Are seed oils toxic to your health?

I recently posted something about my favorite healthy on-the-go snacks and was reminded by my amazing Instagram audience how confusing our modern (highly-processed) food landscape is. Especially when it comes to being able to easily spot what’s actually good for you and what’s not. You asked: Are seed oils toxic?

The snack in question was BjornQorn Popcorn. I touted it as being a great source of fiber, but some of you clocked that it’s popped in sunflower or safflower oil. Both are seed oils, which plenty of health influencers, doctors, and scientific studies will tell you are toxic to your health. 

“I find the topic so confusing,” one of you wrote. “Are there some seed oils to avoid and others that are okay in moderation?”

This is such a good question. And it is confusing—seed oils are high in omega-6 fatty acids, which are essential nutrients. So does that mean seed oils aren’t actually that bad? I hear questions like this so often, I figured it was time to do a deep dive. Here’s what you should know about seed oils: 

The research says

Seed oils are made from the seeds of plants. Think: sunflower oil, safflower oil, peanut oil, canola oil, corn oil, soybean oil, and sesame oil. They’re everywhere in our diets, particularly in ultra-processed and packaged foods (which is reason #1 why seed oils can be problematic for your health). Since seed oils tend to have a higher smoke point than healthier EVOO, they’re also often used as cooking oils at restaurants. 

There are two ways to harvest seed oils, which matters for how nutritious they are: 

  • Method 1: Heat and chemical extraction. Can strip oils of their nutrients.
  • Method 2: Cold pressing. Retains more of the oils’ antioxidants and vitamins. 

As a group, seed oils are high in Omega-6 fatty acids, a type of polyunsaturated fat (or PUFA) that plays an important role in everything from brain function to the regulation of cholesterol

Omega-6s are not inherently bad for you—when consumed the right way But seed oils can also be the cause of many ills when consumed in excess.

Omega-6s tend to promote inflammation (though there are some exceptions to this) and have been linked to an increased risk of cardiovascular disease and autoimmune diseases like inflammatory bowel disease (IBD)

So, how do we consume omega-6s in a healthy way? One thing we can do is opt for unrefined sources of omega-6s like walnuts, sunflower seeds, and pistachios rather than getting omega-6s in the form of seed oils.

But what matters most when it comes to how you consume PUFAs, is the ratio of omega-6 to omega-3s. 

Most people are consuming too many omega-6s in the form of seed oils; in the modern food ecosystem, the average person consumes something like 20x more omega-6s than omega-3s. This is a yikes. 

Ideally, you should be consuming a 3:1 (or even better 1:1) ratio of omega-6 to omega-3s to lower your risk of inflammation and disease. Research shows this ratio is associated with a lower risk of cardiovascular disease, colorectal cancer and improved outcomes for rheumatoid arthritis and asthma.   

What I’m doing for my own body

Unfortunately, refined seed oils are all but impossible to avoid in our modern food landscape. 

I focus less on trying to cut them out entirely, and more on choosing high-quality cold pressed seed oils when possible. And, more importantly, balancing my ratio of omega-6s to omega-3s. This way I’m not stressed when I eat a meal out (even though I know it was probably cooked in a low-quality refined oil) or have the occasional packaged snack like BjornQorn when I’m on-the-go. 

I eat to boost my omega-3s

Increasing my omega-3 intake is key for maintaining a low ratio. I go for a daily tablespoon of EVOO (I’ll literally drink it) plus: 

  • Walnuts (2.5g per serving)
  • Fatty fish like salmon (4g per serving)
  • Chia seeds (4.9g per serving)
  • Sardines if you’re into them (2.2g per serving)

I cook most of my meals

The biggest ways we are exposed to seed oils are in packaged foods and restaurant foods. I cook most of my meals at home and opt for fresh snacks like fruit or veggie sticks most of the time. 

When I’m cooking, I use high-quality EVOO or avocado oil when possible. When that doesn’t work for a recipe, I opt for a cold pressed organic seed oil high in oleic acid (omega-9s). I like Ulli’s Oil Mill and Fresh Press Farms.

What I recommend for you 

At Parsley, we can test your ratio of omega-6 to omega-3 intake. That’s a good place to start. Otherwise, I recommend the following. 

  1. Avoid ultra-processed foods at all costs. I cannot say this enough. When you do need to reach for a packaged snack (Something not even I am immune to!) look for better-for-you options like the BjornQorn I recommended a few weeks ago. The relatively low amount of non-GMO seed oil it contains is way less concerning than the refined carbs and oil you’d get ingesting chips to satisfy a salt craving. 
  2. Opt for cold pressed cooking oils at home. I’m betting the big jug of canola oil you keep in the pantry for frying and baking isn’t cold pressed. (Cold pressed canola oil does exist, but it’s wildly hard to find!) High-quality coconut oil, avocado oil, and EVOO are all excellent swaps. If you can’t get around using a seed oil (maybe you’re doing stir fry and want that sesame taste) opt for a cold pressed version. 

The bottom line: It would be next to impossible to eliminate seed oils from your diet entirely—and honestly you don’t need to. When eaten in a 3:1 (or lower) ratio with foods rich in omega-3s, cold pressed seed oils can be a healthy source of omega-6s.

Want to test your omega-6 to omega-3 ratio and come up with a personalized plan to lower it? Come talk to one of our experts at Parsley. Use my personal code RBMDCREW for $100 off your membership.