Association of Diet and Waist-to-Hip Ratio With Brain Connectivity and Memory in Aging.
Jensen DEA., Ebmeier KP., Akbaraly T., Jansen MG., Singh-Manoux A., Kivimäki M., Zsoldos E., Klein-Flügge MC., Suri S.
IMPORTANCE: Epidemiological studies suggest that lifestyle factors are associated with risk of dementia. However, few studies have examined the association of diet and waist to hip ratio (WHR) with hippocampus connectivity and cognitive health. OBJECTIVE: To ascertain how longitudinal changes in diet quality and WHR during midlife are associated with hippocampal connectivity and cognitive function in later life. DESIGN, SETTING, AND PARTICIPANTS: This cohort study analyzed data from participants in the Whitehall II Study at University College London (study inception: 1985) and Whitehall II Imaging Substudy at the University of Oxford (data collection: 2012-2016). Healthy participants from the Whitehall II Imaging Study with a mean age of 48 years at baseline to 70 years at magnetic resonance imaging (MRI) were included if they had information on diet from at least 1 wave, information on WHR from at least 2 waves, and good-quality MRI scans. Study analyses were completed from October 2019 to November 2024. EXPOSURES: Diet quality was measured in participants(mean age, 48 years at baseline to 60 years) using the Alternative Healthy Eating Index-2010 score, which was assessed 3 times across 11 years. WHR was measured 5 times over 21 years in participants aged 48 to 68 years. MAIN OUTCOMES AND MEASURES: White matter structural connectivity assessed using diffusion tensor imaging, hippocampal functional connectivity assessed using resting-state functional MRI, and cognitive performance measures. Brain imaging and cognitive tests were performed at a mean (SD) age of 70 (5) years. RESULTS: The final diet quality sample comprised 512 participants (403 males [78.7%]; mean [SD] age, 47.8 [5.2] years), and the final WHR sample included 664 participants (532 males [80.1%]; mean [SD] age, 47.7 [5.1] years). Better diet quality in midlife and from midlife to late life was associated with higher hippocampal functional connectivity to the occipital lobe and cerebellum (left hippocampus: 9176 mm3, P