What MAHA’s crusade against seed oils reveals about flaws in America’s food system

You’re reading the first story in The MAHA Diagnosis, a STAT series that examines the major elements of the Make America Healthy Again movement led by Robert F. Kennedy Jr.

When guests at the Make America Healthy Again inaugural ball sat down for dinner last month at the Waldorf Astoria in Washington, D.C., they were greeted with menus featuring butternut squash salad, a choice between a prime filet and lobster dish and a vegetarian chickpea option, and three words sure to appeal to many involved with the movement: “No seed oils.”

Seed oils is a recently coined term that refers to the fats squeezed from the seeds of vegetables like corn and soybeans, then refined with heat and chemical solvents. It’s thanks in part to Robert F. Kennedy Jr. and the MAHA movement that concerns over their health effects are popping up on social media, on Joe Rogan’s podcast, and in Bay Area restaurants where customers request that the kitchen prepare their meals with the beef tallow they’ve brought in their backpacks. In January alone, the salad chain Sweetgreen launched a “seed oil-free” menu, and the fast-food chain Steak ‘n Shake announced it would switch to immersing french fries in beef tallow, promising users on X, “If veg oil broke your heart, our tallow will make you fall in love again.” 

“Seed oils are one of the most unhealthy ingredients that we have in foods,” Kennedy asserted in an interview with Fox News last fall, saying that they’re “associated with all kinds of serious illnesses including body-wide inflammation which affects all of our health.” (His site hawks a “Make Frying Oil Tallow Again” hat for $28.) 

A number of health experts and influencers involved with Kennedy and the MAHA movement have been warning about seed oils known popularly as the “hateful eight” — corn, canola, cottonseed, grapeseed, soy, sunflower, safflower, and rice bran oils — for years. These include siblings and chronic disease entrepreneurs Casey and Calley Means, the latter of whom is also friendly with Sweetgreen co-founder Nicolas Jammet; physician Catherine Shanahan, who published a book focused on seed oils last year entitled “Dark Calories” and who applied to RFK’s crowdsourced site to vet potential appointees; and Nina Teicholz, who wrote an influential book arguing against capping saturated fats and is now head of advocacy group The Nutrition Coalition.

The scientific consensus is that there is no clear evidence seed oils are harmful to health, and that switching to alternatives like butter or lard — as recommended by many in the anti-seed-oil camp — is likely worse. “There’s a fair amount of evidence that shows substituting plant oils for animal fats is good for you,” said nutritionist and molecular biologist Marion Nestle, a professor emerita at New York University. 

But the seed oil backlash is about more than what fats get used in our packaged snacks and veggie stir-fries. Fears about the oils have taken root amid rising concerns about possible links between industrial food processes and chronic disease and a public that’s grown more distrustful about everything from how their food is produced to the government’s ability to ensure its safety. Americans are increasingly convinced that something — possibly a lot of things — in their food is making them sick, and that neither government policies nor the food industry are doing enough to look out for them. That vacuum has given more sway to health-conscious influencers and advocates who question mainstream nutrition advice. And for businesses hawking seed oil alternatives like beef tallow or avocado-oil chips, there’s also a lot of potential for profit. 

“It’s terrific that people are getting really concerned about the quality of our food and understanding it’s making them sick,” said Dariush Mozaffarian, director of the Food Is Medicine Institute at Tufts University. But he says the evidence suggests vegetable oils are relatively healthy. “If we don’t have the right targets, we’re going to either do no good, or even do harm.” 

Twelve months ago, Mozafarrian said, he never got asked about seed oils. Now friends, family members, even people he’s meeting for the first time — they all want to know about them.

A brief history of seed oils

Compared to olive oil or coconut oil, which people have been ingesting for thousands of years, seed oils are pretty new on the culinary scene. That’s because they can only be produced with the help of machines.

Cotton seeds, for example, were once castoffs from machines that separated out the fluffy white fiber for textiles. But with the advent of industrial processes in the late 1800s that improved cottonseed oil’s color, smell, and taste, manufacturers began to push it as an alternative to lard in cooking — which meant convincing the public to overcome negative associations. 

When Procter & Gamble introduced the vegetable shortening Crisco in 1911, the company tended to play down the fact that it was made with cottonseed oil, which was also used in soap and other industrial products and contains the toxic compound gossypol before it’s refined. Instead, Crisco was advertised as containing “vegetable oil,” helping to popularize the term and the use of oils in place of more expensive and perishable butter and lard. 

As concerns over heart disease rose in the post-World War II era, the American Heart Association in 1961 recommended polyunsaturated oils, like vegetable oils, as a replacement for saturated fats. By the 1980s, more restaurants began cooking with vegetable oils. Food manufacturers likewise replaced saturated fats with trans fats from partially hydrogenated oils, which would themselves be banned by the Food and Drug Administration in 2018 after research showed they were linked with higher levels of “bad” LDL cholesterol and heart disease.

