Are Seed Oils Bad for You?

The signs were put up by Seed Oil Scout (SOS), an app that allows users to track which restaurants cook without seed oils — aka cooking oils made from plant seeds like corn oil, sunflower oil, and canola oil — as well as where you can get foods like tallow-fried fries and raw milk, which, according to a certain corner of the nutrition world, are the key to a healthier life.

But spend any time on TikTok or let your YouTube algorithm run too long, and you’ve probably seen at least one fitness guru or self-proclaimed dietician warn about the dangers of inflammation from seed oil, the benefits of a carnivorous diet, and why eating more tallow is better for your heart. The talking points have become so popular that Robert F. Kennedy Jr. has threatened to ban seed oils if he’s put in charge of public health agencies. But like most online diet fads, while there is a kernel of truth at the heart of it, the panic is mostly overblown.

Where did this panic come from?

While a diet high in any amount of fat will probably lead to some problems, a handful of nutritionists began focusing on the particular problems of seed oils a few years ago. In 2017, ophthalmologist Dr. Chris Knobbe published a paper arguing that “harmful vegetable oil,” as well as other processed foods, “are the primary and proximate cause of AMD [age-related macular degeneration].” He began focusing on seed oils specifically, arguing in a talk four years ago that seed oils are responsible for “degenerative diseases of civilization,” like heart disease and diabetes.

The anonymous poster behind Seed Oil Scout, which launched in 2022, said they first became concerned with seed oils during early COVID lockdown, as they noticed their gut health improved after cooking at home instead of eating out in restaurants. They “realized a common thread: Industrially processed seed oils were either demonized or completely absent from traditional recipes,” they tell Eater. Though some seed oils, like sesame oil, are less processed, most are still industrial products.

SOS, like many other anti seed-oil activists, points to high concentrations of omega-6 fatty acids in seed oils, which can cause inflammation in high levels and lead to a host of health problems, especially when heated. They also reference the rise of polyunsaturated fats in the American diet over the past 100 years. “This is an unprecedented change in our body composition that clearly deserves a second look,” they say.

The panic over seed oils has escalated as many have taken seed oil-linked health concerns and projected onto them the idea that this is not how we’re “supposed” to eat. The solution, the thinking goes, lies in an imagined past where foods were not processed, or even regulated in any way. (Though it’s important to note seed oils aren’t new — Native Americans in modern day Arizona and New Mexico were crushing sunflower seeds for oil in 3000 BCE.) This is perhaps why these theories have found ground in the more right-wing reactionary corners of the internet.

The Liver King, a carnivorous diet influencer with millions of followers, takes inspiration from our mythical ancestors, who he believes stayed healthy and fit through a diet of unprocessed raw meat. He warns against eating seed oils and processed foods, suggesting instead a breakfast of six raw eggs and bone marrow. (The Liver King, who claimed to have gotten his buff physique solely from this diet, was recently found out to have been taking steroids). Similarly, a video posted three years ago by What I’ve Learned, a YouTube channel with over 2 million subscribers, argues that seed oils are single handedly responsible for the rise in obesity and heart disease over the past century, and that we were a healthier population before they came along. And podcaster Joe Rogan was also an early platformer of anti seed-oil beliefs, hosting carnivore diet proponent Paul Saladino in 2020, and going on to villainize seed oils on his own.

Seed oil criticism is often espoused by influencers and channels who hold other reactionary beliefs. What I’ve Learned also features videos like “Women Don’t Want Equal Relationships” and an interview with quack psychologist Jordan Peterson. And on TikTok, anti-seed oil content is often produced by self-proclaimed tradwives, who argue that a more patriarchal, Christian society is part of this return to some healthier way of living. And, of course, RFK Jr. has now taken on seed oils as the enemy, wanting to replace all frying oil with tallow as was used in decades past.

Is there any truth to the anti seed-oil activists’ health claims?

Nutritionists have said for years that ingredients like canola oil aren’t particularly nutritionally rich. Olive oil contains less polyunsaturated fat, and more antioxidants than canola oil. It’s also true that Americans’ oil consumption has risen against animal fat consumption. A 2023 study reports that seed oils are the most common source of linoleic acid, a polyunsaturated omega-6 fatty acid, which accounts for “over 25% of the total calorie intake for the average person.” That study also reports that linoleic acid can contribute to the formation of oxidized linoleic acid metabolites, which have been linked to a variety of chronic diseases. But if you’re thinking that you’ve been cooking with sunflower oil your whole life and everything seems fine, you’re probably right.

