The highest intakes of DHA were associated with a 50% reduction in the risk of anxiety disorders, according to an observation study involving 935 women.
Writing in the British Journal of Nutrition, researchers from Deakin University and The University of Melbourne also report that women with higher intakes of DHA were also about 70% less likely to report a current depressive disorder, compared with women with the lowest average levels.
“These are the first observational data to indicate a role for DHA in anxiety disorders, but suggest that the relationship between DHA and depressive disorders may be non-linear,” wrote the researchers, led by Melbourne’s Dr Felice Jacka.
Despite the positive conclusions of the researchers, Harry Rice, PhD, VP of scientific and regulatory affairs for GOED, the omega-3 trade association, told NutraIngredients-USA that the researchers have over-interpreted the results.
“A growing body of epidemiological evidence suggests that low dietary intake and/or tissue levels of the long-chain omega-3s are associated with both anxiety and depression. Due to diagnostic heterogeneity resulting in what can be very dissimilar subject pools, results from both clinical and observational research have been equivocal at best,” he said.
“The current results, which I have no reservation describing as over-interpreted or chance findings, just add to the confusion. Depression and anxiety are not homogeneous entities and shouldn't be treated as such.
“While I believe the O-3s are beneficial for the treatment of anxiety and depression, I would be remiss to pretend the evidence was compelling today.”
The Melbourne-based scientists analyzed data from 935 women aged between 20 and 93 years. Dietary intakes of omega-3 and omega-6 fatty acids were assessed using a dietary questionnaire and psychological symptoms were assessed using the General Health Questionnaire-12 (GHQ-12). A separate clinical interview was used to assess depressive and anxiety disorders.
Results indicated that only DHA intake was associated with both anxiety and depression in the women studied. No benefits were reported for intakes of linoleic acid, alpha-linolenic acid, arachidonic acid, eicosapentaenoic acid, or docosapentaenoic acid.
While the authors claim this to be the first observational study to report a link between the DHA and anxiety disorders, they note there is some clinical and experimental evidence to support the findings.
“Further research should now examine the potential of DHA as a treatment strategy in anxiety and focus on determining the optimal level of DHA intake in the prevention and treatment of depression,” they concluded.
Source: British Journal of Nutrition
Published online ahead of print, FirstView Articles, doi: 10.1017/S0007114512004102
“Dietary intake of fish and PUFA, and clinical depressive and anxiety disorders in women”
Authors: F.N. Jacka, J.A. Pasco, L.J. Williams, B.J. Meyer, R.Digger, M. Berk