Research report
Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients

https://doi.org/10.1016/S0165-0327(97)00166-3Get rights and content

Abstract

Background: There is a hypothesis that lack of n-3 polyunsaturated fatty acids (PUFAs) is of aetiological importance in depression. Docosahexaenoic acid, a member of the n-3 PUFA family, is a crucial component of synaptic cell membranes. The aim of this study was to measure RBC membrane fatty acids in a group of depressed patients relative to a well matched healthy control group. Method: Red blood cell (RBC) membrane levels, and dietary PUFA intake were measured in 10 depressed patients and 14 matched healthy control subjects. Results: There was a significant depletion of RBC membrane n-3 PUFAs in the depressed subjects which was not due to reduced calorie intake. Severity of depression correlated negatively with RBC membrane levels and with dietary intake of n-3 PUFAs. Conclusion: Lower RBC membrane n-3 PUFAs are associated with the severity of depression. Limitations: Although patient numbers were small, confounding factors were well controlled for and the results were highly significant. Results of the dietary data would tend to be weakened due to the limitations associated with dietary assessment. Clinical Relevance: The findings raise the possibility that depressive symptoms may be alleviated by n-3 PUFA supplementation.

Section snippets

Background

It has been suggested that abnormal cell membrane fatty acid composition may be of aetiological significance in depression (Smith, 1991, Hibbeln and Salem, 1995). Cell membranes contain a phospholipid bilayer. Changes in the polyunsaturated fatty acid content of this phospholipid alters membrane micro structure. This can have profound effects upon neurotransmitter receptor function (Stubbs, 1992, Salem and Niebylski, 1995).

The polyunsaturated fatty acids (PUFAs) are classified into two main

Methods

Ten cases with a diagnosis of a major depressive episode according to DSM IV criteria were recruited into the study. None were suffering from physical illness of severity or nature which might be associated with abnormal n-3 fatty acid levels. All were taking antidepressant medication. The cases were matched with 14 healthy control subjects with no history of psychiatric disorder. They were also matched in terms of age, gender, social class, body mass index, number of children, recent life

Results

Patients and controls showed a similar distribution of age (patients 38.7±10.2; controls 39.4±10.9) and gender (patients 8F 2M, controls 12F 2M) and did not differ significantly in smoking habit (patients 7/10 smokers, controls 8/14 smokers) recent life events (patients 8/10 recent life events, controls 6/14) or alcohol habit (patients 1.0±1.4 units per day; controls 0.8±0.8 units per day). BDI score was 26.9±4.7 in the depressed patients and 4.9±4.2 in the controls.

As shown in Fig. 1 and Table

Discussion

We have confirmed our previous finding (Peet et al., 1997) that PUFAs of the n-3 series are significantly depleted in RBC membranes from depressed patients. The absolute values and the magnitude of the differences in the n-3 PUFA series were not significantly different from the previous findings.

Although patient numbers were small, the results are highly significant and in the predicted direction. The findings are consistent with other recent studies of fatty acid levels in phospholipid and

References (27)

  • S Booth-Kewley et al.

    Psychological predictors of heart disease: a quantitative review

    Psychol. Bull.

    (1987)
  • S.E Carlson et al.

    Docosahenaenoate (DHA) and eicosapentaenoate (EPA) status of preterm infants: Relationship to visual acuity in n-3 supplemented and unsupplemented infants

    Pediatr. Res.

    (1989)
  • Cross-National Collaborative Group

    The changing rate of major depression

    J. Am. Med. Assoc.

    (1992)
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