The Effectiveness of GLA in Topical Formulations for the Skin
The essential fatty acid gamma linolenic acid (GLA) from borage and other oils has been shown to be one of the most effective agents for the treatment of skin disorders and for the maintenance of healthy skin. The fatty acid profile of borage is unique in that it contains 20 to 24 percent GLA. Evening primrose oil contains 8 to 10 percent GLA and black currant oil contains 15 to 17 percent.
The popularity of borage oil as an ingredient in topical formulations for the skin is growing rapidly, based on the strong research showing that it is of benefit in the treatment of various skin conditions, including dry skin, eczema, inflammation, wounds, and dermatitis.
Role of GLA in the skin
Healthy skin depends on adequate amounts of lipid, in particular certain polyunsaturated fatty acids called essential fatty acids (EFAs), for moisture, suppleness and smoothness as well as to prevent skin disorders.1 The most important polyunsaturated fatty acids for maintenance of healthy skin and for the alleviation of skin disorders are the essential fatty acids of the omega-6 family, namely linoleic acid (LA) and GLA. Dietary deficiency of these fatty acids results in a characteristic scaly skin disorder, increased epidermal turnover rate, weak cutaneous capillaries that rupture easily, decreased wound healing and increased transepidermal water loss (TEWL) leading to xerosis (dry skin). Dry skin is the most common skin condition and is especially common in the elderly. By the age of 80 years, the epidermis may lose as much as 50% of its thickness, which accelerates water loss. Dry skin also exacerbates many other skin conditions including eczema and psoriasis.
Many skin disorders may be due to disorders in processing essential fatty acids. In particular, the conversion of linoleic acid (LA) to GLA, via the action of a critical enzyme known as the delta-6-desaturase (D6D) enzyme, may be blocked. This leads to insufficient GLA being formed in the body. Both LA and GLA are critical for healthy skin since they are structural components of cell membranes where they ensure fluidity and stability. The proper functioning of the cells of the skin depend upon healthy membranes since they act as “gate-keepers” which maintains epidermal barrier function that keeps moisture locked in while keeping toxins out. This reduces the irritancy caused by skin-irritating noxious substances. Thus, EFAs help to ensure the integrity of the epidermal layer of the skin, maintain the skin water barrier system and regulate moisture loss.
GLA is also the precursor for potent, short-lived, hormone-like compounds called eicosanoids, such as prostaglandin E1, which helps modulate normal skin physiologic processes by improving blood flow and reducing inflammation, as well as reducing water loss.
Relationship of GLA status to Healthy Skin and Skin Disorders
Disorders and problems such as atopic dermatitis or eczema, dry skin, psoriasis, increased transepidermal water loss (TEWL) and impaired epidermal barrier function is associated with deficiencies in GLA.2,3 Direct dietary supplementation of GLA is often required to ensure that adequate level of GLA and PGE1 occurs. Both oral and topical administration of GLA has been effective in reducing the symptoms of a large number of skin disorders including dermatitis, eczema, psoriasis, and acne as well as reducing redness and erythema due to UV radiation and improving healing of wounds.
Topical Administration of Borage Oil
The topical administration of borage oil has been shown to be very effective in preventing and treating inflammatory conditions and skin disorders such as eczema and dermatitis in both animals and humans.3,4 Diezel and co-workers found that artificially induced inflammation was inhibited on mouse skin through the topical administration of borage oil.5 Borage oil was found to be more effective than other oils such as evening primrose oil and olive oil. Elias has reported that a gel containing 1.5% borage oil significantly reduced the TEWL of the skin of hairless mice maintained on EFA deficient diets.6 The effect was progressive, with an initial decrease of 27.3% in TEWL to a 67.8% reduction after four daily applications.