title: Effects of folic acid supplementation on psychomotor performance and hemorheology in healthy elderly subjects.
abstract: Cognitive impairment is associated with increased blood concentrations of homocysteine and high blood viscosity. Previous studies have shown that vitamin B supplementation reduces homocysteine and enhances cognitive function in patients with mild dementia and low serum folic acid. However, whether folic acid enhances cognitive function in elderly subjects without dementia and normal serum folic acid is unknown. Twenty-four healthy elderly subjects (age 73.0+/-5.6 years, mean+/-S.D.) with normal serum folic acid (6.3+/-2.4 microg/l) and Mini Mental State Examination (MMSE) >27/30 were randomized to 4-week treatment with folic acid 5mg/day or placebo in a randomized, placebo-controlled, parallel-group study. Continuous Attention Test (CAT), Four-Choice Reaction Time (FCRT), Digit-Symbol Substitution (DSS), Scanning Memory Sets (SMS), and blood viscosity for different shear rates were measured before and after treatment. Folic acid supplementation induced a significant increase in serum folic acid levels (+13.8 versus +1.6 microg/l, p<0.001) and fall in homocysteine levels (-1.91 versus -0.41 micromol/l, p=0.05) compared to placebo. However, there was no significant change in CAT, FCRT, DSS, SMS, and blood viscosity between the two groups. Short-term folic acid supplementation does not enhance psychomotor performance or reduce blood viscosity in healthy elderly subjects with normal serum folic acid levels and preserved cognitive function.
authors.affiliation: Department of Health Care of the Elderly, Guy's, King's and St Thomas' School of Medicine, King's College London, London SE5 9PJ, UK.
authors.forename: Rohan
authors.initials: R
authors.lastname: Pathansali
authors.forename: Arduino A
authors.initials: AA
authors.lastname: Mangoni
authors.forename: Ben
authors.initials: B
authors.lastname: Creagh-Brown
authors.forename: Zhi-Cheng
authors.initials: ZC
authors.lastname: Lan
authors.forename: Gwo-Liang
authors.initials: GL
authors.lastname: Ngow
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Yuan
authors.forename: Emma L
authors.initials: EL
authors.lastname: Ouldred
authors.forename: Roy A
authors.initials: RA
authors.lastname: Sherwood
authors.forename: Cameron G
authors.initials: CG
authors.lastname: Swift
authors.forename: Stephen H D
authors.initials: SH
authors.lastname: Jackson
mesh_terms: D000368:Aged; D001809:Blood Viscosity; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000494:pharmacology*; D006397:Hematinics / Q000494:pharmacology*; D018056:Hemorheology / Q000187:drug effects*; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000187:drug effects*
chemical_list: D006397:Hematinics; D005492:Folic Acid