Cooking Oils Demystified: What’s the Healthiest Cooking Oil?

Cooking Oils Demystified: What's the Healthiest Cooking Oil?What you eat matters but so does what you cook it in. You need a certain amount of fat in your diet for health reasons, but many people get too much of the wrong kinds of fat and eat too many foods prepared with unhealthy cooking oils. This is particularly true when you go to a restaurant where the emphasis is on controlling costs rather than health. When you prepare your meals at home, you have control over the oils you use. What are the healthiest cooking oils?

Types of Cooking Oils: How Does One Differ from Another?

All cooking oils have about the same number of calories – 120 calories per tablespoon. Where they differ is the ratio of saturated fatty acids, polyunsaturated fatty acids and monounsaturated fats they contain. For example, coconut oil is among the highest in saturated fat with over 90% of its fatty acids being saturated.

At the other end of the spectrum, canola oil is only 6% saturated fat. Most doctors still tell patients to avoid oils that are high in saturated fat because they elevate LDL-cholesterol and increase heart disease risk, although recent studies question the link between saturated fat intake and heart disease.

Are All Saturated Fats Bad?

Some experts believe that coconut oil, despite being very high in saturated fat, doesn’t negatively affect lipid levels or increase the risk of heart disease because it contains medium-chain triglycerides. Medium-chain triglycerides travel directly to the liver where they’re metabolized much like carbohydrates. This means they spend less time circulating around in your bloodstream where they can lodge in your arteries. Plus, some research shows coconut oil raises HDL, the heart-healthy form of cholesterol, and doesn’t raise LDL-cholesterol, the kind that’s linked with a greater risk for heart disease. Other cooking oils that are high in saturated fat are butter, palm oil, cottonseed oil, and peanut oil.

Polyunsaturated and Monounsaturated Fats

Some experts recommend using cooking oil that’s high in polyunsaturated fats based on the fact that polyunsaturates are less unhealthy for your heart. There are two types of polyunsaturated fat – omega-3s and omega-6s. You need a certain amount of both because of your body’s requirement for two essential fatty acids, alpha-linolenic acid, and linoleic acid, but most people get too much omega-6s in their diet and not enough omega-3s. An imbalance like that creates an inflammatory state that may increase the risk for health problems including heart disease. On the other hand, omega-3s help to reduce inflammation and may lower the risk of heart disease.

Cooking oils have different ratios of omega-3s and omega-6s. It’s healthier to choose one that’s higher in omega-3s relative to omega-6. Some vegetable oils like corn oil, sunflower oil, and safflower oil are rich in omega-6s, so you want to limit the amounts of these oils you consume. Unrefined walnut oil and flaxseed oil have a high ratio of omega-3s but they also have a low smoke point that makes them unsuitable for cooking at higher temperatures. They work well for salad dressings where heat isn’t involved. Canola oil is high in omega-3s but some people shy away from it because it may be genetically modified. There’s a way around this – buy organic canola oil from a reputable health food store.

One problem with polyunsaturated fats is they’re more prone towards oxidation. What does this mean? If you take them to high temperatures, they have a tendency to change structure and form free radicals. Monounsaturated fats are less likely to do this and they’re heart-healthy. Olive oil is the classic oil that’s high in monounsaturated fats. The problem with olive oil is it has a relatively low smoke point. You can safely use it for sautéing, baking and stir-frying but you shouldn’t heat it above 325 degrees Fahrenheit.

So what’s a good option to use for searing and frying? Avocado oil, almond oil, and hazelnut oil are good choices because they have high smoke points and have more monounsaturated fat than polyunsaturated or saturated.

The Worst Type of Fat

The fat to strictly avoid is trans-fat. You’ll find trans-fat mainly in margarine and lard substitutes. A number of restaurants use trans-fat containing oils and margarine when they prepare foods so always question a restaurant about whether they use margarine and whether they prepare items with an oil that’s trans-fat free. Some restaurants use partially-hydrogenated soybean oil that contains trans-fat. Steer clear!

 The Bottom Line?

Saturated fat may not be as unhealthy as original studies suggested but it’s best to avoid using oils high in saturated fat for now. Coconut oil is probably better for you than the saturated fat in dairy and meat products but there’s still not enough research to say it’s healthy to use on a regular basis.

Your best options? Stick with olive oil for sautéing and other lower temperature applications. It’s a good source of monounsaturated fats and has other potential health benefits as well. Research shows it is rich in antioxidants and has anti-inflammatory properties. Be sure to buy it in a dark, glass bottle and store it in a cool, dark place. Discard it after six months since it can go rancid over time.

What’s the healthiest cooking oil for high-temperature preparation? Try avocado oil, almond oil or hazelnut oil. They hold up well under heat and are rich in monounsaturated fat.

 The Bottom Line?

There’s no perfect cooking oil that works well for all applications. Olive oil is ideal but is limited by its smoke point. You may need to have more than one oil for high and low-temperature applications. Use these guidelines to make healthier choices when you choose an oil to cook with and make sure you’re not frequenting restaurants that use unhealthy cooking oils.



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Lipids. January 2000, Volume 35, Issue 1, pp 45-54.

Exercise Physiology. Fifth Edition. McArdle, Katch, Katch. (2001)


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