If you(r oil) can't handle the heat, then it should stay out of the kitchen
Does the Oil You Cook With Matter? Aren't Fats and Cholesterol Bad?!? These are all great questions, and I hope to shed some light on this topic for you. While I’m not an expert in oils, I do care deeply about your health, so I’ll give you an overview of the do’s and don’ts when cooking with oils in the kitchen.
Are All Oils the Same?
No, not all oils are created equal. Of course, fryer oil at a fast food restaurant is not the same as the $1,000 truffle oil used in fine dining. But those examples don’t really help you when making daily, healthy choices in your own kitchen. The key factors to consider when choosing an oil for cooking are the smoke point and the peroxidation index. But wait… what is that?
What is the Peroxidation Index?
The peroxidation index is the rate at which fats (lipids) in oils oxidize, releasing free radicals and reactive oxygen species (ROS). In simpler terms, the fats or oils break down and become harmful to your cells. Free radicals and ROS are not something you want in your body—they’re linked to a variety of health problems. When oils break down, they produce these harmful byproducts, which can contribute to obesity, issues with satiety (the feeling of being full), and metabolic dysfunction.
Metabolic dysfunction refers to the series of chemical reactions your body uses to break down nutrients, generate energy, build and repair tissues, regulate temperature, hormone levels, and maintain normal bodily functions. In short, it’s essential for survival.
The fats you cook with can significantly impact these processes. Polyunsaturated fats, like those found in seed oils, can damage your cells, making them weak and leaky. This allows fluids to flow in and out of your cells, leading to increased inflammation and cellular breakdown.
So, What Oils Are Best to Use?
Now that we’ve covered the basics of how oils affect your health, let’s talk about which oils you should use and when.
First Off—GET RID OF MARGARINE!
Margarine is a mix of mostly unhealthy oils and should be avoided. It contains trans fats and other harmful substances that can cause all the issues mentioned above—so just say no to margarine!
Avoid Seed Oils
Stay away from seed oils like canola, grapeseed, rapeseed, cottonseed, and sunflower oils and vegetable oils. These oils have a low peroxidation index and are prone to releasing free radicals and ROS when heated. Additionally, it’s important to consider the production process when choosing an oil. Many seed oils undergo heavy processing, including refining, bleaching, deodorizing, and sometimes even coloring. This further compromises their nutritional value.
What About Avocado Oil?
Avocado oil is a better option. Unlike seed oils, avocado oil comes from the fruit of the avocado (not the seed). This means it’s processed differently—usually with less heat or through cold pressing—helping to preserve the healthy monounsaturated fats.
Avocado oil has a higher smoke point than seed oils, which makes it safer for cooking at higher temperatures. However, it's still not the best option because it still contains some polyunsaturated fats, which can break down into harmful byproducts like free radicals and ROS.
If you choose to cook with avocado oil, make sure to heat the pan well and only add the oil just before cooking your food. You’re heating the food, not the oil itself. Alternatively, avocado oil works great as a dressing, as you don’t need to heat it to consume it.
The Best Oils for Cooking
The best oils for cooking are those that remain solid at room temperature. These include butter, coconut oil, and ghee. These are stable saturated fats, meaning they are less likely to break down and release harmful substances during cooking.
While butter is great, it can smoke if left on a hot pan for too long, so I personally prefer using organic, grass-fed ghee when cooking. It has a higher smoke point and retains more of its nutrients when heated.
Links of research of the above information found below :)
Health Effects of Oxidized Heated Oils
Evaluation of the deleterious health effects of consumption of repeatedly heated vegetable oil
Thomas DeLauer on seed oils (my go to guy for about 5 years on all things nutrition)
Chart made by yours truly - Dr. Kevin Graine D.C.