A meta-analysis of blood fatty acids in people with learning disorders with particular interest in arachidonic acid.

Small individual studies report that people with learning disorders have lower than normal blood concentrations of docosahexaenoic acid and arachidonic acid. The origin and consequence of the subnormal docosahexaenoic acid have been much speculated. However, relatively little attention has been paid to the significance of the low arachidonic acid concentration. Studies were identified through a literature search including subjects with various learning disorders or symptoms thereof and age-matched controls. A meta-analysis of pooled data from the red blood cell and plasma/serum showed that red blood cell arachidonic acid and docosahexanoic acid concentrations were significantly lower than normal [-3.93 and -18.92, respectively (weighted mean difference as a % of weighted mean control)]. Plasma/serum arachidonic acid and docosahexaenoic acid concentrations were also significantly lower than normal [-6.99 and -15.66, respectively (weighted mean difference as a % of weighted mean control)]. However, in absolute amounts the arachidonic acid was as severely depressed as docosahexanoic acid within red blood cells 0.57mg/100mg of fatty acid below normal verses 0.59mg/100mg for docosahexaenoic acid. Plasma/serum arachidonic acid was even lower; 0.71mg/100mg of fatty acid below normal verses 0.34mg/100mg for docosahexaenoic acid. The origin, consequences and relative importance of subnormal arachidonic acid to brain function bears further investigation.

A meta-analysis of randomized, placebo-controlled clinical trials of Efamol evening primrose oil in atopic eczema. Where do we go from here in light of more recent discoveries?

UNLABELLED: The global incidence of atopic eczema is escalating. While new treatment options are becoming available, previous treatments with certain confirmed benefits are still worth investigating as safe and effective therapies. One such treatment, Efamol evening primrose oil (EPO), was proven efficacious in a 1989 meta-analysis of randomized, double-blind, placebo-controlled clinical trials. A decade of further testing and subsequent independent reanalysis of 26 clinical studies including 1207 patients presented here, establishes that Efamol EPO has a simultaneous, beneficial effect on itch/pruritus, crusting, oedema and redness (erythema) that becomes apparent between 4 and 8 weeks after treatment is initiated. However, the magnitude of this effect is reduced in association with increasing frequency of potent steroid use. This and other confounding variables that are now being reported in the literature may account for historically reported inconsistent patient response. Recent research has uncovered unique complexities in fatty acid metabolism and immune response in the atopic condition beyond those previously reported and may well have identified a subcategory of non-responders and has helped established those that can consistently derive significant benefit. Further research is needed to provide a better understanding of the physiology behind this complex disorder and the beneficial role that fatty acids can play in its development and management. CONCLUSION: Efamol EPO has a simultaneous, beneficial effect on itch/pruritus, crusting, oedema and redness (erythema) that becomes apparent between 4 and 8 weeks after treatment is initiated. However, the magnitude of this effect is reduced in association with increasing frequency of potent steroid use.

Breast milk from mothers of children with newly developed atopic eczema has low levels of long chain polyunsaturated fatty acids.

BACKGROUND: Infants at risk of atopic dermatitis have lower than normal levels of long chain polyunsaturated fatty acids. These fatty acids are normally present in substantial quantities in human breast milk. METHODS: Because of the equivocal evidence concerning the ability of breastfeeding to delay the onset or reduce the severity of atopic dermatitis, we have analyzed the fatty acid composition of breast milk from the mothers of children with newly developed disease with the use of gas chromatography. RESULTS: Breast milk lipids from mothers of children with newly developed atopic dermatitis had increased proportions of linoleic acid and significantly decreased proportions of its long chain polyunsaturated derivatives compared with a control group. The ratio of linoleic acid to the sum of its metabolites, gamma-linolenic acid, dihomo-gamma-linolenic acid, and arachidonic acid was 11.78 in the atopic group and 9.02 in the control group (p < 0.01). CONCLUSIONS: These results are consistent with previous findings of an abnormal fatty acid status in atopic subjects and may account for some of the inconsistent results from studies of the effect of breastfeeding on the subsequent development of atopic dermatitis. We conclude that further studies to examine the effects of supplementation of the diet of breastfeeding mothers with long chain polyunsaturates should be done.

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.