Cooking With Oils
Not many Americans are aware of the health benefits and risks associated with the particular oil that they choose to cook with. Oils can be an essential part of the diet and provide an excellent source of healthy fats, nutrients, and antioxidants if they are chosen correctly. Different types of oils have different molecular structures which influence their stability, ultimately contributing to the oil's effect on your health. Although a variety of oils have been shown to have positive health benefits, it is important to note the stability of oils and which are safe to cook with.
Stability of Oils:
One key factor when using oils to cook at higher temperatures is the stability of the oil. When referring to stability, we are talking about the oil's ability to resist heating and harmful free radical formation . Oils that are not very stable can undergo a process called lipid peroxidation when they are heated, causing the formation of harmful free radicals and eventually causing many negative health consequences. The stability of oils mainly depends on their chemical make-up and how many double bonds they possess. Saturated, monounsaturated, polyunsaturate are terms that you likely have heard before and each term refers to the amount of double bonds in the oil, thus relating to the oil's stability.
To put it simply, generally this is how it goes:
Saturated Fats:
No double bonds
most stable
best for high heat cooking
Monounsaturated Fats:
One double bond
stable
usually okay for cooking
Polyunsaturated Fats:
Multiple double bonds
unstable
bad for cooking
Are there any oils I should Avoid Completely?
Vegetable and seed oils can have many negative health consequences if they are cooked with and undergo lipid peroxidation (1). These oils also have an abundance of omega-6 fats which we already get way too much of and they can increase inflammation and the risk of many chronic diseases by increasing the ratio of Omega 6 to Omega 3s in the body (2). Although it is almost impossible to completely eliminate these oils because they are found hidden in many "health" foods and at restaurants, it may be beneficial to try to avoid them. These oils to avoid include corn, rapeseed, soybean, sesame, safflower, canola, soybean, and many other vegetable and seed oils.
How to Choose A Cooking Oil:
The smoke point of a particular oil reflects the resistance and level of saturation. This is a good way to tell if the oil is safe to cook with at a certain temperature. The form of cooking (frying, baking, steaming, etc.) is also important to factor in when choosing a cooking oil. Although there are many different types of oils and fats that are okay to cook with, there are a few that have worked well for me that I prefer to use depending on the type of cooking
Here are some of my go-to choices for healthy oils:
High Heat Cooking: 350-500º F
Avocado Oil:
Avocado Oil is very similar to olive oil and provides many of the same incredible health benefits, but is much better for cooking with due to its high smoke point of over 500º F. This is a do-it-all oil that tastes great, has tons of antioxidants, and has been shown to reduce cardiovascular risk markers in animal studies (3). I prefer this oil for frying and roasting foods like eggs, certain meats, and some vegetables.
Coconut Oil:
Coconut oil is an excellent choice for cooking with high heats due to it's high saturated fat content (92%) and some of it's remarkable health benefits. Not only is coconut an extremely stable oil, it also may provide many health boosting effects like antimicrobial properties (3, 4) and a reduction of cardiovascular disease risks (5). I like to use coconut oil if I am cooking fish or anything sweet at high temperatures.
Low-Medium Heat Cooking: Up to 350º F
Olive Oil:
Olive oil is a staple of the heart-healthy mediterranean diet and comes with many amazing benefits itself. The use of extra virgin* olive oil may be helpful for preventing many diseases like osteoporosis (6), cardiovascular disease (7, 8), and certain types of cancers (9).
Olive oil makes a good choice for low to medium heat cooking with it's smoke point (around 400º F) being lower than the smoke point of avocado oil. Studies have shown olive oil to be fairly resistant to heat (10), but due to the lower smoke point I tend to cook with avocado oil while reserving olive oil for salad dressing or cooled dishes.
No Cooking At All
Fish Oil:
The Omega 3 fatty acids EPA and DHA are critical to so many functions in the body and should be a large part of a healthy diet. These Omega 3s are found abundantly in fish and fish oil. Although they greatly contribute to total health and are needed to keep inflammation in check, fish oil is definitely NOT an oil to cook with. Fish oil's many double bonds in the polyunsaturated fatty acids makes fish oil very unstable and not resistant to heat at all (this is why you store the capsules in a dark + cool place).
Due to it's heat instability, I prefer to get my EPA and DHA from fish oil supplementation and it is recommended to never cook with this oil.
It is important to note that there are many other oils to cook with, these are just the ones that I prefer and recommend for daily cooking. Due to their nutrient and antioxidant content, oils can provide excellent benefits in the body. The key when using oils is balance and using a variety of healthy and safe oils may be the best option. The lipids found in oils are important regulators of inflammation in the body, with a more balanced ratio of these oils (like omega-3 to omega-6) being crucial for lowering inflammation and preventing disease (2). It also may be worthy of noting that proper storage of certain oils in a cool & dark place is important to avoid the old from becoming rancid and forming free radicals before you even get a chance to use them.