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.[1]
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.) [10] Critics "hateful eight" oils consist of seed oils: canola, corn, cottonseed, soy, sunflower, safflower, grapeseed, and rice bran[11] 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.[12] 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. Compared to lard, Crisco is cheaper, easier to stir into a recipe, and can be stored at room temperature for two years without expiring.
Critics of seed oils often point to the health hazards of the solvents used in the industrial process of generating vegetable oils.[13]Hexane, which can be neurotoxic, is extremely effective at oil extraction.[14] Thus, it is often quoted as a danger when consuming vegetable oils as it can be found in finished oils in trace amounts.[15] The United States Environmental Protection Agency studied the toxicity of hexane extensively in the 1980s.[16] The studies found that the hexane used in industrial processes was safe for consumption and did not cause nerve damage.[17]
Processed oils have a higher proportion of omega-6 fatty acids than oils from fish and walnuts. Omega-6 fatty acids constitute a growing proportion of Americans' fat intake and have been hypothesized to contribute to several negative health effects, including inflammation[18] and immunodeficiency.[19] In humans, most cardiovascular health researchers believe omega-6 fatty acids are safe and healthy.[20] The American Heart Association has stated that a reduction in omega-6 fatty acids could lead to an increase, not reduction, in cardiovascular disease.[21] Omega-6 fatty acids are significantly associated with a lowered risk of cardiovascular disease.[22] Research indicates that consumption of omega-6 fatty acids has little effect on inflammatory bowel disease.[23]
Opposition to seed oils has been associated with the political right. Professor of Russian studies Maya Vinokour described the belief as "lifestyle fascism" and "right-wing masculinist discourse."[7]
Former independent U.S. Presidential candidate Robert F. Kennedy Jr. campaigned on health-related conspiracy theories and attracted support from voters opposed to seed oils.[24] In his speech suspending his campaign and endorsing that of Donald Trump, he blamed several health conditions on processed foods' inclusion of seed oils.[25] Later that day, Kennedy appeared alongside Trump to declare that the latter would "make America healthy again," endorsing Trump's health and food policies.[26] Trump's running-mate, JD Vance, has stated that he does not cook with seed oils.[27]
Zaleski 2021: "Last year, Joe Rogan talked to doctor and carnivore diet evangelist Paul Saladino about this for more than three hours."
Williams 2022: "[T]he interview with Saladino resonated with Rogan's curious, hungry, and enormous audience"
Carleton 2022: "Take Dr. Paul Saladino, the doctor behind the Carnivore Diet, which recommends replacing plant foods with meat, for example—he spent three hours on the Joe Rogan Experience in 2020 describing the harms of seed oils, among other fringe views, including that doing cold plunges has the same health benefits as consuming a plate of vegetables. His name is often mentioned on this section of the internet, (one redditor attributed the proliferation of anti-seed oil sentiment entirely to his appearance on the podcast)."
Saladino 2020, 58:23: "I think it's important to understand what we talked about, processed vegetable oils and processed sugars, hugely bad for humans."
^Harvard University 2022: "[P]ushed back on the idea that these oils cause health ills ranging from headaches to heart disease."
^Bailey 2023: "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.'"
^Liao 2022: "[T]hey're blamed for a host of ills, such as headaches, foggy thinking, lowered immunity, heart disease, type 2 diabetes, and more."
^Williams 2022: "[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"
^ abVinokour 2024: "Without ever calling themselves Übermenschen 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."
Zaleski 2021: "On another podcast in 2020, board-certified family physician Cate Shanahan referred to the most common seed oils on the market today as the 'hateful eight,' to be avoided at all costs."
Bailey 2023: "The prime sources of linoleic acid in modern diets are seed oils including soybean, corn, cottonseed, sunflower, canola, safflower, rice bran, and grapeseed oils. The use of these oils has increased in modern diets, and they have been dubbed by some self-proclaimed health and wellness gurus as the 'hateful eight.'"
