Are you still using vegetable oil? Here is how to choose the healthiest option.

Vegetable oils. Found in recipes from baking to stir-fry and listed on labels from granola bars to body lotion. What are these oils? Which should you include in your diet and which should be avoided? Let’s find out. 

Simply put, vegetable oil is a fatty oil extracted from a seed or fruit. 1 The most common vegetable oils you will find on the market today are avocado, coconut, corn, olive, peanut, rapeseed, soybean, safflower, sunflower and canola.

Oh, the beautiful sight and smell of the canola…flower? plant? Wait, what is a canola?  We will get to that in a bit, but let’s first discuss how a seed or fruit is turned into an oil.

Oil quality is determined by purity of the origin plant as well as the method in which it is processed. Meaning, some oils are organic, pure, and unrefined, while others are genetically modified and highly processed. (Hint — the former is healthy; the latter is not!)

All extraction begins the same, where the seed or fruit undergoes a phase of cracking, crushing, or grinding. 2 From there, the meal is pulverized and then either pressed or processed. This step is a major step in determining whether the resulting oil will be healthful or harmful. Let us break it down:

The best option is cold-pressed. Cold pressing is done through the ancient practice of grinding and milling or the modern practice of a slow, hydraulic press. 3 This process will yield the most nutrient-dense product due to the low temperatures being used. Higher temperatures greatly reduce quality of the oil. 4

Your second-best option is expeller pressed. While these oils do undergo some refinement at slightly higher temperatures than cold-pressed, there are no chemicals used in the process, maintaining integrity of the resulting product.

Oils to be avoided are those that are chemically processed and refined, often at very high temperatures. Instead of a physical press, chemicals such as hexane (found in glue and leather cleaners) are used for oil extraction, followed by degumming, neutralization, dewaxing, bleaching, filtration and deodorization, and possible hydrogenation where the oil is re-bleached and re-deodorized. 5 This process degrades the structure of the oil, resulting in a rancid and potentially toxic product.

Now you may be wondering, how will I know which oils are cold-pressed vs. expeller-pressed vs. chemically processed? Rest assured; any high-quality oil will have its process clearly listed on the label. Lower quality oils tend to leave this information out or utilize trickery via fancy marketing. Here is a quick cheat-sheet for your next purchase:

LOOK FOR:

• cold or expeller pressed
• organic
• unfiltered
• unrefined
• virgin
  
  

 AVOID:

• cold or expeller processed
• hydrogenated/partially hydrogenated

Now, going back to canola. Derived from genetically modified rapeseed and highly processed, this oil is one you’ll want to avoid at all costs. Along with canola, you’ll want to avoid corn, rapeseed, and soybean as they all fall into the same category and are detrimental to our health.

The preferred, unrefined and heart healthy vegetables oils are coconut, olive, peanut, safflower and sunflower. But buyer beware, some of these healthy oils do undergo refinement and chemical processing, which can destroy the oil’s beneficial properties. 6 Use the nifty cheat-sheet above to choose the healthiest option!

Now that you’re confidently purchasing the very best oils for your health, ensure they stay fresh by storing them in the refrigerator! 7 The only exception here is olive oil, which should be kept in a dark place, such as the cupboard. 

Don’t forget your other healthy fats, butter, bacon fat (Lard), beef and lamb fats (Tallow), chicken, duck and goose fat (Schmaltz).

Safe for cooking:
(quick stir-frying, light sautéing, and slow/low simmering)

• Olive Oil (Unfiltered is best; should be golden yellow/green in color and cloudy.)
• Peanut Oil
• Avocado Oil
• Macadamia Nut Oil
• Sesame Oil

*These oils should ALWAYS be extracted via expeller-pressing!  Read the label first!
Olive Oil (oleic acid): Olive oil contains 75% MUFAs. It is relatively stable for cooking. There has been a rumor moving its way through the holistic community for the past several years stating that trans fats are formed when olive oil is exposed to higher temperatures. Fat expert Mary Enig did a beautiful job of explaining that this rumor is not only untrue, but completely lacking in supportive scientific evidence. Lightly cooking with olive oil over a medium heat (less than 400 degrees) is considered safe.

