Effects of six days a week low protein dietary intervention on depressive symptoms in elderly diabetic subjects

Objectives. Late-life depression is one of the main health issues among elderly diabetic subjects. In addition, depression is common among renal failure patients and most of these follow a low protein diet regimen (LPD). However, the effects of LPD on depressive symptoms are unclear. Methods. In the present study, the effects of LPD regimen on depressive symptoms in 40 elderly type 2 diabetic subjects with renal failure were investigated. All participants with a normal protein diet regimen providing 1.2 g/kg per d were instructed to consume either a LPD providing 0.8 g/kg per d, 7 d a wk (LPD 7/7), or a LPD providing 0.8 g/kg per 6 d a wk (LPD 6/7) randomly. Results. Mean scores of 15-item Geriatric Depression Scale (GDS-15) (1.9 ± 0.5) and of Beck Depression Inventory (BDI) (3.8±0.9), during normal protein diet regimen, significantly increased to 6.4 ± 1.5 and 11.6 ± 1.3, respectively, after LPD 7/7 (P < 0.05 versus normal protein diet). However, after LPD 6/7, mean GDS-15 and BDI significantly decreased to 3.6 ± 0.6 and 6.4 ± 1.6, respectively (p < 0.05 vs. LPD 7/7). Conclusions. LPD 6/7 regimen significantly decreased depressive symptoms in young-old type 2 diabetic patients.