Impact of Raspberry Seed Oil, Sesame Oil, and Coconut Oil on Skin in Young Women

The skin serves protective roles for internal organs and is responsible for maintaining homeostasis between the body and the environment. The outermost and most exposed part of the skin to environmental factors is the stratum corneum (SC). SC hydration and transepidermal water loss (TEWL) values provide information about the physiological state of the skin. Plant oils, owing to their chemical structure, possess moisturizing and protective functions. This study assessed the impact of a single application of drying oil (Rubus idaeus seed oil), semi-drying oil (Sesamum indicum seed oil), and nondrying oil (Cocos nucifera (coconut) oil) on specific skin characteristics in young, healthy women. Thirty-five female volunteers (age: 20.03 +/- 1.69) participated in the study. Before commencing the investigation, a questionnaire survey on the subjective assessment of skin condition and a body composition test were conducted. Subsequently, each participant had three oils applied to nonoverlapping skin areas on the forearms. Skin characteristics were assessed before and 1 h after the oil application using specialized probes: a corneometer and a tewameter. An enhancement in skin hydration was evident after the application of each of the tested oils (p = 0.001). Raspberry oil demonstrated the most significant moisturizing effect, while coconut oil showed the weakest impact. Only raspberry seed oil (p = 0.012) resulted in a noteworthy decrease in TEWL. The initial skin condition did not correlate with the subjects' body composition, and the improvement induced by the application of the oils was not dependent on body weight, body water content, or BMI (body mass index). The applied vegetable oils positively influence the level of SC hydration. Improvement in barrier function, as measured by TEWL, was observed only for raspberry seed oil.