Olive oil is one of the biggest offenders on the worldwide “food fraud” paradigm. In other words, companies blend their oils with cheaper vegetable oils and sell it as pure olive oil. This is extremely common, especially in Italy. How would you feel if you were a high profile chef, paid $300 for an 8 oz bottle of olive oil, and then found out it was 60% corn oil? 1
Olive oil is high in oleic acid, which is a good mono-unsaturated fat; however, the polyunsaturated fatty acid profile is not optimal. All of the polyunsaturated fats in olive oil are composed of linoleic acid, a n-6 fatty acid, and if it is watered down with other vegetable oils, the ratio of linoleic acids to oleic acids swing in the direction of linoleic acid in a hurry. If you have ever read Weston A. Price, one of the first things that you will come across is that westerners eat way too much polyunsaturated fatty acids, and the ratio of n-3 fatty acids to n-6 is also out of proportion. The Bulletproof Diet attempts to resolve this by limiting PUFA – especially n-6 fats.
Olive oil contains many polyphenols, but the compounds that have biological value are tyrosol, hydroxytyrosol, and oleuropein. The health benefits from these phenols are ascribed to their reduction potential or FRAP (ferric reducing antioxidant power) value as an antioxidant. From the moment the olive is picked, the FRAP value drops following a logarithmic curve. Microbial activity and air have a little to do with the degradation of these compounds, but the biggest factor is light. When a photon collides with the olive oil, the light can either pass through, be reflected, or be attenuated. The opacity and color of the oil play a huge role in the degradation of the polyphenols. The darker and more opaque oils are much more susceptible to attenuation than the lighter, clearer oils. When a photon collides with phenol, it destroys it. The quickly pressed, unfiltered oils will contain the most polyphenols, but they will also attenuate the quickest. If you could pull some right off the tap, it would have an excellent FRAP value, but on the consumer level, people typically buy oils in clear glass, or plastic bottles allowing the light to pass through. Once it reaches the consumer, the FRAP value is insignificant with most brands. 2
The reason why unsaturated fats are liquid at room temperature is because of the double bonds in the fatty acid chains. Saturated fats do not contain double bonds and appear as a straight line, whereas unsaturated fats have a kink in the molecule at the carbon with the double bond. Due to their molecular shape, they displace more space and cannot be “stacked” to solidify. But what happens when you apply heat? “Double bond” sounds like a stronger bond than a “single bond,” but it is much weaker. If you take a tablespoon, or two, of your finest olive oil and heat it on the stove below the smoke point for a few minutes, pour it out into a cup, and chill it in the refrigerator overnight, what happens? You will see a solid layer of fat at the top of the oil. This is because the double bonds have broken and the fats have become denatured. These fats have been oxidized, and when consumed, will begin a biological cascade within the human body that results in low-grade inflammation.
If you have fat malabsorption or bile issues, you may want to limit the amount of extra virgin olive oil you consume and the amount of oleic acid in your diet. Oleic acid is a potent CCK producer that requires ample amounts of bile for processing. You also do not want to eat a lot of extra virgin olive oil in one meal to prevent fat malabsorption; it is best to spread out your ingestion of the oil throughout different meals and not ingest like six tablespoons at one time. 3 4
In conclusion, there are some problems with olive oil including purity, fat ratios, and its susceptibility to air, heat, and light. It is one of the better vegetable oils to consume raw, but I prefer oils comprised mostly of MCT’s for cooking because they are more chemically stable making them better for your health.
Here are some recommendations to help you find good quality extra virgin olive oil and how to maintain the quality:
- Grown and processed in California, and organic if possible. We recommend and use Enzo olive oil here at FYG.
- Look for extra virgin olive oil that is stored in a dark bottle to protect it from light oxidation.
- Only consume extra virgin olive oil, do not heat it and do not cook with it.
- Look for first pressed or cold pressed oil.
- Store it in a cool, dark environment like the back of your pantry.
Consumption of extra virgin Californian olive oil is healthy in moderation. Oleic acid is a very healthy fat, and olive oil does contain important polyphenols that can improve your health.
- http://www.slate.com/blogs/browbeat/2014/01/27/adulterated_olive_oil_how_to_find_out_if_your_extra_virgin_is_really_extra.html ↩
- http://www.ncbi.nlm.nih.gov/pubmed/23070730 ↩
- https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwj-6Pj2zcrMAhVE6CYKHRxZDEwQFgg9MAU&url=https%3A%2F%2Fwww.researchgate.net%2Fpublication%2F225672540_Role_of_secretin_and_cholecystokinin_in_oleic_acid-stimulated_pancreatic_secretion_in_rats&usg=AFQjCNFJYJjTpPo6BGauHZPlj9QGRXfIPQ&sig2=qp2GCdv7v4ZY7CWle-WZgA&bvm=bv.121421273,d.eWE ↩
- http://link.springer.com/article/10.1007%2FBF02785336#page-1 ↩