Is Cooking With Oil Unhealthy? Experts Weigh In

Humans have been using oil for centuries. In Mycenaen Greece, more than 3,500 years ago, olive oil was a valuable commodity traded with other civilizations, like Egyptians and Minoans. The use of sesame oil dates back even further to ancient Mesopotamia, while coconut oil has long been a staple across Southeast Asia.

Today, we still value oil enormously. We drizzle olive oil over tomatoes while they bake in the oven, and heat vegetable oils in the pan before frying up dinner. The cooking oil market is huge—in 2023, it was valued at more than $204 billion.

But is all of this oil actually good for our health? The experts, it seems, are split.

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Are cooking oils bad for your health? A closer look at seed oils

One group of oils, in particular, has garnered increasing criticism recently: seed oils. These are oils extracted from a wide variety of plants—they include sunflower oil, canola oil, flaxseed oil, corn oil, and many more. They are widely used around the world in cooking, and they also appear on the ingredient lists of many processed foods.

According to the Seed Oil Free Alliance, the world’s first seed oil-free certification platform, the average American consumes around 20 percent or more of their daily calories from seed oils. It claims these oils are harmful to our health as they may lead to high omega-6 to omega-3 ratios, which may lead to inflammation.

Healthline agrees. “Scientists have hypothesized that a diet high in omega-6s but low in omega-3s increases inflammation, while a diet that includes balanced amounts of each reduces inflammation,” the publication reports.

Research shows that chronic inflammation is a major health concern. It may increase the risk of life-threatening diseases, including cancer, type 2 diabetes, and heart disease, which is the leading cause of death in the US.

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However, some experts disagree that we should be concerned about seed oils and our omega-3 to omega-6 ratio. Dariush Mozaffarian, MD, DrPH, told Consumer Reports, for example, that research suggests that a diet high in omega-6 fats can help to lower blood sugar and cholesterol levels, both of which reduce the risk of disease. The publication cites one advisory from the journal Circulation, which was published by the American Heart Association Nutrition Subcommittee of the Council on Nutrition, Physical Activity, and Metabolism in 2009, and reads: “A large body of literature suggests that higher intakes of omega-6 (or n-6) polyunsaturated fatty acids (PUFAs) reduce risk for coronary heart disease (CHD).”

Some seed oil critics recommend that people switch to alternatives like animal fats and coconut oil. However, the healthfulness of these foods has also been called into question by some experts.

“I would recommend using coconut oil in moderation as it is high in saturated fat,” Destini Moody, RD, LD, CSSD, a registered dietitian with Garage Gym reviews, told VegNews. “A study from the American Heart Association described the oil as “deleterious” due to the harm it can do to heart health.”

Experts also urge moderation of animal fats, like lard and butter, as they, too, tend to be high in saturated fat. New Zealand’s Heart Foundation says: “The current body of evidence supports replacing saturated fats (such as those found in butter, coconut oil, and fatty meat) with unsaturated fats (such as those found in nuts, seeds, oily fish, avocado and healthy plant oils) to reduce the risk of heart disease.”

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RELATED: 5 Plant-Based Recipes to Improve Heart Health

Is olive oil good or bad for you?

When it comes to oil, most agree that extra virgin olive oil is the best type you can choose for your health. It’s a major part of the Mediterranean diet, which, according to a growing body of research, is one of the best ways we can eat to reduce the risk of disease. Earlier this year, the diet was crowned number one by the US News & World Report for the seventh year in a row.

“The Mediterranean diet focuses on diet quality rather than a single nutrient or food group,” noted the publication, which compiled its list with the help of more than 40 nationally recognized dietitians. “Numerous studies have shown that it reduces the risk of chronic health conditions, including heart disease and type 2 diabetes while promoting longevity and improving quality of life.”

Research suggests that olive oil brings a good dose of monounsaturated fats to the Mediterranean diet, which is associated with a reduced risk of disease. In 2011, researchers looked at records from 7,600 people aged over 65 and found that those who regularly consumed olive oil had a lower risk of stroke, for example. And last year, another study linked half a tablespoon of olive oil per day with a reduced risk of dementia.

“Our study reinforces dietary guidelines recommending vegetable oils such as olive oil and suggests that these recommendations not only support heart health but potentially brain health as well,” said the study’s lead researcher Anne-Julie Tessier, RD, PhD at the time.

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There have been some reports that olive oil creates harmful compounds when it is heated past its smoke point. However, research suggests that high-quality extra virgin olive oil that hasn’t been blended with olive oils is highly stable, even when it’s heated. In fact, according to Real Simple, extra virgin olive oil is “the most stable oil to cook with.”

