Journal Article

Effect of 3-year folic acid supplementation on cognitive function in older adults in the FACIT trial: a randomised, double blind, controlled trial

Schouten, Evert G, Verhoef, Petra, Katan, Martijn B, Durga, Jane, Jolles, Jelle, van Boxtel, Martin PJ, Kok, Frans J

2007

Overview

Low folate and raised homocysteine concentrations in blood are associated with poor cognitive performance in the general population. As part of the FACIT trial to assess the effect of folic acid on markers of atherosclerosis in men and women aged 50–70 years with raised plasma total homocysteine and normal serum vitamin B 12 at screening, we report here the findings for the secondary endpoint: the effect of folic acid supplementation on cognitive performance. Our randomised, double blind, placebo controlled study took place between November, 1999, and December, 2004, in the Netherlands. We randomly assigned 818 participants 800 μg daily oral folic acid or placebo for 3 years. The effect on cognitive performance was measured as the difference between the two groups in the 3-year change in performance for memory, sensorimotor speed, complex speed, information processing speed, and word fluency. Analysis was by intention-to-treat. This trial is registered with clinicaltrials.gov with trial number NCT00110604. Serum folate concentrations increased by 576% (95% CI 539 to 614) and plasma total homocysteine concentrations decreased by 26% (24 to 28) in participants taking folic acid compared with those taking placebo. The 3-year change in memory (difference in Z scores 0·132, 95% CI 0·032 to 0·233), information processing speed (0·087, 0·016 to 0·158) and sensorimotor speed (0·064, −0·001 to 0·129) were significantly better in the folic acid group than in the placebo group. Folic acid supplementation for 3 years significantly improved domains of cognitive function that tend to decline with age.

• Publisher: Elsevier Ltd,Elsevier Limited
• Subject: Aged / Alzheimer's disease / alzheimers-disease / Apolipoproteins E - genetics / Cognition & reasoning / Cognition - drug effects / Cognitive ability / Dementia / Double-Blind Method / education / elderly-patients / Female / folate / Folic acid / Folic Acid - blood / Folic Acid - therapeutic use / homocysteine / Homocysteine - blood / Humans / Internal Medicine / Linear Models / Male / Memory - drug effects / memory performance / methylenetetrahydrofolate reductase / Methylenetetrahydrofolate Reductase (NADPH2) - genetics / Middle Aged / Netherlands / normative data / Nutrition / Older people / participants aged 24-81 / Psychological Tests / vascular-disease / Vitamin B / Vitamin B Complex - blood / Vitamin B Complex - therapeutic use