Associations of Dietary Protein and Fiber Intake with Brain and Blood Amyloid-β

Article type: Research Article

Authors: Fernando, W.M.A.D. Binosha^{a; 1} | Rainey-Smith, Stephanie R.^{a; b; 1} | Gardener, Samantha L.^{a; b} | Villemagne, Victor L.^{c; d} | Burnham, Samantha C.^e | Macaulay, S. Lance^e | Brown, Belinda M.^{b; f} | Gupta, Veer Bala^{a; b} | Sohrabi, Hamid R.^{a; b; g} | Weinborn, Michael^{b; h} | Taddei, Kevin^{a; b} | Laws, Simon M.^{i; j; k} | Goozee, Kathryn^{l; m} | Ames, David^{n; o} | Fowler, Christopher^d | Maruff, Paul^{d; p} | Masters, Colin L.^d | Salvado, Olivier^e | Rowe, Christopher C.^c | Martins, Ralph N.^{a; b; g; l; *} | For the AIBL Research Group^q

Affiliations: [a] Centre of Excellence for Alzheimer’s Disease Research and 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 Molecular Imaging and Therapy, Centre for PET, Austin Health, Heidelberg, VIC, Australia | [d] The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia | [e] CSIRO Health and Biosecurity/Australian e-Health Research Centre, Australia | [f] School of Psychology and Exercise Science, Murdoch University, Murdoch, WA, Australia | [g] School of Biomedical Sciences, Macquarie University, NSW, Australia | [h] School of Psychological Science, University of Western Australia, Crawley, WA, Australia | [i] Collaborative Genomics Group, Centre of Excellence for Alzheimer’s disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia | [j] Cooperative Research Centre for Mental Health, http://www.mentalhealthcrc.com | [k] School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Australia | [l] School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, WA, Australia | [m] McCusker KARVIAH Research Centre, ARV, Sydney, NSW, Australia | [n] Department of Psychiatry, Academic Unit for Psychiatry of Old Age, St. Vincent’s Health, The University of Melbourne, Kew, VIC, Australia | [o] National Ageing Research Institute, Parkville, VIC, Australia | [p] Cogstate Ltd., Melbourne, VIC, Australia | [q] 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].

Note: [1] These authors contributed equally to this work.

Abstract: Accumulating evidence suggests a diet high in protein and fiber may confer some protection against Alzheimer’s disease (AD). However, no human studies to-date have assessed the relationship between protein and fiber intake, and plasma and brain amyloid-β (Aβ). Consequently, this cross-sectional study, investigated the association of self-reported dietary intakes of protein and fiber, with plasma and brain Aβ burden (n = 541, and n = 162 respectively), in a well-characterized cohort of cognitively normal older adults, drawn from the larger Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging. We observed 12.59 and 8.43 higher odds of ‘high’ brain Aβ burden (PiB PET SUVR≥1.5) if protein intake fell in the lowest and middle tertile, respectively, compared to the highest tertile (p = 0.008; p = 0.013). Thus, in this cohort, the more protein consumed, the less likelihood of ‘high’ Aβ burden in the brain. No other significant associations were observed. The results of this study highlight the potentially protective impact of high dietary protein intake on brain Aβ burden in older adults, before objective memory decline is apparent. While longitudinal validation is required, these findings may assist in the development of dietary approaches aimed at preventing or delaying AD onset.

Keywords: Alzheimer’s disease, amyloid-β, dietary fiber, dietary protein, PiB PET

DOI: 10.3233/JAD-170742

Journal: Journal of Alzheimer's Disease, vol. 61, no. 4, pp. 1589-1598, 2018