Olive and its tree has been mentioned a number of times both in the Quran and hadith. Olive is considered a “blessed” fruit in Islam and besides it being a good source of nutrition, it is also used as a health food and used in “ruqyah treatment.” In his books on prophetic medicine, Ibn Al-Qayyim(May Allah have mercy on him) encouraged the use of olives and its oil.
Research in recent years has revealed that the olive is not just a delicious food but also represents an important source of good health. In addition to the olive itself, olive oil is also an important source of nutrition.  
Zaitoon (Olive) has its description in Qur’an, Allah says:
Olive oil is a good preservative for other eatables too. Sardine and other fishes are tinned and preserved in olive oil. The smoke-less burning of olive oil is a peculiar feature, which produces a bright light. Qur’an stresses the importance of Zaitoon on several occasions: (6:141), (6:99), (16:11) etc.
The plant of olive goes up to the height of 3 metres, leaves are bright green and very attractive and the fruits are of bright bluish or violet colour, possesses a metallic taste. The plant is extensively found in Asia minor, Palestine, Roman territory, Greece, Portugal, Spain, Turkey, Italy, North Africa, Algeria, Tunisia, California in America, Mexico, Peru and South zone of Australia. Usually it is imported from Spain, Italy, France, Turkey and Greece. Though olive fruits are very nutritious it is not usually eaten due to its metallic taste. Rather pickles of its fruits are largely consumed in Europe. The fruits preserved in vinegar (Sirka) is imported from Greece and liked very much in Europe and in Arabian countries.
Narrated Umar Ibn Khattab: "The Prophet (ﷺ) said: Eat of its oil and use it (the olives), for indeed it is from a blessed tree." Jami` at-Tirmidhi 1851
'Urwa b. Zubair reported on the authority of 'A'isha, the wife of Allah's Apostle (ﷺ), that she said:
Allah's Messenger (ﷺ) died (in a state) that it never happened that he could eat to his fill the bread with olive oil twice during a day. Sahih Muslim 2974 
On account of all these properties, olive oil has attracted considerable expert attention in recent years as follows:
Jean Carper, a prominent authority in the field of health and nutrition, the CNN award-winning correspondent, columnist and author of The Food Pharmacy and Food-Your Miracle Medicine: New Italian research finds olive oil contains antioxidants… that combat disease processes, including LDL cholesterol's ability to clog arteries.
Pat Baird, a dietician and nutrition consultant: I love the whole idea of olive oil's versatility… the more we know about it, the more we learn about its great contribution to good health.
Dr. Dimitrios Trichopoulos, chairman of the Department of Epidemiology, Harvard University : American women might actually experience as much as a fifty percent (50%) reduction in breast cancer risk if they consumed more olive oil in place of saturated fats.
D. Peck of the School of Medicine, University of Miami:Olive oil has been shown to strengthen the immune system in mice…
Bruno Berra of the Institute of General Physiology and Biological Chemistry, University of Milan: The minor polar components of extra virgin olive oil increase significantly the resistance of LDL to oxidation.
A.A. Rivellese, G. Riccardi and M. Mancini of the Institute of Internal Medicine and Metabolic Diseases at Federico II University, Naples: Olive oil prevents insulin resistance and ensures better control of the glucose in the blood.
Patrizia Galletti, University of Naples, Faculty of Medicine and Surgery: Dietary intake of olive oil polyphenols may lower the risk of reactive oxygen metabolite-mediated diseases such as some gastrointestinal diseases and atherosclerosis. Olive oil hydroxytyrosol protects human erythrocytes against oxidative damage.
Frank Sacks of the Harvard School of Public Health: An olive-oilrich diet is more effective than a low-fat diet in controlling and treating obesity. Moreover, it leads to longer-lasting weight loss and it is easier to keep to…
As we have seen, a great many scientists today think that an olive oil-based diet constitutes the ideal nutritional model. It is stated that on account of these properties, olives and olive oil should be the fundamental constituents of every meal in one's daily nutrition programme. The benefits of the olive plant, emphasised by Allah in many verses of the Qur'an, have been discovered in parallel to the advances made by medical science. 
Olive oil is extracted from the ripened fruits. The unripe and over ripe fruits contain less amount of the oil. The fruits are processed three times. Successively, the first round oil is the best in quality, golden in colour, with a light fragrance and known as virgin oil. Some varieties of olive oil remained unchanged in its effectiveness for years together. It contains therapeutic potential even if it is a thousand years old.
Ibn al-Qayyim described the benefits of olive oilin his Prophetic Medicine. He said that the characteristics of olive oilcorresponded to the type of olivesfrom which it came from; oilpressed from ripe oliveswas the better than oilfrom unripe olives. He also said that the older the oil, the more effective it was, and when olive oilwas more beneficial when it was pressed with water.
Ibn al-Qayyim mentioned that all types of olive oilcould soften the skinand delay whitening of the hair. He also said that the benefits of olive oilwere many times greater than have been mentioned.
It was narrated from ‘Umar that the Messenger of Allah (ﷺ) said: ‘Season (your food) with olive oil and anoint yourselves with it, for it comes from a blessed tree.” Sunan Ibn Majah Hadith 3319
Olives are the fruits that grow on the olive tree, which comes from the Oleaceae family. They contain a single pit and their flesh is filled with oil. The ripe fruits are pressed to extract the oil.
Green and black olivesare essentially the same olive and only vary in the degree of ripeness- black being the most ripe.
Olive oilconsists of 75% heart-healthy monounsaturated fatand only 13% saturated fat. It contains active compounds such as oleocanthal, which has a strong anti-inflammatory action to fight heart-disease and cancer. It also contains the natural antioxidantspolyphenols, whose beneficial effects include lowering cholesterol, blood pressureand the risk of coronary heart disease. Many other nutand seed oils have no polyphenolswhatsoever.
