Homocysteine, a toxic amino acid, is a risk factor for brain atrophy, cognitive impairment and dementia. Homocysteine can however be lowered by using certain B vitamins.
The reason for the following research was to investigate if B vitamins can slow the rate of brain atrophy in subjects with mild cognitive impairment (Smith AD, et.al., 2017).
The participants were over 70 years old and had mild cognitive impairment. MRI scans of the brain were used to measure the rate of atrophy over 2 years. The treatment group was given vitamin B12, folic acid and B6 and compared to a placebo group.
The researchers concluded that elderly people with mild cognitive impairment can slow brain atrophy using homocysteine lowering B vitamins.
Research with a 3 year follow up on men, found that high homocysteine levels were associated with cognitive decline (Tucker KL, et.al., 2005). Blood levels of vitamin B6, B12 and folate were associated with cognitive decline and especially folate was found to be protective in this study. Taking a high-quality vitamin B complex can be very helpful. Ideally you should take a formula which contains the metabolite of folic acid, 5-methyltetrahydrofolate, since it is quite common not to metabolize folic acid well.
Smith AD, Smith SM, de Jager CA, Whitbread P, Johnston C, Agacinski G, Oulhaj A, Bradley KM, Jacoby R, Refsum H. Homocysteine-lowering by B vitamins slows the rate of accelerated brain atrophy in mild cognitive impairment: a randomized controlled trial. PLoS One. 2010 Sep 8;5(9):e12244.
Tucker KL, Qiao N, Scott T, Rosenberg I, Spiro A 3rd. High homocysteine and low B vitamins predict cognitive decline in aging men: the Veterans Affairs Normative Aging Study. Am J Clin Nutr. 2005 Sep;82(3):627-35