Olive oil has long been considered a "healthy" cooking oil. In addition to eating, many people also use it to apply skin, and many skin care lotions use olive oil, claiming that it can bring beauty and skin care functions that ordinary oils do not have. The oil itself helps to moisturize, and the antioxidants in it can also protect the oxidative damage caused by ultraviolet rays in the case of external use. Therefore, it is not surprising that olive oil skin care products are "effective". But to know for sure whether it is effective, it must be tested by modern scientific methods.
Is olive oil good for the skin?
Many studies have evaluated the effect of olive oil on skin protection. For example, the 2008 issue of Pediatric dermatology published a randomized controlled trial in Australia to study the treatment of skin in preterm infants. In the experiment, 173 premature babies were randomly divided into three groups, one using a special ointment on the market, one using an emulsion made of 30% olive oil and 70% lanolin, and the other using no medicine as a control . Within 2 to 4 weeks after the start of the experiment, the skin condition of these infants was scored by the evaluator without knowing which group the infants were in. As a result, the group with the olive oil emulsion had the best skin condition and the control group had the worst. Such an experiment can show that the emulsion of olive oil and lanolin is better than nothing, and it can also show that it is better than the selected "accompaniment student", but is olive oil "extraordinarily effective" as legendary, still Unexplainable.
Another study published by the journal in 2013 had a serious impact on this view. The goal of the study was to compare the effects of olive oil and sunflower oil on the skin. Nineteen adult volunteers with normal skin conditions were divided into two groups: the first group applied olive oil (6 drops each time) twice a day to the forearm of one arm, and the other left untreated for 5 weeks; The two groups were also applied twice daily with 6 drops of olive oil on one forearm and 6 drops of sunflower oil on the other for 4 weeks. Finally, the skin condition was evaluated by measuring the parameters of the stratum corneum integrity and cohesion, moisture retention, skin surface pH and erythema. The results of the study found that the application of olive oil reduced the integrity of the stratum corneum, resulting in mild erythema, while sunflower oil maintained the integrity of the stratum corneum without causing erythema. Therefore, researchers believe that olive oil can damage the skin's barrier effect and should not be used for dry skin and baby massage.
As far as the strength of scientific research evidence is concerned, these two items can only be regarded as "preliminary research", and cannot be said to "prove" or "deny" the effect of olive oil on the skin. Considering that infants and young children are less able to bear, the authors of the second study suggest that it is worth paying more attention from a cautious perspective. However, fashion women are probably more concerned about whether olive oil can produce some "special" effects. For example, many skin care lotions that use olive oil claim that they can prevent or treat stretch marks. Does this statement make sense?
Removing stretch marks olive oil can do nothing
Stretch marks occur in the dermal layer in the middle of the skin. The dermis has collagen and elastin, so it has elasticity and can maintain the shape of the skin. However, if the dermis receives too much tension, or if it lasts for a long time, it may cause the dermis layer to break, which may cause markings. During pregnancy, the fetus continues to grow in the body, causing the abdominal skin to be continuously stretched, and it is easy to form such markings. In Chinese, such marks are called stretch marks. In addition to pregnancy, other factors that cause the skin to continue to stretch can also form such markings. For example, men with significantly increased waist circumference in the short term may also experience "stretch marks". In addition to the tension on the skin, hormone levels can also affect the appearance of skin lines. When the adrenal glucocorticoid level in the body rises, the elastic fibers are more likely to break and produce lines.
Early stretch marks are light red, and gradually turn white afterwards. According to statistics, about 50% to 90% of women will develop stretch marks during pregnancy. Its existence will bring psychological uneasiness to many women, which makes the product known as preventing and eliminating stretch marks particularly attractive.
Because of its long history of use, "Treatment of Stretch Marks" has also become one of the selling points of olive oil and related emulsion products. Unfortunately, the effect of olive oil on stretch marks is basically an urban legend and has not been supported by clinical trials. In November 2012, the Evidence-Based Medicine Systematic Review Database (CDSR) published a review summarizing the 6 medical trials currently available to treat stretch marks with various emulsions, involving a total of about 800 subjects . The results of these studies are very disappointing. These include olive oil, cocoa butter and other common "effect ingredient" emulsions, and placebos that do not contain "effect ingredient", and no treatment. There is no difference in school. In other words, whether you use olive oil or placebo, or do nothing, the condition of stretch marks will not change as a result. It doesn't matter if you have stretch marks or how serious you are. At present, it seems that the measures that can really help reduce stretch marks are probably to avoid excessive weight gain during pregnancy.
Of course, the scale of these studies is limited and the design is not completely rigorous. A more definitive description of the relationship between olive oil and stretch marks requires further research on a larger scale. We can only say that based on the current evidence to prevent and eliminate stretch marks with olive oil, there is no good wish to support scientific evidence.