For decades, dietary fat has been a topic of heated debate. Conflicting headlines, shifting science, and powerful marketing have left many people confused about what fats are healthy and what should be avoided. Cooking oil, in particular, is a daily ingredient that can either support health or silently sabotage it. The type of fat you cook with has a direct effect on inflammation, heart health, hormones, and metabolic function.

This guide breaks down the best and worst cooking oils based on stability, nutritional profile, and how the body processes them—cutting through the noise to offer clarity in the kitchen.

Cook Your Food With: Traditional and Stable Fats

Butter, tallow, ghee, coconut oil, and macadamia nut oil are examples of fats that have stood the test of time. These fats are heat-stable, meaning they don’t easily oxidize or break down into harmful compounds when exposed to high temperatures.

Butter, when sourced from grass-fed cows, is rich in fat-soluble vitamins A, D, E, and K2. It contains a beneficial fatty acid called butyrate, which supports gut health and reduces inflammation. Tallow, rendered beef fat, is also high in fat-soluble nutrients and has been used for centuries in traditional cooking. Ghee, clarified butter, is lactose- and casein-free and ideal for those sensitive to dairy. It has a high smoke point and a rich, nutty flavor.

Coconut oil contains medium-chain triglycerides (MCTs) that are quickly metabolized for energy rather than stored as fat. It has antimicrobial properties and is incredibly heat-stable. Macadamia nut oil is less common but offers a buttery flavor and a high level of monounsaturated fats that promote cardiovascular health. It’s stable at high temperatures and resistant to oxidation.

These oils are nourishing, provide essential fatty acids, and maintain their integrity when heated, making them ideal for sautéing, baking, roasting, and frying.

Do Not Cook Your Food With: Industrial Seed Oils

Sunflower oil, canola oil, grapeseed oil, plant-based butter, and corn oil are common ingredients in processed foods and are widely used in restaurants and home kitchens. However, these oils are highly processed, unstable, and often inflammatory.

Sunflower oil and canola oil are high in omega-6 polyunsaturated fatty acids (PUFAs), which oxidize easily when heated. Excessive omega-6 intake can disrupt the body’s omega-6 to omega-3 ratio, contributing to chronic inflammation. Canola oil, in particular, is often genetically modified and undergoes chemical processing with hexane, a petroleum solvent.

Grapeseed oil is marketed as healthy due to its vitamin E content, but it is very high in PUFAs and extremely prone to oxidation. Cooking with grapeseed oil can release harmful free radicals, increasing oxidative stress in the body.

Plant-based butter may sound appealing, especially to vegans and vegetarians, but it’s typically made from a blend of seed oils and emulsifiers. These spreads often contain industrial trans fats or interesterified fats, which can negatively affect blood lipids and insulin sensitivity.

Corn oil, like the others, is high in omega-6s and is often extracted using high-heat chemical methods. It’s a staple in ultra-processed foods and contributes to systemic inflammation, metabolic syndrome, and poor heart health when consumed regularly.

Understanding Smoke Point vs. Oxidation Stability

Many people choose cooking oils based solely on their smoke point, but that only tells part of the story. While it’s important to avoid oils that smoke and burn easily, oxidation stability—the oil’s resistance to breaking down into harmful compounds—is far more critical for long-term health.

For example, while sunflower oil may have a relatively high smoke point, it is chemically unstable due to its high PUFA content. On the other hand, saturated and monounsaturated fats like those found in ghee, coconut oil, and macadamia oil remain stable under heat and are less likely to produce inflammatory byproducts.

The Omega Balance: Why Fat Type Matters

One of the biggest dietary issues today is the imbalance between omega-6 and omega-3 fatty acids. Historically, humans consumed these fats in roughly a 1:1 ratio. Today, that ratio can exceed 20:1 in favor of omega-6 due to the widespread use of seed oils.

This imbalance promotes inflammation, which is at the root of nearly every chronic disease, including heart disease, obesity, diabetes, autoimmune disorders, and neurodegeneration. Choosing cooking fats low in omega-6 and avoiding seed oils can help restore balance and reduce disease risk.

