With all the misinformation and conflicting opinions in nutrition communities, knowing what cooking oils are harmful and should be avoided versus what cooking oils are healthy isn't easy.
One of the primary features of cooking oil that should concern you is the refinement process. Most vegetable oils undergo heat and chemical processing. The four most commonly-consumed vegetable oils consumed in the US are soybean, canola, palm, and corn oil. Many of them are refined, bleached, and deodorized, and it happens so frequently that the acronym RBD is used to describe the manufacturing process (1).
Most oils in a pure, unprocessed state are healthy in moderate amounts. Many contain excellent health benefits, a good ratio of fatty acids, and are delicious either cooked or raw. But let's look at five popular cooking oils that have recently been at the center of controversy regarding health and wellness.
And when you're finished, check out our Complete Guide To Cooking Oils for a more thorough exploration of everything to do with cooking oils.
A Quick Look At Cooking With Olive Oil
Extra virgin olive oil (EVOO) is one of the healthiest oils you can consume. However, it's not necessarily the best oil with which to cook. Its smoke point is 410°F, which while high, is lower than other types of oil, like coconut oil or avocado oil.
While olive oil is composed primarily of polyunsaturated fatty acids, which are fairly resistant to heat, it does contain some polyunsaturated fat that is more reactive and sensitive to heat. That doesn't mean don't cook with it. Instead, save olive oil for low-temperature sauteing. If it's the flavor you're after, drizzle it raw over top cooked food or on top of raw salads.
Coconut oil went from being a proclaimed healthy oil, known for its weight loss benefits, to being criticized for its high levels of saturated fat. What's the real deal on coconut oil?
There's no doubt that coconut oil is high in saturated fat––its fatty acid profile is 90% saturated, and more than 50% of that comes from naturally-occurring medium-chain triglycerides (MCTs). MCTs are a type of nootropic, especially when paired with buttered coffee. They also have proven microbial properties, potential weight loss benefits, and may help support a healthy blood sugar balance.
So why does coconut oil receive a bad rap in some communities? Well, it may have started with the Harvard professor who described it as "pure poison" (read that story here) because it's very high in saturated fat. This is where moderation is so important. Supporters of coconut oil as a healthy cooking oil don't suggest you drink it by the gallon. Instead, a tablespoon a day is sufficient for average person's daily recommended saturated fat intake and even more is okay if you're on the keto diet. A certain amount of fat is necessary for increasing nutrient absorption from other foods and many other health benefits. Inadequate amounts of saturated fat may result in consuming fillers like extra carbs or sugar to feel satiated.
Coconut oil is one of the most nutritious cooking oils available. Learn more about it in our Complete Guide To Cooking Oils.
When we started this journey of researching the best and worst cooking oils, palm oil led the pack as far as the worst oils were concerned. But we were surprised to discover the health facts about palm oil––for the human body, that is. The health of the environment is a different story, but we'll get to that.
Palm oil contains a fairly even split of saturated fat and monounsaturated fat. Both are less reactive and sensitive to heat and rancidity than polyunsaturated fats. If we take pure, unrefined palm oil, its health benefits are a mile long. It may aid in decreasing cholesterol levels, reduce oxidative stress, support brain health, aid against the progression of heart disease, and improve hair and skin health.
Palm oil is an inexpensive substitute for oils that contain trans fatty acids, which have been banned from food in the US. The problem with palm oil is that it is indirectly harmful to our health because it poses a great risk to huge expanses of rainforests in Africa and Asia, particularly Borneo. Aside from being vital for the world's water cycle and absorbing carbon dioxide, rainforests are also home to many animal species, such as the orangutan. Without these tropical forests, such species become extinct (learn more here).
Palm oil comes from the fruit of the oil palm tree, a type of tree mainly found in warm climates such as Africa and Asia. Palm oil creates some controversy because the trees grow in rainforest regions, and "the harvesting of this type of oil is being blamed for many negative environmental impacts," says New York City-based nutritionist Natalie Rizzo, RD.
Sunflower oil sounds so clean and healthy, doesn't it? But plants are a bit witchy. Some of the seemingly healthiest vegetables and fruits are actually quite harmful to our health. For example––because we know you're curious––kidney beans contain a naturally-occurring toxin called phytohaemagglutinin, which can cause symptoms of food poisoning if eaten raw or undercooked.
While sunflower oil doesn't contain anything quite so dramatic as poison, it is very high in omega-6 fatty acids, which we need to consume in moderation. While omegas are healthy fats that our bodies require for healthy functioning, particularly brain health, the average American diet contains far more omega-6 fatty acids than omega 3s. Omega 3s lower inflammation while excessive omega 6 contributes to it. Experts suggest an omega 3, omega 6 ratio of 2:1.
The controversy continues! Whether you have a fixed or fluid opinion about butter, the facts stay the same: butter is high in saturated fat, and nearly 100% of its calories come from fat. We know now that saturated fat isn't necessarily a bad thing. It depends on its source and how much is consumed. Your genetic profile may also determine whether animal or plant-based sources of saturated fat are best for you.
The main problem with butter is the commercial dairy industry. Wrought with unethical practices and processing that pose health risks to both humans and cows, the dairy industry that relies on camps of grain-fed cattle don't produce a very healthy form of butter. Butter is more nutritious when it is sourced from pasture-raised cows on organic farms.
But here's the thing––if there was an equally delicious and healthier alternative to butter that actually comes from butter, would you opt for it? (And no, we don't mean margarine). If you've never heard of ghee, you're in for a treat. Ghee (pronounced Guy, like the French guy) is like clarified butter, but it's free of the milk sugar lactose and the milk protein casein. It doesn't contain the dairy solids of butter, so it's ideal for people who have a sensitivity to dairy. Ghee also contains more butyric acid, a fatty-acid created from the breakdown of dietary fiber in your colon. Butyric acid aids digestion, calms inflammation, and improves overall gut health (2). Ghee is also slightly higher in conjugated linoleic acid, a type of polyunsaturated fat that may support weight loss.
This was a wildcard. Canola oil is actually that bad for you. It's a vegetable oil, and most vegetable oils are highly refined, a process that removes much of their nutrients and flavor. While it is low in saturated fat that can elevate bad cholesterol, the processing may be more harmful to health.
Canola oil is extracted using a chemical solvent called hexane. If that alone doesn't cause you to shudder, this next bit might. Heat processing interferes with the oil's stability, which can destroy the omega 3s, cause rancidity, and create trans-fat. What started as a heart-healthy vegetable oil becomes deleterious to health through production. While unprocessed versions of canola oil do exist, they are hard to find and usually quite expensive.
For Better Or Worse...
Don't kick oil out of your kitchen. Choosing better versions of most cooking oils begins by looking at their label. Does it have international certification? Is it stored in a dark glass bottle? Is it higher in price than you might be comfortable with? These are all signs of a good-quality cooking oil. To learn everything you need to know about cooking oil, don't forget to check out our free comprehensive guide. Get your copy here, and feel free to share it!
From our kitchen to yours, happy drizzling, dressing, sauteing, frying, and sizzling up some delicious meals with better cooking oils!