Why Seed Oils Are Harmful on Keto (And Better Fats to Use)

Seed oils, such as canola, sunflower, soybean, and corn oils, have become staples in modern diets. Marketed as heart-healthy alternatives to traditional animal fats, these oils have found their way into nearly every processed food. However, recent research has raised concerns about their potential negative impact, especially for individuals following a ketogenic (keto) diet.

The Problem with Seed Oils

Seed oils are extracted from the seeds of various plants and are highly processed. They often undergo chemical treatments like bleaching, deodorizing, and refining, which can create harmful byproducts.

Here are several reasons why seed oils are problematic, particularly for those following a keto lifestyle:

1. High in Omega-6 Fatty Acids

Omega-6 fatty acids, found in abundance in seed oils, are essential fats that the body needs in small amounts. However, when consumed in excess, they can promote inflammation. Western diets, heavy in processed foods, typically contain a high ratio of omega-6 to omega-3 fatty acids, leading to an imbalance that has been linked to chronic diseases such as heart disease, obesity, and diabetes.

For those on a keto diet, which aims to reduce inflammation and stabilize blood sugar levels, consuming excessive omega-6s from seed oils could counteract these benefits.

Omega-6 linoleic acid found in industrial seed oils like soybean, corn, and canola oil promotes inflammation and is associated with an increased risk of chronic diseases. ~ Chris Kresser – Functional Medicine Expert

2. Linked to Increased Inflammation

While omega-6 fatty acids play a role in immune responses, overconsumption can lead to chronic inflammation. Studies show that when omega-6 intake is high, it can stimulate the production of inflammatory compounds called eicosanoids. Chronic inflammation is a root cause of many modern diseases, including cardiovascular disease and metabolic syndrome.

The keto diet is designed to reduce inflammation by minimizing carbs and increasing healthy fats, yet consuming seed oils can increase inflammatory markers, reducing the effectiveness of the diet.

3. Highly Processed and Refined

The process of extracting oils from seeds requires harsh chemical solvents like hexane and high temperatures, which degrade the oil and strip it of any nutritional value. This processing can also create harmful trans fats, which are well-known to contribute to heart disease. Trans fats raise LDL (bad) cholesterol levels while lowering HDL (good) cholesterol levels, leading to an increased risk of heart disease.

Dr. Paul Saladino (author of The Carnivore Code), states: “Seed oils are industrial products that are highly processed and damaging to the human body. They are not evolutionarily consistent with human health.”

4. Oxidation and Free Radicals

Seed oils are polyunsaturated fats (PUFAs), which are prone to oxidation. When these oils are exposed to heat, light, or air, they oxidize and produce harmful free radicals. These free radicals can damage cells, proteins, and DNA, contributing to aging, inflammation, and diseases like cancer.

In contrast, keto-friendly fats, such as saturated and monounsaturated fats, are much more stable and resistant to oxidation, making them safer for cooking at high temperatures.

Healthier Alternatives to Seed Oils

For keto dieters looking to avoid the harmful effects of seed oils, there are plenty of healthier alternatives that provide better nutritional profiles and fit into a ketogenic lifestyle:

1. Coconut Oil

Coconut oil is a popular fat source for keto due to its rich content of medium-chain triglycerides (MCTs), particularly lauric acid. Although lauric acid has slightly different metabolic properties than shorter MCTs (like caprylic and capric acid), it still aids in the production of ketones, providing a sustainable source of energy. Additionally, coconut oil has a relatively high smoke point (around 350°F/177°C) and is resistant to oxidation, making it a stable option for cooking at medium-high temperatures.

2. Olive Oil

Extra virgin olive oil is a staple in the Mediterranean diet and is rich in monounsaturated fats, specifically oleic acid, which has anti-inflammatory properties. It’s also high in antioxidants like polyphenols, which protect the body from oxidative stress and inflammation. Olive oil is best used for salad dressings or drizzling over cooked vegetables rather than high-heat cooking.

3. Avocado Oil

Avocado oil is another excellent alternative to seed oils. It’s high in monounsaturated fats, which support heart health and reduce inflammation. Like olive oil, it contains oleic acid and is stable at high temperatures, making it a versatile option for cooking and baking.

4. Butter and Ghee

Butter and ghee (clarified butter) are rich in saturated fats, which are stable and resistant to heat. These animal fats contain fat-soluble vitamins such as A, D, E, and K2, and conjugated linoleic acid (CLA), which has been linked to fat loss and reduced cancer risk. Ghee, which has the milk solids removed, is particularly good for those sensitive to dairy.

5. Tallow and Lard

Rendered animal fats like tallow (beef fat) and lard (pork fat) are nutrient-dense, traditional fats that our ancestors relied on. These fats are rich in saturated and monounsaturated fats and contain no harmful trans fats. They are excellent for frying, sautéing, and roasting due to their high smoke points.

6. MCT Oil

MCT (medium-chain triglyceride) oil is derived from coconut oil and is rapidly absorbed and converted into ketones, making it a favorite for those on a ketogenic diet. It provides a quick and efficient energy source without causing blood sugar spikes.

Better Fats for Keto: Why You Should Ditch Seed Oils

For anyone, but especially those on a keto diet, opting for fats and oils that are stable and nutrient-rich is essential. These alternatives offer several benefits:

• Anti-inflammatory properties: Healthy fats like olive oil and avocado oil help reduce inflammation rather than exacerbate it like seed oils.
• Supports ketosis: MCT oil, coconut oil, butter, and ghee provide the right kind of fats that encourage ketone production, keeping the body in ketosis—a crucial aspect of the keto diet.
• Nutrient absorption: Saturated fats, such as those found in butter and ghee, enhance the absorption of fat-soluble vitamins and other nutrients from food.
• Stable at high heat: Fats like coconut oil, avocado oil, and ghee are ideal for cooking due to their high smoke points, unlike polyunsaturated seed oils, which break down easily and form toxic compounds when heated.

Final Thoughts on Avoiding Seed Oils for Better Health

The keto diet is all about choosing the right kinds of fats to fuel your body and improve your health. Seed oils, while widely available and marketed as healthy, are highly processed, inflammatory, and harmful in the long term. By replacing seed oils with healthier fats such as coconut oil, olive oil, and butter, you can support your body’s metabolic processes, reduce inflammation, and optimize your health on a keto diet.

Want to dive deeper into the science behind how different fats affect your body on keto? Stay tuned for more blog posts, where we’ll explore the latest research and offer practical tips to incorporate healthy fats into your everyday life.