Oral evening-primrose-seed oil improves atopic eczema

The effects of essential fatty acid supplementation by Efamol in hyperactive children

Thirty-one children, selected for marked inattention and overactivity, were studied in a double-blind, placebo-controlled crossover study of essential fatty acid (EFA) supplementation. Subjects received the active treatment and placebo conditions for 4 weeks each and were assessed on a variety of cognitive, motor, and standardized rating scale measures. EFA supplementation (evening primrose oil; Efamol) resulted in significantly lower levels of palmitoleic acid (a nonessential fatty acid) and higher concentrations of dihomogammalinolenic acid, an EFA previously found to be deficient in some hyperactive children. Supplementation was also associated with significant changes on two performance tasks and with significant improvement to parent ratings on the subscales designated as Attention Problem and Motor Excess of the Revised Behavior Problem Checklist. However, a variety of eight other psychomotor performance tests and two standardized teacher rating scales failed to indicate treatment effects. When the experiment-wise probability level was set at .05, only 2 of 42 variables showed treatment effects. Baseline EFA concentrations appeared to be unrelated to treatment response. It was concluded that EFA supplementation, as employed here, produces minimal or no improvements in hyperactive children selected without regard to baseline EFA concentrations.

Specific application of single nutrients as a basic treatment in immunostimulating therapy

Many results of biochemical and animal experiments as well as clinical trials provide justification for the administration of essential fatty acids (EFAs) as a supplementary therapy in rheumatic diseases, atopic disorders and chronic infections. Defective regulation of inflammatory responses or disordered immune mechanisms are probably central to the pathologic processes encountered in chronic inflammatory diseases and immunologic disorders. Epidemiologic studies indicate that vitamins and trace elements are often provided at levels much below the currently accepted minimum requirement and therefore other factors, namely zinc, selenium, niacin, pyridoxine, vitamin A, E and folic acid must also be considered in substitution. In order to optimize immunostimulating therapy the negative influence of suboptimal levels of EFAs, vitamins and trace elements should always be taken into account.

Incorporation and distribution of dihomo-gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid in cultured human keratinocytes

Human keratinocytes in culture were labelled with 14C-dihomo-gamma-linolenic acid, 14C-arachidonic acid or 14C-eicosapentaenoic acid. All three eicosanoid precursor fatty acids were effectively incorporated into the cells. In phospholipids most of the radioactivity was recovered, in neutral lipids a substantial amount, and as free unesterified fatty acids only a minor amount. The most of the radioactivity was found in phosphatidylethanolamine which was also the major phospholipid as measured by phosphorous assay. The incorporation of dihomo-gamma-linolenic acid and arachidonic acid into lipid subfractions was essentially similar. Eicosapentaenoic acid was, however, much less effectively incorporated into phosphatidylinositol + phosphatidylserine and, correspondingly, more effectively into triacylglycerols as compared to the two other precursor fatty acids. Once incorporated, the distribution of all three precursor fatty acids was relatively stable, and only minor amounts of fatty acids were released into the culture medium during short term culture (two days). Our study demonstrates that eicosanoid precursor fatty acids are avidly taken up by human keratinocytes and esterified into membrane lipids. The clinical implication of this finding is that dietary manipulations might be employed to cause changes in the fatty acid composition of keratinocytes.

Pharmacophysiology of atopic dermatitis

Atopic dermatitis is clearly characterized by altered cutaneous physiologic responses. There is a tendency to acral vasoconstriction. Rubbing causes skin pallor and white dermographism. Vascular instability is demonstrated by responses to cholinergic agents, histamine, and nicotinates. Psychophysiologic studies demonstrate exaggerated vasodilator responses to emotional stress with consequent pruritus and scratching. The itch threshold is low, duration is prolonged, and nighttime scratching movements may be frequent or almost continuous. Regardless of the inciting trigger factors, the scratching causes the damage and the severe dermatitis. Thermal as well as emotional stimuli to sweating cause severe itching in AD, yet the concept of a miliaria-type, poral occlusion mechanism remains unproven. Some studies suggest actually increased sweating along with erythema and pruritus during acute flares of AD. The concept of sweat-borne allergens causing skin reactions during sweating is interesting but has never been proven. Studies of sweat responses to pharmacologic agents have produced conflicting data, and attempts to link these responses to Szentivanyi's beta-adrenergic blockade theory are not convincing. The numerous variables of climate, season, sex, age, and habitus affect sweating greatly. Future studies must carefully control for each of these factors before pharmacologically induced sweat responses can be interpreted clearly. A number of lines of evidence suggest involvement of histamine and other mediators in the evolution of erythema, pruritus, and scratching in AD. Flares of the condition have been reproducibly evoked by only two incitants: experimental emotional stress interviews and specific food challenge in selected sensitive individuals. In the latter, increased plasma histamine has been demonstrated, presumably generated by antigen/IgE stimulated degranulation of mast cells in the gut and/or skin. The demonstrated increased histamine releasability of basophils from atopic individuals may be the result of defective cellular regulatory mechanisms. Recent studies have demonstrated increased cyclic AMP-phosphodiesterase activity in leukocytes from atopic individuals. The resultant decreased intracellular cyclic AMP removes an inhibitory factor, which in turn causes net cellular hyperresponsiveness. This effect has been shown to account, at least in part, for increased histamine release from leukocytes of patients with AD. These and other studies focused upon cell functional regulation are providing better understanding of basic biochemical abnormalities and may lead to improved diagnostic and therapeutic approaches in managing atopic disease.

