OLIVE OIL AND HEALTH
“Let food be thy medicine and medicine be thy food”, Hippocrates 400 B.C.
Olive oil is one of the most precious oils, which is distinguished for its high nutritional value. It contains many valuable ingredients, which are significant to the human health, such as polyphenols and tocopherols, Vitamin Ε and provitamin Α, which have anti-oxidant effects and help fighting against many diseases.
Extra virgin Olive Oil, a gift for your heart, it is worthy of it…
Olive oil contains a set of ingredients which are very beneficial to most of the functions of the human organism. Its phenolic substances have displayed anti-inflammatory and chemical-protective properties.
1. Effects of olive oil on cardiovascular diseases
When it does not exceed certain levels, cholesterol (or cholesterin) is vital for the structure of the cell’s walls. Nevertheless, the cholesterol that is composed in the liver cannot move within the organism on its own. Such role is played by the lipoproteins. The two main types of these are LDL (low density lipoprotein) and HDL (high density lipoprotein). LDL is a lipoprotein that transfers cholesterol to the cells. But the routes to the cells are usually very narrow for LDL. Hence, LDL particles get stuck and overtime fully block the arteries. The higher the HDL levels, the easier it is for the routes to open and for the organism to get rid of the unwanted cholesterol. The organism needs a good HDL/ LDL ratio. The consumption of olive oil increases the composition and the concentration of HDL cholesterol (the “good” cholesterol), whereas at the same time it makes LDL cholesterol (the “bad” cholesterol) less able to cause atheromatic damage, by both preventing its oxidization and altering the size of its molecules. Olive oil constitutes one of the most significant factors, particularly with regard to the arteriosclerosis of the peripheral vessels. Consequently, olive oil controls the level of LDL, whereas it increases the level of HDL, which results in the fact that it influences the frequency of cardiac incidents. The protection of the monounsaturated fatty acids against the risk of cardiovascular diseases was licensed by the US Food and Drug Administration (http://www.fda.gov/-dms/qhchoice/html) for the first time in 2004.
2. Olive Oil, Digestive & Gastrointestinal System
Extra virgin olive oil is the most easily digestible edible fat and helps us digest vitamins Α, D and Κ, i.e. the absorption of the nutrients and particularly the vitamins and the metallic salts, whereas it also protects against gastritis and ulcers. It is a cholagogue and activates the secretion of the hormones of the pancreas and the gall bladder. In other words, it reduces the chances of cystoliths (formation of stones in the gall bladder). Olive oil is not only easy to be digested, but it also helps in the digestion of other fatty substances, because it helps the secretions of the digestive system and stimulates the pancreatic enzyme lipace. Olive oil restructures the form and the function of liver cells, by replacing other lipids in them. Furthermore, as far as the intestine is concerned, olive oil increases the absorption of calcium and, as such, it can reduce osteoporosis. Taking two tablespoons in the morning with an empty stomach seems to have a positive influence on chronic constipation, which was the reason why ancient Greeks used to consume 1-2 tablespoons of olive oil every morning.
3. Olive Oil & Diabetes
Diabetes mellitus is a disease that is widely found throughout the world, which is owed to the fact that the organism cannot generate or use insulin, which results in the dysfunction of the metabolism of carbohydrates, which also includes the metabolism of lipids and proteins. Sirtori (1986) claims that when olive oil is consumed as the only source of fat, and particularly by people with diabetes, then this has beneficial effects on the slow discharge of the stomach’s content to the duodenum. In this way, it brings on better control of glucose in the blood.
4. What are antioxidants and oxidative stress?
Oxidation is a process that occurs not only when oil is being produced, but also inside our own bodies. Reactions occur continually inside the body, giving rise to the formation of free radicals (peroxidants). As a rule, free radicals do not cause severe damage thanks to the protection provided by antioxidants, which help to keep a balance up to a point. If the balance is spoiled, however, "oxidative stress" occurs, leading to deterioration of normal cell functions and even cell death.
Oxidation is a complex, fundamental phenomenon in the process of cell ageing. Lipid or fat peroxidation tends to be proportional to the number of double bonds in a compound, explaining why oleic acid shows little susceptibility to oxidation.
Cell membranes contain a large amount of fat and cholesterol and their composition depends on diet. When the diet contains a lot of olive oil, the cells are more resistant to oxidation, they do not deteriorate as much and ageing is slower.
Approximately 1.5% of olive oil is made up of the unsaponifiable fraction, which contains antioxidants. Virgin olive oil contains the largest quantities of these substances and other minor components.
Antioxidants in olive oil
Vitamin E (alpha-tocopherol), carotenoids and phenolic compounds (simple phenols such as hydroxytyrosol and complex phenols such as oleuropein) are all antioxidants whose activity has been demonstrated in vitro and recently in vivo, revealing further advantages in the prevention of certain diseases and also of ageing.
The phenolic content of olive oils varies according to the climatic conditions in the producing area, when the olives are harvested and how ripe they are when picked. Oil production and storage methods also have an influence. Phenols have countless biological properties, for instance hydroxytyrosol inhibits platelet aggregation and it is anti-inflammatory and oleuropein encourages the formation of nitric acid, which is a powerful vasodilator and exerts a strong anti-bacterial effect.
