Are deep-fried vegetables healthier than boiling?

Are deep-fried vegetables healthier than boiling?

While deep-fried foods are often thought to have no nutritional value, a recent study published in the journal Food Chemistry revealed vegetables are healthier when fried in extra virgin olive oil (EVOO) than when boiled in water.

For the study, researchers selected four vegetables often consumed in the Mediterranean diet – eggplant, potato, pumpkin and tomato. They then cooked them three different ways: frying in olive oil, boiling in water or boiling in a combination of water and olive oil.

The researchers then set out to find which cooking method had the highest levels of phenolic compounds, a healthy antioxidant, in the vegetables. They discovered that out of the three cooking techniques, vegetables fried in EVOO produced the highest levels of healthy antioxidants. The amount of antioxidants in boiled vegetables had similar or lower levels of phenolic compounds compared to the raw vegetables.

“We can confirm that frying is the method that produces the greatest associated increases in the phenolic fraction, which means an improvement in the cooking process, although it increases the energy density by means of the absorbed oil,” said Cristina Samaniego Sanchez, one of the study’s co-authors, in a news release. “Therefore, we must stress that frying and sautéing conserve and enhance the phenolic composition.”

Dr. Armand Krikorian, internal medicine residency program director at Advocate Christ Medical Center in Oak Lawn, Ill., says the study raises interesting questions about the benefits of fried foods using EVOO, especially since Mediterranean diets are known for their health benefits.

“It’s important to remember though that the researchers used only vegetables and no meats, fish or poultry in the study,” says Dr. Krikorian. “Also, there has recently been a controversy over the origin and purity of EVOO with serious concerns over fraud.”

A recent report on CBS revealed that 75 to 80 percent of oil sold in America does not meet the legal grades for EVOO, as it often loses luster due to improper storage or tampering.

Dr. Krikorian also warns that while the presence of phenolic compounds may be beneficial, there is much more to a healthy diet than just antioxidants.

“Eating a well-balanced diet combined with regular physical activity should be emphasized for overall better health,” he says.

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  1. Since it says in the above article that oil sold in America does not meet the legal grades for EVOO how would we know that we are buying a legitimate EVOO?

  2. Look for the NOOAA seal on your olive oil.

  3. I agree with Emilio how do we find out that information about the legitimate EVVO’s otherwise this article is not complete and does not help us.

  4. how about steaming the vegetables???

  5. Whenever I consider eating anything fried I consider the calorie density of the oil. I don’t think you can recommend filling your plate with fried eggplant and it being healthy. This seems like a way to add some tasty nutritional food to a balanced diet.

  6. Question as of Bertolucci Extra Light Olive Oil meets the EVOO requirements as I don’t see rating label in your article?

  7. I don’t think you ever “boil” eggplant, tomatos or pumpkin. Silly to even suggest

  8. Nobody has responded to the question of steaming vegetables. So, is steaming veggies better than, worse than or the same as frying them?

  9. Sure would have been nice if they steamed some veggies for comparison… and what about frying in veggie or canola oil, like most people in the U.S. do when employing the frying method? How do these and other oils compare?

    It’s not a shock that boiling all the nutrients out of the veggies did just that… and I agree with another user’s comment about choice of veggies and cooking methods in this study- pretty silly to suggest boiling pumpkin, tomato, and eggplant is a typical cooking method for these foods. This study is interesting and I’m glad EVOO keeps in some phenols when used in frying, but this is not very helpful in deciding the most healthy way to cook your veggies.

About the Author

Julie Nakis
Julie Nakis

Julie Nakis, health enews contributor, is manager of public affairs at Advocate Children's Hospital. She earned her BA in communications from the University of Iowa – Go Hawkeyes! In her free time, she enjoys spending time with friends and family, exploring the city and cheering on the Chicago Cubs and Blackhawks.