It's easy to get answers about health and nutrition! Just send your question by email to email@example.com and Dr. Harlan will respond to selected questions of general interest. Answers will be posted in the Ask Dr. Gourmet newsletter (sign up now!) and archived in the Ask Dr. Gourmet section of the website.
Is it true that olive oil lose its health benefits when it is used to saute? I read somewhere that it does.
I have read this many times before and there have been numerous people who have written to me about the topic. They have, in fact, been quite adamant that heating olive oil is very bad and unhealthy. The claims range from the heat producing everything from carcinogens contained in the smoke created by heating, to conversion to trans-fats.
Fortunately, the science doesn't support these claims. A group whose report was published in the Journal of Agricultural Food Chemistry heated olive oil to 350°F for 36 hours. (2007 Nov 14;55(23):9646-54) There were some minor changes in the oil, but they found very little oxidation and the smaller antioxidant chemicals were preserved intact. Their conclusion?
"From these results, we can conclude that despite the heating conditions, VOO maintained most of its minor compounds and, therefore, most of its nutritional properties."
There is some research that says using olive oils that are less refined may be better for you: Health and Nutrition Bite: Some Olive Oils are Better For You Than Others.
There are decades of great epidemiologic evidence to prove the value of olive oil. Likewise, there are dozens of great studies proving the safety of olive oil.
Thanks for writing,
Timothy S. Harlan, MD, FACP