Nutrient intake and brain biomarkers of Alzheimer's disease in at-risk cognitively normal individuals: A cross-sectional neuroimaging pilot study

Abstract

Objective: There is increasing evidence to suggestthat diet, one of the most important modifiableenvironmental factors, may play a role in preventing ordelaying cognitive decline and Alzheimer's disease(AD). This study examines the relationship betweendietary nutrients and brain biomarkers of AD incognitively normal individuals (NL) with and withoutAD risk factors.Design: As part of an ongoing brain imaging study,participants received clinical and laboratoryexaminations, a neurocognitive test battery, positronemission tomography (PET) with 11C-PittsburghCompound-B (PiB; a measure of amyloid-? (A?) load)and 18F-fluorodeoxyglucose (FDG; a proxy of neuronalactivity), and completed semiquantitative foodfrequency questionnaires.Setting: Research centre affiliated with the Alzheimer'sdisease Core Center at New York University School ofMedicine.Participants: 49 NL individuals (age 25-72 years,69% women) with dietary information, 11C-PiB and18F-FDG PET scans were examined.Results: Controlling for age and total caloric intake,higher intake of vitamin B12, vitamin D and ?-3polyunsaturated fatty acid (PUFA) was associated withlower A? load in AD regions on PiB-PET, while higherintake of ?-carotene and folate was associated withhigher glucose metabolism on FDG-PET. ?-caroteneand folate were associated with reduced glucosemetabolism for women, apolipoprotein E epsilon 4(APOE4) carriers and participants with positive ADfamily history, but not for their risk-free counterparts.The associations of vitamin B12, vitamin D and ?-3PUFA with PiB retention were independent of gender,APOE and family history. The identified nutrientcombination was associated with higher intake ofvegetables, fruit, whole grains, fish and legumes, andlower intake of high-fat dairies, meat and sweets.Conclusions: Our data provide a potentialpathophysiological mechanism for epidemiological. findings showing that dietary interventions may play a role in the prevention of AD. Longitudinal studies are needed to determine whether there is a direct link betw n nutrient intake, brain biomarkers and risk of AD.