Social media influencers, the federal government and a number of health-focused restaurant concepts have created a lot of buzz around the evils of seed oils recently. But the scientific community is mostly not on the same page.
What’s the true story? Health and Human Services Secretary Robert F. Kennedy Jr. thinks beef tallow is a healthier alternative for cooking french fries than canola oil, but most dietitians don’t agree. Some restaurant concepts, including Sweetgreen and True Food Kitchen, are switching to avocado oil, while others are trying oil made from sugarcane. But is there enough supply to meet demand? And what is it about seed oils that is turning them into the latest dietary villains?
First, a science lesson
Seed oils are extracted from plant seeds, including canola seed, safflower seed, sunflower seed and grapeseed. Opponents lump oils from soybeans and corn into the same category. All are made by crushing or pressing the seeds, then processing the oil to refine it into a neutral-tasting product that is shelf-stable and able to be heated to a high temperature without smoking. That’s a plus for restaurant kitchens that do a lot of frying.
True Food Kitchen created better-for-you, crispy chicken tenders that are air-fried.| Photo courtesy of True Food Kitchen
Vegetable seed oils are composed largely of omega-6 polyunsaturated fatty acids, while olive oil and avocado oil are fruit oils and contain mostly monounsaturated fatty acids. Beef tallow, butter and lard, on the other hand, are saturated animal fats.
“It’s proven that saturated fats are artery clogging,” said Ellie Krieger, a registered dietitian and culinary nutritionist. “Replacing saturated fats with polyunsaturated and monounsaturated is better for your heart health. People are fooling themselves if they think frying in animal fat is healthier.”
However, there are a few small animal studies that show that highly unsaturated oils high in omega-6 fatty acids are associated with inflammation, but the “evidence on inflammation is mixed,” said Dr. Marion Nestle, professor emerita of nutrition at New York University. “And what that means is that there are some studies that show it, some studies that don't, but always, always, always the majority of research shows that substitution of unsaturated fatty acids for saturated fatty acids reduces the risk of heart disease. Everyone who comes to it from the scientific side thinks seed oils are fine.”
But anti-seed oil social media posts and RFK Jr. also claim that a poisonous solvent is used during processing to extract the oil. That solvent is hexane, which is a toxic substance, but it is almost entirely removed when the oils are refined. Cold-pressed seed oils, which are extracted without solvents or heat, are a hexane-free option.
It is true that most omega-6-rich seed oils are not stable in high heat and start to form potentially harmful trans fats when exposed to high temperatures or are stored improperly near heat or light, said Krieger. Extensive reuse of frying or cooking oil can also cause problems.
“If you are frying, use canola oil; it’s the most stable,” she added. “All seed oils are a mix of mono- and polyunsaturated fats and canola is well balanced.”
Eric Decker, professor in the Department of Food Science at University of Massachusetts Amherst, agrees. “Canola oil is 65% oleic acid, comparable to avocado oil,” he said. “Seed oils have a place in a healthy diet, and for people with high cholesterol, omega-6 fatty acids can be beneficial.”
The anti-seed oil crowd often suggests switching to olive oil and avocado oil, and both Krieger and Nestle are in favor of those choices. But there are times when a chef is looking for a neutral-flavored frying or sauteing medium, and olive oil has a characteristic taste. Avocado oil is neutral, but like olive oil, can cost three times as much as other vegetable oils.
While the oils themselves are being blamed for assorted health issues, it’s really the company they keep. “Seed oils are abundant in ultra-processed foods, and the use of them in our food supply increased enormously between 1980 and 2000,” said Nestle. “It happened in parallel with rising rates of obesity. If you’re an epidemiologist, you know that just because things occur in parallel does not mean they're causative. But that kind of logic for non-scientists is very powerful.”
Why are Americans fatter? Blame it on the calories in ultra-processed foods, she added.
“Many people online profit from sparking outrage with misinformation,” said Krieger. “The fear mongering leaves little room for nuance, and in science, things are nuanced.”
The oil gauge
That fear mongering on social media and by Make America Healthy Again cheerleaders would lead one to believe that American consumers are staying clear of seed oils. And while there is a vocal contingent of seed oil haters, they are in the minority.
The non-partisan International Food Information Council (IFIC) commissioned an online survey of 1,000 consumers last fall to pinpoint Americans’ perceptions of seed oils. These are the results:
What consumers think about seed oils
• Americans believe avocado oil and olive oil are the healthiest types of fat or oil
• 3 in 14 Americans are at least somewhat familiar with the term “seed oils”
• Nearly half of Americans believe seed oils are healthy
• The two most cited sources of information about seed oils are friends and family and social media
• Most Americans say what they have heard about seed oils is positive
• More than 7 in 10 Americans do not actively avoid seed oils
• Among those who avoid consuming seed oils, more than 6 in 10 believe seed oils are more processed, more genetically modified and cause more weight gain than other oils
Source: IFIC
Restaurants take a stance
Several concepts that position themselves as “better-for-you” have swapped out seed oils to stay true to their ethos and customer base—even though the scientific evidence is inconclusive. Los Angeles-based Sweetgreen announced in October 2023 that the chain was transitioning to extra virgin olive oil as its cooking oil for all proteins, veggies and grains nationwide. Then this March, the fast casual rolled out Ripple Fries, potato slices tossed with seed-free avocado oil and air-fried.