Lusas et al. 2017, p. 902: "Canola oil, which contains less than 2% erucic acid compared with 20-40% in earlier rapeseeds, was granted GRAS (generally recognized as safe) status by the US-FDA in 1985"
Eskin et al. 2020, p. 5: "In 1985, canola received Generally Recognized as Safe (GRAS) status in the United States"
Sharmila et al. 2020, p. 174: "Seed oil is a form of vegetable oil mainly extracted from seeds of various fruits and vegetables."
Gaber et al. 2023: "Seed oils are extracted from the seed (endosperm) of some plants such as canola, sunflower, and soybeans. This is commonly achieved through industrial processing of thermally conditioned flaked seeds using expellers to extract the oil mechanically."
Zaleski 2021: "On another podcast in 2020, board-certified family physician Cate Shanahan referred to the most common seed oils on the market today as the 'hateful eight,' to be avoided at all costs."
Bailey 2023: "The prime sources of linoleic acid in modern diets are seed oils including soybean, corn, cottonseed, sunflower, canola, safflower, rice bran, and grapeseed oils. The use of these oils has increased in modern diets, and they have been dubbed by some self-proclaimed health and wellness gurus as the 'hateful eight.'"
^Ramsey & Graham 2012: "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."
^Dennett 2023, p. 18: "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."
^Wakelyn & Wan 2003, p. 365: "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."
^Cravotto et al. 2022, p. 18: "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"
^Environmental Protection Agency 1988, p. 3382: "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."
Wakelyn & Wan 2003, p. 366: "[C]ommercial hexane, which contains 52% n-hexane and a mixture of hexane isomers (see composition below), does not cause peripheral nerve damage in animals."
Galvin 1997, p. 83: "The sum total of this mandated testing program indicates that C. hexane is a relatively safe chemical. It is not a neurotoxicant (as is pure n-hexane). It does not cause cancer in rodents in a mechanism relevant to humans as demonstrated by these studies. Commercial hexane has gone through an extensive EPA-mandated testing program. All the tests to date have shown C. hexane to be rather innocuous."
^Ball & Burch 2024: "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."
Myles 2014, p. 4: "Thus, another potential contributor to modern diet-induced immune dysfunction may be the increased consumption of omega-6 in lieu of omega-3 fatty acids."
Harvard University 2019: "The critics argue that we should cut back on our intake of omega-6 fats to improve the ratio of omega-3 to omega-6s."
^Harvard University 2019: "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."
Harris et al. 2009, p. 904: "The data also suggest that higher intakes appear to be safe and may be even more beneficial (as part of a low–saturated-fat, low-cholesterol diet). In summary, the AHA supports an omega-6 PUFA intake of at least 5% to 10% of energy in the context of other AHA lifestyle and dietary recommendations. To reduce omega-6 PUFA intakes from their current levels would be more likely to increase than to decrease risk for CHD."
Petersen 2024: "Seed oils, especially safflower oil, sunflower oil, corn oil and soybean oil, are rich in a kind of unsaturated fat called omega-6. Scientific studies have found that when people swap out some of the saturated fats in their diets (from foods such as butter and red meat) and replace them with omega-6 fats, their levels of LDL cholesterol (the 'bad' cholesterol) lower. Their risk of heart attacks and death from cardiac events also drops."
^Ajabnoor et al. 2021; Dennett 2023, p. 18: "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."
^Hitchens 2023: "His followers include a chunk of the podcast-loving, seed-oil-skeptical, raw-milk-drinking crowd."
^Eckstein 2024a: "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."
^Eckstein 2024b: "'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."
^Breland 2024: "Vance says that he doesn't cook with seed oils, a cause du jour of the online right"
Ajabnoor, Sarah M.; Thorpe, Gabrielle; Abdelhamid, Asmaa; Hooper, Lee (2021). "Long-term effects of increasing omega-3, omega-6 and total polyunsaturated fats on inflammatory bowel disease and markers of inflammation: a systematic review and meta-analysis of randomized controlled trials". European Journal of Nutrition. 60 (5): 2293–2316. doi:10.1007/s00394-020-02413-y. PMID33084958.
