You don't have to be Popeye to love olive oil

Olive oil has achieved celebrity status in the world of foods, and rightly so. Over a decade ago, researchers discovered that Mediterranean populations that consume large amounts of olive oil enjoy a decreased incidence of coronary heart disease.

If you're like me, you probably assumed that it didn't matter what grade of oil you used as long as it was olive. But a study out of Spain reminded me not to make such wide generalizations. 

Extra-virgin olive oil has very low levels of acidity, and it retains the fatty acids and antioxidants present in the whole olive. Refined olive oil (regular "virgin" and "pure") has the same fatty acid composition, but because of additional processing, it loses the antioxidants present in extra-virgin oil. Researchers at the Institute of Nutrition and Food Technology in Spain asked: "Does it make a difference?"

The study, published in the Journal of Nutrition, divided participants - all of whom had been diagnosed with peripheral vascular disease - into two groups.

The first group was instructed to use extra virgin olive oil for three months, followed by three months of no oil at all, then three months using refined olive oil.

The second group followed the routine in reverse order, using refined oil first, then no oil, then extra-virgin.

Researchers noted that when both groups were using extra-virgin oil, the levels of oxidized LDL ("bad") cholesterol were much lower. Oxidative damage of LDL cholesterol has been linked to development of arteriosclerosis and other cardiovascular diseases.

The researchers credit the presence of antioxidants in extra-virgin olive oil with slowing the oxidation process of LDL cholesterol.

You should use extra-virgin oil in cooking as well as in your salads. It's available in all grocery stores. It costs a little more, but what are a few pennies when your health is at stake?