\n<\/p>\n
Kendra Pierre-Louis: For Scientific American\u2019s Science Quickly, I\u2019m Kendra Pierre-Louis, in for Rachel Feltman.<\/p>\n
What do ready-to-bake cinnamon rolls, most french fries and many premade salad dressings have in common? They\u2019re all made with seed oils.<\/p>\n
Until fairly recently many of us might have been concerned about how much oil those foods contained rather than what kind. But these days a lot of people seem to have a problem with seed oils.<\/p>\n
If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.<\/p>\n
Everyone from so-called wellness influencers on social media to Robert F. Kennedy Jr., the secretary of health and human services, wants us to believe that seed oils are uniquely bad for us. The health secretary has gone so far as to say, without evidence, that seed oils are toxic. And some restaurants, including the salad chain Sweetgreen, are increasingly boasting of seed-oil-free options.<\/p>\n
So today we dig into seed oils: What are they, and are they secretly killing us? To answer these questions we reached out to Eric Decker. He\u2019s a professor at the Center for Agriculture, Food and the Environment at the University of Massachusetts Amherst.<\/p>\n
Hi, thanks for taking the time to speak with us today.<\/p>\n
Eric Decker: No problem. It\u2019s my pleasure.<\/p>\n
Pierre-Louis: One of the reasons we wanted to speak with you is you\u2019re something of an expert on seed oils, which have in recent years become the villain of, you know, quote, unquote, \u201cwellness\u201d social media. For me that raises a pretty natural question, which is: What is a seed oil?<\/p>\n
Decker: Basically, the fats we eat could come from animals, so that would be things like lard and tallow and butter; or they can come from fruit, and that would be things like olive and avocado; or they can come from seeds, and those seeds could be soybean, corn, canola, sunflower.<\/p>\n
Pierre-Louis: So something like corn or soybean oil would be a seed oil …<\/p>\n
Decker: Correct.<\/p>\n
Pierre-Louis: But something like olive oil or\u2014my personal nemesis because I\u2019m allergic to it\u2014avocado oil, that is not a seed oil.<\/p>\n
Decker: Correct.<\/p>\n
Pierre-Louis: But when I\u2019m looking in my kitchen cabinet I\u2019m seeing, for the most part, liquid oils that all look exactly the same. Are seed oils different, like, on a chemical level from non-seed oils?<\/p>\n
Decker: Yeah, they\u2019re gonna have a couple differences. So what makes olive oil unique is it\u2019s not a refined oil\u2014extra-virgin olive oil …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Avocado oil, sometimes it\u2019s refined; sometimes it\u2019s not refined. Most of the seed oils that we would buy at the supermarket would be refined. There are some cold-pressed seed oils, but they\u2019re pretty uncommon.<\/p>\n
So because they\u2019re refined or not refined could be one of the reasons that their composition will change. But the other thing is, is that the genetics of the plant dictates the type of fatty acids that are in the oil.<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: And so olive and avocado oil, very high in oleic acid …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Which is a monounsaturated fatty acid.<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: The seed oils, you can find a very broad range of fatty acid composition. So canola oil would be very high in monounsaturated …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Like olive oil and avocado oil. But then the others, like corn and soybean and the safflower or sunflower, these are high in polyunsaturated fatty acids, and the most common one of those is linoleic acid …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Which has two double bonds, versus the monounsaturates with one double bond.<\/p>\n
Pierre-Louis: Okay, so for a regular person who\u2019s just trying to figure out what they should eat in the grocery store aisle, these fatty acids, do they matter?<\/p>\n
Decker: Yeah, so there\u2019s really good human clinical data that show that the polyunsaturated fatty acids will decrease the LDL cholesterol in your blood. And this is important because LDL cholesterol\u2019s been associated with cardiovascular disease and heart attacks …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: So people that\u2014especially people that have high LDL …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Would benefit greatly by using a seed oil that has a high linoleic-acid concentration.<\/p>\n
