Bidirectional associations between food groups and depressive symptoms: longitudinal findings from the Invecchiare in Chianti (InCHIANTI) study

This study investigated bidirectional associations between intake of food groups and depressive symptoms in 1058 Italian participants (aged 20-102 years) of the Invecchiare in Chianti study. Dietary intake, assessed with a validated FFQ, and depressive symptoms, measured with the Center for Epidemiologic Studies Depression scale (CES-D), were assessed at baseline and after 3, 6 and 9 years. Associations of repeated measurements of intakes of thirteen food groups with 3-year changes in depressive symptoms, and vice versa, were analysed using linear mixed models and logistic generalised estimating equations. Fish intake was inversely (quartile (Q)4 v. Q1, B=-0 center dot 97, 95 % CI -1 center dot 74, -0 center dot 21) and sweet food intake positively (Q4 v. Q1, B=1 center dot 03, 95 % CI 0 center dot 25, 1 center dot 81) associated with subsequent CES-D score. In the other direction, higher CES-D scores were associated with decreases in intakes of vegetables (ratio: 0 center dot 995, 95 % CI 0 center dot 990, 0 center dot 999) and red and processed meat (B=-0 center dot 006, 95 % CI -0 center dot 010, -0 center dot 001), an increase in dairy product intake (ratio: 1 center dot 008, 95 % CI 1 center dot 004, 1 center dot 013), and increasing odds of eating savoury snacks (OR: 1 center dot 012, 95 % CI 1 center dot 000, 1 center dot 024). Fruit, nuts and legumes, potatoes, wholegrain bread, olive oil, sugar-sweetened beverages, and coffee and tea were not significantly associated in either direction. Our study confirmed bidirectional associations between food group intakes and depressive symptoms. Fish and sweet food intakes were associated with 3-year improvement and deterioration in depressive symptoms, respectively. Depressive symptoms were associated with 3-year changes in vegetable, meat, dairy product and savoury snack intakes. Trials are necessary to examine the causal associations between food groups and depression.