Processed meat consumption and the risk of incident late-onset depression: a 12-year follow-up of the Salus in Apulia Study.

BACKGROUND: the possible relationship between dietary habits and the incidence of late-onset depression (LOD), defined as first depression onset at later age, is unclear. OBJECTIVE: to investigate the relationship between consumption of different food groups and incident LOD. DESIGN: longitudinal population-based study with a 12-year follow-up. SETTING: Castellana Grotte, Bari, Italy. SUBJECTS: five hundred and forty-six older subjects from the Salus in Apulia Study. METHODS: baseline data were recorded in 2003-06, and diagnostic data were recorded in 2013-18 at follow-up. Dietary intake was assessed with a food frequency questionnaire. Depressive disorders were assessed with the Structured Clinical Interview for DSM-IV Axis I Disorders. Subjects who already suffered from depression or other psychiatric disorders at baseline were excluded from the analysis. The association between LOD and single dietary determinants was examined by Cox regression analysis and then applying the hazard ratio (HR). RESULTS: subjects with incident LOD (n = 34) had lower global cognition and total cholesterol levels and a higher body mass index (BMI) at baseline. Only processed meat significantly increased the risk of incident LOD of about 10% by 5 g/day intake (HR adjusted for age, sex, education, multimorbidity and BMI: 1.13, 95% confidence intervals: 1.04-1.22). A similar relationship was found for single foods in the processed meat food group such as sausages, salami and mortadella and baked ham, but not for raw ham. CONCLUSIONS: in midlife, a higher intake of processed meat was not only associated with an increased risk of cardiovascular- and metabolic-related chronic diseases in older age but also with an increased risk of developing LOD.