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RESEARCH · July 01, 2014
TAKE-HOME MESSAGE
- Cognitively normal individuals (n = 49) participating in an ongoing brain imaging study completed semiquantitative food frequency questionnaires to evaluate the relationship between dietary nutrients and brain biomarkers of Alzheimer’s disease (AD). Vitamin B12, vitamin D, omega-3 polyunsaturated fatty acid, β-carotene, and folate intake were associated with changes in brain biomarkers of AD.
- Results indicated that dietary interventions may have a role in the prevention of AD, although longitudinal studies are needed.
Expert Comment
David Rakel MD, FAAFP
ABSTRACT
OBJECTIVE
There is increasing evidence to suggest that diet, one of the most important modifiable environmental factors, may play a role in preventing or delaying cognitive decline and Alzheimer’s disease (AD). This study examines the relationship between dietary nutrients and brain biomarkers of AD in cognitively normal individuals (NL) with and without AD risk factors.
DESIGN
As part of an ongoing brain imaging study, participants received clinical and laboratory examinations, a neurocognitive test battery, positron emission tomography (PET) with (11)C-Pittsburgh Compound-B (PiB; a measure of amyloid-β (Aβ) load) and (18)F-fluorodeoxyglucose (FDG; a proxy of neuronal activity), and completed semiquantitative food frequency questionnaires.
SETTING
Research centre affiliated with the Alzheimer’s disease Core Center at New York University School of Medicine.
PARTICIPANTS
49 NL individuals (age 25-72 years, 69% women) with dietary information, (11)C-PiB and (18)F-FDG PET scans were examined.
RESULTS
Controlling for age and total caloric intake, higher intake of vitamin B12, vitamin D and ω-3 polyunsaturated fatty acid (PUFA) was associated with lower Aβ load in AD regions on PiB-PET, while higher intake of β-carotene and folate was associated with higher glucose metabolism on FDG-PET. β-carotene and folate were associated with reduced glucose metabolism for women, apolipoprotein E epsilon 4 (APOE4) carriers and participants with positive AD family history, but not for their risk-free counterparts. The associations of vitamin B12, vitamin D and ω-3 PUFA with PiB retention were independent of gender, APOE and family history. The identified nutrient combination was associated with higher intake of vegetables, fruit, whole grains, fish and legumes, and lower intake of high-fat dairies, meat and sweets.
CONCLUSIONS
Our data provide a potential pathophysiological 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 between nutrient intake, brain biomarkers and risk of AD.
BMJ Open
Nutrient Intake and Brain Biomarkers of Alzheimer’s Disease in At-Risk Cognitively Normal Individuals: A Cross-Sectional Neuroimaging Pilot Study
BMJ Open 2014 Jul 01;[EPub Ahead of Print], L Mosconi, J Murray, M Davies, S Williams, E Pirraglia, N Spector, WH Tsui, Y Li, T Butler, RS Osorio, L Glodzik, S Vallabhajosula, P McHugh, CR Marmar, MJ de Leon
PET scans of the brain can detect the amount of glucose metabolism and beta-amyloid load. AD has been associated with low glucose metabolism and a high amount of beta-amyloid deposits. The PET scans confirmed that individuals who ate more foods commonly found in the Mediterranean diet had more glucose metabolism and less beta-amyloid load.
In this study, 41% of the participants were taking nutritional supplements, but the analysis only found a positive correlation with obtaining the nutrients through food intake.
Nutrients associated with the most glucose metabolism and the least beta-amyloid deposits included folate, β-carotene, omega-3 fatty acids, vitamin B12, and vitamin D. These nutrients were obtained through the intake of dark-green leafy and cruciferous vegetables, fruit, legumes, grains, fish, and eggs.
People who may benefit most from these nutritional influences include women, those who have a family history of AD, and those who are positive for the APOE-4 genotype. Eating foods rich in folate and B12 will also lower homocysteine, which data suggest may be associated with a higher AD risk.1
It is somewhat ironic to use these highly advanced diagnostic machines to show how powerful simple whole food can be.
Reference