Since 2018, the health effects of consuming certain processed vegetable oils, or seed oils have been subject to misinformation in popular and social media. The trend grew in 2020 after podcaster and comedian Joe Rogan interviewed fad diet proponent Paul Saladino about the carnivore diet. Saladino made several claims about the health effects of vegetable fats.
The theme of the misinformation is that seed oils are the root cause of most diseases of affluence, including heart disease,: "[P]ushed back on the idea that these oils cause health ills ranging from headaches to heart disease." cancer,: "the bulk of recent research has not been kind to Simopoulos' assertion that the supposedly imbalanced consumption of linoleic acid found in seed oils 'makes you more vulnerable to heart disease, cancer, obesity, inflammations, autoimmune diseases, allergies, diabetes and depression. diabetes,: "[T]hey're blamed for a host of ills, such as headaches, foggy thinking, lowered immunity, heart disease, type 2 diabetes, and more." and liver spots.: "[I]f you want something to blame for everything from cancer to heart disease, dementia to age spots, there are a whole lot of people out there who will tell you the culprit is lurking in your pantry" These claims are not based on evidence, but have nevertheless become popular on the political right. Critics cite a specific "" oils that constitute "seed oils": canola, corn, cottonseed, soybean, sunflower, safflower, grapeseed, and rice bran.
Although critics raise concerns about processing, omega-6 fatty acids, and linoleic acid, scientific evidence finds these oils safe and beneficial, with omega-6s linked to lower cardiovascular risk and no consistent evidence of increased inflammation, cancer, or chronic disease. Claims that seed oils are harmful are not supported by clinical or epidemiological data, and some health organizations warn that reducing omega-6 intake could worsen heart health.
Consumer vegetable oils are generally recognized as safe for human consumption by the United States FDA.
Origins and scientific evaluation
Seed oils are oils extracted from the seed, rather than the pulp or fruit, of a plant. Seed oils are characterized by the industrial process used to extract the oil from the seed and a high content of polyunsaturated fatty acids (PUFAs). Critics' "hateful eight" oils consist of canola, corn, cottonseed, soy, sunflower, safflower, grapeseed, and rice bran oils, which are creations of industrialization in the early twentieth century. In the United States, cottonseed oil was developed and marketed by Procter & Gamble as the creamed shortening Crisco in 1911.: "Soon the company's scientists produced a new creamy, pearly white substance out of cottonseed oil. It looked a lot like the most popular cooking fat of the day: lard. Before long, Procter & Gamble sold this new substance (known today as hydrogenated vegetable oil) to home cooks as a replacement for animal fats." The extracted oil was refined and partially hydrogenated to give a solid at room temperature and thus mimic natural lard, and canned under nitrogen gas.
Industrial solvents Critics of seed oils often point to the health hazards of the solvents used in the industrial process of generating vegetable oils.: "Another criticism is that seed oil manufacturers use heat and solvents, such as hexane, to extract oil from seeds, creating unhealthful trans fats and chemical contaminants." Hexane, which can be neurotoxic, is extremely effective at oil extraction.: "Direct solvent extraction involves the use of a nonpolar solvent, usually commercial hexane, to dissolve the oil from oilseed flakes or collets without removing proteins and other non-oil-soluble compounds. Solvent extraction yields about 11.5% more oil than does the screw press method, and less oil remains in the meal." Thus, it is often quoted as a danger when consuming vegetable oils as it can be found in finished oils in trace amounts.: "Some studies have been conducted on n-hexane residues in commercial products showing the presence of n-hexane in commercial hexane-extracted oils, in food products, and in functional health foods" The United States Environmental Protection Agency studied the toxicity of hexane extensively in the 1980s.: "Pursuant to section 4(a) of the Toxic Substances Control Act (TSCA), EPA is issuing a final test rule requiring manufacturers and processors of commercial hexane to perform testing for subchronic toxicity, oncogenicity, reproductive toxicity, developmental toxicity, mutagencity, neurotoxicity, and inhalation and dermal pharmacokinetics." The studies found that the hexane used in industrial processes was safe for consumption and did not cause nerve damage.
Omega-6 fatty acids
Sunflower, corn, and soybean oil have a higher proportion of omega-6 fatty acids than oils from fish, walnuts, flaxseed, and rapeseed (canola). Omega-6 fatty acids constitute a growing proportion of Americans' fat intake. They have been hypothesized to contribute to several negative health effects, including inflammation: "While all oils contain varying levels of fatty acids, some argue an excessive intake of a specific omega-6 fatty acid in seed oils called 'linoleic acid' may contribute to inflammation in the body." and immunodeficiency, but most cardiovascular health researchers believe the data shows that omega-6 fatty acids are safe and healthy for humans.: "In a science advisory that was two years in the making, nine independent researchers from around the country, including three from Harvard, say that data from dozens of studies support the cardiovascular benefits of eating omega-6 fats." In fact, omega-6 fatty acids are significantly associated with a lowered risk of cardiovascular disease, and the American Heart Association has stated that a reduction in omega-6 fatty acids could lead to an increase, not reduction, in cardiovascular disease. Research indicates that consumption of omega-6 fatty acids has no significant effect on inflammatory bowel disease.; : "What antiseed oil influencers miss is that arachidonic acid also is a building block for compounds that fight inflammation. The inflammatory claims mostly are based on research in rodents, but mice and rats don’t respond to linoleic acid the same way humans do. In fact, human research has found that linoleic acid isn’t inflammatory overall."