Altered arachidonic acid content in polymorphonuclear and mononuclear cells from patients with allergic rhinitis and/or asthma

We previously have found that monocytes from patients with allergic rhinitis and/or asthma produce less PGE2 than cells from normal subjects in response to a histamine-induced lymphokine. In order to investigate this observation further, we measured the fatty acid content in the total phospholipids derived from the plasma, red cells, buffy coat cells, neutrophils, monocytes and lymphocytes of 27 allergic patients and 21 normal controls. There were no substantial differences between atopics and normals in the fatty acid analyses carried out for plasma and red cells. However, linoleic acid (18:2n-6) levels were elevated significantly in the buffy coat fraction, while arachidonic acid (20:4n-6) levels were reduced. Measurement of fatty acid levels after fractionation of the buffy coat population into neutrophils and monocytes yielded similar elevations in 18:2n-6 and reduced 20:4n-6. In contrast, lymphocytes appeared to have the reverse pattern, i.e., significantly reduced 18:2n-6 and elevated 20:4n-6 levels. These data suggest that atopic leukocytes may have altered essential fatty acid metabolism.

Increased requirements for essential fatty acids in atopic individuals: a review with clinical descriptions

Patients with atopic eczema and a mixture of allergic illnesses show biochemical evidence suggesting impairment in the desaturation of linoleic acid and linolenic acid by the enzyme delta-6 dehydrogenase. Consequences of this enzyme defect are 1) diminished synthesis of the 20-carbon polyunsaturated fatty acids, which are prostaglandin precursors and 2) a reduction in the concentration of double bonds in the cell membrane. A distortion in the production of prostaglandins and leukotrienes, which might result from this block, can account for the immunological defects of atopy and a variety of clinical symptoms experienced by atopic individuals. Dietary supplementation with essential fatty acids relieves the signs and symptoms of atopic eczema, may improve other types of allergic inflammation, and may also correct coexisting symptoms as diverse as excessive thirst and dysmenorrhea. Further research is suggested to test the hypothesis that some atopic states represent a condition of essential fatty acid dependency owing to defective desaturation of dietary fatty acids.

Atopic eczema unresponsive to evening primrose oil (linoleic and gamma-linolenic acids)

This study was designed to look at the effect of evening primrose oil (linoleic and gamma-linolenic acids) as an oral supplement for patients with atopic eczema. We used a double-blind, blocked crossover design with random assignment of patients to treatment groups. We used Wilcoxon's signed-ranks method of comparing changes during the trial. We observed no significant effect on erythema, scale, excoriation, lichenification, or overall severity in 123 patients with atopic eczema of average severity while they took oral doses of evening primrose oil (2 or 4 gm in children, 6 or 8 gm in adults).

Chronic arachidonic acid eicosanoid imbalance: a common feature in coronary artery disease, hypercholesterolemia, cancer and other important diseases. Significance of desaturase enzyme inhibition and of the arachidonic acid desaturase-independent pathway

A chronic imbalance between the essential fatty acid metabolites arachidonic acid, gamma-linolenic acid and eicosapentaenoic acid and of their respective eicosanoid derivatives appears to be implicated in the etiology of many intractable disease. Most notable among these are coronary artery disease, cancer and chronic inflammation. The factors leading to such an imbalance and their relatively simple prophylactic and therapeutic circumvention are discussed briefly.

Abnormal essential fatty acid levels in plasma of women with premenstrual syndrome

Premenstrual syndrome is now recognized as a condition that probably has an endocrine or biochemical basis. However, it has proved difficult to demonstrate any consistent significant differences from normal in any parameter measured to date. We have measured essential fatty acid levels in phospholipids in plasma taken from 42 women with well-defined premenstrual syndrome. The women were not on any treatment during the cycles when samples were taken in both follicular and luteal phases. The levels of linoleic acid, the main dietary n-6 essential fatty acid, were significantly above normal, indicating no deficit of intake or absorption. In spite of this, concentrations of all metabolites of linoleic acid were significantly reduced, suggesting a defect in conversion of linoleic acid to gamma-linolenic acid. Possibly in compensation, levels of n-3 essential fatty acids were elevated. The same abnormalities were present in both follicular and luteal phases. This abnormality cannot therefore be the direct cause of the symptoms that appear in the luteal phase, but it may sensitize tissues so that they respond abnormally to normal levels of reproductive hormones.

Extrinsic factors in atopic eczema

The debate over the role of extrinsic allergens in atopic eczema has been enlightened in recent years by some well-controlled studies and improvements in our understanding of conditions which lead to hypersensitivity. This paper reviews some of these findings, which have preventative and therapeutic implications. No attempt is made here to review other aspects of this multifactorial disease, nor to enter into detailed discussion of dietary or allergen avoidance regimens, which have been covered in several recent reviews. Such regimens are not without risk, and require expert supervision.

Essential fatty acids in the plasma phospholipids of patients with atopic eczema

We have measured all the essential fatty acids (EFA) in plasma phospholipids in forty-one adults with atopic eczema and fifty normal controls. The major dietary n-6 EFA, linoleic acid, was significantly elevated, but all its metabolites, 18:3n-6, 20:3n-6, 20:4n-6, 22:4n-6, and 22:5n-6 were significantly reduced. The major dietary n-3 EFA, alpha-linolenic acid, was also elevated, though not significantly, while all its metabolites were also significantly reduced. These observations suggest that atopic eczema is associated not with any defect of EFA intake, but with abnormal metabolism, possibly involving the enzyme delta-6-desaturase. Treatment with oral evening primrose oil produced partial correction of the n-6 EFA abnormality, but had no effect on the n-3 EFAs.

Compliance problems in the dietary management of eczema

We have reviewed the progress of 40 children with severe eczema associated with food intolerance. Even with highly motivated parents and patients the emotional and financial burdens resulted in many finding the diets impossible to maintain. Three of 14 children (21%) under 3 years of age, and 12 of 26 children (46%) over 3 years gave up diets, with a subsequent relapse of their eczema.