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

Abstract

The objectives of the study were to evaluate the associations between antioxidant intake, dietary patterns and depressive symptoms among older men. 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. 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. Inadequacy of antioxidant intake, particularly zinc and vitamin E, is associated with increased risk of clinically significant depressive symptoms in older men.