In general, people on the internet are always looking for the next big food fad, the next magic bullet, whether it’s something to add or remove from our diets to get rid of all our problems with health.
Nowhere is that tendency more acute than on TikTok, where food-related topics go viral in an instant (and often, disappear quickly). But one of them seems to have some staying power: Warnings on the risks of seed oils.
Health gurus on TikTok say seed oils are toxic, causing everything from acne and weight gain to cancer and infertility. But what is the truth? As is often the case, the reality is much more than what TikTok usually reveals.
Registered dietitian Julia Zumpano, RD, LD, explains what seed oils are, what they can do for your body and whether you should cut them out for good or just focus on a healthy, balanced diet (hint: It’s the latter).
What are seed oils?
Seed oils are plant-based cooking oils made from — you guessed it — the seeds of various plants. These seeds (we’ll share the full list in a moment) are made into oil that can be used for cooking and baking.
“It’s made through a chemical process where it’s bleached, refined and heated for use,” Zumpano explained.
You can use seed oils at home, like adding a few tablespoons to a healthy muffin recipe or using one to pan-fry some potato pancakes. And these oils are often used in restaurants, where canola oil, in particular, is the oil of choice for deep frying.
What seed oils are included?
Seed oils first emerged in the late 1900s as an alternative to partially hydrogenated oils. Here are eight seed oils that are commonly used and discussed:
- Canola oil (aka rapeseed oil).
- Corn oil.
- Cotton seed.
- Grapeseed oil.
- Soybean oil.
- Sunflower oil.
- Safflower oil.
- Rice bran oil
- Peanut oil.
You may hear this group of seed oils referred to as the “hateful eight,” a reference to some people’s belief that they are toxic and should be completely removed from your diet. But is the problem with the seed oils themselves or the way they are used?
“Most of the seed oils are consumed in the form of processed packaged foods, fast food and take out,” says Zumpano. “That’s where most of the danger lies.”
Let’s check that out…
Are seed oils bad?
Yes and no (but mostly yes). Because of the way they are made, seed oils are often highly processed. Even worse than that, though, they’re often used to make ultra-processed foods — think fast food burgers and fries and anything else you’d eat at a state fair or get at a grocery store package.
“The oil seeds themselves contain high levels of omega-6 fats, which can lead to inflammation.” Zumpano says, “and it is often used to make ultra-processed foods, which cause inflammation in the body.”
Keep in mind that it is sometimes added to foods marketed as “healthy,” including whole-grain crackers or bread products, protein bars or shakes, sauces, dressings, some frozen foods and even chocolate.
To better understand what it all means for your health, Zumpano helps us sort out the issues with seed oils and how they are used.
They are always processed
Some of these oils would be high in vitamin E and phenols, if not for the refining process itself. Alas…
“Most seed oils go through a refining process, which includes bleaching and deodorizing,” Zumpano explains. “This helps with flavor, color and shelf life, but it also removes antioxidants from the oil.”
The end result is oils with no real health benefits and more than a few health risks.
They are often used in unhealthy foods
Seed oils are not necessary GOOD for you But the real reason they are considered as such BAD for you is the way it is usually used.
“Most of the oil seeds are consumed in the form of processed packaged foods, fast foods and take-out, and even foods that are considered minimally processed but still packaged,” Zumpano reiterated. And therein lies the danger.
Outside of your own home, you are likely to use seed oils when you eat something that that bad for your health — stuff that’s also full of fat, sugar and sodium. It’s not a bad idea to take a look at your wardrobe too, because these oils are so plentiful that it’s wise to avoid them or seriously limit them wherever you can.
They contribute to inflammation in your body
Seed oils are high in omega-6 fatty acids, a type of polyunsaturated fat that isn’t necessarily bad for you. In fact, your body needs less of it! In small amounts, it is good for your cholesterol and helps protect you from heart disease.
But American diets usually include that so many omega-6s. This throws off your body’s ratio of omega-6 fatty acids to omega-3 fatty acids, which leads to inflammation in the body.
While a little inflammation is actually a good thing (it’s your body’s way of repairing cell damage), chronic inflammation is definitely not. It is associated with conditions such as:
“If a food is high in oils that contain a lot of omega-6, you want to avoid it or eat it in moderation,” advises Zumpano.
Should you avoid all seed oil?
If you want to stop consuming seed oils, there are no harms. But Zumpano says you’d be wiser to commit to avoiding processed foods. This is a step that naturally results in scaling back the seed oils, while also allowing you to use them in smaller amounts.
“When you cut out seed oils from your diet, what you’re doing is cutting out a lot of processed foods,” he added. “I think that’s why we hear about them being so bad for your health. But it’s less about the seed oils themselves and more about the fact that they’re often found in ultra-processed foods .
But what about using seed oils at home? Should you throw away the bottle of sunflower oil on your shelf? Experts probably have different opinions on this, but Zumpano believes that they should be limited to home cooking.
“They’re not necessarily the best oil choices,” he said. “But when used in moderation in home cooking, it’s not as bad for you as when you get it from ultra-processed foods, fast food and fried foods.”
However, he recommends most cooking with alternative oils that provide more omega-3s, such as avocado oil or olive oil (more on that in a minute).
And remember, too, that you want to try to increase your omega-3 intake and limit your omega-6s.
“Omega-3s are so important for overall health that we really need to make an effort to get them in our diets,” Zumpano said. “Omega-6, on the other hand, is abundant in Western diets.”
The omega-6 to omega-3 ratio should ideally be 2:1 or 1:1, but for most Americans, the ratio is actually a whopping 10:1 or even 20:1.
If you want to cook with seed oils at home, use them regularly and in small amounts. Importantly, you should also buy pure and unrefined versions, which are not as processed and retain some of their nutrients.
Good substitutes for seed oils
Sometimes frying your breakfast potatoes in a little organic, unrefined sunflower oil won’t harm your body. But Zumpano says there are healthier oils to choose from, so you’re better off just using one of them.
He recommends using extra-virgin olive oil (EVOO) for low-heat cooking and avocado oil for high-heat cooking. They are both high in heart-healthy omega-3 fatty acids instead of extra omega-6.
“Both of these oils have been clinically shown to be higher in monounsaturated fat,” shared Zumpano. “They’re not seed-based, and they don’t go through the same kind of processing, so they’re less refined and have more nutritional benefits.”
Limit your use of oil
In general, it’s best to go easy on oils, seeds and otherwise. And this is especially true when you go out to eat, because most restaurants use cheap cooking oils – that is, refined cooking oils.
But instead of specifically focusing on removing seed oils from your diet, Zumpano reiterates that your first step should be to try to eliminate ultra-processed foods from your diet as much as possible.
“Try to cook at home as much as possible and buy foods with simple ingredients,” he said. “That’s always my No. 1 recommendation.”
Doing so will naturally reduce your intake of seed oil while preventing you from, say, going out to dinner with a friend or having some potato chips at a party. And eating well at home helps balance out the times you eat out and doesn’t have a handle on every single ingredient you consume.
“Eating whole, unprocessed foods at home gives you a bit of a buffer when you go out to eat,” Zumpano says. “If you can maintain and manage what you eat most of the time, then other times won’t have a big impact on your health.”