Earlier in the year, Sweetgreen launched Green Goddess salad dressing made in-house daily with avocado oil. At the time, Chief Concept Officer Nicolas Jammet said, “We want our guests to have it all—great taste, fresh ingredients and options they feel good about—and it’s an exciting step forward in offering seed oil-free choices.”
Sweetgreen's new Ripple Fries are air-fried with avocado oil. | Photo courtesy of Sweetgreen
True Food Kitchen, a health-forward casual-dining chain based in Scottsdale, Arizona, went 100% seed oil-free in January, a major undertaking that began in 2022. “Our guests are increasingly looking for this option and when they walk through our doors, they can switch off their brain,” said Daniella Voysey Olson, chief growth officer at the 46-unit chain. “They can relax and enjoy their time with us, knowing that they can eat fearlessly.”
True Food Kitchen prides itself on its high sourcing standards and cooks everything from scratch, now exclusively using olive and avocado oil.
“Dr. Andrew Weill, a thought leader in integrative medicine, was one of our co-founders, who continues to be an advisor on the brand,” said Voysey Olson. “He had advised us as a brand a handful of years ago that we should be moving away from seed oils because of inflammation.”
To go 100% seed oil-free across the menu, True Food Kitchen had to swap out dried cranberries for raisins in this chopped salad.| Photo Courtesy of True Food Kitchen
While switching over to olive and avocado oil for cooking may be challenging and more expensive, the chain was able to accomplish that over two years ago. Far more challenging was finding suppliers for items like bread and mayonnaise, which is why the transition turned into a multi-year project. Over 100 products had to be re-evaluated.
“Most breads are made with seed oil, so we had to find a new vendor for our burger buns. Now we partner with a bakery that complies with our specs,” said Voysey Olson. “Even the dried cranberries we were sourcing use seed oil as a processing flow ingredient.” Menu items like the Chopped Salad now sub dried raisins for cranberries, sourced from Royal Raisins.
It took some legwork, but “we found vendors who have a shared vision of what our food system can and should be, and then partnered with them,” said Voysey Olson. “It’s this really symbiotic relationship, because we get to grow together and build those relationships for the long term, build out a supply chain that supports our needs.”
Several commercial products are now made in-house, including harissa and mayonnaise blended from avocado oil. True Food Kitchen is able to source enough olive and avocado oil to meet demand. The menu now prints the 100% seed oil-free message across all 46 locations.
But the seed oil-free changeover to olive and avocado oil in itself didn’t lead True Food Kitchen to raise prices, said Voysey Olson. Bowls and salads start at $15 and entrees go up to $35.
“We are committed to invest in high-quality ingredients across the brand, whether that's our sustainably sourced salmon or 100% grass-fed beef,” she said. “We look for regenerative and organic options, and that's part of our ethos. But connecting over food is as important to wellness as the food on the plate.”
Oil exploration
Glaze Teriyaki, a fast-casual bowl concept based in New York City, recently switched 85% of its menu from canola oil to Zero Acre Farms oil, a seed-free product made from sugarcane that also presents a positive environmental image. Glaze’s house-made teriyaki sauces and proteins are now prepared with the oil.
“Zero Acre oil is neutral-tasting and very versatile,” said Paul Krug, CEO of the six-unit chain. “We tested it for a long time to make sure there were no adverse effects on flavor.”
Glaze Teriyaki recently began sourcing seed-free Zero Acres Oil for sauces and cooking.| Photo courtesy of Glaze Teriyaki
Glaze’s menu is primarily off the grill, but items like shishito peppers, gyozas and wings are flash-fried first and then grilled, he added. Others start on the grill and then are stir-fried with some oil in woks. Since Glaze is an Asian-style restaurant, sesame oil is used in salad dressings and other recipes. Some, but not all, consumers lump sesame oil in with the so-called “undesirable” seed oils, but it’s used more for flavor than frying.
“From a cost standpoint, Zero Acre is higher in price than canola oil but has a longer shelf life, so that lessens the expense,” said Krug.
According to Jeff Nobbs, co-founder and CEO of Zero Acre, “the oil is similar in price to avocado oil. Our standard pack size is a 35-pound jug,” he said. Nobbs supplies Zero Acre to a range of independent restaurants as well as larger chains. Austin, Texas-based Hopdoddy Burger Bar was an early adopter back in the fall of 2023, swapping out soybean oil for Zero Acre at a number of locations to cook its fries.
Like Sweetgreen and True Food, Glaze wants to “meet guests where they are,” said Krug. “We noticed that seed oils were in the spotlight and saw a reaction from our customers. They have a great response to what we’re doing.” Glaze prioritizes high-quality ingredients, including Ōra King salmon, organic tofu and fresh vegetables. The gyoza and edamame are the only ingredients from the freezer. Menu prices are in the $12-$16 range, except for the filet mignon option, which goes for $16.
What about beef tallow?
Even though RFK Jr. was widely seen eating at Steak ‘n Shake because the chain made a widely publicized switch from seed oil to beef tallow to cook its fries, the truth is they probably did it for the flavor—not for health reasons. Chicago-based McDonald’s used to fry its French fries in beef tallow, but stopped in 1990 due to the widespread concern over saturated fat and heart disease back then.
There’s a groundswell of support from McDonald’s fans to bring back tallow-fried potatoes but there may be a supply issue for a chain as large as McDonald’s.
“Beef tallow is interesting and it’s not as bad as other saturated fats,” said Professor Decker. “Stearic acid is its main fatty acid, the same as chocolate, and the body converts it to oleic acid."
The bottom line—“consumers should evaluate their own health situation and choose the oil that’s best for them,” he added.