Eskin, Michael N. A.; Aladedunye, Felix; Unger, Ernie H.; Shah, Saleh; Chen, Guanquin; Jones, Peter J. (2020). "Canola oil". In Shahidi, Fereidoon (ed.). Bailey's Industrial Oil and Fat Products. Wiley. pp. 1–63. doi:10.1002/047167849X.bio004.pub2. ISBN978-0-471-38460-1.
Gaber, Mohamed A. Fouad M.; Logan, Amy; Tamborrino, Antonia; Leone, Alessandro; Romaniello, Roberto; Juliano, Pablo (2023). "Innovative technologies to enhance oil recovery". In Gallegos, Crispulo; Ruiz-Méndez, Maria-Victoria (eds.). Advances in Food and Nutrition Research. Vol. 105. Academic Press. pp. 221–254. doi:10.1016/bs.afnr.2023.01.002. ISBN978-0-443-18590-8. OCLC1400102687. OL28018461W.
Galvin, Jennifer B. (1997). "Toxicity data for commercial hexane and hexane isomers". In Wan, Peter J.; Wakelyn, Phillip J. (eds.). Technology and Solvents for Extracting Oilseeds and Nonpetroleum Oils. Champaign, Illinois: AOCS Press. pp. 75–85. ISBN978-0-935315-81-3. OCLC37761985. OL19223158W.
La Pera, Lara; Pellicanò, Teresa Maria; Lo Turco, Pellicano Vincenzo; Di Bella, Giuseppa; Dugo, Giacomo (2010). "Inorganic anions in olive oils: Application of suppressed ion exchange chromatography (IEC) for the analysis of olive oils produced from de-stoned olives and traditional extraction methods". In Preedy, Victor R.; Watson, Ronald Ross (eds.). Olives and Olive Oil in Health and Disease Prevention. Academic Press. pp. 317–324. doi:10.1016/B978-0-12-374420-3.00035-8. ISBN978-0-12-374420-3. OCLC610009055. OL16940721W.
Louis, Winnifred; Davies, Sarah; Smith, Joanne; Terry, Deborah (2007). "Pizza and pop and the student identity: The role of referent group norms in healthy and unhealthy eating". The Journal of Social Psychology. 147 (1): 57–74. doi:10.3200/SOCP.147.1.57-74. PMID17345922.
Lusas, Edmund W.; Riaz, M. N.; Alam, M. S.; Clough, R. (2017). "Animal and vegetable fats, oils, and waxes". In Kent, James A.; Bommaraju, Tilak V.; Barnicki, Scott D. (eds.). Handbook of Industrial Chemistry and Biotechnology. Cham, Switzerland: Springer. pp. 823–932. doi:10.1007/978-3-319-52287-6_14. ISBN978-3-319-52285-2. OCLC999636728. OL19854408W.
Marklund, Matti; Wu, Jason H.Y.; Imamura, Fumiaki; Del Gobbo, Liana C.; Fretts, Amanda; de Goede, Janette; Shi, Peilin; Tintle, Nathan; Wennberg, Maria; Aslibekyan, Stella; Chen, Tzu-An; de Oliveira Otto, Marcia C.; Hirakawa, Yoichiro; Eriksen, Helle Højmark; Kröger, Janine; Laguzzi, Federica; Lankinen, Maria; Murphy, Rachel A.; Prem, Kiesha; Samieri, Cécilia; Virtanen, Jyrki; Wood, Alexis C.; Wong, Kerry; Yang, Wei-Sin; Zhou, Xia; Baylin, Ana; Boer, Jolanda M.A.; Brouwer, Ingeborg A.; Campos, Hannia; Chaves, Paulo H. M.; Chien, Kuo-Liong; de Faire, Ulf; Djoussé, Luc; Eiriksdottir, Gudny; El-Abbadi, Naglaa; Forouhi, Nita G.; Michael Gaziano, J.; Geleijnse, Johanna M.; Gigante, Bruna; Giles, Graham; Guallar, Eliseo; Gudnason, Vilmundur; Harris, Tamara; Harris, William S.; Helmer, Catherine; Hellenius, Mai-Lis; Hodge, Allison; Hu, Frank B.; Jacques, Paul F.; Jansson, Jan-Håkan; Kalsbeek, Anya; Khaw, Kay-Tee; Koh, Woon-Puay; Laakso, Markku; Leander, Karin; Lin, Hung-Ju; Lind, Lars; Luben, Robert; Luo, Juhua; McKnight, Barbara; Mursu, Jaakko; Ninomiya, Toshiharu; Overvad, Kim; Psaty, Bruce