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Rapid Responses: Rapid Responses published:
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Missing the Picture
- Ned Hoke (13 December 2003)
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Essential fatty acids and dermatitis
- Ellen C G Grant (13 December 2003)
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Efficacy and tolerability of borage oil in adults and children with atopic eczema
- Rakesh Kapoor (15 January 2004)
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Ned Hoke, ecological medicine/private Calif/USA
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Given the reasonable complexity and layered expression that eczema is it seems quite unreasonable to imagine or expect a relatively benign nutritional therapeutic element to indicate observable curative effect especially within the time frame and unrewarding larger theapeutic matrix as written. While not a totally mindless question it remains a poorly asked one in this instance. Competing interests: None declared |
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Ellen C G Grant, physician and medical gynaecologist 20 Coombe Ridings, kingston-upon-Thames, Surrey, KT2 7JU
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It is not difficult to measure essential fatty acids in red cells and I have requested this test routinely for many years for my patients. The commonest deficiencies, as David Horrobin was the first to teach me, are due to delta desaturase blocks in the omega-6 and omega-3 pathways because of deficiencies of the co-factors zinc, magnesium and vitamin B6. I quickly discovered that, even when these cofactors were replete, if I only prescribed omega-6 EFAs, a shortage of omega-3 EFAs would be caused and vice versa. No one, who thoroughly investigates their patients, would expect a single nutritional supplement to prevent a complex condition like atopic dermatitis. It is also known that immunogolbulin E levels increase as Vitamin E levels decline making atopy more likely. The treatment or avoidance of dermatitis needs many possible precipitants, such as foods and chemicals, including toxic metals, to be considered. Nutritional therapy is not the same as single drug therapy which, as highlighted in the accompanying editorial, may work only for the few, or, as in the case of HRT, cause more real risks than illusory benefits. Competing interests: None declared |
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Rakesh Kapoor, Director, Science & Technology Bioriginal Food & Science Corp. 102 Melville Street, Saskatoon, SK, S7J 0R1, Canada
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Dear Sir, I read with interest the article published by Takwale et al. investigating the effect of borage oil on atopic eczema treatment. The authors have concluded that the borage oil treatment does not offer any advantage over placebo. This study has some limitations in experimental design that can affect the results. In this study two different placebos were used: Liquid paraffin for adults and olive oil for children. Liquid paraffin is an inert material for its effect on atopic dermatitis whereas; olive oil is not as inert as it can modify cellular fatty acid profile. It has been reported to increase tissue levels of dihomogammalinolenic acid (DGLA) (1;2), a metabolite of gamma linolenic acid (GLA). By increasing tissue levels of DGLA, it may also increase the dermal levels of lipoxygenase and cyclooxygenase metabolites of DGLA that are reported to exert anti- inflammatory actions.(3;4) Therefore, olive oil can show some beneficial effects due to above mentioned biochemical pathways. As the placebo group is also showing the reduction in eczema scores, it appears that these positive action are contributed by olive oil and placebo effect. For accurate analysis of placebo effect and potential superiority of intervention, investigators should have done the separate analysis in adult and children to avoid the potential variations in outcome induced by different placebo. The study does not mention how the compliance was monitored. In this study, blood/tissue levels of GLA or metabolites were not measured. In absence of such data, it is very difficult to ascertain actual compliance with the study protocol. Lack of compliance with the protocol can contribute to failure of treatment in 50% of times (5). In a multicentre trial by Henz et al. (6), it was observed that the subjects with moderate atopic eczema, who showed an increase in erythrocyte DGLA levels, showed significant improvement. In the same study, inclusion of data from patients who did not follow the protocol and did not show an increase in the tissue DGLA levels, resulted in no effect of treatment. This further confirms that monitoring for compliance is most essential part of the clinical study to truly determine the effect of treatment. The other major limitation of the study is the inclusion of data from the patients who did not complete the trial but had at least one observation after randomization. Therefore, they included non compliant patients, who violated the protocol and should not have been included in the analysis. This would have modified the outcome of the study, as was demonstrated in the study by Henz et al. (6). Investigators used Six Area, Six Sign Atopic Dermatitis severity (SASSAD) score. They did not mention if one investigator evaluated the patients or more than one investigators evaluated the patients. Assuming more than one investigator evaluated the patients, one has to look into the reliability of this scoring system as this scoring system is reported to have a very high inter-observer variation (7 – 30, median 15.5, out of a possible score of 108)(7). Based on these limitations, it is premature to conclude that the treatment with borage oil or another source of GLA is no better than placebo. This study definitely indicates requirement for further research with better control and analysis. Reference List 1. Giron MD, Mataix FJ, Suarez MD. Changes in lipid composition and desaturase activities of duodenal mucosa induced by dietary fat. Biochim.Biophys.Acta 1990;1045:69-73. 2. Campbell KL, Dorn GP. Effects of oral sunflower oil and olive oil on serum and cutaneous fatty acid concentrations in dogs. Res.Vet.Sci. 1992;53:172-8. 3. Miller CC, Ziboh VA. Gammalinolenic Acid-enriched Diet Alters Cutaneous Eicosanoids. Biochemical and Biophysical Research Communications 1988;154:967-74. 4. Ziboh VA, Miller CC, Choi Y. Metabolism of Polyunsaturated Fatty Acids by Skin Epidermal Enzymes: Generation of Antiinflammatory and Antiproliferative Metabolites. American Journal of Clinical Nutrition 2000;71:361S-6S. 5. Cork MJ, Britton J, Butler L, Young S, Murphy R, Keohane SG. Comparison of parent knowledge, therapy utilization and severity of atopic eczema before and after explanation and demonstration of topical therapies by a specialist dermatology nurse. Br J Dermatol 2003;149:582-9. 6. Henz BM, Jablonska S, van de Kerkhof P, Stingl G, Blaszczyk M, Vandervalk P. Double-Blind, Multicentre Analysis of the Efficacy of Borage Oil in Patients with Atopic Eczema. Br J Dermatol 1999;140:685-8. 7. Charman CR, Venn AJ, Williams HC. Reliability testing of the Six Area, Six Sign Atopic Dermatitis severity score. Br J Dermatol 2002;146:1057-60. Competing interests: Work for Company manufacturing and selling oils rich in Essential fatty acids including Borage oil |
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