Acute cerebral blood flow response to heavy cream ingestion in older adults: A non-randomized pilot study.

BackgroundHypertension and the APOE4 allele are known risk factors for Alzheimer's disease (AD) and E4 carriers show different blood pressure (BP) and cognitive responses to high fat feeding.ObjectiveWe investigated the influence of these factors on global cerebral blood flow (CBF) and four regions of interest (ROIs) (angular gyrus, hippocampus, posterior cingulate, temporal lobe) using arterial spin labeling (ASL) MRI in fasting state and after ingestion of heavy cream in older adults.Methods29 adults (age in years 66.8 ± 4.1) underwent baseline and 1, 2, 3-h ASL MRI after ingestion of 100 mL heavy cream. We used pCASL MRI with background suppression to measure CBF in ml/100 g/min. Statistical analyses included mixed-effects modeling and Pearson correlation to ascertain whether CBF changed over time and how variables influenced results.ResultsGlobal CBF decreased at 1-, 2-, and 3-h post-heavy cream, compared to time 0 (overall change 7.11%, p < 0.01); recapitulated in 3 of 4 ROIs. Mean arterial pressure emerged as a predictive variable for both baseline and post-heavy cream CBF (β = -0.25, 95% CI = -0.39, -0.10, p = 0.002). Individuals with higher BP demonstrated reduced CBF, particularly in posterior cingulate and temporal lobe (β = -5.50, 95% CI = -9.9, -1.09; β = -6.28, 95% CI = -12.35, -0.21, respectively, both p < 0.05). Examination of correlations with BP and change scores revealed that this relationship was driven largely by E4 carriers.ConclusionsCBF decreased after ingestion of heavy cream, globally and in regions known to be important in AD, and this finding was driven by E4 carriers with higher BP.