The Top 8 Seed Oils To Avoid (+ Exactly What You Should Be Using Instead)

In my telehealth functional medicine clinic, one of the questions I get asked most often is, “What oil is safe to cook with?” and “What are the top seed oils to avoid?” You’ve probably heard the buzz around seed oils lately and their potential negative effects on your health. In fact, the conversation has become so mainstream that even some major food brands and restaurants are making the switch to alternatives like avocado oil. But is avoiding seed oils really that important? And the answer (according to this functional medicine expert) is without hesitation, yes!

While it’s not always black and white when it comes to choosing the best cooking oil, I’m more concerned with what you shouldn’t be using on a regular basis. So let’s break down which seed oils to avoid, what makes them problematic for your health, and exactly what you should use instead.

What are seed oils

On the surface, seed oils don’t actually sound that bad for you. After all, they are just oils that have been extracted from the seeds of various plants. They were first introduced in the early 1900s and have steadily grown in popularity over time, being used in everything from restaurants to your favorite bag of potato chips. In fact, seed oils are in more products that you probably realize:

• Coffee creamer
• Salad dressing
• Nut butters
• Cereal
• Bread and other baked goods

These oils, often labeled generically as vegetable oil, have become so ubiquitous in your food system because they come mostly from government-subsidized crops, which makes them cheap and plentiful. It’s also why seed oils have become such a hot topic as of late because they feel almost impossible to avoid. 

Ultimately, the biggest issue with seed oils comes down to how they are processed. During the extraction and packaging process, each one of these seed oils are bleached, refined, and then heated before packaging. Not only does this process strip seed oils of nutrients, but it actually leaves you with a final product filled with compounds that wreak havoc on your health.

The top seed oils to avoid

You may have heard the phrase the “hateful eight” when talking about what seed oils to avoid. These eight seed oils are the ones most commonly used and have had the most discourse around their negative health effects, earning them a place on the hateful eight list:

• Canola oil
• Corn oil
• Cottonseed oil
• Safflower oil
• Soybean oil
• Sunflower oil
• Peanut oil
• Rice bran oil

While there is some nuance when it comes to what oils you can cook with (which we will get into more later) there is no wiggle room for these. Of course, I understand that you can’t always avoid seed oils. So many ultra-processed foods use seed oils (although we are starting to see a small change) and restaurants mostly use seed oils to cook with. It’s not about perfection, but when we know better we can do our best to make better choices as much as possible.

Why are seed oils unhealthy?

As we touched on earlier, seed oils are extremely processed with methods that involve chemical refining with industrialized chemical solvents like hexane, bleaching, and deodorizing. They also likely come from GMO crops that contain pesticide residue. If this alone wasn’t enough to turn you off from seed oils, the processing ends up removing all the beneficial nutrients, leaving the final product with something much worse — an abundance of linoleic acid, a type of omega-6 polyunsaturated fatty acids (PUFA).

While most of us know that healthy fats are necessary for optimal brain, hormone, and overall health, most people don’t realize that your body requires closer to a 1:1 ratio of omega-6s and omega-3 fatty acids to thrive. When your diet mostly consists of omega-6 fatty acids (the standard American diet) it can lead to systemic inflammation in the body, which is an underlying commonality with all modern chronic degenerative diseases, including heart disease and diabetes.

Plus, these oils are highly unstable, oxidize easily when heated (even your body temperature can cause them to oxidize), and can generate inflammatory free radicals that damage your cells.

READ MORE: Sunflower Oil vs Sunflower Lecithin: Separating Fact From Fiction

What is the healthiest oil to use?

The healthiest oil to use depends on what you are using them for. Unfortunately, it’s not as simple as “use this, avoid that”. Especially when you consider smoke points. Of course, when it comes to the seed oils to avoid, those should be avoided at all costs, regardless of cooking temperature due to the reasons we talked about above. 

However, some “healthy” oils can actually become “unhealthy” when cooked at the wrong temperature. Many people unintentionally turn a good fat into a bad one by overcooking it beyond the smoke point — the highest temperature an oil can reach before the nutrients break down and it begins to release free radicals — causing inflammation in the body.

Using extra virgin olive oil to fry foods is a good example of this. It is a great addition in salad dressings, but you shouldn’t use it to roast your vegetables. It’s important to know the smoke points of various oils to better determine what you should be using when.

Oils to use for for cooking

The smoke points for these oils are a lot higher and therefore can handle roasting, baking, and stir-frying without any issue:

• Coconut oil
• Avocado oil
• Olive oil (other than extra virgin or virgin)
• Hazelnut oil 
• Macadamia nut oil
• Palm fruit oil
• Palm kernel oil

Oils to use for eating with/on food:

• Extra virgin or virgin olive oil
• Walnut oil
• Flaxseed oil
• Almond oil
• Hemp seed oil
• MCT oil

Other options to cook with

Oils are not the only thing you can cook with. In fact, some of my favorite options are not considered oils at all! Animal fats like tallow and lard, butter, and grass-fed ghee (clarified butter) provide an abundance of healthy saturated fats, have a high smoke point, and add a great depth of flavor to whatever you are cooking. As with everything, be sure to read labels and consider the sourcing of whatever you are purchasing as we know that marketing labels aren’t always what they seem!

LISTEN: Nicolas Jammet: Redefining Fast Food, Hot Take On Seed Oils + Secrets To Sweetgreen’s Success

The Takeaway

Eating healthy shouldn’t be complicated. Yet somehow, it has become one of the most difficult things to navigate. But once you know what to look for, making healthier choices at the grocery store and in your own kitchen can be much simpler.

The good news is that avoiding seed oils is one of the easier and most influential changes you can make for your health. You don’t need to overhaul your entire diet overnight to start making a difference. Focusing on one ingredient or food category at a time can be a much more sustainable approach, and switching to anti-inflammatory cooking oils is a great place to start.

In my telehealth functional medicine clinic, we understand just how overwhelming all this can be. That’s why we walk with you every step of the way in making the changes necessary to reclaim your health, including dietary changes. From comprehensive lab work to tailored protocols and recipes, my team and I are dedicated to making healthy living sustainable 

As one of the first functional medicine telehealth clinics in the world, we provide webcam health consultations for people around the globe. 

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