A study at UC Davis found that 82 percent of avocado oils are either rancid or mixed with other oils. Researchers tested 22 domestic and imported avocado oil samples sourced from local stores and online. 15 of 22 samples were oxidized (rancid, stale). 6 samples were mixed with large amounts of lesser quality oils such as soybean, safflower and sunflower oil.
Summary
Good Oils to Buy - Oils that were pure and not rancid
The problem with rancid oils
Rancid oils aren't inherently bad. Rancid oils won't make you sick, but they have strange flavors that can make or break your recipes. Rancid oils also lose some of their antioxidant properties so they don't have the same nutritional boost. The problem is you are paying a premium price for avocado oils when they may have diminished nutritional values and taste awful.
The problem with soybean oil
Soybean oil is commonly found in heavily processed foods such as popcorns, processed meats and cereals. It is popular because it is mass produced at a really cheap price.
Soybean oil is heavily processed, cleaned with chemicals and sourced from GMO soy. Soybeans are soaked in hexane to separate the oils from the rest of the flakes; and trace amounts are left in the actual oil that you eat. Additionally, soybean oil likely has a negative impact on inflammation, obesity and diabetes and is linked to neurological issues.
Why Avocado Oil?
Avocado oils are extracted, of course, from avocados. They contain 30% oil which make it a fantastic oil source. Avocado oil has a high smoke point of over 500 °F which makes it great for frying.
About 70% of avocado oil is high in heart-healthy monounsaturated omega-9 fatty acids.
Avocado oil can reduce blood pressure and cholesterol.
Good source of lutein which functions as an antioxidant that benefits your eyes.
The reason to love avocado oil is not because of these great additional health benefits, but to avoid the more dangerous and chemically refined oils. These refined oils are inflammatory, usually processed from GMO sources and still have trace amounts of solvent.
What can we do?
We need avocado oil regulation, similar to how other cooking oils are regulated. Right now, there are a lot of brands making a killing off of selling you overpriced oils that aren't avocado oil.
In the meantime, we know for certain that there are two brands of avocado oil that are not screwing us over: Chosen Foods Avocado Oil and Marianne’s Avocado Oil. Both of these oils are refined and made in Mexico.
There was another brand that the study mentioned that was better than the rest of the virgin grades, CalPure California Extra Virgin Avocado Oil. That said, Chosen Foods has always been my number one choice; and we should support them for selling us real avocado oil.
While flavors can differ, fresh virgin avocado oil tastes earthy and butter and should be green in color. Refined avocado oil is light yellow and almost clear since its pigments are removed during the refinement process. You can also smell the oil to see if it smells stale; a rancid oil can smell metallic, bitter or soapy.
How close are we to developing standards for avocado oil?
The FDA has not adopted "stands of identity" for avocado oil because it is relatively new to the market. Standards of identity ensure that our ingredients and our foods are labeled properly and authentically.
Selina Wang, my new hero and the author of the study at the Department of Food Science and Technology in UC Davis, is working to encourage FDA officials to establish reasonable stands for avocado oil. Until then, Wang is continuing her work in developing faster and cheaper chemical methods to determine the authenticity of our avocado oils.