The benefits of olive oil are such that it helps in improving cardiovascular system, preventing stroke, reduction of depression risk, reducing breast cancer risk, maintaining healthy cholesterol levels, protecting the liver from oxidative stress, protection from ulcerative colitis, curing Alzheimer's disease, curing acute pancreatitis, relieving constipation and others.
Olive oil, rich in monounsaturated fatty acids, is a liquid fat extracted from olives (fruit of Olea europaea and belonging to the family Oleaceae), a traditional tree crop grown in Mediterranean Basin. The oil is obtained by pressing whole olives. The fruit of olive is a small drupe about 1.0 to 2.5 cm long, thinner-fleshed and smaller in wild plants than those grown in orchard. They are harvested in green to purple stage. They contain a seed commonly referred to in British English as a stone, and in American English as a pit or a rock. The composition of olive oil varies with the cultivar, time of harvest, altitude, and extraction process. Compositionally olive oil predominantly consists of oleic acid (up to 83%), with lesser proportions of other fatty acids including linoleic acid (up to 21%) as well as palmitic acid (up to 20%). Extra-virgin olive oil needs to have no more than 0.8% free acidity and is considered to have favorable flavor characteristics.
Olive oil is the best edible oil in terms of palatability, stability, lipid profile, and safety profiles. For 100g (3.5oz) of olive oil the nutritional value is such that energy is 3,701 kJ (885 kcal), fat is 100g ( of which saturated fat is 14g, monounsaturated fat is 73g, polyunsaturated fat is 11g and omega-3 fat to omega-6 fat is 3.5g to 21g), Vitamin E and Vitamin K is 14 mg and 62 μg respectively. Carbohydrates and proteins are however absent.
It is observed from studies that people who regularly consume olive oil are much less likely to develop cardiovascular diseases, including hypertension (high blood pressure), stroke, and hyperlipidemia (high blood cholesterol and triglyceride levels).
Regular intake of olive oil helps in reducing inflammation, endothelial dysfunction (problems with the inner linings of blood vessels), thrombosis and carbohydrate metabolism.
Olive oil may prevent strokes in older people, who regularly use olive oil for cooking and salad dressing or with bread and it was seen that they had a 41% lower risk of stroke, compared with their counterparts who never consumed it.
People whose diets are high in trans fats - fast foods and mass-produced foods like pastries - may have a higher risk of depression, compared with those whose diets are rich in mono- and polyunsaturated fats such as olive oil. Olive oil appears to have a slight protective effect regarding depression risk.
Studies show that virgin olive oil protects the body against breast cancer, in contrast to other vegetable oils. The researchers decoded a complete cascade of signals within the cells of breast tumors that are activated by virgin olive oil. They concluded that the oil reduces the activity of p21Ras, an oncogene, prevents DNA damage, encourages tumor cell death, and triggers changes in protein signaling pathways.
A Japanese study showed that LDL-cholesterol mean concentrations were lowered in patients who were given olive oil supplements once a day for six weeks. LDL (low density lipoprotein) is often referred to as 'bad cholesterol'. The 'good cholesterol' is called HDL (high density lipoprotein). The study authors concluded that the results pointed to an overwhelmingly beneficial influence of olive oil on the lipoprotein spectrum.
Studies have pointed out that extra virgin olive oil may protect the liver from oxidative stress. Oxidative stress refers to cell damage associated with the chemical reaction between free radicals and other molecules in the body. Laboratory studies showed that rats exposed to a moderately toxic herbicide that were fed on a diet containing olive oil were partially protected from liver damage. So extra virgin olive oil and its extracts protect against oxidative damage of hepatic tissue.
Ulcerative colitis, a fairly common long-term (chronic) disorder, is a kind of inflammatory bowel disease that causes inflammation of the large intestine (colon). Consumption of more olive oil could help fend off ulcerative colitis. People with the highest intake of oleic acid - a component of olive oil had a 90% lower risk of developing ulcerative colitis compared to those with the lowest intake.
Oleocanthal is a type of natural phenolic compound found in extra-virgin olive oil. Researchers have discovered that oleocanthal helps shuttle the abnormal Alzheimer's disease proteins out of the brain. Alzheimer's disease rates are lower in Mediterranean countries, where consumption of olive oil is higher than anywhere else in the world. Oleocanthal might help reduce the accumulation of beta-amyloid, believed to be the main cause of Alzheimer's disease.
Olive oil is rich in oleic acid and hydroxytyrosol, which affect the development of acute pancreatitis (sudden inflammation of the pancreas). Researchers have found that the components of extra virgin olive oil can protect from acute pancreatitis.
Olive oil can be used as a remedy for constipation. Olive oil benefits the gastrointestinal tract and colon. The consistency and texture of olive oil help in stimulating the digestive system, making food move smoothly through the colon. Intake of olive oil on a regular basis helps in complete prevention of constipation.
In a study it was found that people consuming olive oil in their diet might contribute to strong bones. Their blood was found to contain higher levels of osteocalcin, which was an indication of healthy bone formation.
Olive oil, along with a few other ingredients, can work wonders to keep hair healthy. The oil is rich in vitamin E that helps in fighting hairfall problems.
Olive oil has a wide range of uses. It is used as a hair conditioner, used for clearing up acne, as a substitute for shaving cream, for cleaning greasy hands, removing paint from hair, polishing of furnitures, etc.
Side effects of olive oil includes acne (if used excessively), can show acute allergic reactions in people sensitive to it, skin rashes, breaking the skin’s natural moisturizing abilities in case of dry skin, blackheads, inflammations, gall bladder stones, minor to moderate diarrhoea. Regular consumption of unprocessed olive oil can increase the risks of lethal diseases like atherosclerosis, obesity, heart attack, stroke, breast cancer, and colon cancer. Olive oil lowers the blood sugar level below normal and may lead to health problems like hypoglycemia, sweating, trembling, weakness, etc. Over-consumption of olive oil can cause a massive fall in the blood pressure and may lead to problems like dizziness, lightheadedness, stroke, and even kidney failure.
The olive tree is native to the Mediterranean basin. Wild olives were collected by Neolithic peoples as early as the 8th millennium BC. The wild olive tree originated in Asia Minor or in ancient Greece. It is not clear when and where olive trees were first domesticated. Archeological evidences have shown that olives were turned into olive oil by 6000 BC and 4500 BC in Palestine. Until 1500 BC, eastern coastal areas of the Mediterranean were most heavily cultivated. Evidence also suggests that olives were being grown in Crete as long ago as 2,500 BC. The earliest surviving olive oil amphorae date to 3500 BC (Early Minoan times), though the production of olive oil is assumed to have started before 4000 BC. Olive trees were certainly cultivated by the Late Minoan period (1500 BC) in Crete, and perhaps as early as the Early Minoan. The cultivation of olive trees in Crete became particularly intense in the post-palatial period and played an important role in the island's economy, as it did across the Mediterranean. Recent genetic studies suggest that species used by modern cultivators descend from multiple wild populations.