title: Dietary zinc intake and the risk of depression in middle-aged men: a 20-year prospective follow-up study.
abstract: BACKGROUND
  Zinc is an immunomodulatory trace element suggested to be beneficial in the augmentation of antidepressant therapy. Cross-sectional studies have also suggested an association between low dietary zinc and depression. This study examined the association between dietary zinc intake and depression in a prospective setting in initially depression-free men during a 20-year follow-up.
  
  
  METHODS
  The study formed a part of the population-based Kuopio Ischemic Heart Disease Risk Factor (KIHD) Study, and comprised 2317 Finnish men aged 42-61 years. Zinc intake was assessed at baseline by a 4-d food record. Baseline depression severity was recorded with the Human Population Laboratory Depression Scale. In the prospective setting, depression was defined as having received a hospital discharge diagnosis of unipolar depressive disorder. Individuals who at baseline had elevated depressive symptoms were excluded (n=283).
  
  
  RESULTS
  Altogether, 60 (2.7%) individuals received a hospital discharge diagnosis of depression during the 20-year follow-up. In Cox regression analysis adjusted for age, baseline depression severity, smoking, alcohol use, physical exercise and the use of dietary supplements, belonging to the lowest tertile of energy-adjusted zinc intake was not associated with an increased depression risk (RR 1.06, 95% CI 0.59-1.90).
  
  
  CONCLUSIONS
  These observations may not be generalizable to women, or to individuals with a depression level not warranting hospitalization.
  
  
  CONCLUSIONS
  Our findings suggest that a low dietary zinc intake may not longitudinally precede depression in men. Dietary zinc intake may not have relevance for the prevention of depression in middle-aged men with a sufficient dietary zinc intake.
authors: Department of Psychiatry, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland. Soili.Lehto@kuh.fi
authors: Soili M
authors: SM
authors: Lehto
authors: Anu
authors: A
authors: Ruusunen
authors: Tommi
authors: T
authors: Tolmunen
authors: Sari
authors: S
authors: Voutilainen
authors: Tomi-Pekka
authors: TP
authors: Tuomainen
authors: Jussi
authors: J
authors: Kauhanen
mesh_terms: D000328:Adult; D003863:Depression / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D004032:Diet; D019587:Dietary Supplements; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D015032:Zinc / Q000172:deficiency*
chemical_list: D015032:Zinc
keywords: Depression; Diet; Longitudinal; Prospective; Zinc