Seed Oils: Are They Really as Bad as Social Media Says?
Nutrition fact-check | Separating social media claims from nutrition science
Written by Amelia Brunet, MS, RD
Registered Dietitian
If you’ve spent any time on social media lately, you’ve probably seen someone telling you to throw out your canola oil, avoid anything containing soybean oil, and switch to cooking exclusively with beef tallow or butter.
Apparently, seed oils are the latest ingredient we’re supposed to be afraid of.
The claims are pretty dramatic. Seed oils are supposedly inflammatory, toxic, harmful to your hormones, and responsible for everything from chronic disease to weight gain. And, as is usually the case with nutrition trends, the advice is delivered with a whole lot of confidence and not always a whole lot of context.
So, are seed oils actually bad for you? Should you be avoiding them? And is swapping your canola oil for beef tallow really the health upgrade the internet claims it is?
Let’s break it down.
First, what exactly are seed oils?
Seed oils are vegetable oils extracted from the seeds of certain plants. They’re commonly used in home cooking, packaged foods, restaurants, and food manufacturing because they’re affordable, versatile, and relatively neutral in flavor. Some common examples include: canola, soybean, sunflower, corn, safflower, cottonseed.
Most of these oils contain varying amounts of unsaturated fats, particularly polyunsaturated fatty acids (PUFAs). Many are also sources of linoleic acid, an essential omega-6 fatty acid.
Most importantly: essential means your body needs it but cannot produce it on its own. Linoleic acid plays a role in cell membranes, growth, and normal physiological function. It is not inherently harmful simply because it is an omega-6 fatty acid.
Claim #1: Seed oils cause inflammation.
This is probably the biggest claim driving the anti-seed-oil movement. The argument usually goes something like this: seed oils contain high amounts of omega-6 fatty acids, omega-6 fats promote inflammation, and therefore eating seed oils leads to chronic inflammation.
Sounds logical when presented that way. But human nutrition doesn’t work quite so simply.
Omega-6 fatty acids are involved in the production of signaling molecules that participate in inflammatory processes. However, that doesn’t mean eating omega-6 fats automatically causes chronic inflammation.
Research examining linoleic acid intake in humans has generally not found that higher linoleic acid consumption increases common markers of inflammation. Some studies have found neutral effects, while others have reported potentially beneficial changes depending on the population and dietary context.
It’s also worth remembering that inflammation is a normal, necessary part of the body’s immune response and tissue repair. The goal isn’t to eliminate inflammation altogether. It’s to support normal inflammatory regulation.
The takeaway: Current human evidence does not support the broad claim that seed oils cause chronic inflammation simply because they contain omega-6 fatty acids.
Claim #2: Seed oils are worse for you than butter, coconut oil, or beef tallow.
As seed oils have fallen out of favor on social media, animal fats and other saturated-fat-rich alternatives have gained popularity. Beef tallow, butter, and coconut oil are increasingly marketed as more natural or healthier cooking options.
But natural doesn’t automatically mean healthier by looking at the fat composition of some common cooking fats. For example:
Canola oil: Mostly monounsaturated and polyunsaturated
Soybean oil: Mostly polyunsaturated
Sunflower oil: Mostly polyunsaturated
Olive oil: Mostly monounsaturated
Butter: Mostly saturated
Beef tallow: Mostly saturated and monounsaturated
Coconut oil: Predominantly saturated
Why does this matter?
The type of fat you consume can influence your blood lipid profile, including LDL cholesterol, which is a well-established risk factor for cardiovascular disease. Replacing saturated fats with unsaturated fats, particularly polyunsaturated fats, generally lowers LDL cholesterol. Research also suggests that replacing saturated fats with polyunsaturated fats can reduce cardiovascular risk.
A 2025 cohort study summarized by the Academy found that greater intake of plant-based oils was associated with lower mortality, while greater butter intake was associated with higher mortality. The study also reported an association between replacing butter with plant-based oils and lower mortality. These findings are observational, meaning they cannot establish that the oils themselves caused the differences.