Pierre-Louis: Wait, what? Because I have it on good authority from our human health secretary, Robert F. Kennedy Jr., that Americans are being \u201cunknowingly poisoned\u201d by seed oils. Here\u2019s what he said in an interview on Fox & Friends in 2024.<\/p>\n
[CLIP: RFK Jr. speaks in an August 24, 2024, interview on Fox & Friends Weekend: \u201cSeed oils are one of the, the most unhealthy ingredients that we have in foods…. Seed oils, they are associated with all kinds of very, very serious illnesses, including body-wide inflammation.\u201d]<\/p>\n
Decker: Yeah, there\u2019s a lot of theories about this. There\u2019s one theory called the omega-3\/omega-6 ratio …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: And this theory\u2014the omega-6, which is the polyunsaturated linoleic acid, is thought to increase inflammation …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Whereas the omega-3s, most of which we would get from fish oil …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Would decrease inflammation. So even though this, this is a theory and it\u2019s been shown in animals, when you actually look at human clinical trials …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: The linoleic acid, the omega-6, has not been shown to increase inflammation. So right now the research shows that the benefit of the linoleic acid in decreasing your LDL cholesterol is much greater than the potential risk of that fatty acid increasing inflammation.<\/p>\n
I mean the other controversy on the seed oil is they\u2019re extracted with hexane …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Which is a chemical solvent. But there\u2019s pretty good data that shows that for the consumer that\u2019s not really a high risk. Almost all the hexane\u2019s removed from the oil when they process it. And really, the only time you ever see hexane being a, a problem is with workers in factories that are exposed …<\/p>\n
Pierre-Louis: Yeah.<\/p>\n
Decker: To very high levels of hexane.<\/p>\n
Pierre-Louis: From the outside it often seems, when I go to the grocery store and I look at, you know, these seed oils, they\u2019re often lower-cost than some of the other oils that we\u2019re being pushed to consume instead. And I\u2019m wondering\u2014it feels like there\u2019s a little bit of classism at play here and this idea that just because it\u2019s expensive, it must be better for us.<\/p>\n
Decker: So the best example is extra-virgin olive oil. They just press out the fat, and when they press out the fat they don\u2019t get all the fat out of the olive …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: So the yield is somewhat low. Plus, olives can only be grown in warm climates, so there\u2019s …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Limitation of how much that\u2019s out\u2014there\u2019s actually some shortages that are occurring right now because of climate change. So they typically will be more expensive. And when you think about olive oil it\u2019s really\u2014has a lot of flavor to it, and that flavor is very desirable in the olive oil. And so that\u2019s why you don\u2019t wanna refine it, because it takes all the flavor out of it.<\/p>\n
The seed oils, on the other hand, are extracted with hexane …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: And when they\u2019re extracted with hexane this gets all the oil out, so it\u2019s very, very efficient. But it takes out some other fats\u2014it takes out things like phospholipids and free fatty acids and fats that aren\u2019t desirable in the oil. So the refining process removes these other lipid components from the oil, and this makes the oil very bland in flavor; it gives it really good cooking properties, like very high smoke point; and so it makes these oils very, very versatile. But because they are so efficient at extracting it, it also makes the costs much lower.<\/p>\n
Pierre-Louis: And isn\u2019t that also why people love deep-frying in peanut oil, because it has a high smoke point?<\/p>\n
Decker: Yeah, they\u2019re all pretty similar; all the refined oils are pretty similar. When you get into high saturated fats they would be a little bit higher …<\/p>\n
Pierre-Louis: Right.<\/p>\n
Decker: But, you know, peanut oil is a good one\u2014\u2019cause in a lot of those applications when you\u2019re cooking, you want bland, right? You don\u2019t wanna make your sugar cookies with olive oil.<\/p>\n
Pierre-Louis: [Laughs.]<\/p>\n
Decker: [Laughs.] So, so you want, you know, you want a bland\u2014or maybe in the case of a cookie you want butter, right? But in some applications …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: You don\u2019t want the oil to have flavor.<\/p>\n
