Increased Carbohydrate Intake is Associated with Poorer Performance in Verbal Memory and Attention in an APOE Genotype-Dependent Manner

Article type: Research Article

Authors: Gardener, Samantha L.^{a; b} | Rainey-Smith, Stephanie R.^{a; b} | Sohrabi, Hamid R.^{a; b; c} | Weinborn, Michael^{a; b; d} | Verdile, Giuseppe^{a; b; e} | Fernando, W.M.A.D. Binosha^{a; b} | Lim, Yen Ying^f | Harrington, Karra^{f; g} | Burnham, Samantha^h | Taddei, Kevin^{a; b} | Masters, Colin L.^f | Macaulay, Stuart L.ⁱ | Rowe, Christopher C.^j | Ames, David^{k; l} | Maruff, Paul^m | Martins, Ralph N.^{a; b; c; *} | for the AIBL Research Groupⁿ

Affiliations: [a] Centre of Excellence for Alzheimer’s disease Research & Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia | [b] Sir James McCusker Alzheimer’s Disease Research Unit (Hollywood Private Hospital), Perth, WA, Australia | [c] Department of Biomedical Sciences, Macquarie University, NSW, Australia | [d] School of Psychology, University of Western Australia, Crawley, WA, Australia | [e] School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University of Technology, Bentley, WA, Australia | [f] The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia | [g] Cooperative Research Centre (CRC) for Mental Health, Carlton South, VIC, Australia | [h] CSIRO Computational Informatics, Preventative Health Flagship, Floreat, WA, Australia | [i] CSIRO Preventative Health Flagship, CMSE Parkville, VIC, Australia | [j] Department of Molecular Imaging and Therapy, Centre for PET, Austin Health, Heidelberg, VIC, Australia | [k] National Ageing Research Institute, Royal Melbourne Hospital, Melbourne, Australia | [l] Academic Unit for Psychiatry of Old Age, University of Melbourne, Melbourne, Australia. | [m] CogState, Ltd., Melbourne, VIC, Australia | [n] http://www.aibl.csiro.au (For the AIBL Research Group)

Correspondence: [*] Correspondence to: Professor Ralph N. Martins, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia. Tel.: +61 8 9347 4200; Fax: +61 8 9347 4299; E-mail: [email protected].

Abstract: Evidence suggests that a diet low in carbohydrates can impact on cognitive performance among those with Alzheimer’s disease (AD). However, there is a lack of data assessing this relationship among cognitively normal (CN) older adults at increased future risk of developing AD due to carriage of the apolipoprotein E (APOE) ɛ4 allele. We assessed the cross-sectional association between carbohydrate intake, cognitive performance, and cerebral amyloid-β (Aβ) load in CN older adults, genotyped for APOE ɛ4 allele carrier status. Greater carbohydrate intake was associated with poorer performance in verbal memory in APOE ɛ4 allele non-carriers, and poorer performance in attention in APOE ɛ4 allele carriers. There were no associations between carbohydrate intake and cerebral Aβ load. These results provide support to the idea that decreasing carbohydrate intake may offer neurocognitive benefits, with specific cognitive domains affected in an APOE genotype-dependent manner. These findings warrant further investigation utilizing a longitudinal study design.

Keywords: Amyloid load, apolipoprotein E, attention, carbohydrates, cognition, PiB PET, verbal memory

DOI: 10.3233/JAD-161158

Journal: Journal of Alzheimer's Disease, vol. 58, no. 1, pp. 193-201, 2017