title: Critical levels of brain atrophy associated with homocysteine and cognitive decline.
abstract: Few B-vitamin trials to lower homocysteine (Hcy) have reported evidence of beneficial effects on cognition in older adults with cognitive impairment or Alzheimer's disease. This article reviews the role of Hcy in cognitive decline. It also considers some reasons why meta-analyses have failed to find effects of B-vitamin treatment. Findings from the successful VITACOG trial are examined from a new perspective of critical levels of Hcy and brain atrophy that may impact on the efficacy of B-vitamin treatment. It appears that there is a critical level of brain shrinkage, possibly mediated by elevated Hcy, which when reached, results in cognitive decline, especially in episodic memory performance. Supplements, food sources, and effects of folic acid fortification are discussed in relation to B12 deficiency.
authors.affiliation: Oxford Project to Investigate Memory and Ageing, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK. Electronic address: celeste.dejager@uct.ac.za.
authors.forename: Celeste A
authors.initials: CA
authors.lastname: de Jager
mesh_terms: D001284:Atrophy; D001921:Brain / Q000473:pathology*; D003072:Cognition Disorders / Q000188:drug therapy / Q000209:etiology* / Q000378:metabolism / Q000473:pathology*; D005492:Folic Acid / Q000627:therapeutic use; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D014806:Vitamin B 12 Deficiency / Q000150:complications; D014803:Vitamin B Complex / Q000627:therapeutic use
chemical_list: D006710:Homocysteine; D014803:Vitamin B Complex; D005492:Folic Acid
keywords: Alzheimer's disease; Atrophy; B vitamins; B12 deficiency; Cognition; Folic acid; Homocysteine; Mild cognitive impairment