In the last article I presented some information about the quality of olive oil. Some brands labeled as extra virgin may not be extra virgin. They may be just virgin and the quality has been called into question. I also gave a couple of brands that I like as well as a few others from the UC Davis study which looked at the quality of several brands. This article will discuss some of the benefits of olive oil, some of the myths, and a couple of recommendations.
Olive oil is primarily composed of oleic acid, which is a monounsaturated fatty acid. It comprises between 55-83% of the oil’s volume. Because of the single double bond it is much less susceptible to oxidation like the polyunsaturated linoleic acid which is far more easily oxidized and present in many seed and man made oils.
Olive oil also contains linoleic acid at anywhere from 3.5%-21%. Linoleic acid is of course an omega-6 (n-6) fatty acid. Palmitic Acid, a saturated fat, can make up from 7.5-20% of the total volume. Steric acid and linolenic acid are also constituents.
Olive oil may have some great health benefits you won’t find with industrial seed oils and others.
Oleic acid has been studied in women with breast cancer. Women given oleic acid (OA) were found to have cancer cells that downregulated Her-2/neu by up to 46% and by up to 70% with concomitant trastuzumab. Her-2 is a growth receptor and responsible for progression in breast cancer. Thus OA may be beneficial in treatment of this disease.
Olive oil contains phenols which are considered antioxidants. The three types present are simple phenols, secoiridoids, and lignans. Hydroxytyrosol and oleuropein (two of these phenols) scavenge free radicals and inhibit low density lipoprotein (LDL) oxidation.  That is very important when considering cardiovascular disease as oxidized LDL likely plays a role in the development of the disease.
One study found that EVOO and virgin olive oil had significantly more antioxidants than seed oils. 
Another study showed that these phenols are able to scavenge free radicals in your poo  which may be helpful in colorectal cancer prevention.
DNA oxidation may play a part in cancer because once your DNA is oxidized and damaged it may start to do things it normally wouldn’t. These compounds are also able to prevent that oxidation from occurring. 
One small study found that subjects with hypertension reduced the dosage of hypertension medications used.  A different study found that olive oil lowered both systolic and diastolic pressure in untreated women with hypertension, but not high oleic acid sunflower oil, which is the main constituent of olive oil. 
I discussed in a previous post the benefit of olive oil in rheumatoid arthritis. It is thought to decrease inflammatory cytokines that create problems in the joints. One theory is that the oleic acid becomes a component of the membranes of the cell and helps to eliminate competition between n-6 and n-3 for expression.
Good quality olive oil may contribute to some of the benefits of the “Mediterranean Diet”. Not to mention it tastes divine and enjoying good food (ie not wolfing it down, actually sitting and enjoying food with friends and family while under no stress) is probably just as important as exercise and good lifestyle.
One of my favorite things is to sit down with my wife and enjoy some cheese, chorizo and a little oil on some bread. Is it the healthiest food? Well maybe everything but the bread, but the experience of relaxed dining is more important to my well being than a little sourdough. That’s an article in and of itself.
What about cooking?
Heat can be beneficial to preparing good food yet detrimental to certain fatty acids Degradation or oxidation of fatty acids can produce a bad tasting product as well as eliminate any health benefits associated with them. Is cooking with olive oil bad?
Microwaving the oil for 10 min resulted in a minimal loss of polyphenols, the antioxidants.  They also found that the longer the oil is exposed to heat the more likely it is to oxidize. No real surprise there. A good quality olive oil should have a smoke point around 350 degrees F (176 C). Cooking with olive oil on the stove should be ok provided the heat isn’t high and it’s not deep frying or something that will keep it on the heat for a long time.
Cold preps for olive oil are great in dressings or just plain on a salad, and yes, on my sourdough. I’ve used it with sweet potatoes too with wonderful results.
Remember to store the oil in a dark place and preferably in a dark container as light will eventually cause oxidation. As discussed in the last post, don’t wait for months at a time before you use it all after opening the bottle.
In the next post I’ll share some ways I use olive oil.
1.Menendez, J. A., et al. “Oleic acid, the main monounsaturated fatty acid of olive oil, suppresses Her-2/neu (erbB-2) expression and synergistically enhances the growth inhibitory effects of trastuzumab (Herceptin™) in breast cancer cells with Her-2/neu oncogene amplification.” Annals of oncology 16.3 (2005): 359-371.
2. Waterman, Emily, and Brian Lockwood. “Active components and clinical applications of olive oil.” Alternative Medicine Review 12.4 (2007).
3. Owen, R. W., et al. “Phenolic compounds and squalene in olive oils: the concentration and antioxidant potential of total phenols, simple phenols, secoiridoids, lignansand squalene.” Food and Chemical Toxicology 38.8 (2000): 647-659.
4. Owen, Robert W., et al. “Olive-oil consumption and health: the possible role of antioxidants.” The lancet oncology 1.2 (2000): 107-112.
5. Visioli, Francesco, Andrea Poli, and Claudio Gall. “Antioxidant and other biological activities of phenols from olives and olive oil.” Medicinal research reviews 22.1 (2002): 65-75.
6. Ferrara, L. Aldo, et al. “Olive oil and reduced need for antihypertensive medications.” Archives of Internal Medicine 160.6 (2000): 837-842.
7. Ruiz-Gutiérrez, Valentina, et al. “Plasma lipids, erythrocyte membrane lipids and blood pressure of hypertensive women after ingestion of dietary oleic acid from two different sources.” Journal of hypertension 14.12 (1996): 1483-1490.
8. Brenes, Manuel, et al. “Influence of thermal treatments simulating cooking processes on the polyphenol content in virgin olive oil.” Journal of Agricultural and Food Chemistry 50.21 (2002): 5962-5967.