Gamma linolenic acid and atopic dermatitis
Onakpoya I., Taylor JA.
Atopic dermatitis (AD) is a chronic inflammatory skin disorder, characterized by itching and scaling. Known more commonly as eczema, its precise etiology is unknown, but genetic, immunologic and epidermal barrier factors are believed to play a role in its pathogenesis. Environmental factors such as light, age, season, and temperature are also thought to be involved in the pathology of this condition. Its prevalence reaches 10 to 20% in the pediatric populations of some countries. Diagnosis is usually made clinically. Conventional management options include the use of steroids, tacrolimus ointment, and emollients. Dietary habits have been speculated to play a role in the development of AD, and results from cohort studies have suggested that eating foods rich in polyunsaturated fatty acids (PUFA) during pregnancy may decrease the risk of having AD in offspring of mothers. Dietary management with gamma (γ) linolenic acid (GLA) has been advocated for the treatment of AD. GLA is an omega-6 fatty acid which is present naturally in breast milk, beef, pork and poultry. It is commonly available as evening primrose oil (EPO), Borage oil (BO), and black currant seed oil (BCSO). Some authors have reported that a failure of conversion of linoleic acid (LA) to GLA is a factor causing AD; therefore increasing the amount of GLA through dietary supplementation, and thereby increasing the GLA/LA ratio may be beneficial in treating AD. Though several clinical trials investigating the effects of GLA on AD have been conducted, its use in the management of this condition remains controversial. This chapter investigates the purported mechanisms of actions of GLA in AD, and reviews the results of some clinical trials evaluating the efficacy of GLA in the prophylaxis and treatment of AD. We will also discuss the results of systematic reviews analysing the effects of GLA on AD. © 2012 by Nova Science Publishers, Inc. All rights reserved.