Oil is extracted from a paste of crushed olives. RELATED LINKS Take the Healthy Living IQ Quiz Watch Healthy Living Videos

Whether used at the altar for religious rites or in the kitchen as part of traditional recipes, olive oil has held a special place in countless societies throughout history. This sacred slippery substance has remained popular for centuries due to its unmistakable texture and taste, and according current nutritional wisdom, it can be a healthy food choice. To learn a little more about what it is and how it's made, we went to a cooking expert.

Chef Evan Kleiman is the owner of Los Angeles' much-imitated Angeli Caffe, a modern family restaurant serving light, simple and affordable food. She is also the author of several best-selling cookbooks and host of the NPR show "Good Food." Here she offers a basic primer on olive oil:

• The juice of the olive.
  Olive oil, simply speaking is the juice of the olive, which is a fruit. After the olives are picked, they are cleaned, and mashed into a paste. The oil is then extracted from this olive paste.
  
• Virgin: no heat or chemicals.
  For an oil to be labeled "virgin," no heat or chemicals can be used in the extraction process.
  
• Extra Virgin: extremely low in acids.
  If virgin olive oil has an acidity of less than one percent, it can be called "extra virgin."
  
• Good for the heart.
  Kleiman believes that our ancestors instinctively knew that olive oil was a magical food. Today, we understand that including olive oil in a diet can be very healthy. The Oleic acid in olive oil can help maintain a healthy cardiovascular system. Olive oil is also very high in antioxidants.
  
• A good choice among fats.
  Olive oil is a fat, and it has the same amount of calories as other other fats. But because it has many demonstrated health benefits, it can be a better choice than other types of fat.

For more about olive oil, check out the following website:

The Olive Oil Source
www.oliveoilsource.com