One thing about olive oil, it\u2019s actually not good to high-temperature-cook olive oil \u2019cause it\u2019s got a low smoke point and you\u2019ll lose a lot of the flavor that you\u2019re paying for. So it\u2019s, like, you should use it in cold applications or in\u2014you know, you can use it in a frying pan, which doesn\u2019t get too hot.<\/p>\n
I think a, a risk in all oils …<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: Is if you heat \u2019em too high and they start to smoke, you\u2019re now decomposing the oil into other compounds, which have health risks. So really managing your oil when you\u2019re cooking with it and not letting it get too high of temperature and start to smoke is also very important.<\/p>\n
Pierre-Louis: Right, and that\u2019s where it comes into handy to know how to cook a little and to look for the smoke point. But I guess it feels like there\u2019s a health halo around kind of the more expensive oils and we\u2019re vilifying sort of the cheaper, more accessible oils.<\/p>\n
Decker: Yeah, I mean, extra-virgin olive oil does have this halo, and there\u2019s a lot of good research that shows that it has health benefits beyond just normal oils. A really good contrast is your favorite, avocado oil.<\/p>\n
Pierre-Louis: [Laughs.] Which, to be clear, I am only vilifying because it wants me dead, so. [Laughs.]<\/p>\n
Decker: [Laughs.] So avocado oil doesn\u2019t really have any data that shows that it has major health benefits, and actually, its fatty acid composition, in terms of the amount of monounsaturated fatty acids, is very similar to canola oil. So\u2014and when you go to the store and you look at olive oil\u2014or avocado oil, you find that a lot of times it\u2019s refined; it\u2019s not cold-pressed. And so if it\u2019s refined, then you\u2019re taking out other potential beneficial compounds in the oil, and it becomes even more like canola oil, except it\u2019s probably four times more expensive.<\/p>\n
So it\u2019s more that people are making these cold-pressed oils into being these superfoods when there\u2019s really no evidence to show, especially with avocado oil, that that\u2019s true.<\/p>\n
Pierre-Louis: That\u2019s, A, awesome to know, and, B, I hope the word gets out because people are putting avocado oil in everything for no reason [Laughs], as someone who\u2019s allergic.<\/p>\n
But something I\u2019ve noticed is that the people who really hate seed oils aren\u2019t just pushing other plant-based oils, like olive or palm oils. They\u2019re really pushing for us to use animal fats, like butter or rendered beef, a.k.a. tallow.<\/p>\n
You\u2019ve probably heard that the fast-food chain Steak \u2019n Shake, for example, has said it\u2019s gonna eliminate seed oils in favor of beef tallow. And actually, if you go on the website, they\u2019re selling jars of beef tallow. And this kind of makes me think\u2014Steak \u2019n Shake is just fundamentally processed fast foods. And I can\u2019t imagine that even if you were to switch whatever oil they were using before for a, quote, unquote, \u201chealthier\u201d oil, it\u2019s gonna make that much big of a difference in the health of ordinary people.<\/p>\n
Decker: Yeah, there\u2019s two parts of this controversy. One is that some people don\u2019t feel that saturated fats are that bad for you, but again, there\u2019s pretty good clinical evidence to show that saturated fats increase your LDL cholesterol. They do the opposite of the polyunsaturated fats. So especially if you were to replace polyunsaturated fats with saturated fats, you would decrease the benefit of the healthy polyunsaturated fats in your diet.<\/p>\n
However, on the other side, there\u2019s an oxidation that occurs in oils, and when those oils oxidize they start to decompose into a whole variety of compounds, some of which, in animal studies, have shown to have some toxicity. So if you do something, like, in, uh, food-service operations and you deep-fry foods with these highly polyunsaturated fatty acids, they can oxidize and produce these products, where if you use something like tallow, which is saturated, it\u2019s much more stable against the oxidation and doesn\u2019t present, again, that risk.<\/p>\n
Now, as long as you take care of the oil that you\u2019re using in the fryer, there\u2019s no real risk there. The risk becomes\u2014is when the oil is not used properly.<\/p>\n
Pierre-Louis: And what does \u201cused properly\u201d mean?<\/p>\n
Decker: It just means you have to make sure that you maintain the oil in the freshest state possible. Good food-service operations will actually filter and clean their oil on a regular basis. And then you have to monitor the oil, and when it gets to be older you need to discard and start with fresh oil.<\/p>\n
