title: Status of vitamins B-12 and B-6 but not of folate, homocysteine, and the methylenetetrahydrofolate reductase C677T polymorphism are associated with impaired cognition and depression in adults.
abstract: The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene differs in frequency in various ethnic groups that have differing prevalence of age-related cognitive impairments. We used a series of neuro-psychological tests to examine the association of the MTHFR C677T polymorphism with cognition and depression and also to assess whether genotype modifies the association of folate and homocysteine with these outcomes. This study analyzed pooled cross-sectional data from 2 ethnically diverse cohorts of community-living adults: the Boston Puerto Rican Health Study (n = 939) and the Nutrition, Aging, and Memory in Elders study (n = 1017). Individuals in both cohorts underwent anthropometric and laboratory measurements and dietary and health assessments using validated questionnaires between the years 2003 and 2007. Cognitive outcomes included measures of global cognition [Mini-Mental Status Exam (MMSE)], depression (Center for Epidemiological Studies Depression Scale), and 3 factor scores for the domains of attention, executive function, and memory that were derived from a detailed set of neuropsychological tests. Low plasma vitamin B-12 concentrations were associated with poorer MMSE scores and higher depression scores, and low vitamin B-6 concentrations were associated with lower MMSE and worse attention and executive function in the multivariate analysis. In contrast, MTHFR genotype, folate, and homocysteine were not associated with cognition or depression in either ethnicity-pooled or stratified analysis. The current study did not find evidence of an association between the MTHFR C677T TT genotype and impaired cognition or depression in a population with adequate folate status and a high prevalence of cognitive impairment and depression.
authors: Neuroscience and Aging Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA. DMoorthy@tuftsmedicalcenter.org
authors: Denish
authors: D
authors: Moorthy
authors: Inga
authors: I
authors: Peter
authors: Tammy M
authors: TM
authors: Scott
authors: Laurence D
authors: LD
authors: Parnell
authors: Chao-Qiang
authors: CQ
authors: Lai
authors: Jimmy W
authors: JW
authors: Crott
authors: José M
authors: JM
authors: Ordovás
authors: Jacob
authors: J
authors: Selhub
authors: John
authors: J
authors: Griffith
authors: Irwin H
authors: IH
authors: Rosenberg
authors: Katherine L
authors: KL
authors: Tucker
authors: Aron M
authors: AM
authors: Troen
mesh_terms: D000328:Adult; D000368:Aged; D003072:Cognition Disorders / Q000097:blood / Q000235:genetics; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood / Q000235:genetics; D005260:Female; D005492:Folic Acid / Q000097:blood*; D015971:Gene Expression Regulation, Enzymologic; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D014805:Vitamin B 12 / Q000097:blood*; D025101:Vitamin B 6 / Q000097:blood*
chemical_list: D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12