Exploring the Health Benefits of Extra Virgin Olive Oil vs. Plain Old Olive Oil

​As the primary fat in the Mediterranean Diet, olive oil has been studied extensively for its health-promoting benefits. Regular consumption, defined as 1.5 - 4 tablespoons a day, has been observed to reduce the risk of total and cause-specific mortality. But not all olive oils are created the same. Thus, a study comparing the health benefits of EVOO to OO recently caught my eye.
 
Extra virgin olive oil (EVOO) is distinguished from olive oil (OO) by the extraction process. OO is produced via chemical extraction and processing, whereas EVOO is produced by crushing the olive thereby retaining and preserving the phenol content of the fruit (yes, olives are classified as a fruit!). It is the phenol content of the EVOO which is thought to impart the health-promoting benefits, not the fatty acid content (aka MUFAs).
 
The study participants
 
In the study comparing the two, 12,161 participants were assessed for variables such as sociodemographic factors, self-reported health conditions and medications, and diet, specifically their adherence to the Mediterranean Diet and type of olive oil consumed each day. Participants were followed for a mean 10.7 years.
 
The findings
 
Researchers found the risk of all-cause mortality and cardiovascular mortality was lower in those with the highest reported daily EVOO consumption, and this association was not replicated in those reporting OO consumption.
 
When total daily olive oil consumption was combined (i.e. adding together both OO and EVOO consumption), the risk of mortality was also reduced—but not as low for those with higher daily EVOO consumption (not combined with OO).
 
Interestingly, deeper reductions in all-cause mortality were noted in those reporting both higher EVOO consumption and physical activity, indicating a synergistic effect between the two, the mechanism of action for which is not fully understood.
 
How do we interpret this study?
 
We can start by noting it is not a randomized clinical trial (RCT). Instead, this study is strictly observational, meaning we can observe the results, but we cannot draw conclusions. Had the researchers randomly assigned half the participants to EVOO consumption and half to OO, we would have more conclusive results. So, I dug a little more into the research in PubMed. A review article of 34 studies in which EVOO was compared to other fats found EVOO superior in a variety of biomarkers and health outcomes—this was again believed to be imparted by the phenol content.
 
Where does this leave us?
 
It would seem that EVOO might have benefits above and beyond that of other fats, including plain old olive oil. Specifically, a serving of 2 tablespoons of EVOO a day appears to be beneficial. It’s important to also remember the statistically observed synergy between EVOO and physical activity—so keep moving!
 
Buying EVOO
 
When purchasing, remember to read the label to make sure it says EXTRA VIRGIN olive oil and if you can find it unfiltered that’s even better! Check the expiration date, as phenol content wanes with time. Pesticide residue studies of European olive oils do not indicate contamination above threshold levels, thus if purchasing European olive oils, it may not be important to choose an organic version. And be sure to keep your EVOO away from heat (not next to or above the stove or oven) and away from light.
 
There exists both controversy and contradictory research results regarding the degradation of phenols with cooking. It seems prudent to save the pricey EVOO variety for salad dressings and for finishing/topping soups and vegetables for flavor and mouthfeel.
 
If you have questions about your specific EVOO recommendations in relation to your personal health, please reach out for a chat. You may also feel free to share this blog with your friends and family.

 
SOURCES:
 
Ambra R, Lucchetti S, Pastore G. A Review of the Effects of Olive Oil-Cooking on Phenolic Compounds. Molecules. 2022 Jan 20;27(3):661. doi: 10.3390/molecules27030661. PMID: 35163926; PMCID: PMC8838846.
 
Donat-Vargas, C., Lopez-Garcia, E., Banegas, J.R. et al. Only virgin type of olive oil consumption reduces the risk of mortality. Results from a Mediterranean population-based cohort. Eur J Clin Nutr 77, 226–234 (2023). https://doi.org/10.1038/s41430-022-01221-3