Olive Oil and Health

OIL AND HEALTH

Introduction

Extra virgin olive oil, unlike any other culinary fat, is a concentrated source of energy, an irreplaceable carrier of essential fatty acids and the ideal vehicle for natural fat-soluble vitamins.

It is rich in monounsaturated oleic acid (60-80%), contains a significant amount of polyunsaturated linoleic acid (around 10%), essential to the human organism, as it cannot be synthesised and must be ingested, and a moderate amount of saturated fatty acids, giving olive oil the ideal nutritional composition to cover the organism’s metabolic needs.

The nonsaponifiable fraction, representing between 1 and 2 % of the content of oil, is formed by tocopherol (provitamin E) and polyphenols, which have antioxidant properties that delay the rancidity process. Also, the polyphenols give the oil palatability, an unmistakeable flavour and, together with other volatile substances, a characteristic aroma. The pigments (chlorophyll and carotenes) determine the colour while the triterpenic alcohols, such as cycloartenol and beta sitosterol have the effect of blocking the intestinal absorption of cholesterol.

The main component of olive oil plays a fundamental role in the development of the nervous system of newborn babies, as the formation of the myelinic membrane requires saturated, polyunsaturated and monounsaturated fatty acids in the diet. In this context, it is worth mentioning that breast milk is very rich in oleic acid.

Polyunsaturated and essential fatty acids are fundamental in forming the cell membrane and regulating its function, as well as being essential precursors to prostaglandins, thromboxanes, prostacyclins and leukotrienes , required for different functions of the organisms, such as platelet aggregation, the regulation of blood pressure, muscular contraction and many others.

From the study of the effects of different fats on the digestive system, it has been deduced that olive oil is the most suitable for the scarring and reducing of gastric ulcers. It is also produces the best results for intestinal motility and the regulation of the pyloric antrum. It improves the cholagogic and choleretic functions of the gall bladder and, as a result, the percentage of gallstones is lower in people whose diets contain olive oil.

Cardiovascular diseases, the main cause of death in developed countries, are caused by the hardening and stiffening of arteries due to the formation of atheromatous plaque leading to the progressive narrowing of the blood vessels.

hromboses in areas with atheromatous plaque cause occlusion and the resulting vascular problems. The consumption of olive oil increases low-density lipoproteins (LDL) which favour the formation of “bad cholesterol” deposits and prevent the lowering of high-density lipoproteins (HDL). The result is that when significant amounts of olive oil are consumed, there is a major reduction in the rate of cardiovascular disease and arteriosclerosis.

The conservation of cell structure from the deterioration caused by oxidation is closely linked to lower rates of tumours. The consumption of olive oil, especially the positive action of oleic acid, acts to prevent or weaken the appearance of cancer, as less oxidative damage occurs. It is clear that with many types of cancer there is a significantly lower rate of occurrence when the main dietary fat is olive oil.

As our knowledge of nutrition increases, greater value is being placed on the antioxidant properties of food, to the extent that it is considered the main health-giving property of olive oil, leading to the destruction of free radicals that cause cells, and therefore the organism, to age. It is highly likely that this is the main reason for the positive effects and the importance of the Mediterranean diet.

New lines of res earch continue to confirm further beneficial properties of olive oil, many of which are already intuitively known in popular wisdom.

There is therefore plenty of reason to believe that the healthiest fat, the one that is most beneficial to the organism, is olive oil, and in particular virgin oil.

Beneficial Effects on Cholesterol

The use of olive oil reduces cholesterol in the blood, with the singular effect that while the levels of HDL, the fraction that protects against arteriosclerosis, are maintained, LDL levels drop considerably, leading to a lower accumulation of cholesterol on the artery walls, while excess amounts are transported by the HDL to the liver, where it is metabolised and eliminatedfromtheorganism.

