title: B-Vitamin Intake and Biomarker Status in Relation to Cognitive Decline in Healthy Older Adults in a 4-Year Follow-Up Study.
abstract: Advancing age can be associated with an increase in cognitive dysfunction, a spectrum of disability that ranges in severity from mild cognitive impairment to dementia. Folate and the other B-vitamins involved in one-carbon metabolism are associated with cognition in ageing but the evidence is not entirely clear. The hypothesis addressed in this study was that lower dietary intake or biomarker status of folate and/or the metabolically related B-vitamins would be associated with a greater than expected rate of cognitive decline over a 4-year follow-up period in healthy older adults. Participants (aged 60-88 years;n= 155) who had been previously screened for cognitive function were reassessed four years after initial investigation using the Mini-Mental State Examination (MMSE). At the 4-year follow-up assessment when participants were aged 73.4 ± 7.1 years, mean cognitive MMSE scores had declined from 29.1 ± 1.3 at baseline to 27.5 ± 2.4 (p< 0.001), but some 27% of participants showed a greater than expected rate of cognitive decline (i.e., decrease in MMSE > 0.56 points per year). Lower vitamin B6 status, as measured using pyridoxal-5-phosphate (PLP; <43 nmol/L) was associated with a 3.5 times higher risk of accelerated cognitive decline, after adjustment for age and baseline MMSE score (OR, 3.48; 95% CI, 1.58 to 7.63;p< 0.05). Correspondingly, lower dietary intake (0.9-1.4 mg/day) of vitamin B6 was also associated with a greater rate of cognitive decline (OR, 4.22; 95% CI, 1.28-13.90;p< 0.05). No significant relationships of dietary intake or biomarker status with cognitive decline were observed for the other B-vitamins. In conclusion, lower dietary and biomarker status of vitamin B6 at baseline predicted a greater than expected rate of cognitive decline over a 4-year period in healthy older adults. Vitamin B6 may be an important protective factor in helping maintain cognitive health in ageing.
authors.affiliation: Northern Ireland Centre for Food and Health, Ulster University, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK. h.mcnulty@ulster.ac.uk.
authors.forename: Catherine F
authors.initials: CF
authors.lastname: Hughes
authors.affiliation: Northern Ireland Centre for Food and Health, Ulster University, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK. mw.ward@ulster.ac.uk.
authors.forename: Mary
authors.initials: M
authors.lastname: Ward
authors.affiliation: Causeway Hospital, Northern Health and Social Care Trust, Coleraine BT52 1HS, Northern Ireland, UK. Fergal.Tracey@northerntrust.hscni.net.
authors.forename: Fergal
authors.initials: F
authors.lastname: Tracey
authors.affiliation: Northern Ireland Centre for Food and Health, Ulster University, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK. l.hoey@ulster.ac.uk.
authors.forename: Leane
authors.initials: L
authors.lastname: Hoey
authors.affiliation: School of Medicine, Trinity College Dublin, Dublin 2, Ireland. AMOLLOY@tcd.ie.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Molloy
authors.affiliation: Northern Ireland Centre for Food and Health, Ulster University, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK. k.pentieva@ulster.ac.uk.
authors.forename: Kristina
authors.initials: K
authors.lastname: Pentieva
authors.affiliation: Northern Ireland Centre for Food and Health, Ulster University, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK. h.mcnulty@ulster.ac.uk.
authors.forename: Helene
authors.initials: H
authors.lastname: McNulty
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000187:drug effects* / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D003071:Cognition / Q000187:drug effects; D060825:Cognitive Dysfunction / Q000097:blood*; D015331:Cohort Studies; D004032:Diet; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009752:Nutritional Status; D012307:Risk Factors; D025101:Vitamin B 6 / Q000008:administration & dosage / Q000097:blood; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000097:blood*
chemical_list: D015415:Biomarkers; D014803:Vitamin B Complex; D025101:Vitamin B 6
keywords: B-vitamin biomarkers; ageing; cognition; dietary intakes; one-carbon metabolism; pyridoxal-5-phosphate (PLP); vitamin B6