Best Oils to Cook with and Best Oils to Avoid
by Judy Nicassio, Certified Nutritionist
We all know the health benefits of consuming raw foods, but since most of us are also including cooked foods in our diets, doesn’t it make sense to choose cooking oils that will preserve our health as opposed to contributing to illness? Of course! After all, we don’t want to be spending our hard-earned money on good quality foods only to negate any health benefits by destroying them in the cooking process.
Keep this in mind when cooking with oil: Heating it too much can cause oxidation and lead to the formation of carcinogens and other unhealthy compounds. If the oil begins to change color, it’s a telltale sign that it’s starting to degrade from too much heat.
Fatty Acids in Cooking Oils:
There are three types of fatty acids found in cooking oils.
- Saturated fatty acids are extremely stable - even when exposed to heat and light. These are the best choice for cooking.
- Monounsaturated fatty acids are only relatively stable when heated and work best when cooking at low to medium temperatures.
- The polyunsaturated fatty acids are basically unstable and can produce lots of free radicals when exposed to heat. Therefore, these oils should be avoided when cooking.
Healthy Oils for Cooking with High Heat:
The most important factor in determining an oil’s resistance to oxidation and rancidity, both at high and low heat, is the relative degree of saturation of the fatty acids in it.
- Coconut oil – a healthy, high-saturated fat that can withstand high heat. This is our favorite choice for cooking purposes. Coconut oil can also help regulate blood sugar and boost thyroid function to increase metabolism, energy, and endurance. It supports proper digestion and helps absorb fat soluble vitamins.
- Red palm oil –a healthy, highly-saturated fat and stable cooking oil. It also has a high content of carotenes, including lycopene and tocotrienols (a particularly potent form of vitamin E).
- Avocado oil – this oil can withstand heat and is loaded with healthy fats. It also works well in salad dressings and has the added bonus of reducing heart disease.
- Almond oil – good for all kinds of cooking and contains healthy omega-3 fatty acids.
Healthy Oils for Cooking with Low-to-Medium Heat:
- Extra-virgin olive oil – a great source of healthy monounsaturated fats, which help control cholesterol levels and have been linked with heart health. Unfortunately, olive oil can oxidize at temps over 200 degrees. It’s best to use for either low-heat sautéing or unheated for drizzling on steamed veggies or on a cold salad.
- Walnut oil – can take heat up to 400 degrees (refined) and is full of healthy omega-3 fatty acids. Good for salads, marinades, and low-to-medium heat sautés.
- Peanut oil – use sparingly (due to its high level of omega-6 fatty acids). Good for light sautéing, cooking fish, and stir-fry dishes.
- Sesame seed oil – best used for light sautéing and low-heat baking. Has a rich, nutty flavor and is linked to health benefits such as lowering blood pressure and reducing risk for heart disease.
Healthy Oils NOT Good for Cooking Purposes:
- Grapeseed oil – because it’s mostly comprised of polyunsaturated fats, it can oxidize easily when exposed to light, air, and heat. Unheated, it’s a good source of vitamin E.
- Flaxseed oil – a great source of omega-3’s but has a low smoking point and will oxidize quickly. Never use it for cooking purposes.
- Evening primrose oil – high in healthy omega-3 fatty acids but cannot withstand heat.
- Hemp oil – lots of beneficial fatty acids but unable to withstand heat. Better for dips and dressings.
- Hazelnut oil – high in healthy monounsaturated fats but too delicate for cooking. Try it on oatmeal, rice, or quinoa.
Oils to Minimize or Avoid:
Omega-6 fatty acids aren’t inherently unhealthy, but they have been linked with obesity, diabetes, and heart disease because most of us are simply getting too much of them in our diet. In addition, studies have indicated that many of the polyunsaturated vegetable oils become rancid more easily.
- Soybean oil – not only high in omega-6 fats, but the sources for this oil are more than likely genetically modified and highly processed with chemicals. The omega-6 found in soybean oil promotes chronic inflammation in your body, which is an underlying issue for virtually all chronic diseases. Even if you’ve found an organic source of soybean oil, goitrogens are found in all unfermented soy - whether organic or not. These are substances that block the synthesis of thyroid hormones and interfere with iodine metabolism, thereby interfering with your thyroid function. Avoid this oil at all costs.
- Sunflower oil – high in omega-6’s and when found in packaged foods is often partially hydrogenated (unhealthy trans fats).
- Safflower oil –can form dangerous free radicals when exposed to heat or oxygen.
- Canola oil – goes rancid quite easily and can form high concentrations of trans fatty acids. In addition, most canola oil in the United States is genetically altered. The extraction process of canola oil from seeds involves a combination of high temperature processes. Hexane is added to extract oil from the seeds, causing minute amounts of the dangerous gas byproduct to appear in cooking oils. Another oil to avoid at all costs.
- Cottonseed oil – made up of about 50% of unstable polyunsaturated fatty acids and high in omega-6’s.
- Corn oil – high in omega-6’s and can produce harmful chemicals when heated. And like soybean and canola oils, most of the corn oil in the U.S. comes from genetically engineered plants.