The association between antioxidant intake, dietary pattern and depressive symptoms in older Australian men: the Concord Health and Ageing in Men Project.

ABSTRACT

PURPOSE: The objectives of the study were to evaluate the associations between antioxidant intake, dietary patterns and depressive symptoms among older men. METHOD: 794 men participated in a detailed diet history interview at the Concord Health and Ageing in Men Project 3rd wave (considered baseline nutrition) and 781 men participated at the 4th wave (considered 3-year follow-up). Depressive symptoms were measured using the Geriatric Depression Scale (GDS ≥ 5). Dietary adequacy of antioxidant intake was assessed by comparing participants' median intake of vitamin A, E, C and zinc to the Nutrient Reference Values for Australia. Attainment of NRVs of antioxidant was categorised into a dichotomised variable 'poor' (meeting ≤ 2) or 'good' (meeting ≥ 3). Individual antioxidant nutrient was categorised into quartiles. The Australian and Mediterranean diet scores were assessed as predictor variables. RESULTS: The prevalence of GDS ≥ 5 was 12.8% at baseline nutrition and 13.2% of men developed GDS ≥ 5 at a 3-year follow-up. There was a significant cross-sectional association between poor antioxidant intake and GDS ≥ 5 in adjusted analyses [OR 1.95 (95% CI 1.03, 3.70)]. Poor antioxidant intake at baseline nutrition remained prospectively associated with incident GDS ≥ 5 [OR 2.46 (95% CI 1.24, 4.88)] in adjusted analyses. This association was also found for the lowest quartile of zinc [OR 2.72 (95% CI 1.37, 5.42)] and vitamin E intake [OR 2.18 (95% CI 1.05, 4.51)]. None of the other antioxidants and dietary patterns had a significant association with incident depressive symptoms. CONCLUSION: Inadequacy of antioxidant intake, particularly zinc and vitamin E, is associated with increased risk of clinically significant depressive symptoms in older men.