The Healing Power of Olive Oil The ancients had it right. Olive oil, first discovered and pressed from olives over 6,000 years ago, has played an important role in a healthy diet. Recent studies have shown that olive oil helps in the prevention of cardiovascular diseases, has a cleansing effect on the digestive system as well as promoting healthy cell development. It also offers protection against many illnesses such as arthritis and cancer. Olive oil falls into the category of oils which are touted for their monounsaturated fats which have been shown to have a protective effect on the entire body. Olive oil is made up of 77 percent of this good fat. Research has also shown that olive oil may lower the risk of heart disease since it reduces LDL (bad cholesterol) while leaving HDL (the good cholesterol) intact.