The Real Truth About Cooking Oils

When it comes to cooking oils, many of us reach for avocado or olive oil without a second thought. After all, these oils are praised for their health benefits and high smoke points, making them seemingly perfect for everything from sautéing to frying. But what if I told you that heating these oils might be undoing all the good they’re supposed to bring to your meals? It’s time to dig deeper into what happens when these oils meet high heat—and why you might want to rethink your healthy cooking strategy.

The Hidden Dangers of Heating Healthy Oils

Avocado and olive oils are known for their rich content of monounsaturated fats, antioxidants, and polyphenols. When consumed raw, these compounds contribute to heart health, reduce inflammation, and provide numerous other benefits. However, the story changes once these oils are exposed to heat, especially at high temperatures.

Oxidation and Degradation: Even though avocado and olive oils have relatively high smoke points—meaning they can be heated to a high temperature before they smoke and break down—this doesn’t make them invincible. Regardless of the smoke point, both oils begin to oxidize when heated. Oxidation is a chemical reaction when oil is exposed to oxygen, particularly at high temperatures.^[1] This process degrades the oil and generates free radicals—unstable molecules that can damage cells and lead to inflammation and chronic diseases like cancer.

Loss of Nutrients: Heating these oils also causes the breakdown of their most beneficial compounds. Antioxidants like vitamin E and polyphenols are particularly heat-sensitive and can lose their potency when exposed.^[1] The result is that your meal, which should have been packed with nutrients, provides far fewer health benefits than intended. Worse still, the damaged fats and broken-down compounds could contribute to health issues rather than prevent them.

Formation of Harmful Compounds: Another concern is the formation of toxic compounds like aldehydes and lipid peroxides during heating. These substances are byproducts of fat oxidation and have been linked to a variety of health problems, including neurodegenerative diseases and cardiovascular issues. Even though you might not notice any immediate effects, long-term consumption of these oxidized oils could increase your risk of chronic illnesses.^[2]

Why Seed Oils Are Even Worse

While avocado and olive oils degrade when heated, seed oils like canola, soy, and corn oil are even more problematic. These oils are typically high in polyunsaturated fats, which are far more prone to oxidation than the monounsaturated fats found in olive and avocado oils. Additionally, seed oils are often heavily processed, which means they may already contain damaged fats and residual solvents before they hit the pan.

Health Risks of Polyunsaturated Fats: Polyunsaturated fats, especially omega-6 fatty acids, are unstable when exposed to heat. When these fats oxidize, they produce toxic compounds much faster than monounsaturated fats. Over time, a diet high in oxidized polyunsaturated fats can contribute to inflammation, which is a root cause of many chronic diseases.[3]

Industrial Processing: Seed oils are typically extracted through industrial processes that involve high heat and chemical solvents. This processing can damage the oils before they reach your kitchen, making them even more likely to degrade when you cook with them. The result? A cocktail of unhealthy fats and toxic byproducts that can wreak havoc on your health.

The Right Oils for High-Heat Cooking

If you’re serious about maintaining the health benefits of your cooking oils, it’s time to switch to fats that can withstand high temperatures without degrading. Saturated fats are the most stable when exposed to heat, making them the best choice for cooking.

Organic Ghee: Ghee, a form of clarified butter, is an excellent option for high-heat cooking. It has a high smoke point, around 485°F (250°C), and is rich in butyrate, a short-chain fatty acid that supports gut health. Ghee also lacks the milk solids that can burn in regular butter, making it a more stable choice.^[4]

Organic Coconut Oil: Its high saturated fat content makes it highly resistant to oxidation, even at high temperatures. It also imparts a subtle coconut flavor that works well in various dishes, from stir-fries to baked goods. Coconut oil contains medium-chain triglycerides (MCTs), which are metabolized differently than other fats and can provide a quick energy source.^[5]

Grass-Fed Butter: While regular butter can burn easily due to its milk solids, grass-fed butter can still be used for lower-temperature cooking or adding flavor to already-cooked foods. It’s rich in fat-soluble vitamins like A, D, and K2 and provides a good source of conjugated linoleic acid (CLA), a type of fat linked to various health benefits.

Organic Camel Fat and Beef Tallow: For those looking to diversify their fat sources, camel fat, and beef tallow are excellent options. These animal fats are solid at room temperature and highly stable under heat. They’re also rich in saturated fats and provide a unique flavor profile that can enhance many dishes.^[5]

How to Use Healthy Oils Wisely

While saturated fats are best for cooking, you don’t have to give up on your favorite healthy oils like avocado and olive oil. The key is to use them in a way that preserves their nutritional benefits.

Use as a Finishing Touch: Instead of cooking with avocado or olive oil, consider using them as a finishing touch. Drizzle these oils over salads, cooked vegetables, or grilled meats to add flavor and nutrition without exposing them to high heat.

Cold Applications: Avocado and olive oils are perfect for cold dishes. Mix them into salad dressings, dips, or spreads. They can also be used in marinades—just add them after cooking if you’re using high heat to prepare your protein.

Low-Temperature Cooking: If you do choose to cook with these oils, keep the heat low. Gentle sautéing or light frying at lower temperatures can help reduce the risk of oxidation and preserve some of the oils’ beneficial compounds.

The Bottom Line: Cook Smarter, Not Harder

Rethinking your cooking oil strategy is a simple yet powerful way to protect your health. By choosing the right oils for the right purposes, you can enjoy delicious meals without compromising the nutritional value of your food. Stick to saturated fats for high-heat cooking, and reserve delicate oils like avocado and olive for cold dishes or as a finishing touch. With these tips, you’ll enhance your dishes' flavor and safeguard your well-being.

1. Resende, Lívia Maria Braga, et al. “Changes in Quality and Phytochemical Contents of Avocado Oil under Different Temperatures.” Journal of Food Science and Technology, vol. 56, no. 1, Jan. 2019, pp. 401–08. PubMed Central.
2. Pizzimenti, Stefania, et al. “Interaction of Aldehydes Derived from Lipid Peroxidation and Membrane Proteins.” Frontiers in Physiology, vol. 4, Sept. 2013, p. 242. PubMed Central.
3. Liu, Wen, et al. “Comparison of the Effects of Monounsaturated Fatty Acids and Polyunsaturated Fatty Acids on Liver Lipid Disorders in Obese Mice.” Nutrients, vol. 15, no. 14, July 2023, p. 3200. PubMed Central.
4. Kataria, Deepshikha, and Gurmeet Singh. “Health Benefits of Ghee: Review of Ayurveda and Modern Science Perspectives.” Journal of Ayurveda and Integrative Medicine, vol. 15, no. 1, 2024, p. 100819. PubMed Central.
5. Denke, M. A. “Role of Beef and Beef Tallow, an Enriched Source of Stearic Acid, in a Cholesterol-Lowering Diet.” The American Journal of Clinical Nutrition, vol. 60, no. 6 Suppl, Dec. 1994, pp. 1044S-1049S. PubMed