“Some omega-6 fatty acids are essential for human nutrition. We must have them. Just not much,” says Marion Nestle, the Paulette Goddard professor emerita of nutrition, food studies, and public health at New York University. According to the American Heart Association, polyunsaturated fats can help in reducing bad cholesterol, and moderate amounts are part of a heart-healthy diet. “The misleading charge is that seed oils are high in omega-6 fatty acids that break down into toxins when used for cooking, causing inflammation, weakening the immune system, and contributing to chronic illnesses,” it says.

The real health concern isn’t with seed oils, but with processed foods in general. Cooking with canola oil means you can control exactly how much you’re eating, but many processed foods contain seed oils, as well as high-fructose corn syrup and added sugar and sodium, at levels that consumers might not realize are high.

It’s also hard to pin our health woes on one ingredient. “People are eating more oils, but also everything else,” says Nestle. A 2022 study published in Frontiers in Nutrition about the relationship between the American diet and noncommunicable diseases (NCDs) found that while NCDs were certainly on the rise, and the consumption of saturated fats from animals had declined since 1909, “untangling the causes of NCDs is complex, multifactorial, and controversially unresolved,” the authors write. “The profound dietary changes were accompanied by other lifestyle and demographic changes, including increased urbanization and population density, reduced physical activity commuting to and at work, longer commutes, higher stress, less sleep, more machine and less human time, higher rates of mental health disorders, increased prescription and over-the-counter drug use, many of which increase appetite, and higher salt intake.”

The AHA does acknowledge that the American diet tends to include high amounts of omega-6. The American diet is high in both fried foods (likely fried in seed oil) and red meat. Beef contains twice as much omega-6 fatty acid as omega-3, and American meat consumption has risen in the last century, with 12 percent of Americans responsible for half of the world’s consumption of beef. And while this may not account for the sole rise in omega-6 consumption, there’s a good chance red meat is a culprit. Which would throw a wrench into some carnivore influencers’ theories, and presumably their bottom lines. In general, the AHA recommends following a Mediterranean diet for heart health.

How are restaurants like Carbone responding to seed-oil panic?

All this talk about seed oils has more customers wondering where they’re used, which is leading some restaurants to be more transparent about their ingredients and advertising themselves as not using seed oils in order to lure customers. After all, aside from any health panic, seed oils are industrial products, so it makes sense that many restaurants that prioritize holistically grown ingredients and small-batch producers don’t want to give their money to Crisco.

Presumably, restaurants that have a lot of fried food on the menu may be particularly concerned about backlash. Coqodaq, a fried chicken-focused restaurant in Manhattan, advertises on its menu that it uses Zero Acre oil, made from fermented sugarcane, which “has 35% more healthy, heat-stable monounsaturated fats than even olive or avocado oils and minimizes the formation of toxic aldehydes, compared to seed oils with high omega-6.” Sweetgreen ditched seed oils last year, and Shake Shack tested out Zero Acre in its fryers, praising the company’s mission to “end the food industry’s dependence on destructive vegetable oils.” If concern over seed oils continues to grow, you’ll probably see more restaurants making it clear whether they use them or not.

Carbone, however, isn’t taking the SOS fliers lying down. In documents provided to Eater by SOS, Major Food Group has sent a cease and desist letter, demanding that SOS remove all signs saying Carbone uses seed oil in its spicy rigatoni. MFG calls the claims “false and misleading,” accuses SOS of attempting to deter customers from dining at Carbone, and says SOS may be in violation of Section 43(a) of the Lanham Act, which covers false advertising and trade libel.

In response via a lawyer, SOS says it has email confirmation from a Carbone employee dated July 31, 2023 saying that the chile oil used in the spicy rigatoni has a sunflower oil base. However, SOS writes that it would be happy to remove the signs if Carbone confirms the recipe has been changed since then.

Okay, so should I eat seed oils or not?

There are some real concerns at play here. American foodways make it cheaper and easier for us to eat processed, low-nutrient foods, whether that’s fast food fried chicken or packaged frozen meals. There’s nothing wrong with avoiding seed oils, though as both the American Heart Association and SOS agree, it may be impossible unless you commit to cooking all of your own meals.

But you really don’t need to. “Seed oils are not poison. Like just about everything else in nutrition, they are best consumed in balance with other fat sources and in moderation to control calories,” says Nestle. Eating Cocodaq fried chicken four times a week would probably not be great for your cholesterol whether they were using canola or Zero Acre or tallow. So no, seed oils are not single-handedly responsible for all of society’s health problems. Eat them mindfully. And a spoonful of chile oil in pasta is not a problem.