Lipids refers to a group of biological molecules that are insoluble in aqueous solutions and soluble in organic solvents and includes fats and oils, waxes, phospholipids, steroids (like cholesterol), and some other related compounds. Lipophilic bile acids assist in lipid solubilization. Lipids serve as:
Lipid Profile
Energy reserves
Vitamins and hormones
Structural components of biological membranes.
Cholesterol is a soft, waxy sterol, seen in the bloodstream and cells. It is used to form cell membranes, hormones and so on. Hypercholesterolemia (> 200 mg/dl), an increase in blood cholesterol is a major risk factor for coronary heart disease, thereby leading to heart attack. Cholesterol is transported in the blood plasma of all animals as it is insoluble in blood. It is transported by the lipoproteins, which act as carriers in blood. These are spherical particles which have an exterior composed mainly of water-soluble proteins. Cholesterol is the main culprit in the development of atherosclerosis (plaques that form on the inside of blood vessels) thereby, resulting in heart attacks.
Triglycerides or triacylglycerol is the main constituent in vegetable oils and is the chemical form in which most fat exists in food as well as in the body. Triglycerides in plasma are derived from fats eaten in foods or made in the body, from other energy sources like carbohydrates. The normal levels should be less than 150 mg/dl. Excess triglycerides in plasma is called hypertriglyceridemia. It is linked to the occurrence of coronary artery disease.
Low-density lipoprotein (LDL) or ‘bad cholesterol’ is the major cholesterol carrier in the blood. Excessive LDL cholesterol circulates in the blood, and builds up in the walls of the arteries. It forms plaque, a thick, hard deposit that congest the arteries resulting in atherosclerosis. A thrombus near this plaque obstructs the blood flow to the heart and results in a heart attack. Paralysis is a result of blockage of blood flow to a part of the brain. A high level of LDL cholesterol (160 mg/dl and above) reflects an increased risk of heart disease. The normal LDL cholesterol levels should be less than 100 mg/dl.
About one-fourth of blood cholesterol is carried by High density lipoproteins (HDL).The normal range is > 50 mg/dl. It carries the cholesterol away from the arteries and back to the liver, where it is broken down. HDL cholesterol is known as ‘good cholesterol’. The high HDL level has a protective nature, preventing heart attacks. It removes the surplus cholesterol from plaques and thus slows their growth. A low HDL cholesterol level also may raise stroke risk.
Major dietary sources of cholesterol include eggs, beef and poultry. Plant products (e.g. flax seed, peanut), also contain cholesterol-like compounds, phytosterols, which lowers serum cholesterol. Sunflower seeds contain a substantial amount of linoleic acid which reduces cholesterol deposits on the arterial walls. Substituting sunflower oil for saturated fats like, butter & cream brings a great improvement in health by lowering cholesterol levels.