BUYING GUIDE

Buy cold-pressed or cold-extracted olive oil. Adding heat to the olives allows producers to extract more oil from each olive, but the heat can damage the antioxidants and thus reduce the health benefits.

Buy extra virgin olive oil, sometimes known as EVOO. What else is out there? “Virgin olive oil” is not treated with heat but has less-rigid production standards than extra virgin. “Olive oil” (no “extra virgin”) may be heat-treated or refined with chemicals. “Light olive oil” is refined to get a more neutral flavour. “Pure olive oil” is misleading because it sounds good but usually denotes the lowest-quality olive oil. Pure olive oil does not need to be extra virgin, so it can be refined or treated with chemicals. This allows it to be a more versatile cooking oil with a higher smoke point but leaves it with fewer nutrients.

A dark glass container protects the oil from oxygen and light. Avoid the bottles on the top shelf, as they may be older or damaged by the light and heat above. Look for a harvest date and buy within 15 months of this date to be sure that no oxidization has taken place.

The organic label does not necessarily assure high quality, but it does mean the olives have been grown under standard organic practices, which will mean no pesticide residue. A “product of Italy” or “product of Spain” label means that the bottle is packaged in Italy or Spain; it does not mean that all of the olives were grown there. (That said, there doesn’t seem to be any proof that olive oil from any specific country is healthier.)

COOKING GUIDE

Cook at low temperatures, as cooking at high heats causes olive oil to smoke, which leads it to change structure. The polyphenols and vitamin E are destroyed at high heats, and free radicals that can damage our bodies are released. If you need an oil for high-heat cooking, grapeseed oil is a good alternative.

Toss on salads, pastas, vegetables and other room-temperature dishes.

Store in a cabinet to avoid light and heat from a nearby stove or oven.

A note to my kids who teased me in the grocery store: Just as you spend hours deciding which new Nike shoe you want for Christmas, I have good reason to spend time picking out my olive oils. Your shoe choices make a style statement, which is important to you as a teenager, while my olive oil choices make an impact on our health, which is important to all of us at every age.