Evidence suggests that olive and olive oilconsumption as part of a healthy Mediterranean diethas cancer-protective properties. Research also found that active ingredients in olive oilprevented human colon cancercells from multiplying.
A study published in 2007 in the Journal of Nutrition found that introducing moderate consumption of olive oilin the dietreduced systolic blood pressure. 
According to researchers' reports, people who consume large quantities of olive oil and cooked vegetables can have a reduced risk of rheumatic arthritis, a chronic inflammatory disease of the joints.
important from the point of view of assisting bone development in adults and children, and in strengthening the bones by fixing calcium.
It is also recommended for the elderly as it is easily digested and through its minerals, it assists with the use of vitamins in the body. It also prevents calcium loss by stimulating bone mineralisation. Bones are the organism's mineral structure storehouses and an absence of mineral accumulation in the bones can lead to serious complications such as bone softening. Olive oil has a most beneficial effect on the skeleton in this regard.
Since the vitamins contained in olive oil have a cell renewing effect they are also employed in the treatment of the elderly, as well as nourishing and protecting the skin. As foodstuffs are transformed into energy in our bodies, certain substances known as oxidants are formed. With the high levels of anti-oxidants it contains, olive oil prevents damage by harmful substances, renews our cells and delays aging in the tissues and organs. Olive oil is also rich in vitamin E, which suppresses the free radicals that destroy the cells in our bodies and cause aging.
Due to the linoleic acid (omega-6 fatty acid) contained in olives and olive oil, these are a most healthy food for newborn babies and growing children. A deficiency in linoleic acid leads to the emergence of a retardation of development in babyhood and various skin disorders.
Olive oil contains anti-oxidant elements that prevent the destructive effects of harmful substances in our bodies, and fatty acids of great importance to human health. These support the hormones and assist in cell membrane formation.
Olive oil possesses a balanced polyunsaturated compound at a similar level to that in human milk. Olive oil is a sufficient source of these fatty acids, which cannot be obtained from the human body but which are of the most essential importance to it. These factors make olive oil very important for new-born babies. Since it contributes to the natural development of the baby's brain and nervous system before and after birth, olive oil is the only oil recommended for mothers by experts. As well as containing similar levels of linoleic acid to those of mother's milk, when olive oil is added to fatless cow's milk, it becomes as natural a food source as mother's milk itself.
One study published in the of Archives of Internal Medicine stressed the beneficial effect of olive oil on high blood pressure. Medicines to reduce high blood pressure are also made from olive leaves.
Whether consumed hot or cold, olive oil protects the stomach against diseases such as gastritis and ulcers by reducing gastric acid levels. In addition to this, by activating the bile, it makes it perfect. It regulates the discharge of the gall bladder and reduces the risk of bile stone formation. Moreover, thanks to the chloride it contains, it also assists the functioning of the liver and thus helps the body eliminate waste products. In addition, it also has a beneficial effect on the brain arteries. 
According to Zahbi it strengthens the hairs and body, hence could be used as a good tonic in old age problems and to delay the ageing process. It is also useful in sexual weakness. Combination of normal saline with olive oil is highly effective in burns cases.
The decoction of olive leaves in water is effective against mouth and lips ulcers and allergic dermatitis also. The concentrated aqueous extract of olive leaves and fruits is very effective against dental cavities and application of this solution shows very good effects on Leukoplaquea in mouth. This solution is applied with vinegar on Alopecia, grows the hair and removes the Alopecia. It is also stated that the local application of this extract removes the scars of small pox and boils. The powder of seeds mixed with butter is effective in brittle nails. The pickles prepared from olive fruits is a good appetizer and removes constipation. The smashed leaves are applied locally to check excessive perspiration. The water extracted from the leaves with honey is used as Ear drops and effective in various Ear ailments. The oil procured by burning of olive wood is effective against all fungal infection viz, Ringworm, T.versicolor etc. in addition to Eczema, Psoriasis, Dandruff and Alopecia. The local application of olive oil on scalp is highly effective against dandruff. It grows the hairs and checks, the loss of hair. The application of olive oil in eyes relieves the inflammation.
The massage of olive oil over the body tones up the muscles and organs, it relieves muscular pains. Some physicians also advocate the massage of olive oil for epilepsy. It relieves the Sciatic and arthritis. The ointment prepared from olive oil are very good healing agents. It heals the sinus and fistula very quickly. 25ml of olive oil mixed with 250ml of barley water, if taken internally, is highly effective against chronic constipation. It is good Diuretic, hence is used in Ascites. It also removes the kidney stones.
A conventional regimen is also available comprising of olive oil and other herbal drugs having potential against the Gall bladder stones. It is stated that this regimen dissolves and expels the Gall bladder stone.
In view of the researches carried out in USA and England, it is concluded that it is a good nourishing diet during the ailments of kidney, where nitrogen containing food/proteins in take is contra indicated. Hence for the same complaint patients were advised to take two spoonful of olive oil at bedtime and an ointment was applied on fissure locally at retiring and in morning, prepared from 8 spoonfuls of olive oil and 2 spoonfuls of ground henna leaves. This showed very good effects against the problem. It is a good tonic for hair and maintains the lustre. Its combination with other prescribed drugs of Tibb-al-Nabwi is a good remedy for Psoriasis and Eczema. The impressions of several doctors practising in middle east and North Africa reveal that no case was detected of Gastro Intestinal Carcinoma, among those who were used to consuming olive oil. Japanese doctors also endorse this fact and have the opinion that olive oil prevents the incidence of Carcinoma in G.I.T.
Therefore it was used in the cases of G.I.T ulcers and found very much effective. It is also observed that no remedy equates the benefits of olive oil in hyper acidity and gas troubles.