Cooking With Olive Oil May Cause Cancer

frying in olive oil

It started in the 1990s: Someone told me about all the health benefits of olive oil, and I was hooked. Favorite easy dinner? Something green sauteed in olive oil. Guilt-free way to make chips? Toss thinly sliced vegetable with olive oil, and roast. My formative cooking years were marked by non-stick pans and tablespoon-portions of olive oil, and if the recipe called for butter, I nixed it in favor of the healthy fats. Extra virgin olive oil (or EVOO, thanks to Rachael Ray) has always been my religion in the kitchen.

That’s why at an event last month hosted by Organic Avenue, I was shocked, skeptical, and potentially devastated when the panel of expert speakers on “inner beauty” all agreed that cooking with olive oil is bad for you. The first to slander EVOO was New York-based nutritionist Christian Henderson. “Never cook with olive oil,” she said. “There’s a reason why oils are cold-pressed; they break down at higher temperatures, and they’re not good for you.” Boom.

All I could think was: WTF? Was this lady off her rocker, or had I been given bad health advice by magazines, chefs, and family members for the past two decades? When someone asked Henderson for suggestions about what to use instead of EVOO, her answer confused me even more: “Cook with vegetable broth and then finish with olive oil at the end,” she said. “Or, I like to use butter, because it can handle higher heats.” BUTTER? Had this woman ever read butter’s nutrition information? Doesn’t she know how bad all that saturated fat is for your health?

To find out if cooking with EVOO would really wreak havoc on my health, I got in touch with Henderson. Why is she challenging the conventional wisdom that olive oil is beneficial for you, I asked? And could cooking with butter really be healthier than olive oil? Henderson, a registered dietitian and certified dietitian nutritionist who runs Pure Nutrition in New York City, was more than happy to explain her side of the story:

It’s a confusing topic, definitely. You watch The Food Network and they’re cooking with oil, and even this morning I saw Joy Bauer on The Today Show cooking with olive oil. I cook; I’m not a raw foodist. I’m actually a very conventional eater. But I first found out about this when I was working at NYU Medical Center and went to an anti-cancer talk. They were listing the top things you can do to avoid getting cancer, and a huge one was not cooking at high temperatures. I was really surprised.

She then explained that there’s some real science behind the idea that cooking with oil is bad:

It’s all about the smoke point. Smoke points vary for different oils, but it’s the temperature at which the oil structure changes and begins to decompose and lose flavor. It’s also going to go from something healthy to something unhealthy. Cooking at high temperatures decreases flavor and nutritional value, and can cause the development of carcinogens (at high enough temperatures).

What Henderson said didn’t seem so off-base. In fact, a recent New York Times article touched on the same science, but from the perspective of taste, not health. “Is It Time for an Oil Change In the Kitchen,” by the Curious Cook, Harold McGee, explained that, once cooked, many oils taste the same. (And some of them taste terrible.) “Partisans of the olive maintain that a high-quality extra virgin oil brings its special flavor and health benefits to foods cooked in it. But does it make enough difference that it’s worth a tenfold premium in price?” McGee’s article asked. To find out, he heated 15 different kinds of oil, including four types of olive oil, and served them to trained olive oil judges to find out what effects heat had on their taste. The result? “We were surprised at how thoroughly heat obliterated the flavors in cooking oil until they all tasted more or less the same. Even prize-winning (and costly) extra virgin olive oils lost much of what makes them special.”

While taste is a major factor in what I eat, I’m more concerned about my $30 bottle of organic olive oil possibly giving me cancer than about the degradation of flavor. But McGee’s article just supports the idea that at high temperatures, our heart-healthy, gourmet oils start losing their price-worthy benefits.

In fact, several studies have explored the impact of heat on oil and food. Two of the most dangerous carcinogens created by cooking at high temperatures are aldehydes and acrylamides. Aldehydes are a toxic chemical released into the air during high-temperature cooking, like flash-frying, and can be absorbed into the airway while cooking. Acrylamides are another carcinogen found in foods cooked at high temperatures, but they’re typically associated with high-carbohydrate foods that have been fried or broiled. (Think crispy, blackened hash browns.) Both types have been associated with higher cancer rates, and according to the FDA, at every high exposure, aldehydes have even been linked to nerve damage.

So are we supposed to forever eat lukewarm soup and steam our vegetables, instead of fry them? A world without pan-frying my kale in olive oil sounds pretty bleak to me, so I turned to Blisstree contributor, nutritionist, and Foodtrainers founder Lauren Slayton for a second opinion. She had a slightly more moderate point of view:

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    • geezertron

      it’s not as widley know as it should be, but extra virgin olive oil is in no way intended for frying/cooking. if you read the label on any bottle of ‘extra virgin’ olive it usually states that it’s suitable for dressings, salads and the like, and mentions nothing of cooking (for exactly the reasons mentioned above).
      It’s strait Olive oil WITHOUT the ‘extra virgin’ part that is intended for frying, as again is stated on the label. This is a very important element with the different types of olive oils that isn’t ever really made clear enough, and most often fails to be mentioned at all….!

    • greenznick

      wiping your ass with toilet paper causes cancer too…..

    • MikeCatrina

      F.Y.I. whoever came up with that theory better go back to school.We have used Extra Virgin Olive Oil for who knows how long and there is no such thing that says that it is no good for as a matter of fact it is the best thing to use especially for people with certain conditions until you are certain about this do not print anything negative about this.

    • grammyshawna

      Wow. Intelligent article until the gratuitous use of the f-bomb. C’mon. Credibility went right out the window. Shame on you.

    • Dormi

      Take a look at this page, which refers to research
      http://cooking.stackexchange.com/questions/6148/is-cooking-with-olive-oil-bad-or-toxic
      It suggests that all oils can be problematic when they go above their smoke point and that extra vrigin olive oil holds up better than most and produces fewer aldehydes under stress.
      Researchers investigated processes of oxidative degradation – notably that caused at 70?C with ventilation – of a broad group of oils with very wide-ranging compositions. Another degradation process studied was that which is caused by microwave action that does not heat greater than a temperature of 190 ?C.

      In both processes deterioration of the oils takes place. In the first type of process (70 ?C with ventilation) hydroperoxides are first produced and subsequently aldehydes. In the second kind of process (microwave) it is basically aldehydes produced. It has to be pointed out that both the oxidative conditions and the composition of the oil determined the velocity of the degradation and both the nature and concentration of the compounds produced.

      These studies have shown, for the first time, that degradation of lipids in foods can produce toxic oxygenated aldehydes. These compounds, well-known in medical studies for their geno- and cytotoxic activity, considered as markers of oxidative stress in cells as well as being causal agents of degenerative illnesses, had not previously been detected in foodstuffs.

      Researchers have shown that some oils produce these toxic substances in greater quantities and at a greater rate. *Virgin olive oil was, amongst all the oils studied, that which took longer to produce this type of compounds and produced a lower concentration of them.*

      It is certainly good for us to consume more and less heavily processed animal fats. However the information that butter has a higher smoke point than virgin olive oil is contradicted by research I received from a technician in the field, which gave a smoke point of 420F……. 216C for virgin olive oil and only 350F……. 177C for butter. I think the main safety point is not to overuse oils for frying and not to heat them to burning point. Cooking in broth seems a good idea and many cultures do this.