Topical Olive Oil and Acne

A 2002 study published in the journal of Acta Paediatrica examined the effect of vegetable oils on the skin barrier function in mice. To perform this study, the researchers gently damaged the skin of mice and then topically applied various oils to examine how well each oil repaired the skin's barrier function. They found that olive oil delayed recovery of the barrier function, while oils like sunflower oil increased the barrier function. Therefore, the scientists concluded that using olive oil on the skin should be avoided.⁶

A 2013 study published in the journal of Pediatric Dermatology examined the effect of olive oil and sunflower oil on the skin barrier in adults with a skin disease called atopic dermatitis. Atopic dermatitis causes skin rashes, dryness, bumps, redness, and itching. To perform this study, the researchers had 19 volunteers with and without atopic dermatitis apply olive oil and sunflower oil twice daily to each forearm for five weeks. The researchers found that olive oil caused a dramatic decrease in the integrity of the skin barrier and caused itchiness, while sunflower oil was beneficial for the skin barrier. Therefore, the scientists concluded that treatment of the skin with olive oil should be avoided.⁷

A 2008 study published in the journal of Pediatric Dermatology examined the effect of oil creams on premature infants. The researchers divided 173 premature infants to three groups. Each group of infants received a cream containing either olive oil, a mixture of water and oil, or a control without oil. This cream was then applied topically to the newborn's skin daily for four weeks. The study found that premature infants treated with the olive oil cream had less skin irritation and improved skin hydration compared to infants that receive either of the other two creams. Therefore, the scientists concluded that the olive oil cream improved the skin barrier.⁸

A 2016 study published in the journal of Acta Dermato-Venereologica examined the effect of olive oil and sunflower oil on the skin hydration in newborn babies. The researchers divided 115 newborn babies into three groups. Each group of babies had olive oil, sunflower oil, or no oil applied topically to the skin twice daily for four weeks. The study found that both oil groups significantly improved skin hydration in newborn babies.³

A 2005 study published in Archives of Medical Research investigated the antibacterial effect of a mixture of olive oil, beeswax, and honey. To perform this study, the researchers grew two bacterial strains in a plate containing either agar or an agar and honey mixture. Agar is a gelatin-like substance often used to grow bacteria. Then they added varying concentrations of honey, olive oil, and beeswax onto the plate to determine which combination had the most effective antibacterial properties. The researchers found that honey had the strongest antibacterial properties and, if present at a high enough concentration, could entirely prevent bacterial growth. Olive oil also had antibacterial properties, which, although not as strong as honey, could delay growth of bacteria.⁹

A 2013 paper published in the African Journal of Traditional, Complementary, and Alternative Medicine reported on three studies investigating the antibacterial properties of olive oil. These three studies all found that olive oil had antibacterial properties against H. pylori bacteria isolated from human patients. While H. pylori is not the bacteria involved in acne, olive oil might have similar effects against C. acnes, the bacteria implicated in some of the inflammation characteristic in the latter stages of acne lesions. Attempting to repeat the results of this experiment, the authors of this article examined the antibacterial effects of an olive oil and lime cream. However, unlike the previous three studies, the authors of this article found that olive oil had no antibacterial properties. The reason for the conflicting results of these four experiments is unknown.⁵

A 2015 study published in journal of Physical Therapy studied the antibacterial effects of olive oil byproducts obtained from the leaves, stems, flower, fruit pulp, and seeds of the olive oil tree. The researchers first prepared extracts from the olive oil byproducts and tested them for a variety of properties. The researchers found that these byproducts have antibacterial, antioxidant, and anti-aging properties.¹⁰

A 2014 study published in the journal of Advances in Skin and Wound Care examined the healing effect of olive oil when administered topically on burn wounds in rats. The researchers treated a group of 60 rats with either olive oil or a mixture of olive oil and other oils daily for 28 days. The researchers found that olive oil by itself, as well as any oil mixture that contained olive oil, caused faster wound healing. Therefore, the researchers concluded that olive oil was beneficial in the treatment of burn wounds in rats.¹³

A 2014 study published in the journal of Wound Repair and Regeneration examined the effects of oral olive oil supplementation on wound healing in mice. To perform this study, the scientists wounded the skin of mice, and then provided the mice with oral olive or fish oil supplementation for 14 days. They concluded that olive oil, but not fish oil, improved wound healing by supporting skin cell and blood vessel growth in the mouse skin.¹⁴

A 2015 study published in the Journal of Wound Care examined the efficacy of aloe vera and olive oil combinations on treatment of 60 patients with chronic wounds. To perform this study, the researchers had the participants apply an aloe vera/olive oil cream or a control cream topically to their skin lesions twice daily for 30 days. The researchers found that the aloe vera/olive oil cream reduced wound size, depth, damaged tissue, swelling, and improved wound color. However, the study examined a cream containing a combination of aloe vera and olive oil, and therefore the researchers were unable to determine whether the olive oil by itself could induce the same level of wound healing as the combination of aloe and olive oil.¹⁵

A 2015 study published in the journal Burns examined the effect of oral olive oil supplementation on wound healing in human patients. To perform this study, the researchers gave hospitalized patients with second-degree burns oral olive oil supplements in their diet. The scientists concluded that the wounds of patients treated with olive oil supplementation healed faster and the patients had a decreased hospitalization stay compared to the control group. Therefore, the researchers concluded that oral supplementation of olive oil may "accelerate wound healing" in human burn patients.¹⁶

A 2016 study published in Journal of Dermatological Science examined the effect of olive oil on wound healing in mice. In this study, ulcers on the skin of mice were treated daily with topical application of olive oil or water. The researchers found that olive oil reduced inflammation and the production of inflammatory molecules in the mouse skin. Further, skin cell repair was accelerated in the olive oil treated mice. Therefore, the researchers concluded that olive oil improves wound healing and inflammation in mice.¹⁷