Olive oil
Olive oil is a fat obtained from the olive (the fruit of Olea europaea; family Oleaceae), a traditional treecrop of the Mediterranean Basin. The oil is produced by pressing whole olives.
It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps. Olive oil is used throughout the world, but especially in the Mediterranean countries and, in particular, in Greece, which has the highest consumption per person.[2]
As they are the least processed forms of olive oil, extra virgin or virgin olive oil have more monounsaturated fatty acids than other olive oil. These types also contain more polyphenols, which may have benefits for the heart.[63]
Olive oil has a long history of being used as a home remedy for skincare. Egyptians used it alongside beeswax as a cleanser, moisturizer, and antibacterial agent since pharaonic times.[65] In ancient Greece, the substance was used during massage to prevent sports injuries, relieve muscle fatigue, and eliminate lactic acid buildup.[66] In 2000, Japan was the top importer of olive oil in Asia (13,000 tons annually) because consumers there believe both the ingestion and topical application of olive oil to be good for skin and health.[67]
There has been relatively little scientific work done on the effect of olive oil on acne and other skin conditions. However, one study noted that the abundance of squalene in oils in general shows promise for sufferers of seborrheic dermatitis, acne, psoriasis, and atopic dermatitis. Squalene is used as an antioxidant, moisturizer, and as a convenient vehicle to carry other substances in topical application.[68] Another researcher reported that a mixture of honey, beeswax, and olive oil alleviates diaper dermatitis, psoriasis, and eczema by inhibiting the growth of Staphylococcus aureus andCandida albicans.[69]
Olive oil is popular for use in massaging infants and toddlers, but scientific proof of its efficacy is mixed. One analysis of olive oil versus mineral oil found that, when used for infant massage, olive oil can be considered a safe alternative to sunflower, grapeseed and fractionated coconut oils. This stands true particularly when it is mixed with a lighter oil like sunflower, which "would have the further effect of reducing the already low levels of free fatty acids present in olive oil." The study also notes that there appears to be much confusion surrounding mineral oil, and that further studies should be done on refined mineral oil to back up claims about its superiority to olive oil.[70] Another trial echoes this claim, stating that olive oil lowers the risk of dermatitis for infants in all gestational stages when compared with emollient cream.[71] However, yet another study found that topical treatment with olive oil for newborns "significantly damages the skin barrier" when compared to sunflower oil, and that it may make existing atopic dermatitis worse. The researchers conclude that they do not recommend the use of olive oil for the treatment of dry skin and infant massage.[72]
Clinical trials have found that olive oil does not act to prevent or reduce stretch marks.[73][74]
The fatty substance was found to reduce inflammation via oleuropein, which is touted for its antioxidant, anti-atherosclerotic, and anti-inflammatory characteristics.[75]
Preliminary clinical studies provide evidence that consumption of olive oil may lower risk of heart disease risk factors such as lower blood cholesterollevels and reduced LDL cholesterol oxidation,[76] and that it may also possibly influence inflammatory, thrombotic, hypertensive and vasodilatorymechanisms.[35][77][78][79] Although epidemiological studies indicate that a higher proportion of monounsaturated fats in the diet may be linked with a reduction in the risk of coronary heart disease,[80] a cause and effect relationship has not yet been established with sufficient scientific evidence.[81]
In the United States, producers of olive oil may place the following restricted health claim on product labels:
- Limited and not conclusive scientific evidence suggests that eating about 2 tbsp. (23 g) of olive oil daily may reduce the risk of coronary heart disease due to the monounsaturated fat in olive oil. To achieve this possible benefit, olive oil is to replace a similar amount of saturated fat and not increase the total number of calories you eat in a day.[82]
This decision was announced November 1, 2004, by the Food and Drug Administration after application was made to the FDA by producers.[83] Similar labels are permitted for foods rich in omega-3 fatty acids such as walnuts and hemp seed.[84]
Other possible effects of olive oil may be a property to balance omega-6 fats and omega-3 fats[citation needed] and to affect blood sugar levels and blood pressure,[85] but these effects were dismissed in reviews by the Scientific Committee of the European Food Safety Authority.[81]
Olive oil contains the monounsaturated fatty acid oleic acid, vitamin E and oleuropein, a chemical that may affect the oxidation of LDL particles.[86]
Preliminary research indicates that olive oil could possibly be a chemopreventive agent for peptic ulcer or gastric cancer, but confirmation requires further in vivo study.[87] Pilot studies showed that olive oil may reduce oxidative damage to DNA and RNA, revealing a possible anti-carcinogenicfactor.[88] Consumption of olive oil may affect onset of Alzheimer's disease, possibly through a mechanism related to oleocanthal inhibiting fibrillization of tau protein.[89][90]
One tablespoon of olive oil (13.5g) contains the following nutritional information according to the USDA:[64]
- Calories : 119
- Fat: 13.50
- Carbohydrates: 0
- Fibers: 0
- Protein: 0