Pierre-Louis: In a way you\u2019re saying that using beef tallow gives fast-food restaurants an easier margin, so they\u2019re able to, essentially, use older oil than they would if they were using a seed oil.<\/p>\n
Decker: Yeah, the, the tallow would last a lot longer. And it costs a lot of money to fill up that fryer with oil, as you can imagine, so the longer you can make your oil last, the more money you\u2019ll save.<\/p>\n
Now, another part of beef tallow is that beef tallow can have very positive flavors to it.<\/p>\n
Pierre-Louis: Mm-hmm.<\/p>\n
Decker: So for many years McDonald\u2019s used beef tallow. And then what happened is people were concerned about the cholesterol in the beef tallow, so McDonald\u2019s stopped using the beef tallow. But many times if you go to fancy restaurants, you can get fries that are cooked in beef tallow\u2014or even duck fat …<\/p>\n
Pierre-Louis: Yeah.<\/p>\n
Decker: Sometimes you see duck-fat fries. And that\u2019s part of the advantage of that, is you\u2019re getting a flavor in addition to the stability of the fat.<\/p>\n
Pierre-Louis: And it also just sort of seems like for your everyday, you\u2019re not looking for a flavor, maybe you\u2019re making a stir-fry, a seed oil is fine. If you really want, like, a strong\u2014like, maybe you\u2019re making a pasta dish or a salad, that\u2019s a really good place to use your extra-virgin olive oil because it adds a really good flavor profile.<\/p>\n
Decker: Exactly.<\/p>\n
Pierre-Louis: And to be clear, I love a good duck-fat french fry; they are very tasty. But I\u2019m also not under the belief system that a potato deep-fried in duck fat is heart-healthy. [Laughs.] I\u2019m not making a health claim. And I think the thing that, with seed oils in particular, is many of the people who are vilifying them is they\u2019re making an explicit health claim and telling people to eat diets that are really heavy in these saturated fats and to really pivot away from eating, you know, canola oil or oils that are, for many people, lower-cost, more accessible and\u2014it seems to be, based on the available evidence\u2014better for our health.<\/p>\n
Decker: Yeah, I mean, I would say that the influencers who have had so many negative comments about seed oil, those aren\u2019t really based on strong scientific evidence.<\/p>\n
And you know, like you said, the recommendation should really be, \u201cEat less fried food,\u201d right, because fried food\u2019s gonna be, generally, very high in calories. If it\u2019s potatoes or chicken nuggets, it\u2019s not gonna be very high in positive nutrients.<\/p>\n
So the messaging is\u2014seems to be all messed up. We shouldn\u2019t worry about, \u201cIs seed oil better than tallow?\u201d We should be worried about people that eat so much fried food in their diet.<\/p>\n
Pierre-Louis: That\u2019s our show. Join us on Friday, when we\u2019ll dig into Venezuela\u2019s oil reserves and why the U.S. seems to want it.<\/p>\n
Science Quickly is produced by me, Kendra Pierre-Louis, along with Fonda Mwangi, Sushmita Pathak and Jeff DelViscio. This episode was edited by Alex Sugiura. Shayna Posses and Aaron Shattuck fact-check our show. Our theme music was composed by Dominic Smith. Subscribe to Scientific American for more up-to-date and in-depth science news.<\/p>\n
For Scientific American, this is Kendra Pierre-Louis. See you next time!<\/p>\n","protected":false},"excerpt":{"rendered":"
Kendra Pierre-Louis: For Scientific American\u2019s Science Quickly, I\u2019m Kendra Pierre-Louis, in for Rachel Feltman. What do ready-to-bake cinnamon rolls, most french fries and many premade salad dressings have in common? They\u2019re all made with seed oils. Until fairly recently many of us might have been concerned about how much oil those foods contained rather than<\/p>\n","protected":false},"author":1,"featured_media":41714,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[50],"tags":[1295,10396,205,1379,22161,6551,204,4982],"class_list":{"0":"post-41713","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-bad","9":"tag-debunking","10":"tag-media","11":"tag-myth","12":"tag-oils","13":"tag-seed","14":"tag-social","15":"tag-viral"},"_links":{"self":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/41713","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=41713"}],"version-history":[{"count":0,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/41713\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/media\/41714"}],"wp:attachment":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=41713"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41713"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}