Some of the modern-day concern with seed oils may be bound up with the cultural memory of the dangers associated with trans fats and the industrial processes used to make them, Mozaffarian suggested. “On average, processes are worse for you, so there’s some truth to that,” he said. “If you have a choice between two oils, and one is virgin produced and one is not, yeah, get the virgin one.” 

A lot of ultra-processed foods today now contain seed oils because they’re relatively inexpensive, and many nutrition experts say the reason people may feel better after eliminating seed oils from their diets is that they’re eating healthier foods in general.

“Why would a big business care about the health of any one individual consumer?” said Gregory Katz, a cardiologist at NYU Langone. “To me, the incentives are not set up so that a large business that is selling food to millions or tens of millions or hundreds of millions of people has an interest in doing anything other than selling more food.”

The seed oil skeptics

As vegetable oils grew in use, some researchers got curious about their health effects. Among the earliest was physician and endocrinologist Artemis Simopoulos, who began studying the oils at the National Institutes of Health in the 1980s. In her 1997 book “The Omega Plan,” Simopoulos recommended a Mediterranean diet rich in omega-3 fatty acids while limiting the omega-6 fatty acids found in many vegetable oils, which she says are pro-inflammatory and linked to chronic diseases and obesity.

Simopoulos has been trying to raise awareness about the issue ever since, though she objects to the category of seed oils itself.

“‘Seed oils’ does not mean anything,” Simopoulos told STAT. “It’s the composition of fatty acids and the high amounts of omega-6 fatty acids that are pro-inflammatory.” She recommends organic canola oil (often lumped in with the “hateful eight”) as well as other oils high in monounsaturates like avocado, hazelnut, chia, and camellia oils that are popular in various parts of the world.

Simopoulos isn’t alone in raising concerns about the ratio of omega-3 to omega-6 fatty acids in the Western diet. Nestle noted that she was impressed by the case made by researcher Anthony J. Hulbert for changing the ratio in his 2023 book “Omega Balance.” And even seed oil’s defenders note that in science, research is always evolving, and identifying how individual foods or nutrients affect health outcomes is notoriously complex to study.

“Do I think that seed oils are bad for you? The real answer is I don’t really know,” said Katz. “The evidence that I’ve seen suggests that it’s probably no worse than other oils, and it’s probably a little bit better than saturated fat. But I think that with most things in nutrition, there is a heterogeneity in how people respond to things.”

On the other hand, many of the alternatives that critics of seed oils champion are nutritionally controversial in their own right. Coconut oil contains more saturated fat than butter, and many experts recommend that it be consumed in moderation. Avocado oil is generally considered fine, if it is indeed avocado oil — much of it turns out to be cut with cheaper safflower, sunflower, and canola oils. 

Butter, lard, and beef tallow are all high in saturated fats, too. But as paleo, keto, and Atkins diets in the 2000s got people to embrace once-vilified animal products, research on seed oils converged with broader nutritional trends.

In 2014, Teicholz published her book “The Big Fat Surprise: Why Butter, Meat, and Cheese Belong in a Healthy Diet,” which was lauded as one of the best books of the year by The Wall Street Journal and The Economist. Teicholz recalls spending her first few years of book research focusing on the seed oil industry. “I went to their conferences, joined their professional association and even visited a seed oil plant where trans fats were made,” she told STAT via email.

In her book, Teicholz took issue with the idea that saturated fats contribute to heart disease. Instead, she argued, the problem lay with vegetable oils. Since founding The Nutrition Coalition with backing from the philanthropists John and Laura Arnold, she’s championed reforming the U.S. dietary guidelines and its recommendations to minimize consumption of saturated fats. Now, she tells STAT, she thinks the data on seed oils is strong enough for “the government to re-evaluate the safety of these oils for human consumption.” 

Criticism and capitalism take off

Over the last decade, more personalities have adopted the anti-seed oil message, making it a prominent part of their brand and, in some cases, monetizing the cause. 

Shanahan got press for putting the Los Angeles Lakers on a nutrition performance-improvement plan that avoided seed oils. Physician and influencer Mark Hyman, who’s also been connected with RFK Jr. and founded the MAHA-favorite lab testing startup Function Health, tells people to steer clear of seed oils — and offers a lab test that helps people calculate their omega-3 to omega-6 ratio as part of their Function Health membership.

Some had clear financial stakes in encouraging people to try alternatives. Fitness and nutrition writer Mark Sisson, for example, advised against seed oils in his book “The Primal Blueprint” in 2009. He went on to found the company Primal Kitchen, which touts seed oil-free mayonnaise and salad dressings and which sold to Kraft Heinz for $200 million in 2019.

