Antioxidants in Alzheimer's disease-vitamin C delivery to a demanding brain.
Levels of several antioxidants and related markers were measured in cerebrospinal fluid (CSF) and plasma of 10 Alzheimer's disease (AD) patients and 10 controls. Daily dosage of vitamin C was significantly correlated with both plasma (R=0.662; p=0.0015) and CSF level (R=0.639, p=0.0024). Plasma and CSF vitamin C levels were also highly correlated R=0.793, p<0.0001). Similarly, daily dosage of Vitamin E was significantly correlated with plasma vitamin E (R=0.681; p=0.0009) and showed a trend toward correlation with CSF vitamin E (R=0.422, p=0.06). There were no significant differences between groups in absolute CSF or plasma levels of any analyte. However, the CSF: plasma ratio of vitamin C was significantly greater in the AD patients compared to the controls (p=0.048). In a subset of AD patients, hippocampal volume was significantly correlated with plasma (R2=0.833; p=0.004) and CSF (R2 =0.603; p=0.04) vitamin C levels, and inversely correlated with CSF:plasma vitamin C ratio (R2 =0.717; p=0.016). We conclude that oral vitamin C supplements are delivered to the brain, and speculate that the increased CSF: plasma ratio of vitamin C in AD reflects increased antioxidant consumption by the AD brain.
Quinn
Joseph
J
Department of Neurology, the Portland Veteran's Affairs Medical Center and Oregon Health and Science University, Portland OR 97201, USA. quinnj@ohsu.edu
Suh
Jung
J
Moore
M Milar
MM
Kaye
Jeffrey
J
Frei
Balz
B
D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000188:drug therapy*; D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000378:metabolism; D001812:Blood-Brain Barrier; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged
D000975:Antioxidants; D001205:Ascorbic Acid