Linoleic acid
Opponents of seed oils have argued that linoleic acid, an essential fatty acid found in seed oils such as safflower oil and sunflower oil increases chronic disease risk such as cardiovascular disease, cancer and systemic inflammation. This idea is not supported by data from recent clinical trials or long-term epidemiological studies. It has been shown that higher in vivo circulating and tissue levels of linoleic acid are associated with lower risk of major cardiovascular events.: "In pooled global analyses, higher in vivo circulating and tissue levels of LA and possibly AA were associated with lower risk of major cardiovascular events. These results support a favorable role for LA in CVD prevention." A 2025 review of human outcome data concluded that linoleic acid from seed oils does not increase chronic disease risk. The review also noted that the human research evidence shows that linoleic acid intake does not affect inflammation or increase inflammatory biomarkers. "The current human research evidence shows that linoleic acid does not affect inflammation."
The World Cancer Research Fund and Cancer Council Australia have stated that there is no scientific evidence that consuming seed oils increases cancer risk.
Omega-6:omega-3 ratio A 2024 review stated that dietary recommendations should not be made based on the omega-6:omega-3 ratio, but rather on their absolute dietary intake levels. The omega-6:omega-3 ratio is calculated by accounting for all of the omega-6 fatty acids in the diet or blood divided by the sum of all omega-3 fatty acids. Concern about a high omega-6:omega-3 ratio was based on the competition between linoleic acid and alpha-linolenic acid for desaturation enzymes, and because metabolites of omega-6 fatty acids were considered to be pro-inflammatory.
However, there is insufficient evidence in humans that omega-6 fats are pro-inflammatory and that omega-3 fats are anti-inflammatory. In contrast, higher omega-6 levels are associated with lower inflammatory status, indicating that intake of omega-6 fats is not a dietary concern, and that relatively low intake of dietary omega-3 fats may lead to inflammation. Accordingly, use of the omega-6:omega-3 ratio has been rejected as an inflammation biomarker by health agencies worldwide. Numerous health and scientific organizations recommend intake of omega-6 seed oils as part of a healthy diet to replace sources of saturated fats, such as in palm and coconut oils, butter, tallow, and lard.
Political connotations Opposition to seed oils has been associated with the political right. Maya Vinokour, an assistant professor at NYU, writing for Jacobin, described the belief as "lifestyle fascism" and "right-wing masculinist discourse".: "Without ever calling themselves or decrying modern ways of living as 'degenerate,' the Johnsons slot their intention to recover a lost golden age (Brian) or attain futuristic utopia (Bryan) among myriad online wellness trends. Against this background, their contributions to right-wing masculinist discourse seem almost incidental. It is true that Liver King proscribes the consumption of seed oils as one of his 'ancestral tenets,' and that programmatic opposition to seed oils correlates with conspiratorial right-wing thinking."
Robert F. Kennedy Jr., United States Secretary of Health and Human Services since 2025, has expressed opposition to seed oils. In the 2024 U.S. presidential election, Kennedy ran as an independent candidate and campaigned on health-related misinformation.: "His followers include a chunk of the podcast-loving, seed-oil-skeptical, raw-milk-drinking crowd." In his speech suspending his campaign and endorsing that of Donald Trump, he blamed several health conditions on processed foods' inclusion of seed oils.: "Kennedy, who spent tens of minutes ranting about seed oils, estrogen and pharmaceutical companies, also promoted in his speech the same conspiracy theories against vaccines that he's lobbed for years." Later that day, Kennedy appeared alongside Trump to declare that the latter would "Make America Healthy Again," endorsing Trump's health and food policies.: Don't you want a president that's going to make America healthy again?' the famously vaccine-skeptic Kennedy asked, hours after blaming seed oils and processed foods for America's position during the Trump administration as a world leader in COVID deaths."
US vice president JD Vance has also stated that he does not cook with seed oils.: "Vance says that he doesn't cook with seed oils, a cause du jour of the online right"
In response to the growing political opposition from the Trump administration's MAHA movement, agricultural trade groups and industry lobbyists have begun campaigning to defend the safety of seed oils to lawmakers and food corporations.
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