Association between the consumption of omega-3-rich fish and depressive symptoms in older adults living in a middle-income country: EpiFloripa Aging cohort study

Abstract

This study aimed to verify the association between the consumption of omega-3-rich (n-3) fish and depressive symptoms in older adults living in Southern Brazil. This is a cross-sectional analysis with data from the second wave of the EpiFloripa Aging cohort study (2013/2014) including 1,130 individuals aged 60 years or older. The presence of depressive symptoms was measured by the 15-items Geriatric Depression Scale (GDS-15), and the consumption of n-3-rich fish by a question of weekly frequency. The minimum set of variables for adjustment was defined using directed acyclic graph (DAG). Poisson regression with robust error variance was applied (adjusted by Model 1: demographic and socioeconomic variables, Model 2: added behavioral variables, Model 3: added health variables). We identified the prevalence of depressive symptoms in 19% of older adults and 51.8% reported eating n-3-rich fish once a week. Models 1 and 3 showed an inverse association between n-3-rich fish and depressive symptoms. However, the association was reduced when behavioral factors (leisure-time physical activity) were included in Model 2. These findings suggest that n-3-rich fish intake tends to be associated with depressive symptoms in older adults. However, other factors, such as physical exercise, are as pivotal as n-3 fatty acids in preventing the development of depressive symptoms.