Folic acid & vitamin B12 may not improve cognitive performance, says 2-year study
The study, published in the the American Academy of Neurology’s journal Neurology, looked at the impact of daily supplementation on 2,919 people with an average age of 74.1 and elevated blood levels of homocysteine – an amino acid which has been linked to memory loss and Alzheimer’s disease.
The participants took either 400 μg (micrograms) of folic acid and 500 μg of vitamin B12 – both tablets also containing 15 µg vitamin D3 – or a placebo every day for two years.
The researchers from Wageningen University, Erasmus University, VU University and Radboud University, then assessed cognitive functioning by using a mini-mental state examination and tests of episodic memory, attention and working memory, information processing speed and executive function at the beginning and end of the study.
They found homocysteine concentrations decreased by 5.0 µmol/L in the B-vitamin group and 1.3 µmol/L in the placebo group. However, cognitive test scores did not differ over time between the two groups across the four cognitive areas.
The researchers said: “It may slightly slow the rate of decline of global cognition, but the reported small difference may be attributable to chance.”
Disappointed hopes
One of the study’s authors, Dr Rosalie Dhonukshe-Rutten, said: “Since homocysteine levels can be lowered with folic acid and vitamin B12 supplements, the hope has been that taking these vitamins could also reduce the risk of memory loss and Alzheimer’s disease.
“While the homocysteine levels decreased by more in the group taking the B vitamins than in the group taking the placebo, unfortunately there was no difference between the two groups in the scores on the thinking and memory tests.”
The research was supported by various Netherlands organisations including the Netherlands Organization for Health Research and Development, the Dutch Dairy Association, MCO [managed care organisation] Health, Netherlands Consortium Healthy Ageing, the Dutch Ministry of Economic Affairs, Agriculture and Innovation and the respective author universities.
EFSA backed
Vitamin B12 holds approved European Union health claims for its contribution to “normal homocysteine metabolism”.
Other vitamin B approvals include:
• Contributes to normal functioning of the nervous system (B1, B2, B3, B6, B12)
• Contributes to normal mental/psychological function (B1, B3, B5, B6, B9, B12)
• Contributes to the reduction of tiredness and fatigue (B2, B3, B5, B6, B9, B12)
Source: Neurology
Published online ahead of print, doi: 10.1212/WNL.0000000000001050
“Results of 2-year vitamin B treatment on cognitive performance: Secondary data from an RCT"
Authors:N. L. van der Zwaluw, R. A.M. Dhonukshe-Rutten, J. P. van Wijngaarden, E. M. Brouwer-Brolsma, O. van de Rest, P. H. In 't Veld, A. W. Enneman, S. C. van Dijk, A. C. Ham, K. M.A. Swart, N. van der Velde, N. M. van Schoor, T. J.M. van der Cammen, A. G. Uitterlinden, P. Lips, R. P.C. Kessels and L. C.P.G.M. de Groot