More recently, social media, YouTube, Substack, and podcasts have amplified the seed oil criticism, featuring influencers Max Lugavere and Tucker Goodrich; carnivore diet proponent Paul Saladino; Vani Hari, the blogger known as “Food Babe”; and the raw-meat-touting Liver King, whose real name is Brian Johnson, and whose muscle-y physique turned out be the result of steroid use. 

“We’re living in this ecosystem where these wellness influencers have gotten this inordinate amount of power because of the information channels that people are using,” said Andrea Love, an immunologist whose newsletter Immunologic is aimed at combating health misinformation. “And I think they have no qualms with taking advertiser money from supplement companies or food companies.” 

Saladino’s businesses, for example, include Lineage Provisions, which sells beef tallow as well as meat sticks, and Heart & Soil, a supplement line that hawks beef organs as “nature’s ultimate multivitamin.” The Liver King’s Ancestral Supplements line shares anti-seed oil messaging on social media while hawking protein powder and pills made from beef liver and thyroid.  

Seed oil skepticism means there’s also a growing market for companies like Zero Acre Farms, which sells oil made from sugarcane plants that it advertises as a healthier and better-tasting alternative to vegetable oils. (Goodrich and Shanahan are both advisers to Zero Acre.) The company has received investment from Chipotle and partnered with hundreds of restaurants, including Shake Shack and the Texas-based chain Hopdoddy Burger Bar.

When Zero Acre first launched in 2020, “we would start conversations with potential restaurants needing to sell them on why their current oils are bad,” said co-founder and CEO Jeff Nobbs. “Now, most of the conversations start with restaurants saying, ‘OK, so obviously seed oils are bad’ or ‘Everyone knows we’re trying to find alternatives to canola oil.’”

Meanwhile, the Seed Oil Free Alliance is a third-party certification business that offers to verify manufacturers’ food products as seed oil-free for a lab testing fee of $400. The Seed Oil Scout app — which helps users locate restaurants that don’t use seed oils and has cracked the top 50 most popular apps in Apple’s food and drink category — in January unveiled a certification badge of its own, with partners including the beef tallow company fatworks and the potato chips Vandy Crisps. 

All this is to say that while vegetable oil companies have undoubtedly profited by positioning their products as heart-healthy options over the years, there’s money to be made in helping people avoid vegetable oils, too. Love said that point often gets elided by seed oil critics. “They want to convince people that these processes or these food ingredients that are actually well-characterized, regulated, well-understood by actual scientific experts are harmful,” Love said, “and their alternatives — that they have an affiliate link for or that they’re selling directly or they’re profiting from in some capacity — are somehow altruistic.”

A crisis of trust

Some aspects of the seed oil backlash seem relatively harmless and possibly even beneficial — say, if people cut back on the deep-fried foods that are often made with vegetable oils. Far fewer health experts are on board with subbing in saturated fats or piling on animal products. (One recent study of a man who’d been adhering to the carnivore diet for eight months, with plenty of butter, cheese, and hamburgers, reported that he had cholesterol deposits coming out of his skin.) 

And there may be more abstract consequences to the seed oil debate, according to Love. 

For one thing, it draws attention away from what she sees as far more important food and nutrition issues. “We should be focusing on how to address food deserts where people don’t have access to affordable and nutritious frozen or fresh produce,” she said. Instead, conversations about seed oils are “just scaring people about foods where if you eat those in moderation, they’re not posing a risk to you. You spend all this energy and time trying to explain nuance. ”

Already, the MAHA movement means that nutrition experts are spending more time explaining what they see as settled science. “I was interviewed this afternoon about raw water — give me a break,” Nestle said. “Raw water, raw milk, seed oils — all these things are anti-government, anti-authority, pro-natural, anti-industry, without a whole lot of science to back them up, in my view.”

And yet in an era in which people up until now have had no way of knowing whether baby food contains elevated levels of lead and it took the FDA decades to ban a synthetic red dye known to cause cancer in rats, the public has plenty of reason to be wary of government and industry. The future of nutrition literacy may rely on teaching  people to bring a healthy skepticism to what they hear on social media, too, and to anyone who claims with one hundred percent certainty that there’s a single villain — whether seed oils, dairy, gluten, or sugar — in American diets. A tenet of responsible public health messaging, after all, involves admitting room for doubt.

“I think that the things that we put into our bodies dictate a lot of our health outcomes,” said Katz. The trouble lies with pinpointing the problems with those choices, when nutrition advice fluctuates on everything from low-fat diets to eggs and alcohol.

When you start medical school, Katz said, “they tell you that in 10 years, 50% of what you learn in medical school is going to be proven wrong. The problem is that we don’t know which 50%. Things change, and we learn more. Things that are new are not always better, but sometimes they are.”

STAT’s coverage of chronic health issues is supported by a grant from Bloomberg Philanthropies. Our financial supporters are not involved in any decisions about our journalism.