What Are Seed Oils, and Should You Be Concerned?

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Seed oils have recently become a hot topic in health discussions, with some labeling them as harmful and others defending their place in a balanced diet. Understandably, this can cause pause when we are trying to make choices that work towards improving our health. So, allow me to share what seed oils are, why they're under scrutiny, and what science says about their health effects.

What Are Seed Oils?

Seed oils are extracted from the seeds of plants and are commonly used in cooking and food production. A few examples are:

• Canola oil (the oil of choice for deep-frying)
• Corn oil
• Cottonseed oil
• Grapeseed oil
• Soybean oil
• Sunflower oil
• Safflower oil
• Rice bran oil
• Peanut oil

These oils are prevalent in processed foods, restaurant cooking, and home kitchens due to their affordability and high smoke points. They can also be used to add flavor, fragrance, and texture to various dishes.

Why the Controversy?

Like all oils, seed oils are a source of dietary fat. While dietary fats are an important part of a healthy diet when consumed in moderation, critics argue that seed oils are highly processed and rich in omega-6 fatty acids, which have been shown to lead to inflammation and chronic diseases when consumed in excess. Concerns also revolve around the chemical extraction processes, such as the use of hexane, and the potential formation of harmful compounds when these oils are heated.

However, many of these claims lack strong scientific backing.

What Does the Science Say?

• Omega-6 Fatty Acids: While it's true that seed oils are high in omega-6s, these are essential fats that the body needs. The key is balance; an excessive omega-6 to omega-3 ratio may contribute to inflammation, but moderate consumption within a balanced diet is not inherently harmful.
• Processing Concerns: The use of hexane in oil extraction is common, but the final product undergoes refining processes that remove residual solvents, making the oils safe for consumption. The processing methods do, however, result in seed oils having some vitamins and healthy compounds that are naturally found in seeds removed.
  
• Health Impacts: Saturated fats are the type of fat that have been shown to raise both the “good” and the “bad” cholesterol levels. However, unsaturated fats are a healthier option. Research has shown that replacing saturated fats with polyunsaturated fats, like those derived from plants and found in seed oils, can reduce the risk of heart disease and improve blood sugar regulation. The American Heart Association supports the inclusion of these fats as part of a healthy diet, in the appropriate quantities.

Bottom Line

Seed oils are not inherently "toxic" or "poisonous." The concerns often stem from their overuse in ultra-processed foods, which are linked to various health issues. As with most other aspects of a healthy lifestyle, moderation is key.  When used in moderation and as part of a diet rich in whole foods, seed oils can be a component of a healthy eating pattern.

Author: Dr. Colleen Gulick, Ph.D. (ExPhys), MS (ExPhys), BS (BioE), EIT (ME), CSCS

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