What benefits does olive oil provide for the skin?

Another study, conducted by Romana-Souza et al. in 2016, evaluated the effects of orally administered olive oil on wound healing in mice. The animals were divided into two groups: one received olive oil daily, the other received water only. The researchers observed a significant reduction in inflammatory cell infiltration in injured tissues in mice that consumed olive oil, accompanied by reduced expression of TNF-α, a pro-inflammatory marker, and of elastase, an enzyme involved in tissue degradation.

These results suggest that olive oil consumption may modulate local inflammation in a beneficial way.

The exact mechanism of this anti-inflammatory action has not yet been elucidated. However, the authors hypothesize that oleic acid, one of the main fatty acids in olive oil, could reduce levels of matrix metalloproteinase type 1, enzymes that degrade extracellular matrix collagen and certain growth factors, impairing tissue repair. By limiting their activity, olive oil may help preserve regenerating tissue. However, it should be noted that in this study the anti-inflammatory effects of olive oil were observed after oral ingestion and not by topical application. Further research is needed to confirm the potential of olive oil for local wound and irritation management.

In 2020, FEI and the team investigated the potential antibacterial activity of olive oil and its polyphenolic compounds against Staphylococcus aureus, one of the bacteria most frequently found on the skin’s surface. The study aimed not only to assess olive oil’s antimicrobial efficacy but also to clarify its mechanism of action.

The results showed that adding olive oil to the culture medium led to a alteration of bacterial physiological functions. In particular, olive oil disrupted the integrity of the bacterial cell membrane, causing a loss of permeability. This structural change led to a significant decrease in intracellular ATP concentration and inhibited cellular energy metabolism. A depolarization of the cell membrane was observed, indicating a collapse of the electrochemical gradient essential for normal bacterial cell function. This imbalance promoted extensive leakage of intracellular contents, including proteins, into the extracellular medium.

Olive oil appears to exert a bactericidal effect by altering the membrane of Staphylococcus aureus, causing a loss of cytoplasmic content.

We should note that these results were obtained in vitro and not on human skin. It is not yet known whether they translate to real-life conditions or whether olive oil could help in cases of dysbiosis, such as acne.

Olive oil contains several fatty acids, mainly monounsaturated fatty acids such as oleic acid, and polyunsaturated fatty acids such as linoleic acid. These two molecules help maintain skin hydration. Oleic acid, present in sebum, forms a film on the skin surface that helps to limit water evaporation from the stratum corneum while protecting it from external aggressors. Linoleic acid inserts between intercellular lipids and strengthens corneocyte cohesion. It thus improves the skin barrier and reduces transepidermal water loss.

The rich fatty acid profile of olive oil suggests it may support skin hydration.

The potential moisturizing effect of olive oil was investigated in a pilot study by Lavender and colleagues. They enrolled newborns. A total of 115 infants were assigned to three groups that received two daily applications for four weeks: olive oil, sunflower oil, or no oil (control group). The results showed that overall skin hydration showed a slight improvement in the group treated with olive oil. However, transepidermal water loss, a key indicator of skin hydration, did not change. These findings suggest olive oil may act as an emollient due to its lipid content, but its moisturizing effect requires clarification.