This doesn’t mean butter or beef tallow can never be part of a healthy diet. It simply means that replacing unsaturated oils with large amounts of saturated fat isn’t automatically a health improvement.
The takeaway: When comparing cooking fats, consider the fatty acid composition and what one fat is replacing, rather than relying on labels like natural, traditional, or seed-oil-free.
Claim #3: The omega-6 to omega-3 ratio is ruining our health.
You’ve probably heard that modern diets contain too many omega-6 fats and not enough omega-3 fats.
There is some truth to that fact that many Western dietary patterns are relatively low in omega-2 rich foods and contain substantial amounts of omega-6 fats. But the idea that there’s one ideal omega-6 to omega-3 ratio everyone must achieve is not well established.
Omega-3 and omega-6 fatty acids are both essential. They play different but interconnected roles in the body.
Omega-3 fats, particularly EPA and DHA, are involved in normal cardiovascular and neurological functions. Omega-6 fats, including linoleic acid, are important for cell membranes and normal growth and development.
While some omega-6 derived compounds participate in inflammation, this does not mean that dietary omega-6 intake necessarily promotes chronic inflammation. Human intervention studies have generally not found that increasing linoleic acid raises common inflammatory markers.
Instead of obsessing over a numerical ratio, a more practical approach is to regularly include omega-3-rich foods in your diet.
Think: salmon, sardines, trout, chia seeds, ground flaxseed, walnuts & hemp seeds.
And remember, many nutritious foods contain both omega-3 and omega-6 fats. You don’t have to eliminate one to benefit from the other.
The takeaway: Focus on getting adequate omega-3s while maintaining a balanced intake of essential fats. You don’t need to calculate your omega-6 to omega-3 ratio at every meal.
So, should you avoid seed oils?
Short answer: no, there’s no compelling evidence that most people need to eliminate seed oils from their diet.
The available human research generally supports the use of unsaturated plant oils, particularly when they replace saturated fats. This doesn’t mean every food containing soybean oil or sunflower oil is automatically nutritious. It means that the presence of seed oil alone is not a useful measure of a food’s overall healthfulness.
If you enjoy cooking with olive oil, use it. If you prefer canola oil for roasting or baking, that’s perfectly reasonable, too. If you occasionally use butter for flavor, there’s room for that as well.
The goal isn’t to find one perfect cooking fat. It’s to build a dietary pattern that supports your health, meets your nutritional needs, and is realistic enough to maintain.
Your health isn’t determined by whether you cook with canola oil or butter. It’s influenced by the bigger picture: your overall eating pattern, lifestyle, genetics, and long-term habits.
So the next time a social media video tells you to throw out every bottle of vegetable oil in your pantry, take a breath. You probably don’t need a kitchen overhaul. You may just need a little more nutrition context.
IN CLOSING
Feeling overwhelmed by all the nutrition advice you see online? That’s where I can help. As a registered dietitian, my goal is to help you cut through the noise, separate nutrition facts from social media trends, and feel confident in the choices you’re making for your health. Nutrition isn’t one-size-fits-all, and you don’t need to follow every new trend or fear every ingredient to make progress. Let’s make nutrition feel a little less confusing and a lot more sustainable. - LEARN MORE
References
Academy of Nutrition and Dietetics.
Nutrition Fact Check: Seed Oils
(updated June 2025). This is the primary reference for the discussion of fatty acid composition, inflammation, processing, and current research.Farvid MS, et al. Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies. Circulation. 2014;130(18):1568–1578.
Hooper L, et al. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database of Systematic Reviews. 2020;8(8):CD011737.
Schwingshackl L, et al. Effects of oils and solid fats on blood lipids: a systematic review and network meta-analysis. Journal of Lipid Research. 2018;59(9):1771–1782.
