The Truth About Seed Oils: Fact vs. Fiction

March 12, 2026 Food and the Environment, Nutrition, Spoonful

You may have seen headlines or social media posts claiming that seed oils are bad for your health. With so much conflicting health information being circulated, these claims have many people wondering if they should toss their canola oil for good. However, much of the buzz surrounding these oils doesn’t match up with the research. Let’s break down what seed oils are and how they can be a healthy part of a balanced diet.

What Are Seed Oils?

Seed oils are oils extracted from the seeds of plants. Common examples include canola, corn, peanut, soybean, sunflower, and sesame oils. Even the vegetable oil in your pantry is typically just a blend of various seed oils. These oils are a staple in most kitchens because they have a neutral flavor and a high smoke point. Their low cost and long shelf-life make them a popular choice for processed foods and restaurant meals. You’ll find them in everything from store-bought crackers, cookies, and potato chips to salad dressings and fast-food favorites like french fries, chicken nuggets, burger buns, and condiments.
Seed oils contain two types of essential fats that our bodies need to stay healthy.

Omega-6 fats: Found in high amounts in seed oils, nuts, and seeds. They help with brain and heart function and cell growth and development.
Omega-3 fats: Found in foods like salmon, walnuts, and flaxseeds. They support heart and brain health.

Why the Controversy?

The debate around seed oils usually centers around three main topics.

Omega-6 Fats: Much of the debate around seed oils centers on their high omega-6 fat content, with the worry that this type of fat promotes inflammation within the body.
How the Oil is Made: Most seed oils are refined using high heat and chemical solvents like hexane to give them a more neutral taste, a longer shelf life, and the ability to handle high cooking temperatures. This has led to concerns about whether these industrial methods make the oil less healthy or safe to consume.
Seeds Oils in Processed Foods: Seed oils are commonly found in many processed foods, leading to concerns that the seed oils in these types of foods are a key contributor to long-term health issues.

Clearing up the Confusion

While these concerns might sound concerning, let’s break them all down.

Omega-6 Fats

While seed oils are often high in omega-6 fats, both omega-6 and omega-3 fats are essential for our health. Since our bodies cannot make these fats on their own, we must get them from our food to support heart health, brain health, and cell growth. Omega-6 fats play a very positive role in our health, as long as we are getting the right amount. Research has shown that omega-6 fats can improve blood cholesterol levels, thereby reducing risk for heart disease, which is why the American Heart Association recommends including them as part of a healthy diet. Ultimately, it all comes down to the balance between these two fats. Modern Western diets often contain higher amounts of omega-6 than omega-3, oftentimes as much as ten times more. Since most people are getting more than enough omega-6 fats in their diet, the best way to support your health is to focus on adding more omega-3-rich foods in your diet. Try swapping a few meat-based meals a week with fresh or canned fish high in omega-3 fats such as salmon, sardines, or mackerel. When shopping for canned fish options, look for labels that say “packed in water”, “low sodium”, or “no salt added” to keep your meals as heart-healthy as possible. For plant-based sources, try adding ground flaxseeds or chia seeds into your morning oatmeal or smoothie or snack on a handful of walnuts.

How the Oil is Made

Although most seed oils are refined using heat and chemical solvents, leftover chemicals like hexane are almost entirely removed before the oil reaches the bottle, remaining well below safety limits. However, for those who want extra peace of mind, there are products made without any chemicals or high heat. These are usually labeled as “cold pressed” or “expeller pressed” but often have lower smoke points, shorter shelf lives, and are more expensive. Regardless of which oil you choose to use, it is important to store it properly to prevent it from going rancid. Keep cooking oils tightly sealed in a cool, dark place away from light or heat. Unopened oils stay fresh for about a year, while opened oils should be used within six months for best quality.

Seeds Oils in Processed Foods

While it is true that seed oils are often found in many of the processed foods we eat, seed oils aren’t the key reason why many of these foods are associated with health issues such as heart disease or diabetes. Most of the processed foods that contain seed oils are foods high in added sugars, sodium, and saturated fats that have little to no nutritional value, which can increase risk for heart disease or diabetes if consumed in large amounts over time. Using a splash of canola oil to saute fresh vegetables or to make a homemade salad dressing is much different than eating a bag of store-bought chips. By moderating your intake of processed foods and focusing on whole foods, you can include oils as part of a healthy diet.

The Bottom Line

At the end of the day, seed oils aren’t as bad for your health as some may claim. While it is always a good idea to eat fewer highly processed foods, seed oils can be a safe and healthy part of your diet. One of my favorite ways to use canola oil is as an ingredient in the Carrot Fries recipe. It has a neutral taste that lets the flavor of the carrots shine while making them perfectly crispy. Try using a splash of canola oil or even sesame oil to bring out the flavors in our Green Bean & Broccoli Salad with Ginger Dressing recipe. By focusing on a balance of different fats and choosing whole, fresh foods most of the time, you can feel confident using these oils in your daily cooking.

Resources

Author

Alex Bosse has been with University of Maine Cooperative Extension as a Youth Curriculum Coordinator and Supervisor for the Expanded Food and Nutrition Education Program since November of 2020. He completed his supervised dietetic internship at the University of Kentucky in August of 2020 and is currently working towards obtaining his Masters in Public Health at the University of Southern Maine. Alex has a passion for research, community nutrition, and working with food insecure/low-income populations to make healthier food choices and to better access food.