LDL-cholesterol, often called the “bad cholesterol” deposits cholesterol onto the walls of blood vessels and is associated with the risk of cardiovascular diseases. On the other hand, HDL-cholesterol, the “good cholesterol” keeps the blood vessels clean by transporting excess cholesterol to the liver for excretion as bile.
Saturated fats in meat and fatty dairy products increase bad cholesterol and decrease good cholesterol. Polyunsaturated fats in most vegetable oil lower both the bad and good cholesterol. In contrast, high oleic acid (a monounsaturated fat) content in olive oil lowers the bad cholesterol while maintaining the good cholesterol. The overall lower ratio of LDL to HDL lowers the risk of heart disease.Arteriosclerosis
Arteriosclerosis is a slow process in which cholesterols, cellular wastes and other substances build up on the walls of arteries as plaques. Causes of arteriosclerosis include excess LDL-cholesterol in the blood, high blood pressure, cigarette smoke and diabetes. When plaques burst, blood clots are formed. Blood clots blocking coronary arteries cause heart attacks and sudden cardiac deaths. In the brain, they cause strokes.
Olive oil fights arteriosclerosis in two ways. It reduces the blood’s ability to form clots encouraged by fatty foods. High antioxidant properties of olive oil improve resistance of LDL against oxidation by free radicals, thereby reducing the risk of damaged LDL forming plaques on arterial walls. These factors may explain why the lowest rates of coronary heart diseases are recorded in the Mediterranean countries where olive oil is the dominant source of fats. The United States Food and Drugs Administration (USFDA) has credited olive oil with decreasing the risk of heart disease.High Blood Pressure
Researches have shown that regular consumption of olive oil has a lowering effect on both the systolic (maximum) and diastolic (minimum) blood pressure. Patients on olive oil-based diets for a year have actually cut down by half their daily dosage of high blood pressure medication. This may be attributed to the presence of as many as 5 milligrams of antioxidant polyphenols in every 10 grams of olive oil. Polyphenols are known to reduce risk of heart disease and may be the substance in olive oil that lowers the blood pressure. Antioxidants also increase nitric acid levels, a substance in the body known to reduce blood pressure.view the handbook article