Associations between serum homocysteine, holotranscobalamin, folate and cognition in the elderly: a longitudinal study.
Vitamin B12 and folate are essential vitamins that are part of the homocysteine metabolic cycle. Low B12 and folate can result in increased homocysteine levels, which may lead to a variety of disorders including cardiovascular and cerebrovascular conditions. In addition, they have been linked to dementia, worse cognitive performance, and structural brain changes in some, but not all, longitudinal studies. In this study, the blood levels of holotranscobalamin (the active part of vitamin B12), folate, and homocysteine were measured at baseline in 274 dementia-free Finnish subjects aged 65-79 years. Subjects were re-examined after 7 years and their levels of cognition was assessed through several tests both at baseline and at follow-up. Results of this study show that holotranscobalamin, folate, and homocysteine are related to cognitive performance even in those elderly who were cognitively intact after 7-years,highlighting the need for randomized controlled trials to determine the impact of vitamin B12 and folate supplementations on preventing cognitive decline in the elderly.