Can olive oil and its MUFA molecules be damaged at high heats resulting in free radical production? Yes, but these unstable molecules are different from trans fats, so please do not confuse the two. Again, to form a true trans-fat, the fat must be exposed to extreme pressure and temperatures, metal catalysts, chemical solvents, etc., in a closed container to actually alter the chemical structure of a fatty acid molecule from its natural “cis” formation to a “trans” formation.

Peanut Oil: Peanut oil is relatively stable due to its MUFA content. Use it occasionally for a quick stir-fry, but the key word here is “occasional”. Peanut oil also has a significant PUFA content, so limited use is recommended.

Avocado Oil: A relatively new edible oil to the market since 1999, avocado oil has been previously used for many years as a moisturizing agent in cosmetic and hygiene products. Avocado oil is not extracted from the pit, rather, it is extracted from the fatty pulp, which is high in MUFA’s. It is similar to olive oil, so the same cooking rules apply.

Macadamia Nut Oil: Macadamia nut oil contains nearly 80% MUFA’s. It is very close to the fatty acid profile of olive oil, so the same cooking rules apply. Mac Nut oil has a distinctive, nutty flavor and is delicious in salad dressings. Look for expeller-pressed, organic UNBLENDED versions of this oil. It stores well in the refrigerator for up to one year.

Sesame Oil: Like peanut oil, sesame oil is relatively stable. Sesame oil falls right between a MUFA and a PUFA (42% MUFA, 43% PUFA), but it has high levels of antioxidants for protection against oxidation, so sesame oil may be used for low-heat stir-frying or a quick sauté on a very limited basis. Combining sesame oil with olive oil and/or other stable saturated animal fats will help protect sesame oil when cooking.

Unsafe for any kind of heat exposure, do not use for cooking!
Vegetable/Soybean Oil
Corn Oil
Flax Oil
Hemp Oil
Pine Nut Oil
Pumpkin Oil (safely roasted or raw versions)
Safflower Oil (80% omega 6!)
Sunflower Oil
Grapeseed Oil

*These PUFA oils are comprised of nearly half omega-6 fatty acids and should NEVER be used for cooking! If you do wish to consume these oils, do so in moderation, buy them from healthy sources and be sure that they are never refined or processed, although finding truly unprocessed versions of these oils is a difficult task. Corn and soybean oils are best avoided due to their genetically modified status and heavy pesticide levels.

Use omega-3 rich oils like Flax Oil sparingly in salad dressings (add flax in small amounts to a base of olive oil), in small servings in a condiment such as homemade mayonnaise, stir them in small amounts into freshly prepared smoothies, lightly drizzle them over cold soups, dips, and hors d’oeuvres, or consume them right off the spoon in very limited quantities as a dietary supplement.

Grapeseed oil: There are many conflicting opinions about the safety of cooking with grapeseed oil. Like sesame oil, it has a higher smoke point due to its antioxidant content. Regardless, grapeseed oil is extremely high in PUFA’s and should not be used for cooking.

1  “Vegetable Oil.” Merriam-Webster, Merriam-Webster, www.merriam-webster.com/dictionary/vegetable%20oil.
2  Know Your Fats: the Complete Primer for Understanding the Nutrition of Fats, Oils and Cholesterol, by Mary G. Enig, Bethesda Press, 2000, p. 148.
3 Broaddus, Hannah. “The Difference Between Solvent Expelled, Expeller Pressed and Cold Pressed Oil.” Non-GMO & Organic Oil Supplier & Packer, 17 July 2017,https://www.centrafoods.com/blog/difference-between-solvent-expelled-expeller-pressed-cold-pressed
4 Sionek, B. “Cold Pressed Oils.” Roczniki Panstwowego Zakladu Higieny, U.S. National Library of Medicine, 1997, https://pubmed.ncbi.nlm.nih.gov/9432706/
5 Know Your Fats:the Complete Primer for Understanding the Nutrition of Fats, Oils and Cholesterol, by Mary G. Enig, Bethesda Press, 2000, p. 9.
6 Axe, Josh. “Coconut Oil: 20 Health Benefits, Nutrition and Popular Uses.” Dr. Axe, 24 Apr. 2019, https://draxe.com/nutrition/coconut-oil-benefits/
7 Staying Healthy with Nutrition the Complete Guide to Diet and Nutritional Medicine, by Elson M. Haas and Buck Levin, Celestial Arts, 2006, p. 529.