Cholesterol is waxy, fat-like substance found in the walls of cells in all parts of the body. The body also uses cholesterol to make hormones, bile acids, vitamin D, and other substances.
Cholesterol comes from diet and also the body makes the cholesterol needed. As Cholesterol is not water-soluble, it circulates in the bloodstream in packages called lipoproteins, which have fat (lipid) inside and protein outside.
Two main kinds of lipoproteins carry cholesterol in the blood:
- Low density lipoprotein (LDL) which is also called the “bad” cholesterol because it carries
cholesterol to all the tissues, including the arteries. Most of the cholesterol in the blood is in the LDL form. The higher the level of LDL cholesterol in the blood, the greater is the risk for heart disease.
- High density lipoprotein (HDL) which is also called the “good” cholesterol because it carries cholesterol from tissues to the liver, which removes it from the body. A low level of HDL cholesterol increases your risk for heart disease.
- Triglycerides which are produced in the liver, are another type of fat (not cholesterol) found in the blood and in food. Recent research indicates that triglyceride levels that are borderline high (150 -199 mg/dL) or high (200-499 mg/dL) may increase your risk for heart disease. (Levels of 500 mg/dL or more need to be lowered with medication to prevent the pancreas from becoming inflamed). A triglyceride level of 150 mg / dL or higher is also one of the risk factors of the metabolic syndrome.
If there is too much bad cholesterol in the blood, some of it becomes trapped in the artery walls. Over time, this builds up and is called plaque. The plaque can narrow vessels and make them less flexible, a condition called atherosclerosis or “hardening of the arteries”. This process can happen to blood vessels anywhere in the body. When atherosclerosis affects the blood vessels supplying the heart leading to their narrowing, it is called coronary artery disease. When these plaques become unstable as some of them do, they produce sudden occlusion of the blood vessel supplying the heart leading to the condition called a heart attack.
Factors that affect cholesterol levels in the blood:
- Factors that cannot be changed: heredity, age, sex.
- Factors that can be controlled:
» Diet: high Cholesterol, Saturated fats, and Transfats in the diet raise cholesterol levels.
» Overweight: overweight increases both LDL and Triglycerides and decreases HDL
» Physical inactivity: it increases LDL and decreases HDL
Cholesterol level in blood can be lowered by:
Therapeutic lifestlye changes :
- Decrease saturated fat – it is found in the greatest amount in foods from animals like meat,
organ meats like liver and kidney etc., poultry with skin, whole-milk dairy products including full
fat cheese and ice creams, coconut oil, palm oil, etc.
- Decrease transfats – it is found in hydrogenated oils like Dalda and Vanaspati ghee;
bakery products like crackers, biscuits, cookies, doughnuts, cakes; foods fried in hydrogenated
shortening such as French fries, fried chicken, potato chips; Indian fried snacks, bhatura, parantha, puri; instant noodles; frozen food, etc.,
- Decrease cholesterol – it is found in high quantities in whole milk products, egg yolk, poultry
with skin, fatty meat, and organ meat.
Increase the share of unsaturated fats – they occur in vegetable oils mostly nuts, olives,
avocados, fatty fish such as salmon.
- Consume good quantities of fruits, vegetables, and whole-grain
- Consume fat-free milk and milk products, fish and skinless chicken.
Become Physically Active:
- Becoming physically active has many benefits. Lack of physical activity is a major risk factor for heart disease. It affects your risk of heart disease both on its own and by its effects on other major risk factors, Regular physical activity can help you manage your weight and in that way, help lower your LDL. It also can help raise HDL and lower triglycerides, improve the fitness of your heart and lungs, and lower blood pressure. And it can reduce your risk for developing diabetes or if you already have the condition, lessen your need for medication.
- You don’t have to run marathons to become physically active. In fact, if you haven’t been active, the key to success is starting slowly and gradually increasing your effort. For instance, start by taking a walk during breaks at work and gradually lengthen your walks or increase your pace. Try to get at least 30 minutes of a moderate – intensity activity such as brisk walking on most and preferably all days of the week. You can do the activity all at once or break it up into shorter periods of at least 10 minutes each.
Maintaining a healthy weight:
- Being overweight or obese increases your chances of having high triglycerides, a low HDL, and a high LDL. You’re also more likely to develop high blood pressure, diabetes, heart disease, some cancers, and other serious health problems. If you have excess weight around your waist, you’re more likely to develop metabolic syndrome.
- Losing your extra weight reduces these risks and improves your cholesterol and triglyceride levels. Body mass index is a good way of knowing the status of our weight. It is calculated as weight (in kgs)/ height (in mts)2. The desirable BMI for Indians is 18 to 23. A BMI of 23 to 25 is classified as overweight and more than 25 as obesity.
Various medicines are now available for managing the lipid levels in the blood like statins, fibrates, niacin, Omega 3 fatty acids, ezetimibe etc. Of them, Statins are the most important ones with a proven mortality benefit in primary and secondary prevention of coronary artery disease. They may be prescribed to you by your physician or cardiologist as appropriate depending on your lipid profile report and your risk factor level.
Causes of raised triglycerides are overweight/obesity, physical inactivity, cigarette smoking, excess alcohol intake, and diet very high in carbohydrates (60 percent of calories or higher). To reduce blood triglyceride levels: control your weight, be physically active, don’t smoke, limit alcohol intake, and limit simple sugars and sugar-sweetened beverages. Sometimes, medication also is needed.
Target lipid levels:
LDL cholesterol: Less than 100 mg/dl (less than 70 mg/dl in CAD pts)
HDL cholesterol: More than 40 mg/dl in males and more than 50 mg/dl in females.
Triglycerides : Less than 150 mg/dl