Differences in carotenoid content of normal elderly and Alzheimerˈs brains

Abstract

Alzheimerˈs Disease (AD) is a severe neurodegenerative disease that inflicts >4,500,000 US elderly. Antioxidants, such as carotenoids, have been implicated in the prevention of degenerative diseases and recent data correlates blood and macular carotenoid levels with cognition.PurposeTo measure and compare the major carotenoids in normal elderly and AD human brain.MethodsSamples of normal and AD brain tissue from frontal lobe cortex and occipital cortex were examined. Sections were dissected into gray and white matter, extracted with organic solvents, and analyzed by HPLC.ResultsAt least 16 carotenoids, 3 tocopherols, and retinol were present in human brain. Xanthophylls accounted for >70% of carotenoids in the brain. Mean concentrations of carotenoids ranged from 3.5–15.3 pmol/g. Combining all brains, lutein (LUT, P<0.001) and zeaxanthin (ZX, P<0.02) were higher in gray vs white matter. ZX and LUT were lower in AD brain (P<0.002, P<0.04, respectively). Healthy brain had 2× more ZX and 30% more LUT than AD brain. Retinol and α‐tocopherol were lower in AD brain, (p<0.002, P<0.006).ConclusionsAD status is negatively correlated with levels of ZX, LUT, vitamins A and E in specific brain tissue.