Recent discoveries show that LDL needs to undergo an oxidation process before becoming attached to the artery walls, altering the internal structure of the vessel, hardening it and reducing its elasticity and ability to dilate. Oxidised lipoproteins produce an inflammatory reaction leading to the growth of atheromatous plaque, reducing the diameter of blood
vessels and increasing the likelihood of thrombi being retained. The oxidation-reducing property of olive oil delays, and even impedes, the appearance of vascular disease,

because it strengthens cells at the same time, making them less sensitive to the toxic action of oxidants, which causes cells to age.

Diets rich in extra virgin olive oil reduce the risk of arteriosclerosis and even delay the effects of the disease when it has already become established.

Beneficial Effects on Ageing

Although oxidation and the formation of free radicals occurs in all cellular systems, it is in the Mitochondria in which the fullest intensity of their effect is felt. When the diet of laboratory animals is rich in olive oil, it has been observed that this leads to greater resistance of the mitochondrial membrane to degenerative processes, in comparison to animals who have been fed a control diet.

There are still a number of uncertainties to resolve, particularly because the studies, still at an early stage, have not sufficiently explained how the different components of olive oil actually operate. Amongst such components are monounsaturated fatty acids and specifically oleic acid, which are indicated as being responsible for this fascinating antioxidating process, together with vitamin E and polyphenoles, some of which, such as hydroxytyrosol, are known to play an important antioxidating role.

The experiments are on-going and constitute one of the main areas of research at the Centro de Excelencia Investigadora en Aceite de Oliva y Salud (CEAS: the Olive Oil and Health Research Excellence Centre), set up by the Andalusian Government in order to clarify not so much the effects, more than sufficiently proven, but the actual process by which olive oil gives longevity and vigour to the cells making up a particular organism. There are certain natural antioxidants, such as vitamina E and tocopheroles, which are partly destroyed in the refining process; in light of this, it is particularly recommendable for the beneficial effects to take place that the oil should be virgin.

Digestion

The digestion of foods involves four different processes, which although separate, can occur simultaneously. Swallowing, which is a voluntary act, moves food from the mouth to the oesophagus entrance, from where it continues down through the digestive tract. At the same time, the secretion process starts, in which various glands (salivary, pancreatic, hepatic and others) produce substances the facilitate the digestion of foods, i.e. the transformation of food into simpler, smaller, assimilable molecules so that absorption may take place, in which nutrients pass through the mucous membrane into the bloodstream to be distributed throughout the organism.

The digestion of fats, and consequently olive oil, is produced by emulsion with the rest of the food after a long period in the stomach, as the lipid mix that is formed is eliminated at the end, so that its passage through the intestine is slow enough and at the appropriate quantities for optimum digestion and absorption. Oleic acid, a fundamental component of olive oil, stimulates the release of cholecystokinin and gastrointestinal peptides that facilitate digestion. This produces a very positive response in the pancreas, as the presence and activity of pancreatic lipase in the duodenum is increased. Gall bladder activity is also enhanced, producing more bile for longer periods and with a greater concentration of biliary acids, aiding digestion. To sum up, olive oil is an excellent fat, which aids the gastric, pancreatic, biliary and intestinal digestive processes, making its use in food highly advisable. Indeed, doctors often recommend a spoonful of virgin olive oil on an empty stomach to combat certain digestive problems.

Common Wisdom

• Oil and wine, balsam divine.
• Find a good pruner, as good as can be, because there’s more money to be made from a well-pruned olive tree.
• A salad dressing is better with a bit of olive oil.
• The oil should be ready in San Silvestre. This refers to the benefits of harvesting olives early to prevent over-ripening.
• Do not beat the olive tree, caress it with your hand. A phrase against the beating of olives to harvest them.
• Olive flower in May, oil every day. Abundant flowers are a good omen for a plentiful harvest.
• Make me poor in wood and I’ll make you rich in oil. The olive tree should be well pruned.
• Olives are from God and oil from the master.
• Don’t call me olive until I’ve been harvested. This refers to the possibility of the fruit spoiling before harvest.