Alteration of brain function and systemic inflammatory tone in older adults by decreasing the dietary palmitic acid intake
Julie A. Dumas,
Janice Y. Bunn,
Michael A. LaMantia,
Catherine McIsaac,
Anna Senft Miller,
Olivia Nop,
Abigail Testo,
Bruno P. Soares,
Madeleine M. Mank,
Matthew E. Poynter,
C. Lawrence Kien
Affiliations
Julie A. Dumas
Department of Psychiatry, Larner College of Medicine, The University of Vermont, Burlington, VT, USA; Corresponding authors at: Department of Psychiatry, 1 South Prospect St, Burlington, VT 05401, USA (Julie A. Dumas). Department of Pediatrics, Larner College of Medicine, The University of Vermont, Burlington, VT, USA (C. Lawrence Kien).
Janice Y. Bunn
Department of Medical Biostatistics, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
Michael A. LaMantia
Department of Medicine, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
Catherine McIsaac
Clinical Research Center, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
Anna Senft Miller
Department of Psychiatry, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
Olivia Nop
Department of Psychiatry, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
Abigail Testo
Department of Psychiatry, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
Bruno P. Soares
Department of Radiology, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
Madeleine M. Mank
Department of Medicine, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
Matthew E. Poynter
Department of Medicine, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
C. Lawrence Kien
Department of Medicine, Larner College of Medicine, The University of Vermont, Burlington, VT, USA; Department of Pediatrics, Larner College of Medicine, The University of Vermont, Burlington, VT, USA; Corresponding authors at: Department of Psychiatry, 1 South Prospect St, Burlington, VT 05401, USA (Julie A. Dumas). Department of Pediatrics, Larner College of Medicine, The University of Vermont, Burlington, VT, USA (C. Lawrence Kien).
Prior studies in younger adults showed that reducing the normally high intake of the saturated fatty acid, palmitic acid (PA), in the North American diet by replacing it with the monounsaturated fatty acid, oleic acid (OA), decreased blood concentrations and secretion by peripheral blood mononuclear cells (PBMCs) of interleukin (IL)-1β and IL-6 and changed brain activation in regions of the working memory network. We examined the effects of these fatty acid manipulations in the diet of older adults. Ten subjects, aged 65–75 years, participated in a randomized, cross-over trial comparing 1-week high PA versus low PA/high OA diets. We evaluated functional magnetic resonance imaging (fMRI) using an N-back test of working memory and a resting state scan, cytokine secretion by lipopolysaccharide (LPS)-stimulated PBMCs, and plasma cytokine concentrations. During the low PA compared to the high PA diet, we observed increased activation for the 2-back minus 0-back conditions in the right dorsolateral prefrontal cortex (Broadman Area (BA) 9; p < 0.005), but the effect of diet on working memory performance was not significant (p = 0.09). We observed increased connectivity between anterior regions of the salience network during the low PA/high OA diet (p < 0.001). The concentrations of IL-1β (p = 0.026), IL-8 (p = 0.013), and IL-6 (p = 0.009) in conditioned media from LPS-stimulated PBMCs were lower during the low PA/high OA diet. This study suggests that lowering the dietary intake of PA down-regulated pro-inflammatory cytokine secretion and altered working memory, task-based activation and resting state functional connectivity in older adults.
