Many studies on human ecology have drawn a strong correlation between the Mediterranean diet and longevity through its preventative effects on diseases associated with the cardiovascular, immune and neurological systems, as well as cancer.
The benefits of bioactive compounds found in olive oil have been studied in research labs, humans and entire populations, attributing to the wide range of evidence behind its medicinal and positive effects on human health.
In the Mediterranean diet, one of the main sources of fats is olive oil, used for salad dressings, frying and flavouring. When olive oil is produced it has been found that its higher fatty acid content is associated with an increased quantity of beneficial compounds. A good quality olive oil will have a nutritional profile comprised of vitamin A, fatty acids, plant sterols, and most significant to human health, polyphenols.
Olive Oil Quality
The quality of olive oil is largely based on the extraction and processing methods undertaken on the fruit, and some part, the soil of the original plant.
The extraction of olive oil with the use of pressure is done through crushing of the olives followed by the separation of the oil from the fruity flesh. Pressure extraction produces an oil with a three key features.
- Strong colour
- Weak aroma
- High content of fatty acids.
In contrast, cheaper and highly processed varieties of olive oil undergo chemical extraction. This method of extraction must then undergo a refining process to remove harmful solvents and impurities to be safely consumed by humans. Not only does the refining process strip the olive oil of impurities, but it also strips it of any nutritional value, such as the vitamins, fatty acids, polyphenols and other plant compounds previously mentioned that possess its health benefits. This results in a product characteristically light in colour and lacking in strong flavour.
The outcome and compassion of these processing methods makes virgin olive oil significantly higher in nutritional value and beneficial to human health and wellbeing. In addition, the natural chemicals extracted within virgin olive oil not only protect human health but prolong the quality of the oil itself extending its shelf life.
As mentioned previously, polyphenols are one of more significant medicinal compounds derived from olive oil, playing a major role in the prevention of disease. Polyphenols are found in a range of plant parts from fruit and vegetables, nuts and seeds, barks and roots, leaves and herbs, and our favourites, coffee and wine. With a special interest in olive oil, its polyphenols have been studied more so due to the oil’s large contribution in the Mediterranean Diet, being one of the healthiest in the world.
In a range of studies, polyphenols have shown neuroprotective, anti-cancer, anti-thrombotic and anti-inflammatory effects on a chemical level. This is due to their strong antioxidant capabilities, meaning they stabilise cell our membranes and moderate inflammatory processes caused by the production of compounds called reactive oxygen species (ROS). As inflammation and the activity of ROS are key drivers in diseases like cardiovascular disease, diabetes and neurodegeneration, olive oil works as a promising and easily accessible food as medicine type intervention for better health.
Olive oils fatty acid content also brings with it positive impacts on health. In contrast to the western diet where the main source of fat is butter, which is a saturated fat, olive oil’s fatty acid profile is primarily monounsaturated.
The dietary substitution of saturated fats such as butter, or trans-fats like margarine with olive oil results in a significant reduction in LDL cholesterol levels and the incidence of heart disease due to simultaneously increasing omega 3 and omega 6, polyphenols and antioxidants.
“An increase in consumption of virgin olive oil and other plant products rich in polyphenolic compounds, specifically in populations with low olive oil intake, does seem to be rational and provide diverse health benefits” (Gorzynik-Debicka et al., 2018)
(Gorzynik-Debicka et al., 2018)
Cooking with Olive Oil
Olive oil contains 55% to 83% of monounsaturated oleic acid, which is 50 times less prone to oxidation than the fatty acid linoleic acid that is found in higher quantities in a majority of common vegetable oils.
High frying temperatures are handled well with olive oil as its smoking point (210 °C) is well above the suggested temperature for frying food. This may be because it contains those beneficial health compounds like antioxidants, contributing to its protection against the effects of oxidative deterioration, which would commonly occur at high temperatures.
Phenolics are regarded as components that play a fundamental role in olive oil stability.
Topical Olive Oil
Not only within the body do we see benefits from this amazing oil. Topical application of high-quality olive oil on skin in the form of oils, soaps, creams and lotions have been effective in reducing inflammation and assisting in wound healing. The action of olive oil for topical use actually works through the monounsaturated fatty acids causing a mild and controlled disruption to the skin barrier allowing the beneficial compounds of the olive oil itself as well as any added oils and ingredients to pass deeper into the skin. Just like the oils we eat; unrefined cold pressed oils have better nutritional value managing inflammation and exhibiting antioxidant effects. This is why olive oil has been a key ingredient in skin and hair care since traditional times and across so many cultures.
Chiou, A., & Kalogeropoulos, N. (2017). Virgin Olive Oil as Frying Oil. Comprehensive Reviews in Food Science and Food Safety, 16(4), 632–646. https://doi.org/10.1111/1541-4337.12268
Forouhi, N. G., Krauss, R. M., Taubes, G., & Willett, W. (2018). Dietary fat and cardiometabolic health: Evidence, controversies, and consensus for guidance. BMJ, k2139. https://doi.org/10.1136/bmj.k2139
Gorzynik-Debicka, M., Przychodzen, P., Cappello, F., Kuban-Jankowska, A., Marino Gammazza, A., Knap, N., … Gorska-Ponikowska, M. (2018). Potential Health Benefits of Olive Oil and Plant Polyphenols. International Journal of Molecular Sciences, 19(3), 686. https://doi.org/10.3390/ijms19030686
Lin, T.-K., Zhong, L., & Santiago, J. (2017). Anti-Inflammatory and Skin Barrier Repair Effects of Topical Application of Some Plant Oils. International Journal of Molecular Sciences, 19(1), 70. https://doi.org/10.3390/ijms19010070
Visioli, F., Franco, M., Toledo, E., Luchsinger, J., Willett, W. C., Hu, F. B., & Martinez-Gonzalez, M. A. (2018). Olive oil and prevention of chronic diseases: Summary of an International conference. Nutrition, Metabolism and Cardiovascular Diseases, 28(7), 649–656. https://doi.org/10.1016/j.numecd.2018.04.004