The potential role of B-vitamins to support brain health is based on its ability to reduce levels of homocysteine, an amino acid linked to wasting in the brain, or atrophy.
Previously, epidemiological studies have reported that high levels of homocysteine are associated with suspected or confirmed dementia. Indeed, the Framingham study reported that people with homocysteine levels above 14 micromoles per liter of serum had twice the risk of dementia.
The epidemiological studies have been followed by high profile clinical trials, including the Vitacog study, which involved 266 people over the age of 70 with diagnosed mild cognitive impairment.
Data published in the International Journal of Geriatric Psychiatry indicated that participants receiving a B vitamin supplement providing 0.8 mg per day of folic acid, 0.5 mg of vitamin B12, and 20 mg of vitamin B6 for two years had 30% lower homocysteine levels, compared with placebo. In addition, executive mental function was stabilized in the B vitamin group, compared with placebo.
While this study reported benefits for B vitamin supplementation on cognitive function, others have not. Commenting on this issue, the Vitacog researchers said that this may be related to study design differences.
“We included participants with mild cognitive impairment, who were followed for two years, during which the placebo group underwent significant cognitive decline.
“Several of the trials without treatment effect may have been too short in duration, excluded vitamin B12 or B6 supplements or had participants who were either healthy and therefore did not decline or included patients who already have dementia too advanced for an improvement to be readily detected.”