Doppelblinde plazebokontrollierte Studie zur Bedeutung der topischen Anwendung mehrfach ungesattigter Fettsauren fur die Barrierefunktion der Epidermis

The effects of polyunsaturated fatty acids on skin physiological parameters were investigated to study the function of the epidermal barrier. 47 healthy volunteers (30 women, 17 men; age bracket: 40-66 years) who felt to have a dry skin (5-point score) were treated for 4 to 11 weeks comparing cream with 1.3% gammalinolenic acid (Bepanthol® Roche Gesichtscreme), and without gamma-linolenic acid in a double-blind placebo-controlled manner. The creams were applicated on defined areas of the left and the right forearm, respectively. Comparing both sites, physiological parameters of skin were measured before, during and after treatment by corneometry, evaporimetry and sebumetry. The study shows higher hydration of skin surface and lower transepidermal water loss in areas treated by cream containing gamma-linolenic acid. However, the difference to the effects of the cream without gamma-linolenic acid was not significant. Investigating only the subgroup of volunteers with proven low lipid content of the skin as measured by sebumetry (<120 μg/cm ²), this difference, however, became significant in evaporimetry. In conclusion the epidermal barrier in volunteers with a dry skin can be improved by gamma-linolenic acid containing topicals.