PhD Oral Defense of Laura Gougeon, School of Dietetics and Human Nutrition
Depression is associated with decreased quality of life and high mortality risk at all ages. Late-life depression is defined as first onset after 65 years of age and, despite having lower prevalence in community–dwelling seniors compared to other stages of the life span, it negatively affects health outcomes. Most evidence linking dietary factors with depression in old age comes from cross-sectional studies, which cannot provide information on the direction of the association. The Québec Longitudinal Study on Nutrition and Aging (NuAge) provides an ideal setting to explore such a relationship among a healthy, community-dwelling elderly population. The three objectives of this thesis were to explore the longitudinal associations of i) dietary patterns and macronutrient intake and of ii) B6, B12 and folate intakes with the incidence of depression in late life; and iii) to investigate whether depression significantly affects short-term nutrient intakes (reverse causality effect) in comparison to intakes among non-depressed seniors.