I recently got this question from a client: “Why is vegetable oil bad if it’s made from vegetables?” Great, great question. The simple answer is any healthy oil can be turned unhealthy for the body depending on how it is processed and how high it is heated.
What makes all this so confusing is that not all vegetable oils are created equal when it comes to health. While all vegetable oils are labeled and considered “heart healthy” (in comparison to saturated fat from animals), it really depends on factors like the plant’s origin, how it’s processed, the smoke point and the volume of consumption.
Let’s look at a few of these factors in more detail:
First, how the vegetable oil is processed is one of the most important factors as it determines whether it causes an inflammatory or anti-inflammatory state in your body.
So, the big question is “what oils should you avoid, and which ones should you buy?”
Terms to lean toward when shopping for oils include “cold pressed,” “expeller pressed,” “extra virgin,” “virgin” or “unrefined.” The processing of these oils does not use chemical solvents or high heat that degrades the oil.
Terms to be cautious of on the label include things such as “high oleic” or “refined,” as these are not the healthiest oils to be buying. These terms mean they either use genetically manipulated seeds or have impurities filtered out. While the processing can increase shelf life and allow for higher temperature cooking, it also reduces the amount of healthy fats and can cause an inflammatory response in the body. Examples of these oils include soybean oil, corn oil, canola, hydrogenated oils, vegetable oils, refined sesame oil and grapeseed oil.
Another key term to understand when choosing a healthy oil is “smoke point.” Smoke point is one of the most important factors to consider when choosing your cooking oil. Smoke point is the temperature of the oil at which it stops shimmering and starts smoking. When the oil reaches its smoke point, it breaks down and releases chemicals that cause an undesirable burnt or bitter flavor in the food and free-radical damage, which increases the risk of disease and cancer.
Healthy, unrefined oils that are high-heat oils (375 degrees or lower) are beef tallow, duck fat, coconut oil, avocado oil. It’s true some avocado and coconut oil can be heated higher than 375, but these are the refined versions. Healthy unrefined oils that are medium to low heat cooking (350 degrees or lower) include olive oil, unrefined sesame seed oil, ghee or clarified butter.
Some oils are their healthiest in their raw state and are great for salads because they have a low smoke point and can’t withstand heat. These oils include almond oil, hazelnut oil, pumpkin seed oil, walnut oil, apricot kernel oil, flaxseed oil, hemp seed oil and sunflower oil.
To sum it all up, you want to stick to unrefined vegetables oils while paying attention to the smoke point of the oil for cooking. A good rule of thumb is cooking at or below 375 degrees Fahrenheit use unrefined coconut oil or unrefined avocado oil as your high heat oils. When cooking at medium to low heat, you can always count on extra virgin olive oil.
Fran Sutherlin, RD, MS is a local registered dietitian, specializing in the use of digestive wellness to prevent or manage chronic disease. She has a master’s degree in nutrition, is a personal health coach, speaker and owner of Sustainable Nutrition. She can be reached at 444-2122 or firstname.lastname@example.org.