Are seed oils actually made from seeds?

December 30, 2025 •

4 min read

While the term 'vegetable oil' is widely used, the answer to the question, 'are seed oils actually made from seeds?' is yes. This has become a focus of debate and concern regarding manufacturing practices.

Quick Summary

Seed oils, like those from sunflowers and canola, are extracted from seeds, but the manufacturing involves refining. Mechanical pressing versus solvent extraction influence the final product. Quality, nutrition, and flavor depend on these methods.

Key Points

Origin of Seed Oils: Seed oils like sunflower, canola, and corn are extracted from seeds.
Vegetable Oil is a Broader Term: Not all vegetable oils are from seeds; olive and avocado oils, for example, come from fruit flesh.
Dual Extraction Methods: Mechanical pressing and chemical solvent extraction using hexane are the main methods.
Refining Impacts Nutrients: Commercial seed oils are often refined, which removes color, flavor, and some nutrients.
Health Concerns Are Often Exaggerated: Scientific evidence often suggests low risk from hexane and high omega-6 content, when viewed within the context of a balanced diet.
The Health Context Matters Most: The biggest health factor is often how seed oils are used, such as in ultra-processed and fried foods.

The Core of Seed Oils: Yes, They Come from Seeds

At their base, seed oils are vegetable oils derived from plant seeds. The main point of complexity is not the origin, but the extraction and refining processes that follow the harvest. Seed oils include sunflower, canola (rapeseed), sesame, and flaxseed oil.

The Difference Between Seed Oils and Other Vegetable Oils

Not all vegetable oils are seed oils. The term 'vegetable oil' can include oils from other parts of a plant, like the fruit or nut.

Seed Oils: Sourced from seeds, including corn, soybean, canola, and sunflower.
Fruit Oils: Extracted from the fleshy part of the fruit, such as olive oil and avocado oil.
Nut Oils: Derived from nuts, like walnut oil or almond oil.

The Extraction Process: Mechanical vs. Solvent Methods

The journey from seed to oil on the grocery store shelf involves different methods. Two primary methods are used for oil extraction: mechanical pressing and solvent extraction.

Mechanical Extraction: Uses physical pressure to squeeze the oil from the seeds. Cold-pressing is a form of mechanical extraction done without added heat. This method is less efficient and more expensive. Oils produced this way, like extra virgin olive oil, are often more flavorful but have a lower smoke point.
Solvent Extraction: Used for most commercial seed oils, this method is significantly more efficient at removing oil from the seeds. It uses a petroleum-based solvent, most commonly hexane, to maximize yield. After the solvent and oil are mixed, the mixture is heated to evaporate the solvent, which is then recycled. Trace amounts of hexane may remain in the oil, although experts suggest levels are well below safety thresholds. Many organic oils are produced without chemical solvents.

Refining, Bleaching, and Deodorizing (RBD)

Following extraction, most commercially produced seed oils undergo refinement to achieve the clear color, neutral taste, and high smoke point. This process, known as Refining, Bleaching, and Deodorizing (RBD), is a key reason for the difference between a raw pressed oil and a typical supermarket cooking oil.

Refining: Removes gums and free fatty acids that can cause off-flavors or rancidity.
Bleaching: Uses bleaching clays to remove undesirable colors and contaminants.
Deodorizing: Involves heating the oil under a vacuum with steam to remove any leftover odors and flavors, resulting in a neutral product.

Refined vs. Cold-Pressed Oils: A Comparison


Feature	Refined Seed Oils	Cold-Pressed Seed Oils (e.g., some organic sunflower)	Other Unrefined Oils (e.g., EVOO)
Extraction Method	Solvent extraction, high heat, and mechanical pre-pressing	Mechanical pressing without added heat	Mechanical pressing without added heat
Processing	Refined, bleached, and deodorized (RBD)	Unrefined or minimally processed	Unrefined
Smoke Point	High	Lower	Lower
Flavor	Neutral	More pronounced, retains seed's flavor	Strong flavor, retains fruit's character
Nutritional Profile	Fewer antioxidants and vitamins due to processing	Retains more natural nutrients like Vitamin E	High in antioxidants
Best For	High-heat cooking, frying, baking	Low to medium heat cooking, dressings	Dressings, finishing, sautéing

Addressing Health Concerns and Misinformation

Concerns about seed oils often center on their high omega-6 fatty acid content, inflammatory potential, and the use of solvents like hexane. The science on these topics is more nuanced.

Omega-6 Balance: Increasing dietary linoleic acid (a key omega-6) does not significantly affect inflammatory markers. A balanced diet rich in omega-3s is a good approach.
Hexane Concerns: Regulatory standards ensure trace amounts of hexane do not exceed safe levels. Organic oils are not processed with hexane.
Ultra-Processed Food Context: Much of the health risk associated with seed oils comes from their common use in ultra-processed, fried, and fast foods. The issue may be the food itself, which is often high in calories, sodium, and refined carbs, rather than the oil. A healthy diet emphasizes whole foods and minimal processing, regardless of the oil used for cooking.

For additional information on oilseed processing, a resource such as the Penn State Extension can provide further insights. https://extension.psu.edu/processing-edible-oils

Conclusion: Seed Oils' True Nature

Yes, seed oils are made from seeds. The process, however, is not a simple squeeze for most commercial products. From mechanical pressing to chemical solvent extraction and extensive refining, the methods used are designed for efficiency, shelf-stability, and a neutral flavor profile. For consumers, the choice comes down to personal preference, cooking needs, and desired level of processing. Those concerned about solvents or processing chemicals can opt for cold-pressed or organic oils, while others can confidently use common refined seed oils for their high-heat cooking applications, understanding that their overall dietary context is most important for health.

Frequently Asked Questions

Common seed oils include canola (rapeseed), corn, soybean, sunflower, safflower, cottonseed, grapeseed, and sesame oil.

No, 'vegetable oil' is a broad category. While all seed oils are vegetable oils, not all vegetable oils are seed oils; for example, olive oil and avocado oil come from the fruit, not the seed.

Oil can be extracted through mechanical pressing (like expeller or cold-pressing) or by using chemical solvents, most commonly hexane, which is more efficient.

Experts note that trace amounts of hexane may remain, but they are at levels well below safety thresholds, and there is no evidence of health risk from consuming seed oils processed with hexane.

Cold-pressed oils are generally less processed, retaining more natural nutrients like vitamin E. However, they also have lower smoke points, making them less suitable for high-heat cooking.

While seed oils are high in omega-6 fatty acids, research does not consistently show that they cause significant inflammation. Inflammation is a complex process, and a balanced diet with sufficient omega-3s is more important.

Avoiding all seed oils is not necessary for most people. A focus on a balanced diet rich in whole foods is more impactful for overall health. The healthiest cooking oil choice depends on the specific use, and personal preferences on processing level can be a factor.