Olive oil is nutritionally considered to be the best source of fatty acids. It is also highly appreciated for its positive effect on human health and its excellent taste and aroma. Why is olive oil more beneficial to human health than seed oils or saturated fats such as butter?
The shortest answer is that olive oil has the perfect fatty acid composition, which is mainly monounsaturated fatty acids (MUFA).
These acids, in contrast to polyunsaturated fatty acids (PUFA) that are found in seeds oils, are more stable against oxidation, and therefore the production of peroxides and free radicals, which have been linked to induce carcinogenesis, is hindered. The fatty acid composition also affects the low density lipoprotein (LDL) cholesterol (i.e.‘bad’ cholesterol) level which is responsible for atherosclerosis (thickening of the artery wall) and is known to be linked to the heart disease. The MUFA and PUFA have been found to decrease the LDL cholesterol levels; olive oil with high level of MUFA is clearly beneficial to our health.
Though people focus on the fatty acid composition, they often ignore some minor, but also important components of olive oil. Those minor compounds, which appear in olive oil in low concentration, indeed have significant health benefits as they play major biological roles in the body. They can also be used as effective finger prints (i.e. biomarkers) to evaluate quality and authentication of the olive oils. The most important minor compounds of olive oil are polyphenols/tocopherols (including vitamin E), sterols and squalene.
Polyphenols, such as oleuropein, tyrosol, hydroxytyrosol, oleocanthal and oleacein found in olive oil, are extremely strong antioxidants. Their antioxidant activity is comparable with artificial antioxidants like Butylated hydroxyanisole (BHA) and Butylated hydroxytoluene (BHT), and they are known to play multiple positive roles in our health. Polyphenols furnish the immune system, protect us from heart diseases and display anticancer activity as they act as free radicals traps. They protect olive oil from oxidative damage and they contribute to its superior oxidative stability among other edible oils. They also affect its taste, specifically for a distinctive bitter taste. The concentration of polyphenols in olive oil ranges from 100 to 1000 mg/kg.
Sterols are considered important elements for human nutrition and health. Clinical studies have shown that the dietary intake of phytosterols decrease the blood cholesterol levels and is likely to inhibit its absorption from the small intestine. Moreover, sterols have been shown to act as anti-inflammatory, anti-bacterial, anti-fungal, anti-ulcerative, anti-oxidant and anti-tumor. The total sterols content in olive oil ranges between 1,000 to 2,200 mg/kg.
Squalene is believed to offer positive effects on human health as it may have a chemopreventive effect in some type of cancer and it is beneficial for patients with heart disease and diabetes. Olive oil has the highest concentration of squalene compared to other edible oils. Its concentration in olive oil ranges from 1,000 to 7,500 mg/kg whereas in corn oil, for example, ranges from 190 to 360 mg/kg.
Other minor compounds that affect the olive oil quality and have an impact to our health are phospholipids which are known to reinforce the phosphorous compounds in the brain and tissues and have anti-inflammatory activity, diglycerydes, glycerol, water, β‑carotene, triterpenic acids such as maslinic acid and oleanolic acid and triterpenic alcohols such as erythrodiol and uvaol.
In summary, olive oil has superior nutritional value in comparison to other types of edible oils not only because of its fatty acids composition but also because of the presence of many important minor compounds that positively affect our health.