Oxidised LDLs are known to be atherogenic, which is where olive oil steps in because it has a beneficial, protective effect against LDL oxidation. Moreover, it also strengthens other cells in the body against the toxic effects of oxidants.
The high antioxidant content of the Mediterranean diet appears to contribute significantly to its effect on longevity.
These antioxidants are found in fresh fruit and vegetables. Because it is the only oil to be obtained from a fruit, olive oil retains a host of substances, antioxidants and vitamins that give it added nutritional value.
The explanation behind this high content of antioxidants is probably that because the olive is a fruit that is exposed to the air, it has to defend itself from oxygen. It therefore synthesises a larger amount of antioxidants, which pass through to the oil.
Virgin olive oil, i.e. olive oil that has not been refined or industrially treated, is particularly rich in these substances and it has a strong antioxidant effect, protecting against damage from free radicals (scavenger activity) and against the formation of cancer. www.internationaloliveoil.org
5. Olive oil and cancer
Epidemiological studies suggest that olive oil exerts a protective effect against certain malignant tumours (breast, prostate, endometrium, digestive tract, …).
A number of research studies have documented that olive oil reduces the risk of breast cancer. Eating a healthy diet with olive oil as the main source of fat could considerably lower cancer incidence. The reason is that the cell mutations caused by cancer are partly due to toxins which, when consumed through the diet, attack DNA. On passing through the liver, these toxins produce free radicals that then attack DNA. To combat such free radicals, the body needs vitamins and antioxidants like those contained in olive oil.
It has also been reported that an olive-oil-rich diet is associated with reduced risk of bowel cancer. The protective effect of olive oil is irrespective of the amount of fruit and vegetables eaten in the diet.
Recent studies have demonstrated that olive oil provides protection against cancer of the colon. Lately, research has been looking into the metabolic implications of fats, more specifically the protective role of olive oil in chronic liver disease and in the disorder of the intestines known as Crohn's disease. Results point to beneficial effects of olive oil on pre-cancerous lesions. After analysing three types of diet, research scientists arrived at various conclusions. The olive oil diet reduced the number of cancerous lesions; the number of tumours that developed was clearly and significantly low; and the tumours were less aggressive and had a better prognosis.
This beneficial effect could be related to oleic acid, the predominant monounsaturated fatty acid in olive oil. It has been observed that this fatty acid lowers the production of prostaglandins derived from arachidonic acid, which in turn plays a significant part in the production and development of tumours.
However, it is not excluded that other constituents of olive oil, such as antioxidants, flavonoids, polyphenols and squalene may also have a positive influence. Squalene is believed to have a favourable effect on the skin by reducing the incidence of melanomas.
Olive oil also adds to the taste of vegetables and pulses whose benefits in cancer prevention have been amply proved.
Some very promising, current research is centred on the protection provided by olive oil against child leukaemia and various cancers, such as oesophageal squamous cell cancer. www.internationaloliveoil.org
6. Olive oil and during pregnancy and childhood
Olive oil plays a key role in foetal development during pregnancy and a shortage may have pernicious effects on the baby's subsequent development.
It has been demonstrated that the post-natal development of babies of mothers who consumed olive oil when pregnant is better in terms of height, weight, behaviour and psychomotor reflexes.
The foetus needs vitamin E to grow. The newborn baby also needs a store of vitamin E to fight against the oxidative stress caused on entering an oxygen atmosphere. Although not very abundant in olive oil, it is present in sufficient quantity thanks to the resistance of olive oil to oxidation.
So, both the amount and the type of food consumed in the diet during pregnancy play a key part in the metabolic adaptations that occur in the mother and in her functional relationship with the foetus.
Olive oil and breast feeding
During labour, the vitamin E in the mother's blood is concentrated in the breast glands and so, during breast feeding, the mother continues to supply vitamin E. It is essential to maintain the levels of this vitamin during breast feeding.
Vitamin E is also recommended for premature and new-born infants with kidney or pancreas failure because of the favourable effect it has on the hepato-biliary system.
But olive oil not only provides enough essential fatty acids for the development of the new-born child; its ratio of linoleic acid to linolenic acid (essential fatty acids) is similar to that of breast milk.
The beneficial effect of oleic acid lasts beyond pregnancy. Besides its documented effectiveness in preventing hypercholesterolaemia and atherosclerosis, which is a process that can begin in childhood, oleic acid also appears to exert a positive influence on growth and bone mineralisation and development during infancy.
During pregnancy and breast feeding it is advisable to consume more fat, primarily monounsaturated fat, while reducing saturated fat and cholesterol as far as possible. General dietary guidelines should be followed and calorie intake should be controlled to avoid excessive weight gain.
Under-three-year-olds have different dietary requirements to children over this age. Forty per cent of the energy they consume comes from fat, whether it be in breast milk or any other kind of milk. It is recommended to maintain this dietary pattern and to ensure that energy and nutritional intake cover the developmental requirements of the child. www.internationaloliveoil.org