Among cooking oils, olive oil is touted as one of the healthiest. Olive oil contains monounsaturated fat, which can lower total cholesterol and low-density lipoprotein (LDL or cholesterol in the blood.

Choosing olive oil is a bit like choosing wine. There are different grades, and some are more flavorful and offer more health benefits. The August issue of Mayo Clinic Womens HealthSource offers tips on choosing an olive oil.

Virgin, extra-virgin or refined: Virgin and extra-virgin olive oils tend to be higher in polyphenols (a powerful antioxidant) than are the more-processed, refined olive oils. Antioxidants are considered beneficial because they help the body rid itself of unstable molecules called free radicals and minimize harmful cellular inflammation. A recent study comparing virgin olive oil, refined olive oil, and the combination of both found that virgin olive oil appears to have greater heart-health benefits.

Here are some things to consider when purchasing olive oils:

Freshness: The fresher the oil, the greater the antioxidant properties. Quality olive oils generally include a packaging date. At purchase, it should be no more than one year old.

Price/flavor: Olive oils run the gamut in prices. Shoppers could opt for lower cost, less flavorful virgin olive oil for cooking and invest in the pricier and more flavorful virgin or extra-virgin oils for use in vinaigrettes or drizzling over salads or side dishes.

Storage: Olive oils have a shelf life of about one to two years. Storage in a cool dark place is best.