Association between carbohydrate nutrition and prevalence of depressive symptoms in older adults

We aimed to examine the relationship between dietary glycaemic index (GI) and glycaemic load of foods consumed, intakes of carbohydrates, sugars and fibre, and the prevalence of depressive symptoms in older adults. Data collected from 2334 participants aged 55+ years and 1952 participants aged 60+ years were analysed. Dietary information was collected using a semi-quantitative FFQ. Depressive symptoms were based on antidepressant use or either the 36-Item Short-Form Survey, which included the Mental Health Index (MHI), or the Center for Epidemiologic Studies Depression-10 Scale. Participants in the highest v. lowest tertile of dietary GI intake had increased odds of depressive symptoms (assessed by the MHI scale), multivariable-adjusted OR 1·55 (95 % CI 1·12, 2·14). Participants in the highest compared with lowest tertile of fruit consumption had reduced odds of prevalent depressive symptoms, multivariable-adjusted OR 0·66 (95 % CI 0·46, 0·95). Total fibre, vegetable fibre and breads/cereal fibre intakes were all inversely associated with the prevalence of depressive symptoms, with global P values of 0·03, 0·01 and 0·03, respectively. Participants in the second v. first tertile of vegetable consumption had 41 % reduced odds of prevalent depressive symptoms, multivariable-adjusted OR 0·59 (95 % CI 0·40, 0·88). We show that dietary GI and fibre intakes as well as consumption of fruits and vegetables are associated with the prevalence of depressive symptoms.