Psoriasis: Essential Fatty Acids and Prostaglandins
Essential Fatty Acids and Prostaglandins
Psoriasis is a difficult problem to treat. I have had success recommending GLA-rich borage oil supplements, used both orally and topically, i.e. direct application to the psoriatic plaques.
"There is considerable evidence to suggest that essential fatty acids can benefit psoriasis sufferers. A double-blind, placebo-controlled trial by Bittiner et al. (1988) concluded that `dietary supplementation with small amounts of oils from marine fish can reduce the itching, erythema and scaling in psoriasis with a trend towards decreasing the area of affected skin'. A possible reason for this is that a disordered arachidonic acid (AA) metabolism may play a part in psoriasis, with inflammatory leukotrienes derived from AA stimulating DNA synthesis. The production of such leukotrienes is many times greater than normal in the skin of psoriasis patients (Murray and Pizzorno, 1990). Eicosapentaenoic acid (EPA), which was used in the trial, is structurally very similar to arachidonic acid, and forms prostaglandins of the 3 series and leukotrienes of the 5 series, which seem to be biologically less active than those derived from AA (2-series prostaglandins); they may thus act as competitive inhibitors.
"Some practitioners (e.g. Rowland, 1986) prescribe evening primrose oil (Oenothera biennis) as part of their treatment. There is so far no incontrovertible evidence that this is successful, but it is possible that the oil operates in a similar way to EPA. Evening primrose contains gamma-linolenic acid (GLA), which gives rise to the anti-inflammatory series 1 prostaglandins; these have been shown to benefit a wide range of disorders, including multiple sclerosis, high blood cholesterol, rheumatoid arthritis, diabetic retinopathy and mastalgia (Erasmus, 1986; Graham, 1984).
"In view of these facts, it is interesting to note Weiss's (1988) recommendation that linseed oil be used as a topical application for psoriasis. Linseed (Linum usitatissimum) tops Udo Erasmus's table of nutritionally valuable oils (Erasmus, 1986), as it contains an optimum balance of linoleic acid (omega 6 series) and alpha-linolenic acid (omega 3 series), which give rise respectively to series 1 and series 3 prostaglandins. The AA study (Bittiner et al., 1988) goes some way towards providing a theoretical basis for the use of linseed, and suggests that patients might derive even more benefit from taking it internally. Linseed is, incidentally, mentioned as a possible cure for eczema in the lexicon piled by the Traditional Chinese Medicine Institute of Nanjing (Scott, 1987a).
"One major problem, however, with pure linseed oil is that it quickly degrades, particularly in the presence of light and heat, and can only be obtained at limited outlets.
(Nichols, Colin, British Journal of Phytotherapy, The 12-31-90 V.1; N.3/4 p. 19-25
An interesting, if somewhat technical explanation was presented in a chapter in Annual Review of Nutrition, Volume 10, 1990, titled Essential Fatty Acids and Polyunsaturated Fatty Acids: Significance in Cutaneous Biology, by Vincent Ziboh and Craig Miller, Dept of Dermatology, UC Davis:
MODULATION OF EPIDERMAL FATTY ACIDS AND EICOSANOIDS BY DIETARY OILS CONTAINING N-6 AND N-3 PUFAs
The excitement generated by reports of clinical improvement of patients with atopic eczema (a disease of still undefined etiology but characterized by abnormalities related to defective immune responses) after oral administration of primrose oil (34,58) signalled a possible role of GLA (gamma linolenic acid) and n-6-containing vegetable oils in cutaneous biology. For instance, orally administered EPO (ev