Many people think of olive oil as a healthy cooking oil, but is extra virgin olive oil better than regular olive oil?
There are many types of olive oil in supermarkets. Common terms include virgin, extra virgin, cold pressed, light and pure. These words refer to the process used to produce olive oil, with extra virgin olive oil being the least processed. When manufacturers process refined olive oil, they chemically clean it before heating it. These procedures extend the shelf life and lighten the flavor of the olive oil, making it suitable for use in meals.
But processing removes polyphenols from olives, which are antioxidants that have health benefits. In addition, refined olive oil removes not only polyphenols but also vitamins and other natural substances. Although some olive oils have been processed, their calorie and fat content has not changed, that is, all types of olive oil contain beneficial fats, especially monounsaturated fats (Omega 9), which provide 120 calories per tablespoon.
Due to the least amount of processing, extra virgin olive oil has the highest polyphenol content. But after all, olive oil is just an edible oil, and the daily food amount is not much, so does higher polyphenol content equal more beneficial?
An interesting recent study on olive oil looked at the role of the Mediterranean diet in diabetes and related metabolic diseases, stabilizing blood sugar and improving inflammation. Olive oil is a staple of the Mediterranean diet, so the researchers wanted to see if extra virgin olive oil was actually healthier than regular olive oil.
Spanish researchers recruited 91 obese and prediabetic patients and randomly assigned them to their main cooking oil. The researchers provided participants with the oils, but did not instruct them how or how much to eat. The participants ate their prescribed cooking oil for 30 days and made no specific changes in lifestyle or physical activity. After 30 days, there will be a washout period of 15 days, and then another cooking oil change for another 30 days.
During the study, the researchers measured the following indices: blood levels of anti-inflammatory and pro-inflammatory cytokines, measurements of “oxidative stress”, body weight and measures of metabolic status, including fasting blood glucose, insulin, A1C and fatty acid profile.
The results showed that switching from regular processed olive oil to extra virgin olive oil improved markers of “oxidative stress” and inflammation, significantly reduced inflammatory cytokines, and increased total antioxidant quality. In addition, there was a reduction in body weight when consuming both types of olive oil, but the weight loss was more significant in the group consuming extra virgin olive oil.
Although the number of people taking part in this study was small, it will be determined in a larger study in the future. However, there is strong evidence that extra virgin olive oil is higher in antioxidant polyphenols. If the price of both is similar at the time of purchase, you may want to choose extra virgin olive oil. (This column is published every Friday)
Written by: Zeng Xinxin Registered Dietitian, Speaker, Writer. Facebook page: Gloria Tsang
Column Name: What Xinxin Eats