Cholesterol is a substance produced from the liver from certain fats in the diet. A small amount is derived from animal based foods such as meat and egg yolk. Educated people are getting increasingly aware about "high cholesterol”, but they also need to know that all cholesterol is not bad.

As other substances, cholesterol is also needed by the body. It acts as a binding substance for cell membranes, provides cover to body cells. It also helps in manufacture and storage of sex hormones and fat soluble vitamins like A.D and E. It aids in manufacture of bile acids, which are essential for digestion of fats in the body.

Cholesterol is transported in the body bound with proteins(lipoproteins). The names of different kinds of cholesterol are based on density of lipoproteins.

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 heart and brain, increasing risk of heart diseases, heart attacks and strokes. HDL also pushes back LDL from the blood vessels into the liver for processing.

The amount and type of cholesterol the body makes, is usually dependant on genetic and life style factors including the diet consumed in 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, protease inhibitors used for treating HIV can also raise blood lipid levels including HDL.

The risk for developing a heart problem in the coming few years can be worked out for a person, based on age, gender, body weight, blood pressure and even amount and type of cholesterol present. Therefore a person wishing to be healthy should aim for keeping his total cholesterol in normal range (up to 200-250mg/dl) and 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, as well as 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 the bad cholesterol are dairy products like butter and cheese, deep fried foods, ice creams, cakes, meat products other than fish, poultry products, among others.

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. One should aim to exercise for minimum 150 minutes per week. Being physically active throughout the day, is also beneficial.

Alcohol and cigarette smoking are harmful for the body in multiple ways. They also contribute to clogging of blood vessels, raising levels of bad cholesterol, hence should be avoided.

A word of caution here, excess of good cholesterol is also not good for the body. Usually if sufficient amount of cholesterol is present in the body, production of new cholesterol particles is suppressed by the liver. But this feedback system may not be very effective, if load of cholesterol put on it is heavy. Moreover if one consumes food promoting good cholesterol, more than what is needed, the extra amount is converted into fat and deposited in the body, contributing to obesity. This negates the beneficial effects of good cholesterol.