M.; Rimm, Eric; Schulze, Matthias B.; Siscovick, David; Skjelbo Nielsen, Michael; Smith, Albert V.; Steffen, Brian T.; Steffen, Lyn; Sun, Qi; Sundström, Johan; Tsai, Michael Y.; Tunstall-Pedoe, Hugh; Uusitupa, Matti I. J.; van Dam, Rob M.; Veenstra, Jenna; Monique Verschuren, W.M.; Wareham, Nick; Willett, Walter; Woodward, Mark; Yuan, Jian-Min; Micha, Renata; Lemaitre, Rozenn N.; Mozaffarian, Dariush; Risérus, Ulf (2019). "Biomarkers of dietary omega-6 fatty acids and incident cardiovascular disease and mortality: An individual-level pooled analysis of 30 cohort studies". Circulation. 139 (21): 2422–2436. doi:10.1161/CIRCULATIONAHA.118.038908. hdl:1871.1/0b141433-4a11-4053-a505-c2ed9696b5cf. PMC6582360. PMID30971107.
Sharmila, V. Godvin; Kavitha, S.; Obulisamy, Parthiba Karthikeyan; Rajesh Banu, J. (2020). "Production of fine chemicals from food wastes". In Rajesh Banu, J.; Kumar, Gopalakrishnan; Gunasekaran, M.; Kavitha, S. (eds.). Food Waste to Valuable Resources: Applications and Management. Academic Press. pp. 163–188. doi:10.1016/B978-0-12-818353-3.00008-0. ISBN978-0-12-818353-3. OCLC1153831835. OL20736477W.
Su, Hang; Liu, Ruijie; Chang, Ming; Huang, Jianhua; Wang, Xingguo (2017). "Dietary linoleic acid intake and blood inflammatory markers: a systematic review and meta-analysis of randomized controlled trials". Food & Function. 8 (9): 3091–3103. doi:10.1039/C7FO00433H. PMID28752873.
Tung, Shih-Jui; Tsay, Jenner C.; Lin, Meng-Chu (2015). "Life course, diet-related identity and consumer choice of organic food in Taiwan". British Food Journal. 117 (2): 688–704. doi:10.1108/BFJ-11-2013-0334.
Wakelyn, Phillip J.; Wan, Peter J. (2003). "Solvent extraction: Safety, health, and environmental issues". In Tzia, Constantina; Liadakis, George (eds.). Extraction Optimization in Food Engineering. New York: Marcel Dekker, Inc. pp. 359–396. doi:10.1201/9780824756185-19. ISBN978-0-429-16457-6. OCLC54108923. OL19618454W.
Wakelyn, Phillip J.; Wan, Peter J. (2006). "Solvent extraction to obtain edible oil products". In Akoh, Casimir C. (ed.). Handbook of Functional Lipids. Functional Foods and Nutraceuticals Series. Boca Raton, Florida: Taylor & Francis. pp. 89–131. ISBN978-0-8493-2162-7. OCLC86117425. OL19126779W.
Vinokour, Maya (January 10, 2024). "Beware lifestyle fascism". Ideology. Jacobin. Archived from the original on January 10, 2024. Retrieved August 30, 2024.
Zumpano, Julia (October 4, 2023). "Seed oils: Are they actually toxic?". Health Essentials. Cleveland, Ohio: Cleveland Clinic. Archived from the original on July 18, 2024. Retrieved July 26, 2024.
"No need to avoid healthy omega-6 fats". Harvard Health Publishing. Boston, Massachusetts: Harvard Medical School. August 20, 2019. Archived from the original on December 15, 2019. Retrieved August 28, 2024.
"Should I be concerned about seed oils?". Nutrition Connection. Fort Collins, Colorado: Colorado State University Kendall Reagan Nutrition Center. 2023. Archived from the original on January 16, 2024. Retrieved July 26, 2024.