heart health.
But cholesterol is also needed by the body, like other substances. It acts as a binding substance for cell membranes and provides cover to body cells. It also helps in the manufacture and storage of sex hormones and fat-soluble vitamins like A.D and E. It aids in the manufacture of bile acids, which are essential for the digestion of fats in the body.
Cholesterol is transported in the body bound with proteins (lipoproteins) and different kinds of cholesterol are based on the density of lipoproteins with which they are bound. High-density lipoprotein (HDL) cholesterol is the good cholesterol. It protects against heart diseases. In contrast, low-density lipoprotein cholesterol (LDL) is considered bad, because it tends to choke blood vessels, including those of the heart and brain, increasing the risk of heart diseases, heart attacks, and strokes. HDL pushes back LDL from the blood vessels into the liver for processing.
The amount and type of cholesterol the body makes is usually dependent on genetic and lifestyle factors, including the diet consumed by the majority of the people. Few individuals can have abnormal lipid levels due to disease conditions like diabetes, hypothyroidism, pancreatitis, obstructive jaundice, or biliary cirrhosis.
Drugs like anabolic steroids, oral contraceptives, and protease inhibitors used for treating HIV can also raise blood lipid levels including HDL.
The likelihood of developing a heart condition in the next few years can be calculated for an individual, considering age, gender, weight, blood pressure, substance abuse, and cholesterol levels.
A person aiming for good health should strive to keep their total cholesterol within the normal range (up to 200mg/dL), have high levels of HDL (ideally 40-60mg/dL), and low levels of LDL (less than 130mg/dL). A lipid profile can be ordered by the doctor, which shows levels of total blood cholesterol, HDL, and LDL.
One’s daily diet should include food substances, which help augment HDL cholesterol levels in the blood. These are vegetable oils like olive oil, sunflower oil, vegetables, beans, whole grains, nuts, fruits like avocado, apple, prune, etc., and fish.
LDL cholesterol is present in transfats which are present in ready-to-eat fast foods like chips and animal fat used for cooking. Other food substances that can increase levels of bad cholesterol are dairy products like butter and cheese, deep-fried foods, ice cream, cakes, meat products other than fish, poultry products, etc.
Apart from diet, regular physical exercise is helpful in keeping total cholesterol within normal range and increasing levels of good cholesterol. It helps to burn body fats and also helps to regulate the lipid levels. Being physically active throughout the day is also beneficial.
Alcohol and smoking are harmful to the body in many ways. They also contribute to clogging blood vessels and raising levels of bad cholesterol, so they should be avoided.
Be cautious, as an excess of good cholesterol is also not good for the body. When the body has a sufficient amount of cholesterol, the liver suppresses the production of new cholesterol particles.
However, this feedback system may not be very effective if the cholesterol load is heavy. Additionally, consuming food that promotes good cholesterol in excess results in the extra amount being converted into fat and deposited in the body, contributing to obesity, which negates the beneficial effects of good cholesterol.
Dr Rachna Pande is a specialist in internal medicine.