Learn about the risks of seed oils, like inflammation and chronic health issues, and discover healthier options such as avocado oil, coconut oil, and algae oil.
Key Takeaways:
Seed oils have become a staple in modern cooking and food production. From condiments to processed snacks and even meals at your favorite restaurants, these oils are widely used because they’re affordable and versatile.
That said, convenience doesn’t always equal the best choice for health. Some research has raised concerns about the potential effects of certain seed oils, particularly when consumed in large amounts.
Building awareness can help you make more informed choices. In this article, you’ll find an overview of commonly used seed oils and a list of ones you may want to limit in your diet.
Seed oils are types of vegetable oils extracted from the seeds of various plants, such as sunflower, soybean, corn, canola, cottonseed, and safflower. They are commonly used in cooking, processed foods, and packaged snacks due to their affordability and long shelf life.
Most seed oils are produced using industrial methods that often involve high heat, chemical solvents, and refining steps, which can alter their natural composition.
Many seed oils are also relatively high in omega-6 fatty acids (with linoleic acid being the most common). Omega-6 is an essential fat, but some researchers suggest that consuming it in large amounts compared to omega-3s may have unwanted health effects ❶❷.
Although seed oils are often promoted as healthy, their processing methods and fatty acid balance have led to ongoing debate among health experts.
Related: Your Ultimate Seed Oil-Free Grocery List
The processes used to create seed oils, along with their high levels of omega-6 fatty acids and tendency to oxidize, can have serious long-term effects on your health. Let’s dive deeper into the dangers of these oils and why you might want to reconsider their place in your diet.
The extraction of seed oils often involves industrial processes that use high heat and chemical solvents like hexane, which is also used as a solvent in the production of gasoline, adhesives, coatings, paints, and varnishes due to its properties ❸. These methods not only strip the oil of its natural nutrients but can also create harmful byproducts.
Refining also removes certain antioxidants, which can make the oil more prone to oxidation over time. In some cases, processing may produce small amounts of compounds like trans fats, which health organizations generally recommend limiting in the diet ❹❺.
While omega-6 fatty acids are essential for health, it’s important to keep a balance between omega-6 and omega-3 fatty acids. A diet too high in omega-6 compared to omega-3 may affect the body’s inflammatory responses.
Some studies suggest that this imbalance could play a role in certain long-term health concerns, which is why many nutrition experts emphasize including more omega-3–rich foods alongside sources of omega-6.
Related: The Best and Worst Cooking Oils for an Anti-Inflammatory Diet
Seed oils contain a high proportion of polyunsaturated fats, which are more sensitive to heat, light, and air. When exposed to these conditions during cooking or storage, they can oxidize more readily ❻.
Oxidation may lead to the formation of byproducts such as lipid peroxides and free radicals, which are being studied for their potential effects on health, including their role in chronic conditions ❼.
Cooking methods that use very high heat, such as deep-frying, can accelerate this process. For this reason, some experts suggest choosing oils that are more stable at high temperatures depending on the type of cooking you’re doing.
Seed oils are high in the omega-6 fatty acid linoleic acid. While omega-6 is essential for functions like cell structure and energy, too much linoleic acid can upset the balance with omega-3 fatty acids.
Below is a list of seed oils to avoid due to their high linoleic acid content:
Related: Linoleic Acid in Cooking Oils: What It Is and Why It Matters
Many foods contain seed oils, even unexpected ones. Packaged snacks, fast food, fried foods, salad dressings, sauces, and plant-based products, like veggie burgers and dairy-free cheeses, often have them. Breads and cereals also use seed oils to stay fresh longer.
These foods use seed oils because they are cheap, last a long time, and mix well with other ingredients. Many people don’t realize how often they eat seed oils because they are hidden in ingredient lists under names like "vegetable oil" or "soybean oil." Since seed oils are in so many foods, avoiding them can be tricky without checking labels carefully.
Related: No Seed Oils: Seed Oil Alternatives for a Healthier Kitchen
The easiest way to spot seed oils in food is to learn their names and check ingredient lists. Common seed oils include soybean, canola, corn, sunflower, safflower, cottonseed, and grapeseed oil. When buying packaged food, look at the ingredients on the label. If you see "vegetable oil," it often means a mix of seed oils. Some foods also have labels like "made with olive oil," but still include seed oils, so reading carefully is important.
At restaurants, ask what oils they use for cooking. Some food brands also have certifications or labels like "seed oil-free." Check for these labels when shopping for packaged foods, especially salad dressings, sauces, and snacks. If a product claims to be made with healthier oils like olive or avocado oil, still check the ingredient list to make sure no seed oils are mixed in.
If you're looking to replace seed oils with healthier options, there are several alternatives that offer better fat profiles and stability. These oils not only provide nutrients but also help reduce the risks associated with oxidative damage and inflammation.
Here are some excellent choices:
Algae oil is a heart-healthy oil, rich in omega-9 monounsaturated fats that help lower bad cholesterol. Compared to olive and avocado oils, it contains 75% less saturated fat and more beneficial omega-9s — it’s an even better choice for heart health.
Many people choose seed oils because of their mild taste, but algae cooking oil offers the same benefit without the harmful consequences. In addition to algae cooking oil’s neutral flavor, it has a high smoke point of 535°F, so it’s stable at high temperatures and perfect for all types of cooking without the risks of oxidation or free radical formation.
Learn these algae oil benefits and make a smarter choice.
Avocado oil is rich in monounsaturated fats that help support heart health by lowering bad cholesterol and reducing inflammation ❽. Unlike seed oils, which are high in omega-6 fatty acids, avocado oil maintains a healthier balance of fats.
Unrefined avocado oil also has a high smoke point (between 350 and 400°F), which makes it more stable. Seed oils, especially those high in polyunsaturated fats like soybean or sunflower oil, tend to oxidize and form harmful compounds, including free radicals when heated to high temperatures.
Related: Avocado Oil Substitutes
Extra virgin olive oil (EVOO) is packed with antioxidants and monounsaturated fats. Monounsaturated fats are known for their heart-protective benefits, including lowering blood pressure and raising good cholesterol (HDL) levels ❾.
EVOO is minimally processed compared to many seed oils, which are often refined and may contain harmful byproducts. The extraction of EVOO helps retain its beneficial nutrients and antioxidants.
Related: Olive Oil Substitutes
Coconut oil is considered a healthier alternative to seed oils due to its unique composition and stability. It is primarily made up of medium-chain triglycerides (MCTs), which are less likely to break down into harmful substances like lipid peroxides and free radicals.
Moreover, MCTs are known for their rapid absorption — they’re a quick source of fuel for the body. However, coconut oil is high in saturated fat, so most health guidelines recommend using it in moderation as part of a balanced diet.
Related: Coconut Oil Substitutes
Seed oils have become a common part of many kitchens due to their affordability and versatility, but their negative impact on health cannot be ignored. Given the risks associated with industrial processing, excessive omega-6 fatty acids, and the instability of seed oils when exposed to heat, it's important to consider healthier alternatives.
If you're looking for a reliable, healthy cooking oil, Algae Cooking Club’s chef-grade algae cooking oil is an excellent choice. It’s not only seed oil-free but also glyphosate and hexane-free, and it is 3rd-party tested to ensure its quality and purity.
Tiffany Joy Yamut is a registered nurse with a focus on health and wellness. With over 10 years of writing experience, she combines her expertise in diet and nutrition coaching to help others adopt healthier lifestyles through balanced eating habits. A foodie at heart, Tiffany believes that food is essential to feeling your best.
