Healthy Oils for Healthy Eating

Healthy oils are a significant element of a healthy diet. Your body needs them to build new cell membranes, provide you with energy, absorb certain vitamins, support brain health, reduce inflammation, and potentially increase HDL (good) cholesterol while lowering LDL (bad) cholesterol. But while some oils help you stay well, others could have a negative impact on your health over time.

Types of Fat

What makes an oil healthy or unhealthy is determined by its fat composition, how it was processed, and whether it is consumed raw or used for high-heat cooking. There are two main kinds of dietary fats: saturated and unsaturated. These terms refer to the fats’ differing chemical structure.

• Saturated fats are usually solid at room temperature – think butter or cheese. Other than palm kernel or coconut oils, the most common sources of saturated fats are meats and dairy products.
• Unsaturated fats are usually liquid at room temperature. Vegetable oils, nuts and fish have mostly unsaturated fats. There are two types of unsaturated fats, each with a different chemical structure:
  • Monounsaturated fats reduce LDL cholesterol levels and inflammation and provide your body with essential nutrients for cell health.
  • Polyunsaturated fats support heart health by providing omega-6 and omega-3 fatty acids.
• Trans fats are an unhealthy subtype of unsaturated fat. Small amounts of these fats are found in meat and dairy, but the main dietary source is vegetable oils that have been processed into semi-solid fats through partial hydrogenation. Trans fats are used to manufacture many sweet and savory processed foods and baked goods. They raise LDL cholesterol levels and lower protective HDL cholesterol levels, increasing your risk for heart disease and stroke.

Healthy Oils

Healthy cooking oils are primarily high in unsaturated fats like monounsaturated and polyunsaturated fats and often contain antioxidants and/or omega-3 fatty acids.

• Avocado Oil is rich in monounsaturated fats and vitamin E. Its high smoke point makes it ideal for grilling or frying but it works in salads too.
• Canola Oil is low in saturated fat and high in omega-3s. It is virtuously tasteless, making it ideal for cooking and baking.
• Extra Virgin Olive Oil, a Mediterranean Diet basic, is high in monounsaturated fats and contains anti-inflammatory compounds and antioxidants known as polyphenols. It is best used for salad dressing and light sautéing.
• Grapeseed Oil is high in monounsaturated fats, vitamin E, and linoleic acid, and omega-6. It has a high smoke point and is good for cooking and baking but should be consumed in moderation.
• Flaxseed Oil is very high in a plant-based omega-3 fatty acid called ALA. Flaxseed oil is not heat stable and cannot be used for cooking.
• Macadamia Nut Oil Is exceptionally high in beneficial monounsaturated fats. It can be used for cooking and adds a delicate nutty flavor to salads.
• Rice Bran Oil is high in beneficial monounsaturated fats and has been shown to lower cholesterol. With a mild flavor and high smoke point, this oil is suitable for both cooking and salads.
• Sesame Oil, used in many Asian dishes, contains both mono- and polyunsaturated fats and antioxidants called lignans. It is best used for sautéing or as a finishing oil.
• Walnut Oil is high in polyunsaturated fats, including omega-3s. While you can’t cook with it, walnut oil works well in salad dressing or as a finishing oil.

Less Healthy and Unhealthy Oils

Oils deemed bad for you are typically heavily refined through industrial processes that use high heat and chemical solvents. These oils tend to contain omega-6 polyunsaturated fats or saturated fats. While omega-6 fats are essential for a healthy metabolism, used in excess they can promote inflammation and are linked to arthritis and heart disease. The consumption of omega-6 fats should be balanced out by omega-3 fats. According to a 2012 review in the Journal of Nutrition and Metabolism, a healthy dietary ratio of omega-6 to omega-3 is between 1:1 and 4:1. The typical Western diet ratio is between 10:1 and 20:1! To balance out a diet high in omega-6, consume more flax seed, walnut, and canola oil. Unhealthy oils that should be avoided or used sparingly include:

• Cottonseed Oil is often contaminated with pesticide residue, and it is high in saturated and omega-6 fats.
• Corn Oil is high in omega-6 and usually highly refined.
• Palm Oil is high in saturated fats.
• Partially Hydrogenated Oils contain artificial trans fats, which raise LDL and lower HDL cholesterols. Some countries heavily restrict or even ban the use of these oils.
• Soybean Oil is processed and oxidized and high in omega-6 fats.
• Sunflower Oil is high in monounsaturated fats but also in omega 6 fats, which contributes to inflammation.
• Vegetable Oil is chemically processed and has a high omega-6 content.
• Coconut Oil is perhaps the most controversial of all oils right now. It’s mostly saturated fat, and has been shown to increase HDL, but also LDL. For that reason, it’s wise to use only in moderation and select and unsaturated oil for most of your cooking needs.

Understand the Glossary

When you are reading the label on an oil bottle, look for “cold-pressed” or “expeller-pressed” and avoid “partially hydrogenated.” Some oils are labeled “high oleic” because of their increased monounsaturated fat content. These are both good for cooking and heart health.

Cold-pressed oil is extracted mechanically from seeds or fruits without using heat. Extra virgin olive oil is an example of cold-pressed oil. This is a low-yield process so cold-pressed oils tend to cost more.

Expeller-pressed oil is made using a device called an extractor. The device uses a lot of pressure, which generates some heat, but no chemical solvents are used.

Refined oil undergoes a process called RBD (Refined, Bleached, Deodorized) to remove impurities. The result is a clear, tasteless, odorless oil with a high smoke point, often used in restaurants. Soybean, canola, sunflower, and corn oils are all examples of refined oils.

Unrefined oil is filtered but not processed and retains its flavor and aroma.

Hydrogenated oil is made using a chemical process that adds hydrogen to liquid vegetable oil to make it more shelf-stable at room temperature. This process creates unhealthy trans fats.

Partially hydrogenated oil is not fully saturated with hydrogen but still contains some trans fats.

Virgin and Extra Virgin are terms for oil that was extracted using a mechanical cold-pressing method and meets specific quality standards. Extra Virgin is the highest quality.

Smoke Point refers to the temperature at which an oil begins to break down and produce smoke during heating. Oils with higher smoke points, such as refined canola and avocado oil, are best for frying.

This article first appeared in the September 2025 edition of the HealthPerks newsletter.