Frying veggies doesn’t just make them more delicious—it actually makes them healthier than boiling them in water. These are the findings of a most excellent new study out of the University of Granada, Spain.
The study was conceived to test whether common cooking methods destroy antioxidants and phenols in the vegetables that form a large part of the Mediterranean diet. It is thought that cooking reduces vitamins C and E, along with beta-carotenes and phenols which, says the study’s lead author Jessica del Pilar Ramírez Anaya, are an important non-nutritive antioxidant.
In the tests, potato, tomato, eggplant and pumpkin were boiled, fried in EVOO, or boiled in a mixture of oil and water. Levels of "moisture, fat, dry matter, and phenol contents, along with their antioxidant capacity" were measured before and after cooking.
The result? Frying in extra-virgin olive oil raised the levels of phenols in the food, because extra phenols are transferred from the oil itself. "The presence of EVOO in cooking increased the phenolics identified in the raw foods as oleuropein, pinoresinol, hydroxytyrosol and tyrosol, and the contents of vegetable phenolics such as chlorogenic acid and rutin," says the study.
The other surprise finding is that cooking in general doesn’t lower the levels of antioxidants. While EVOO contributes its own goodies to the target vegetable, the worst that can be said of boiling in water is that it brings, as Alton Brown might say, nothing to the party. Remember this next time you’re arguing with a raw-food zealot—cooking doesn’t destroy antioxidants.
There is one obvious downside to frying your food in oil—the calories. "We can conclude that frying in EVOO [can] be considered an improvement in the cooking process," said study co-author Cristina Samaniego-Sánchez, "although it also increases the calorie density of the food because of the amount of oil absorbed."
So, if calories aren’t your worry, then frying you food will not only make your dinner more delicious, it will also make it healthier, antioxidant-wise at least. And before you go, maybe you’d like to know why olive oil gets the absurd designation of "extra virgin"?
In Spain, "extra" means "high quality" when used in this way. For instance, you might find fresas (strawberries) extra in the market. It’s similar to the Class I and Class II designations used for fruit and vegetables in the U.K. The absurdity, then, comes from the translation of the word extra. It would more correctly be translated at high-grade olive oil, or first-quality olive oil, but that wouldn’t be nearly as much fun.