Even olive oil—with its much-established health halo—isn’t immune from some disagreement in the medical world. While it is a good source of monounsaturated fats, olive oil also does contain some saturated fat.

Earlier this year, research from the Journal of the American Heart Association compared a whole food, plant-based diet with oil to one with very little oil, and suggested that the low-oil version of the diet was healthier. The study followed 40 people who were at risk for heart disease and noted that the participants who were eating a low-oil diet (no more than a teaspoon per day) had greater improvements in their cholesterol and other heart health markers than the higher-oil group.

This builds on what some doctors have said previously. For example, in 2022, Neal Barnard, MD, FACC, who is the president of the Physicians Committee for Responsible Medicine, said: “Olive oil is better than chicken fat, beef fat, cheese fat, dairy fat. … Chicken fat is 30 percent saturated fat. Beef is 50 percent saturated fat. But for olive oil, it’s all the way down to 14 percent. That’s good. But what if instead I get a nonstick pan and I don’t use any fat at all?”

“Every gram of fat, no matter where it’s from, has nine calories, and our research has shown that when people get away from these fats in general they do best of all.”

Matthew Lederman, M.D., co-author of The Forks Over Knives Plan, also believes that people should stay away from sources of saturated fat. Instead, he advises that people move towards whole food sources of monounsaturated fats. “Push yourself to make dishes using other sources of rich fatty flavors and textures, like avocados, nuts, seeds, olives,” he says. “Get it from a whole food if you can.”

How to go oil-free

If you read the research and decide you want to experiment with reducing your use of oil, there are a few things to keep in mind. First, make sure you’re getting enough healthy fats from elsewhere.

“Some drawbacks of the [oil-free diet] is the potential to miss out on key nutrients, especially dietary fat,” says Moody. “The body needs sufficient amounts of dietary fat for many vital functions including the absorption of fat-soluble vitamins, regulation of body temperature, and production of hormones.” Like Lederman, she advises topping up on avocados, nuts, and seeds.

But overall the dietitian is generally in support of oil-free diets. “The principles of an oil-free diet are to promote a diet that focuses on whole foods such as fruits, vegetables, and whole grains,” she notes. “Considering these are all health-promoting foods that are high in antioxidants and other key nutrients, it’s hard to say that promoting consumption of these foods is a bad thing.”

To help you go oil-free, Moody advises steaming, boiling, and air-frying over pan-frying. “When baking, you may be able to substitute other ingredients for oil. For example, you can use applesauce in place of oil to make brownies or yogurt in muffins for most recipes,” she says. When you need to sauté, you can also opt for a broth, like vegetable stock, instead of oil.

5 oil-free plant-based recipes

If you’re looking for inspiration on how to cook oil-free, below we’ve included a few of our favorite plant-based recipes, from wedge salad to pasta to stir-fry. 

HealthyGirl Kitchen

1 Vegan Wedge Salad With Smoky Coconut Bacon and Hemp Seed Ranch Dressing

With crispy coconut bacon, creamy hemp seed ranch dressing, and plenty of crispy, crunchy greens, this delicious oil-free wedge salad is hard to beat. It’s perfect for end-of-summer cookouts, lunches, and adding a little extra to weeknight meals. 
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Danielle Keith

2 Two-Step Oil-Free Vegan Kale Pesto Pasta

Pesto pasta is a classic, much-loved dish for most people. This recipe keeps it simple but ups the nutritional value by swapping regular pesto for an oil-free kale version. Made with almonds, lemons, nutritional yeast, basil, salt, and garlic, it’s delicious and packed with goodness.
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Julieanna Hever

3 Oil-Free Sweet Chili Tofu Broccoli Mushroom Stir-Fry

If you thought going oil-free meant giving up stir-fries, think again. This tasty recipe proves that you can still have your favorite midweek dinner dish without any oil at all. Instead, just opt for a delicious homemade sauce, made with ingredients like vegetable broth and rice wine vinegar, to cook your vegetables in.
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Danielle Keith

4 Vegan Teriyaki Sesame Cauliflower Bites

These crispy, cauliflower bites are guaranteed to become your new favorite snack. They’re baked instead of fried, before being tossed in a delicious sweet and tangy sauce made with teriyaki, garlic, ginger, and red chilli flakes.
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5 Hearty Vegan Mushroom Bolognese With Fettuccine

This hearty, warming mushroom bolognese dish is perfect for cozy fall evenings. It’s packed with goodness, bursting with flavor, and it’s easy to make. Instead of oil, just sauté the garlic and onions in water, before adding in the rest of your vegetables, like mushrooms and bell peppers.
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