Carotenoids and lipid peroxidation in human brains with and without Alzheimer's disease

Abstract

BackgroundOxidative stress may be involved in the development and progression of Alzheimer's disease (AD). Carotenoids are lipophilic antioxidants found in human brain, and may protect against lipid peroxidation.ObjectiveTo determine carotenoid concentrations and the magnitude of lipid peroxidation in brain tissue of decedents with and without AD.MethodsCarotenoids in brain tissue were analyzed by HPLC. Lipid peroxidation was assessed by determining malondialdehyde (MDA) using a HPLC method. Data were expressed by wet weight. Carotenoid and MDA concentrations were log transformed to obtain normal distributions, and concentrations were compared between age‐ and sex‐matched AD (n=15) and non‐demented (n=15) groups using a Student's t‐test. Pearson's correlations were used to assess the relationship between MDA and carotenoid levels.ResultsLutein, zeaxanthin, and lycopene concentrations were not different between groups. Cryptoxanthin and beta‐carotene concentrations were higher in the AD brains (p <0.01). There was no significant difference in MDA between groups or correlation with carotenoid concentrations within either group.ConclusionsElevated concentrations of cryptoxanthin and beta‐carotene in AD brains suggest that carotenoids may play a role in this disease. This pilot study was limited by the sample size, but demonstrates the feasibility of exploring these relationships in a larger study.Support: USDA#51000‐073‐02S; DSM Nutritionals