title: Dietary intake of n-3 and n-6 fatty acids and the risk of clinical depression in women: a 10-y prospective follow-up study.
abstract: BACKGROUND
  The associations between different sources of dietary n-3 (omega-3) and n-6 (omega-6) fatty acids and the risk of depression have not been prospectively studied.
  
  
  OBJECTIVE
  The objective was to examine the relation between different n-3 and n-6 types with clinical depression incidence.
  
  
  METHODS
  We prospectively studied 54,632 US women from the Nurses' Health Study who were 50-77 y of age and free from depressive symptoms at baseline. Information on diet was obtained from validated food-frequency questionnaires. Clinical depression was defined as reporting both physician-diagnosed depression and regular antidepressant medication use.
  
  
  RESULTS
  During 10 y of follow-up (1996-2006), 2823 incident cases of depression were documented. Intake of long-chain n-3 fatty acids from fish was not associated with depression risk [relative risk (RR) for 0.3-g/d increment: 0.99; 95% CI: 0.88, 1.10], whereas α-linolenic acid (ALA) intake was inversely associated with depression risk (multivariate RR for 0.5-g/d increment: 0.82; 95% CI: 0.71, 0.94). The inverse association between ALA and depression was stronger in women with low linoleic acid (LA) intake (P for interaction = 0.02): a 0.5-g/d increment in ALA was inversely associated with depression in the first, second, and third LA quintiles [RR (95% CI): 0.57 (0.37, 0.87), 0.62 (0.41, 0.93), and 0.68 (0.47, 0.96), respectively] but not in the fourth and fifth quintiles.
  
  
  CONCLUSIONS
  The results of this large longitudinal study do not support a protective effect of long-chain n-3 from fish on depression risk. Although these data support the hypothesis that higher ALA and lower LA intakes reduce depression risk, this relation warrants further investigation.
authors.affiliation: Departments of Nutrition and Society, Human Development, and Health, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Michel
authors.initials: M
authors.lastname: Lucas
authors.forename: Fariba
authors.initials: F
authors.lastname: Mirzaei
authors.forename: Eilis J
authors.initials: EJ
authors.lastname: O'Reilly
authors.forename: An
authors.initials: A
authors.lastname: Pan
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawachi
authors.forename: Karestan
authors.initials: K
authors.lastname: Koenen
authors.forename: Alberto
authors.initials: A
authors.lastname: Ascherio
mesh_terms: D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use*; D003863:Depression / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D004034:Diet Surveys; D004041:Dietary Fats / Q000627:therapeutic use*; D015525:Fatty Acids, Omega-3 / Q000627:therapeutic use*; D043371:Fatty Acids, Omega-6 / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D012307:Risk Factors; D017747:Seafood; D011795:Surveys and Questionnaires; D017962:alpha-Linolenic Acid / Q000627:therapeutic use
chemical_list: D000928:Antidepressive Agents; D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D017962:alpha-Linolenic Acid