Are We Cuckoo Over Cooking Oils?

Understand the different kinds and which is best

Olive oil and vinegar in bottles on the table / Getty Images

I have long lamented the strange subordination of epidemiology to ideology where diet is concerned. Over recent decades, as a sequence of nutrient fixations has been proposed to us as panacea or scapegoat, the population has divided into camps marching into battle behind their respective banners: low-fat; low-carb; vegan; Paleo; gluten-free; non-GMO. As for me, I have been preaching the gospel of Common Ground for quite some time, and in excellent company I might add.

I have suggested a separation of church and plate, too. Almost every menu is better when dogma-free.

But alas, dogma often prevails, and perhaps nowhere more fervently than in the realm of dietary fats. For today’s purposes, the focus is on cooking oils.

Given what I do, it’s no surprise that I hear about people’s dietary opinions often. But even I am surprised how often passion, and even vitriol, are evoked by the choice of oil for any given recipe. In particular, there seems to be fervent antipathy for canola oil, and ardor for coconut oil. I find both rather misguided.

Opinions Around Canola Oil

The main concern raised about canola oil is that it is a product of genetic modification. The topic of GMO foods deserves attention in its own right, but this isn’t the time. Suffice to say here that genetic modification is simply a method that can lead to products either good, or bad. Any failure to differentiate warrants a reminder about babies in bathwater.

For now, though, the point is this: canola oil is not a GMO food in the first place. The plants from which canola oil is obtained have been modified in the traditional way—selective breeding—that is equally responsible for turning wolves into cocker spaniels. In the case of the oil, it was done to improve the fatty acid profile.

Those efforts succeeded. There are various canola oils on the market, and all have a generally salutary mix of fatty acids, generally featuring oleic acid, the monounsaturated fat that predominates in olive oil. The best canola oils are notably rich in omega-3 fats as well, and may be labeled accordingly.

Where there is cause for valid concerns about canola oil is in the processing of it. Seed oils can be extracted by mechanical, cold pressing, often called “expeller pressed.” However, industrial production is often more efficiently achieved with solvents to extract the oil from the seed. This can involve bleaching and deodorization. The main problem with this is not that anything winds up being added to the oil, but rather changes to the oil itself. Some of the fatty acids can be induced to change their configuration from cis to trans. The chemical details of this are unimportant. What’s important is that trans fats, as we have all heard, aren’t good for us.

The ideal solution is get the benefits of canola oil (in other words, its great fatty acid profile and mild flavor ideal for baked goods) and avoid any potential mischief by getting virgin, cold-pressed canola oil that is not subject to any chemical extraction.

That exists, but is hard to find other than in bulk for restaurants. Often, then, this for me becomes a “don’t make perfect the enemy of good” scenario. There might be a very small amount of trans fat formed in canola oil from processing, but there is often a small amount of trans fat formed in olive oil when it is heated. The overall profile of these oils is highly favorable overall just the same, and that is almost certainly what matters most. Canola oil figures in my own diet accordingly, and I know the same is true for some leading experts in this very area.

Opinions About Coconut Oil

Coconut oil, in contrast, is the current pop culture darling. While it’s true that the particular saturated fat that predominates in coconut oil, lauric acid, is likely to be harmless, I have seen nothing to back up the claims of health benefit. Perhaps more importantly, most commercial coconut oil is processed in much the same way as coconut oil, with all the same potential liabilities. For the same reasons, then, coconut oil should be “virgin” whenever possible. Even then, the claims of health benefit are not based on any meaningful evidence I, or colleagues with whom I have conferred, can find. Virgin coconut oil is a reasonable choice, but I see not basis for adding it to one’s diet preferentially.

Using Olive Oil

The journeyman oil in the kitchen of foodies and health nuts alike is generally olive oil, and with good reason. Olive oil is exceptionally high in monounsaturated oleic acid, can be delightfully flavorful, is supported by a large volume of evidence showing health benefits, and figures prominently in the traditional Mediterranean diets that are among the world’s most healthful. As we have all seen, however, there are countless varieties of olive oil. Here, too, the virgin options are best, as these indicate the least processing of any kind. Extra virgin, cold pressed olive oil is a great choice.

But, of course, no oil is right for every job. Olive oil can be too flavorful for some applications, and has only modest heat tolerance. It works well for sautéing, but certainly not for deep frying. When the temperature gets dialed up high, peanut oil and avocado oil are among the choices able to stand it, and stay in the kitchen.

Factoring in Sustainability and More

Another crucial consideration when choosing oils, or any food, is sustainability. We can no longer afford to leave this off our priority list. One argument this tends to make is for a variety of oils, since undue emphasis on any one favors monocultures, which generally have very adverse environmental effects.

Some specialty oils are wonderfully healthful, but their use is limited by flavor, cost, and shelf-life. Notables in this category are walnut oil, and flaxseed oil, both quite rich in omega-3. A new variety of soybean oil is being introduced into the U.S. market with a fatty acid profile much like olive oil. A product of selective plant breeding, this will make another excellent choice, and take some pressure off the olive supply.

Perhaps the most useful synopsis here is a product of practice rather than preaching. Many of us use olive oil (extra virgin) preferentially. Some of us bake routinely with canola oil but our overall intake is modest. We make occasional use of the other oils noted above.

We have, it seems, gone a bit cuckoo over cooking oils. The heat tolerance of arguments, like that of oils themselves, is often limited. When rhetoric gets overcooked, it tends to generate a lot more heat than light. I am hoping this sheds a little light on the subject, and dials down the temperature.

Special thanks to Dr. Tom Brenna of Cornell University for sharing his expert insights.

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