The 'Western diet' which is characterized by high saturated fat and high glycemic index foods (high diet) is a risk factor for Alzheimer's disease (AD). However, we have found paradoxically that experimental feeding with a Western style high diet acutely improves cognition in APOE E4 carriers, who are at increased risk for AD. The purpose of this project is to examine mechanisms that underlie this response. Based on known intrinsic differences in brain chemistry in E4 carriers, we hypothesize that in this group, a high meal will result in increased brain transport of lipids and insulin, increased ApoE lipidation, increased brain amyloid clearance, and ultimately improved cognition. We will test these hypotheses by conducting a controlled meal challenge in a crossover design in older adults with both a high meal, as well as a meal low in saturated fat and glycemic index foods (low). After the meal, participants will undergo cognitive testing and collection of blood and spinal fluid for analysis of lipids, insulin, and known AD biomarkers. This work will contribute to our broader understanding about the risks of diet and AD, and how APOE genotype moderates that risk. In addition to advancing our understanding about AD pathogenesis, this career development award will give me the necessary tools to become an independent clinical investigator in the field of metabolism and Alzheimer's disease.

Public Health Relevance

A 'Western diet' which is characterized by high saturated fat and simple sugars is a risk factor for Alzheimer's disease (AD). However, such a diet acutely improves cognition in individuals who carry the AD risk gene APOE E4. The goal of this proposal is to understand the mechanisms that underlie this paradox, which will inform about AD pathogenesis and optimal diet recommendations for patients with AD.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Mentored Patient-Oriented Research Career Development Award (K23)
Project #
1K23AG047978-01A1
Application #
8966525
Study Section
National Institute on Aging Initial Review Group (NIA)
Program Officer
Anderson, Dallas
Project Start
2015-09-01
Project End
2020-05-31
Budget Start
2015-09-01
Budget End
2016-05-31
Support Year
1
Fiscal Year
2015
Total Cost
$153,387
Indirect Cost
$11,362
Name
University of Washington
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Rhea, Elizabeth M; Salameh, Therese S; Logsdon, Aric F et al. (2017) Blood-Brain Barriers in Obesity. AAPS J 19:921-930
Salameh, Therese S; Rhea, Elizabeth M; Banks, William A et al. (2016) Insulin resistance, dyslipidemia, and apolipoprotein E interactions as mechanisms in cognitive impairment and Alzheimer's disease. Exp Biol Med (Maywood) 241:1676-83