How to choose a healthy cooking oil
Some of the messages about the health benefits and drawbacks of certain oils can be confusing. Coconut oil, for instance, has soared in popularity in recent years, with its proponents making unproven claims that it can do everything from sparking weight loss to preventing Alzheimer’s. On the other end of the spectrum, there’s a hashtag making the rounds on social media — #seedoilfree — referring to the mistaken idea that seed oils such as sunflower and canola oil are toxic.
And then there’s the question of price. All prices, even at the “basic” end of the oil spectrum, have hit record highs in the past two years because of factors that include the invasion of Ukraine, labor shortages, drought in some parts of the world and too-wet weather in others, says Mintak Joo, a senior research analyst at Gro Intelligence, an agriculture data platform.
But choosing and using (and saving on) cooking oil doesn’t have to ratchet up your stress levels or harm your health. Here’s the science-backed, dietitian-approved, recipe-friendly skinny on cooking oil.
How are cooking oils made?
Cooking oil starts out as the natural oil found inside a wide variety of plants: seeds (such as soybean, sunflower, sesame, safflower and grapeseed); fruits (palm, olive and avocado); grains (corn and wheat germ); and nuts (walnut, pecan, hazelnut and others). “Vegetable” oil is usually soybean oil or a blend of oils such as soybean and canola.
This natural oil is squeezed from the plant using mechanical methods, such as putting the seeds or fruit through a press known as an expeller. Manufacturers also may use chemical solvents and high heat to extract the oil, or a combination of mechanical and chemical methods. Many oils are then “refined,” using more chemicals and high temperatures. This step removes impurities and helps create oil with a more uniform color, a more neutral taste and better shelf stability.
Refining has a downside: Exposure to high heat can destroy some of an oil’s nutrients, such as antioxidant polyphenols, says Dariush Mozaffarian, dean for policy at the Friedman School of Nutrition Science and Policy at Tufts University.
Some mass-produced oils may have antioxidants added back in after processing, but for a more nutrient-rich oil, look for the word “unrefined” on the label, or “cold-pressed,” which indicates that the oil was pressed at a temperature no greater than 120 degrees. And choose oils labeled “organic” if you’d like to avoid those that have been through chemical processing.
How do I choose a healthy cooking oil?
Most oils contain roughly 120 calories and 14 grams of fat per tablespoon. But it’s the type of fat in them that’s most important. “What’s really linked to [good] health is unsaturated fat that comes from plant oils and plant fats,” Mozaffarian says.
Fortunately, most cooking oils are high in unsaturated fats, with a combination of monounsaturated, polyunsaturated and saturated fats, albeit in different proportions. Those proportions matter, because while monounsaturated and polyunsaturated fats have been linked to a lower risk of obesity, cardiovascular disease and stroke, saturated fats have been shown to raise blood levels of LDL “bad” cholesterol. (High levels can cause artery blockages that may lead to heart attacks and strokes.)
Olive oil is a great choice due to its high levels of good monounsaturated fats, antioxidant polyphenols, low amount of saturated fat and vitamins like E and K. Studies have shown that consuming olive oil can help lower the risk of cardiovascular disease, several types of cancer and death from all causes.
“Two other oils for good health are canola oil and soybean oil,” Mozaffarian says. Both have ample amounts of polyunsaturated fats and omega-3 and omega-6, which are essential fats that you can get only through your diet.
To limit saturated fat (the 2015-2020 Dietary Guidelines for Americans suggest keeping it to less than 10 percent of your daily calories), you’ll want to use a light hand with coconut oil, butter and ghee.
Quick tip: If a fat is solid at room temperature (think: butter, ghee, unrefined coconut oil), it’s mostly saturated. If it’s liquid, like a majority of cooking oils, it’s mostly unsaturated.
What are the different smoke points of cooking oils?
Every cooking oil has a specific smoke point, the temperature at which it begins to smoke and burn. Try to fry with an oil that has a low smoke point — such as walnut oil — and you could end up with a smoky (and possibly very dangerous) mess.
And then there’s flavor. Some cooking oils have a neutral one that won’t steal the spotlight from your other ingredients. Others assert themselves a little bit more, enlivening the taste of your dish. A lot of the choice comes down to personal preference.
But it’s wise to keep a few essentials on hand: an olive oil for sautéing, dressings, dipping and drizzling; canola or soybean for stir-frying, deep-frying and baking; coconut oil for dairy-free baking or when you want a mild tropical note; and plain or toasted sesame oil for stir-frying or adding aromatic flavor.
For freshness, most cooking oils should be stored in a dark glass bottle or container away from sunlight, but a few are best refrigerated.
Which oils are bad for you?
Processed foods often contain palm, palm kernel and cottonseed oils. Palm oils — which resist oxidation, extending their shelf life — are found in many foods, including ice cream and pizza. Most home cooks in the United States. use other oils, but palm oils are a staple in African and Asian kitchens. Cottonseed oil is used commercially to give spreads their creamy texture and lend a rich flavor to fried foods (such as potato chips). All three are high in saturated fat, so check the package label before you buy. And palm oil production raises environmental concerns. Organizations including the World Wildlife Fund say certain methods are leading to deforestation, endangering species.
Are more expensive oils worth it?
You might wonder why one olive oil costs three times more than another when they’re both labeled “extra virgin” and the bottles contain the same amount. Or why some types of oils are so much more expensive than standbys such as canola.
One big reason is that mechanical methods (like the expeller pressing used for cold-pressed extra-virgin olive oil) are less efficient; they extract less oil from the plant. So producers have to start out with more raw materials, adding to the base cost. And walnut, almond and avocado crops (and to a lesser degree, coconut) have been hit by drought and other challenges that affect the price of their oils.
When to use them? You can sauté your veggies in bargain olive oil just fine, but a cold-pressed artisanal olive oil might offer more nutrients or a more complex flavor that’s worth splurging on (and perhaps using sparingly). Here’s how to save if you’d like to use specialty oils.
Buy private label or store brands. They’re not only better priced than brand-name cooking oils but also offer a quality that’s often just as good. Examples: Wellsley Farms Organic for BJ’s Wholesale Club, Kirkland Signature for Costco, Great Value for Walmart and Good & Gather for Target.
Shop at stores where cooking oils are permanently discounted. Prices at BJ’s Wholesale Club, Costco, Kroger, Target, Trader Joe’s, Walmart, and WinCo tend to be lower than at other stores that have cut or eliminated their usual promotional offers.
Buy in bulk or stock up on multiples of the same size. But check best-by dates because oils should be used within 30 to 60 days after opening.
Time your purchases. Cooking oils are typically discounted in stores during the first week of the month.
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