HDL Cholesterol
High blood pressure or hypertension is known as the "silent killer" because it often goes undetected until severe damage has been done to the heart and cardiovascular system. One of the protective benefits of olive oil is that it decreases many risk factors for heart disease. The FDA now recommends replacing certain dietary fats with 2 tablespoons of olive oil a day to see these heart benefits. Olive oil has been shown to decrease bad LDL (low-density lipoprotein) cholesterol. Fats that increase LDL cholesterol include saturated and trans fats from butter, animal fat and partially hydrogenated oils. Olive oil can increase HDL or high-density lipoprotein, also known as good cholesterol.
Polyphenol Activity
Olive oil is high in a class of antioxidants known as polyphenols. Many herbs, fruits and vegetables contain free-radical-fighting polyphenol antioxidants. The polyphenols in olive oil protect LDL cholesterol from oxidation. When too much oxidation occurs in blood vessels, they can become calcified or rigid, which in turn increases blood pressure. This hardening of the arteries is called atherosclerosis, and it is a major risk factor for all forms of heart disease. By reducing oxidation in arteries, olive oil's polyphenols also decrease the risk of high blood pressure.
Oleic Acid
Olive oil is high in monounsaturated fatty acids. One such fat, known as oleic acid, makes up 55 to 80 percent of olive oil. An omega-9 fatty acid, oleic acid has been shown to contribute to the body's membrane lipid structures. Our bodies make lipid (fat) components, such as cell membranes, out of the fats we ingest. Strengthening membranes and other tissue of the body, particularly in blood vessels and arterial walls, can help to prevent high blood pressure. In a Naples, Italy, study, six months of olive oil use decreased systolic blood pressure from 134 mmHg to 127 mm Hg, accompanied by a diastolic decrease from 90 mmHg to 84 mmHg. The olive oil group was also able to decrease blood pressure medication by 48 percent. The increased oleic acid was seen as a major factor in the result.
