DEAR DR. BLONZ: I use an extra-light olive oil for my cooking and salads. I have heard that the extra-light type may not have the same healthful benefits that fruity extra-virgin olive oil has. How do the two types of olive oil compare as far as their beneficial properties? -- M.T., Sun City, Arizona
DEAR M.T.: First, let’s look at how the various types are alike. Calorie content is similar in all olive oils. The composition of an olive’s fatty acids is approximately 77% monounsaturated, 9% polyunsaturated and 14% saturated. Extra-virgin olive oil will contain a higher concentration of phytochemicals than oils described as “light.”
Oils tend to be present as triglycerides: three fatty acids bound to glycerol. Fatty acids can begin to split off as olives age; measurements of their free-acidity are used as a gauge of olive quality. Premium olive oils often declare a maximum level of free-acidity on their labels.
The various grades of olive oil are distinguished by the order in which they emerge from specialized presses. The first pressing of the fruit provides the extra-virgin olive oil: the darkest, most flavorful and highest in quality. It also has the lowest free-acid level.
Next out is the virgin olive oil. It has less color, but still contains some of the olive’s fruitiness. The remaining oil is the standard, or “pure” olive oil, which has even less olive flavor. Some companies make a “light” (or “lite”) olive oil, which has little, if any, olive flavor, but is still quite functional. Many companies blend their oils to achieve a more standardized flavor. In Europe, you can even find pomace oil: a solvent extraction of the olive mash leftovers.
Understanding the idea of health benefits between the extra-virgin and the lighter types becomes apparent when you consider that the olive is the olive tree’s fruit. The oil is there to nurture the developing seed until it can begin to grow on its own. Rancid oil is less able to help the seed grow, and the olive has evolved to produce protective components. In the olive, we find some vitamin E and other antioxidant compounds known as polyphenols. These compounds help maintain the olive’s vitality while providing the distinct flavor characteristics detectable in premium oils.
Oil producers from around the Mediterranean, in addition to those in California, speak with understandable pride about the healthful attributes of their olive oil. They often tout that only the extra-virgin olive oil has the right stuff. Once you understand that it is the extra-virgin oil that contains the bulk of the beneficial phytochemicals, you can better appreciate the logic of their message.
Expect differences between, and within, brands of oils. Quality varies with the olive variety, the age of the tree, the geographical area, the method of cultivation, the weather and the length of the growing season. Some producers date the vintage of their oils, while others blend to achieve a consistent taste for their brand. We find the same types of differences with fruits and vegetables, as well as with products such as wine.
While tasting olive oils around the world, I noticed differences in pungency, buttery mouthfeel and peppery aftertaste -- each, no doubt, due to specific chemical compounds. Olives picked earlier in the harvest might have higher levels of certain constituents than those left until the end of the season.
Suffice it to say that sticking with extra-virgin will ensure that you are getting the best that an olive variety has to offer. When possible, taste several to find the type that meets your particular needs. For more, see b.link/bw-olive.
Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.