Americans Have Lost the Plot on Cooking Oil


Every meal I make begins with a single choice: extra-virgin olive oil or canola? For as long as I’ve cooked, these have been my kitchen workhorses, because they’re versatile, affordable, and—most of all—healthy. Or so I thought.

These days, every trip to the grocery store makes me second-guess myself. Lined up next to the bottles of basics such as canola, vegetable, and corn oil are relatively exotic—and expensive—options: grapeseed oil, pumpkin-seed oil, walnut oil. Some are labeled with technical-sounding terms such as “high-oleic,” “cold-pressed,” and “expeller-pressed.” There’s “hexane-free” coconut oil and “naturally refined” avocado oil—if you can make any sense of what these labels mean. Picking an olive oil alone is like trying to plan a European vacation: Greece, Italy, or Spain? Or how about a Mediterranean blend?

The confusion doesn’t end at the checkout counter. Concerns about the smoke point of various oils have prompted terrifying headlines such as “What You Need to Know About Cooking Oils and Cancer.” There are countless guides to selecting the best oil for specific styles of cooking, which discuss distinctions between deep and shallow frying, and the pros and cons of processed oils. And trepidation around “seed oils,” a group that includes common options such as canola, soybean, and corn, has recently gone mainstream: Last year, the national salad chain Sweetgreen announced that it would stop using the oils altogether, citing customer concerns about their healthiness.

Health concerns seem to abound about practically every oil available. So what on earth are we supposed to cook with? “People get truly suffocated by all those details,” Penny Kris-Etherton, a professor emerita of nutrition at Penn State University, told me. Obsessing over the nutritional benefits of cooking oil won’t drastically improve anyone’s diet. In fact, at a certain point, it becomes a distraction from eating well.

You can’t cook without oil or other kinds of fat—or, at least, cook well. Oil is primarily a vehicle for heat; without it, perfectly seared steak, caramelized onions, and crispy potatoes wouldn’t exist. Oil adds flavor too: Extra-virgin olive oil imparts richness to a caprese salad, and a drizzle of sesame oil transforms boiled greens into a savory side dish.

But consuming certain oils and other kinds of fats can be harmful for your health. Whatever oil, or oils, you keep in your kitchen you’ll probably consume in large amounts, so putting some thought into picking a healthy one is worthwhile.

One distinction matters most. Saturated fats, which tend to be solid at room temperature and include butter and lard, are linked to an increased risk of death from all causes, including heart disease and cancer. Their unsaturated kin, usually liquid at room temperature and typically derived from plants, are considered far healthier, because they can lower cholesterol and reduce the risk of heart disease. “What we really want to do is replace the saturated fat in our diets with unsaturated fats,” Kris-Etherton said.

This idea has greatly influenced the oil aisle: You don’t see unhealthy solid fats such as lard and tallow much anymore, and most artificial trans fats were banned in 2015. “We’ve improved the fats in the U.S. food supply a lot in the last 20 years,” Walter Willett, a nutrition professor at Harvard, told me. “What’s left of the liquid plant oils are basically all healthy.”

Let this reassure you: Olive oil is always a good idea, but pretty much all other oils are too. Most plant-based oils contain so-called monounsaturated fatty acids and polyunsaturated fatty acids (PUFAs), which are genuinely good for you. (Maybe you’ve heard of the golden child of PUFAs: omega-3.)

Yes, even seed oils. Fears about these oils are fueled by another PUFA: omega-6, which has a complex link to inflammation. Because seed oils contain omega-6, detractors have claimed that cooking with them can cause many illnesses driven by inflammation, and that it competes with omega-3, diminishing the latter’s benefit. The reality is more nuanced: Omega-6 is associated with some inflammation, but consuming it is also linked to a reduced risk of heart disease and cancer. It does compete with omega-3, but not significantly, Willett told me. Besides, framing these fatty acids as being in opposition is counterproductive. “We need both,” he said.

If seed oils are unfairly vilified, the health properties of certain other oils get too much attention. Polyphenols, compounds known for being great antioxidants and anti-inflammatory molecules, are abundant in olive oil, especially those that have been minimally processed. Labels describing heatless methods for extracting oil, such as “cold-pressed” or “expeller-pressed,” or highlighting a lack of processing, such as “unfiltered” or “unrefined,” are meant to convey an abundance of healthy bioactive molecules. These aspects are worth considering, but they won’t make or break the healthiness of an oil. If it’s unsaturated, any oil is fine, “as long as people use them properly,” Ana Baylin, a nutrition professor at the University of Michigan, told me.

If any concern is worth paying attention to, it’s how to use oil well. Past its smoke point—the temperature at which an oil begins smoking—oil breaks down into harmful by-products. Overheating butter, which has one of the lowest smoke points of all cooking fats, leads to a kitchen full of fumes, and food that has potentially harmful compounds. Frying chicken in extra-virgin olive oil, which has a moderately high smoke point (though low compared with other neutral oils), might be less dangerous—albeit expensive. Overheated oil usually isn’t a problem in home cooking, Willett said, though it can be in commercial deep-fried foods, including those sold at fast-food chains. At home, the more common issues are reusing old oil and storing Costco-size jugs of it for long periods of time, which also creates hazardous by-products (and rancid odors).

For such a basic ingredient, oil can be complicated. But in getting hung up on the minutiae of cooking oil, it’s easy to lose the plot. All of this quibbling may be about optimizing nutrition, but it’s a distraction from the goal: health. If you’re deciding on a good oil to use for a chocolate cake, Kris-Etherton said, “that’s not the issue.” Using the right oil for deep-frying might avoid creating carcinogenic compounds, but it won’t negate the health impacts of eating deep-fried foods. Conversely, “bad” oils can be used in healthy ways. Even saturated fat can be reasonable in the right context. “Fat makes food taste better,” Willett said. If a pat of butter entices someone to eat a wider variety of vegetables and whole grains, its benefits may outweigh the costs. (The foundation of French cuisine is butter, but France has lower heart-disease mortality rates than most other G20 countries. The simplest explanation is that the French eat relatively small portions, Baylin said.)

Cooking oil is hardly the only food that has generated disproportionate levels of nutritional discourse. Minor health aspects of practically every food—sweeteners, caffeine, protein—are constantly surfaced and debated, fueled by an endless cycle of nutrition research and media coverage, and turbocharged by wellness influencers. Those discussions can sometimes lead to meaningful insights. But more often, they’re just confusing. Unless every other aspect of your diet has been optimized to be as nutritious as possible, it probably doesn’t matter if you exclusively cook with extra-virgin olive oil that’s cold-pressed, unfiltered, and imported straight from a pristine Greek island. But hey, if you do, it’ll probably taste amazing.

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