How to choose olive oil?

Olive oil is a primary source of fat in the Mediterranean diet, but there are several kinds.  So should you go with light, virgin or extra virgin olive oil?

“Extra virgin olive oil is the best choice because it’s the least processed compared with other oil grades, including light and virgin,” says Julia Zumpano, RD, LD, a registered dietitian in Cleveland Clinic’s section of Preventive Cardiology.

Olive oil is produced by grinding olives and extracting the oil by mechanical or chemical means. The word virgin means the oil was produced by the use of mechanical means only.

Extra virgin olive oil, or EVOO, is of higher quality. Among other attributes, it contains no more than 0.8 percent free acidity, and is judged to have a superior taste. EVOO also has a higher nutritional content, with antioxidants that have been linked with better health.

The best use of extra virgin olive oil, which is the most expensive grade, is at room temperature, such as in salad dressings, Zumpano says.

Be careful when cooking with extra virgin olive oil at high temperates, due to its medium-high smoke point.

The smoke point is the temperature that causes oil to start smoking, which produces toxic fumes and harmful free radicals. Different oils have different smoke points, due to their chemical make-up. This means some oils are better suited for cooking at higher temperatures than others. A good rule of thumb is that the more refined the oil, the higher the smoke point.

Heating EVOO higher than 300 degrees can cause oxidation, which kills antioxidants and may create some toxins such as acrylamide, she says.

Acrylamide is a chemical that has been found in certain foods, with especially high levels in potato chips, French fries and other food products produced by high-temperature cooking.

“If you’re going to heat olive oil, do so at the lowest temperature possible and use a more refined version of olive oil such as light, fine, virgin or pure, which is a blend of refined and virgin,” she says. “Or try a more stable oil at high heat such as sunflower, sesame or corn oil.”

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