The nutritional value of olive oil is primarily due to its chemical composition. Olive oil is mostly a mixture of esters of glycerol (triglycerides) with higher fatty acids. This mixture is the soapable fraction of olive oil and represents 99% of the oil.
Higher fatty acids found in this mixture are distinguished in saturated and unsaturated and the latter in mono-unsaturated and poly-unsaturated.
The usual composition of fatty acids in olive oil – in accordance with the limits set by the international olive oil Council - is as follows:
Oleic (mono-unsaturated): | 56% - 83% |
Palmitic (saturated): | 7,5% - 20% |
Palmitelaic (mono-unsaturated): | 0,3 % - 3,5% |
Steatic (saturated): | 0,5% - 5% |
Linelaic (poly-unsaturated): | 3,5% - 20% |
Linolinic (poly-unsaturated): | 0,0% - 1,5% |
Mono-unsaturated fatty acids dominate at a percentage of 56.3%-86.5% vs. poly-unsaturated at 3.5%-21.5% and saturated at 8.0%-25.0%. As the vegetable oils contain mostly poly-unsaturated fatty acids while animal fats mainly saturated, it is concluded that olive oil is the main source of mono-unsaturated fatty acids for the human organism.
The prevalence of mono-unsaturated fatty acids in olive oil only, is the main reason that olive oil is the best ally of our health, in a way that will be mentioned below. The remaining 1% of the oil is the non soapable fraction in which are included numerous substances that give it its particular organoleptic characteristics – flavor and taste - as well as its great nutrient value.
Among the substances included in the non-soapable fraction of olive oil are: vitamins, minerals, phenols and polyphenols, tocopherols, eleuropain, hydrocarbons, squalene, beta-carotene, fiber and other alcohols. These ingredients can be classified roughly according to their properties as follows:
-Antioxidant substances: Tocopherols, phenols and polyphenols, squalene, beta-carotene antioxidant substances etc. first of all they protect the olive oil from self-oxidation and high temperatures (cooking) but they also protect the human body as they reduce free radicals which are involved in the development of chronic diseases and aging.
-Pigments: Carotenes, chlorophyll. Mainly the chlorophyll stimulates the metabolism, the development of cells, the production of blood and speeds the healing of wounds.
-Eleuropain: increases the production of «pepsin» and facilitates digestion of proteins and digestion in general.
-Alcohols: it is estimated that the increase of bile secretion helps the removal of cholesterol.
-Vitamins: help the organism in various ways. Vitamin E specially helps when, according to studies, the ratio between linelaic acid and vitamin E has a value larger than 0.79 mg vitamin E per 1g linelaic acid. A related table for various fats is listed below.
Fats |
Vitamin Ε (mg/100gr oil) |
Total poly-unsaturated (%) |
Relation |
Extra virgin olive oil | 15,0 | 8 | 1,87 |
Soybean oil | 17,5 | 57 | 0,30 |
Cottonseed oil | 30,0 | 40 | 0,75 |
Sunflower oil | 25,0 | 57 | 0,40 |
Corn oil | 20,0 | 40 | 0,50 |
Rapeseed oil | 17,5 | 17 | 1,00 |
All the components of the olive oil have a global effect to the organism and according to reports of nutritionists-dietitians and researchers, the benefits from the consumption of olive oil as the principal source of fat intake, can be summarized briefly as follows:
-Reduction of "bad" cholesterol (LDL) in the blood
-Preservation of blood content in "good" cholesterol (HDL)
-Protection against arteriosclerosis
-Reduction of coronary heart disease and cardiovascular disease
-Protection against memory loss and cognitive processing failures
-Improvement of bowel function
-Therapeutic effect on ulcer of stomach and duodenum
-Reduction of gastric juices and their modification
- Improvement of the function of the bile
-Prevention and protective action of many forms of cancer
-Improvement of glucose metabolism of diabetics
-Better absorption of calcium, fat soluble vitamins and proteins
-Skin rejuvenation
Many of the above occur in conjunction with the Mediterranean diet and physical exercise.
All the benefits of olive oil in the human body are a result of its unique combined characteristics which are:
a) Good relation between saturated and mono-unsaturated fatty acids
b) Good relation between vitamin e and poly-unsaturated fatty acids
c) Presence of natural antioxidants in optimum concentration
d) Small percentage of poly-unsaturated fatty acids
e) Great content in hydrocarbon squalene which plays a special role in the metabolism
f) Pleasant smell and taste that causes change in the composition of the gastric juices – increasing pepsin content - facilitating digestion and absorption of nutrients from food.
Bibliography around the world contains more than 2000 scientific articles on the effect of olive oil in various diseases.