The association of dietary patterns with cognition through the lens of neuroimaging—a systematic review

Despite the reported benefits of diet on cognition in older adults, randomized controlled trials (RCT) testing the impact of dietary interventions on cognitive scores have yielded less promising results when cognition was assessed via neuropsychological tests. More recently, neuroimaging has been used to identify more subtle brain-related changes associated to cognition. Hence, employing a combination of neuroimaging techniques with neuropsychological tests could clarify this controversy. To determine the effect of diet on cognitive performance, we conducted a systematic review of PubMed and Scopus databases for all studies, on middle-aged and older adults, combining neuroimaging, neuropsychological tests, and data on dietary patterns. The inclusion criteria were met by 14 observational studies and no RCTs. The range of brain measures assessed varied from volumes to white matter integrity, functional connectivity, brain glucose metabolism and beta-amyloid deposition. Given the variability of methods used in assessing cognitive performance, diet and brain correlates, conducting a meta-analysis was not possible. Here the evidence suggests that, in observational studies, dietary patterns may be associated with brain correlates that have been shown to precede cognitive decline. As such, neuroimaging should be included in future RCTs to identify any benefits of diet on brain measures linked with cognitive health

Knowledge of Nutrition and Physical Activity Guidelines is Not Associated with Physical Function in Dutch Older Adults Attending a Healthy Ageing Public Engagement Event

Keenan A Ramsey,1 Suey SY Yeung,1 Anna GM Rojer,1 Noémie Gensous,2 Evans A Asamane,3 Justin Avery Aunger,3 Dmitriy Bondarev,4 Andrea Cabbia,5 Paul Doody,3 Barbara Iadarola,6,7 Belina Rodrigues,8,9 Muhammad R Tahir,10 Victor Kallen,10 Paola Pazienza,6,7 Nadine Correia Santos,8,9 Sarianna Sipilä,4 Janice L Thompson,3 Carel GM Meskers,1,11 Marijke C Trappenburg,12,13 Anna C Whittaker,15 Andrea B Maier1,14,16,17 1Department of Human Movement Sciences, @AgeAmsterdam, Amsterdam Movement Sciences, Vrije Universiteit, Faculty of Behavioural and Human Movement Sciences, Amsterdam, the Netherlands; 2Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy; 3School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, UK; 4Gerontology Research Center & Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland; 5Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; 6Personal Genomics s.r.l., Verona, Italy; 7Department of Biotechnology, University of Verona, Verona, Italy; 8Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; 9ICVS/3B’s, PT Government Associate Laboratory, Guimarães, Portugal; 10Department of Microbiology and System Biology, The Netherlands Organization for Applied Scientific Research, Zeist, the Netherlands; 11Department of Rehabilitation Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; 12Department of Internal Medicine, Section of Gerontology and Geriatrics, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; 13Department of Internal Medicine, Amstelland Hospital, Amstelveen, the Netherlands; 14Department of Medicine and Aged Care, @Age, The University of Melbourne, The Royal Melbourne Hospital, Parkville, Victoria, Australia; 15Faculty of Health Sciences and Sport, University of Stirling, Scotland, UK; 16Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 17Centre for Healthy Longevity, @AgeSingapore, National University Health System, SingaporeCorrespondence: Andrea B Maier, Department of Human Movement Sciences, @AgeAmsterdam, Amsterdam Movement Sciences, Vrije Universiteit, Faculty of Behavioural and Human Movement Sciences, Van der Boechorststraat 7, Amsterdam, 1081 BT, the Netherlands, Tel +31 20 59 82000, Email [email protected]: Evidence-based guidelines on nutrition and physical activity are used to increase knowledge in order to promote a healthy lifestyle. However, actual knowledge of guidelines is limited and whether it is associated with health outcomes is unclear.Participants and Methods: This inception cohort study aimed to investigate the association of knowledge of nutrition and physical activity guidelines with objective measures of physical function and physical activity in community-dwelling older adults attending a public engagement event in Amsterdam, The Netherlands. Knowledge of nutrition and physical activity according to Dutch guidelines was assessed using customized questionnaires. Gait speed and handgrip strength were proxies of physical function and the Minnesota Leisure Time Physical Activity Questionnaire was used to assess physical activity in minutes/week. Linear regression analysis, stratified by gender and adjusted for age, was used to study the association between continuous and categorical knowledge scores with outcomes.Results: In 106 older adults (mean age=70.1 SD=6.6, years) who were highly educated, well-functioning, and generally healthy, there were distinct knowledge gaps in nutrition and physical activity which did not correlate with one another (R2=0.013, p=0.245). Knowledge of nutrition or physical activity guidelines was not associated with physical function or physical activity. However, before age-adjustment nutrition knowledge was positively associated with HGS in males (B= 0.64 (95% CI: 0.05, 1.22)) and having knowledge above the median was associated with faster gait speed in females (B=0.10 (95% CI: 0.01, 0.19)).Conclusion: Our findings may represent a ceiling effect of the impact knowledge has on physical function and activity in the this high performing and educated population and that there may be other determinants of behavior leading to health status such as attitude and perception to consider in future studies.Keywords: health knowledge, attitudes, practice, lifestyle, physical performance, age