What About Olive Oil?

Olive oil is often praised for its heart-healthy benefits due to its high monounsaturated fat content and polyphenols. While it’s excellent for salad dressings and low-heat cooking, extra virgin olive oil is best used raw or at medium temperatures to preserve its antioxidants and prevent degradation. For high-heat cooking, it’s still better to stick with more saturated or stable oils.

The History of Seed Oils in the Food Supply

Seed oils like cottonseed, soybean, and corn oil were originally industrial byproducts. They gained popularity in the 20th century due to their low cost and long shelf life. Procter & Gamble’s Crisco was one of the first household names, marketed as a healthier alternative to lard despite being chemically altered through hydrogenation. These oils found their way into everything from baked goods to margarine to processed snacks.

Decades of misinformation—often backed by flawed studies and food industry lobbying—led to the demonization of saturated fats and the rise of seed oils. Government dietary guidelines favored polyunsaturated fats, and major health organizations echoed the advice. This ushered in an era where processed, omega-6-rich oils were considered the healthy choice, even as chronic diseases soared.

Health Risks of Chronic Seed Oil Consumption

The overconsumption of industrial seed oils is now linked to a wide range of health problems. The high omega-6 content of these oils can disrupt cellular communication, fuel systemic inflammation, and alter the structure of cell membranes. This contributes to insulin resistance, weight gain, joint pain, hormonal imbalance, mood disorders, and oxidative stress.

Moreover, when heated, these oils produce toxic aldehydes and lipid peroxides that can damage DNA and proteins. Even cold-pressed versions of seed oils are not ideal for cooking, as they still degrade under heat. Some studies suggest that regular consumption of oxidized fats can increase the risk of cancer, cognitive decline, and cardiovascular disease.

Economic Incentives and the Seed Oil Industry

The prevalence of seed oils is not just about nutrition—it’s also about economics. Crops like soy, corn, and canola are heavily subsidized, making their oils extremely cheap to produce and profitable to sell. The food industry relies on these oils for shelf-stable, low-cost manufacturing.

Marketing campaigns have played a major role in shaping public perception. Labels boasting “cholesterol-free” or “heart-healthy” reinforce the false notion that seed oils are beneficial. Meanwhile, traditional fats like tallow and lard are difficult to find in mainstream stores, despite their superior nutritional profile.

Choosing the Right Oil for the Right Purpose

Each oil has its own flavor, nutrient profile, and ideal culinary use. Coconut oil is great for sautéing and baking due to its mild flavor and high heat resistance. Ghee enhances the richness of dishes and is perfect for frying. Macadamia nut oil and avocado oil are excellent for roasting or grilling thanks to their high smoke points and monounsaturated fats. Butter adds richness to eggs, vegetables, and baked goods.

Avoid using fragile oils like flaxseed or walnut oil for cooking. These should be reserved for dressings or drizzling after cooking to preserve their delicate structure.

How to Transition Away from Seed Oils

Making the switch to healthier cooking fats doesn’t have to be overwhelming. Start by replacing one oil at a time. Use butter or coconut oil instead of vegetable oil for baking. Choose ghee or tallow for frying or sautéing. Read ingredient labels and avoid packaged foods that list “vegetable oil,” “canola oil,” or “soybean oil.”

If eating out, ask what oils are used in cooking. Many restaurants use canola or soybean oil by default. Opt for grilled or steamed options when uncertain, or choose establishments that cook with butter or olive oil.

Conclusion: Quality Fats Are a Foundation of Health

The fats you use to cook your food are not just carriers of flavor—they are powerful influencers of health. Traditional fats like butter, tallow, ghee, coconut oil, and macadamia nut oil are nutrient-dense, heat-stable, and anti-inflammatory. In contrast, industrial seed oils like sunflower, canola, corn, grapeseed, and plant-based butter contribute to inflammation and chronic disease.

By choosing the right cooking oils, you protect your cells, support your metabolism, and reclaim a foundation of ancestral health that industrial food stripped away. Let the stove be a place of healing, not harm—starting with what goes in the pan.