In biblical times, almost every village had an olive grove and olive press. In Deuteronomy, Palestine is described as a land of olive trees, fig trees, and pomegranates. Olives and olive oil are commonly used in Mediterranean cuisines. Olive oil tends to be more expensive than other vegetable oils because of the labor intensive method of harvesting the crop.

Olives and olive oil vary greatly in flavor, depending upon the variety, time of harvesting, and processing techniques. Green olives are unripe and are usually preserved in brine, while ripe olives are black, soft, and oily. The oil is used for cooking as well as in salad dressings, mayonnaise, sauces, and dips.

Extra virgin olive oil is made from slicing the olives and soaking them in water near room temperature. Alternatively, olives can be crushed by a revolving stone. The olive oil extract has a pleasant flavor due to its very low acidity. Extra virgin oil has its own characteristic flavor, dependent upon its origin. Spanish oils are fruity; the Italian are peppery, while French olive oils are sweet and the Greek oils have a leafy aroma.

Southern Europeans, living in the Mediterranean region, have much lower rates of cardiovascular disease, cancer, and diabetes than Northern Europeans and Americans. One reason given for this advantage is the predominant use of olive oil in the Mediterranean diet rather than fats of animal origin. Olive oil is largely monounsaturated fat and has a composition similar to that of avocado oil. In addition, virgin olive oil has a high level of phenolic antioxidants that enables the consumer to enjoy lower blood cholesterol levels, lower risk of blood clots, and a lower risk of breast and bowel cancer.

In addition, the use of olive oil enables one to better control their blood glucose levels and HDL cholesterol (the "good cholesterol") levels are not decreased as occurs with many plant oils. French patients who survived a heart attack had a reduced risk of a second heart attack when fed an olive oil-rich diet.

Olive oil may be refined to remove excess acidity, color, or flavor. The refined oil is then blended with virgin oil to give a neutral-tasting oil. This is marketed as pure olive oil. Unfortunately, a large percentage of the health-promoting phytochemicals are removed in the processing of the oil.

California is the major producer of olives in the United States. The olives are used principally for canning. While most of the calories in an olive come from fat, four ripe olives contain only 15 calories. Green olives, which are picked in the fall before they reach maturation, have less than half the calories of the mature black olives.

The increased life expectancy and low rates of chronic diseases among the Southern Europeans may be due in part to their simple, physically active lifestyle, and the unique Mediterranean diet that includes a regular use of olive oil, along with bread, vegetables, and fruit.

Winston Craig, R.D., Ph.D., is a professor of nutrition at Andrews University.

Four olives contain only 15 calories.

Olive oil protects you against heart disease and cancer.

The Mediterranean diet is associated with greater longevity.