Reply to UN Das

School of Psychology
Queen's University of Belfast
18–30 Malone Road
Belfast BT9 5BP
United Kingdom
E-mail k.appleton{at}qub.ac.uk

Robert C Hayward and Peter J Rogers

Department of Experimental Psychology
University of Bristol
8 Woodland Road
Bristol
United Kingdom

David Gunnell

Department of Social Medicine
University of Bristol
Canynge Hall
Whiteladies Road
Bristol
United Kingdom

Tim J Peters and David Kessler

Academic Unit of Primary Health Care
Department of Community Based Medicine
University of Bristol
25 Belgrave Road
Bristol
United Kingdom

Andrew R Ness

University of Paediatric and Perinatal Epidemiology
University of Bristol
24 Tyndalls Avenue
Bristol
United Kingdom

Dear Sir:

We thank Das for highlighting the potential role of inflammatory processes in depressive illness; however, this discussion is based on a misinterpretation of our recent meta-analysis (1). The meta-analysis concluded that there is very limited trial evidence currently available on the effects of n–3 long-chain polyunsaturated fatty acids (LCPUFAs) on depressed mood and that, because of the heterogeneity of this evidence, any conclusions concerning the benefits of n–3 LCPUFAs for depressed mood should be drawn with considerable caution.

Although previous biochemical studies, as reported in our article and elsewhere (2), have suggested that depression is more likely in those whose intake of n–3 LCPUFAs is low, information on n–3 LCPUFA intakes before supplementation was not given in our article. Furthermore, only 3 of the 18 trials detailed in our article were specifically conducted in individuals with low n–3 LCPUFA intakes before supplementation (3–5), and 2 of these trials showed no effects of n–3 LCPUFA supplementation on depressed mood (3, 4).

Second, although a meta-analysis of a limited number of trials that involved individuals with major depression suggests benefits, these trials were small and evidence of heterogeneity among them suggests that conclusions should be tentative. We do agree with Das on the need for well-planned larger trials with adequate power to detect clinically important effects, but, until such trials indicate a benefit, we do not advocate the use of n–3 LCPUFAs for the treatment of depression.

ACKNOWLEDGMENTS

The authors had no conflicts of interest to declare.

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