Differential Effects of Meal Challenges on Cognition, Metabolism, and Biomarkers for Apolipoprotein E ɛ4 Carriers and Adults with Mild Cognitive Impairment

Article type: Research Article

Authors: Hanson, Angela J.^a | Bayer, Jennifer L.^b | Baker, Laura D.^c | Cholerton, Brenna^a | VanFossen, Brian^d | Trittschuh, Emily^d | Rissman, Robert A.^e | Donohue, Michael C.^e | Moghadam, Setareh H.^e | Plymate, Stephen R. | Craft, Suzanne^{c; *}

Affiliations: [a] Department of Medicine, University of Washington Medical Center, Seattle, WA, USA | [b] University of Iowa, Iowa City, IA, USA | [c] Sticht Center on Aging, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA | [d] VA Puget Sound Healthcare System, Seattle, WA, USA | [e] Alzheimer’s Disease Cooperative Study, Department of Neurosciences, University of California San Diego, La Jolla, CA, USA

Correspondence: [*] Correspondence to: Suzanne Craft, PhD, Sticht Center on Aging, Department of Internal Medicine, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157-1207, USA. Tel.: +1 336 713 8832; Fax: +1 336 713 8800; [email protected]

Abstract: Background: High intake of saturated fat (SF) and glycemic index (GI) foods is a risk factor for sporadic Alzheimer’s disease. Meal challenges may elucidate mechanisms that contribute to this risk, enabling development of targeted interventions. Objective: To assess cognitive and metabolic changes after a meal high in SF and GI calories (HIGH) versus a meal low in these macronutrients (LOW) in older adults with and without cognitive impairment, and with and without the apolipoprotein E4 risk factor. Methods: 46 adults with either cognitive impairment (CI) or normal cognition (NC) ingested a LOW (25% total fat, 7% SF, GI <55) and a HIGH meal (50% total fat, 25% SF, GI >70) in a blinded random fashion. Participants then underwent cognitive testing and blood sampling for metabolic and Alzheimer’s disease biomarkers. Data were analyzed using repeated measures ANOVA and Spearman correlations. Results: E4–adults with NC demonstrated lower delayed memory scores after the HIGH compared to the LOW meal, whereas normal E4+ and CI E4– groups had higher scores after the HIGH meal (ANOVA p = 0.03). These findings were associated with meal-induced changes in glucose (p = 0.05), insulin (p = 0.004), triglycerides (p <  0.01), and plasma Aβ42 (p = 0.05). Conclusions: These preliminary data suggest that cognitive performance of adults without CI may worsen following high SF and sugar meals, whereas adults with CI or those at risk for CI due to E4 status may benefit acutely from such meals. Furthermore, plasma Aβ was affected by meal type, suggesting a relationship between metabolic response and amyloid regulation.

Keywords: Alzheimer’s disease, APOE genotype, glycemic index, insulin, plasma amyloid, saturated fat, triglycerides

DOI: 10.3233/JAD-150273

Journal: Journal of Alzheimer's Disease, vol. 48, no. 1, pp. 205-218, 2015